83 results on '"Saliva artificial"'
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2. In Vitro Evaluation of Remineralization Potential of Five Toothpastes on Soft Drink-Eroded Human Enamel and Dentine.
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Alhamdan MM, Knowles JC, and McDonald AV
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Objective: The purpose of this in vitro study was to evaluate the potential remineralization of enamel and dentine erosion lesions after the application of five different toothpastes., Methodology: A total of 104 enamel and dentine samples were prepared from maxillary third molars. Each group was divided according to the toothpaste application mode (topical = 56; brushing = 48) and the toothpaste used seven topical groups and six brushing groups (n = 8). The groups included negative control (NC), positive control (PC), Sensodyne Pronamel (SP), Regenerate (R), Regenerate with boosting serum (R+), Colgate Duraphat 5000 (CD), and tooth mousse (TM)., Results: The statistical analysis showed significant surface microhardness (SMH) change. All enamel groups showed a significant decrease in SMH compared to NC for both application modes. However, no significance was recorded between test groups. Similar results were observed between dentine groups and their relevant controls for both application modes, except brushed R and R+ groups, which were insignificant to their NC. For topical groups, TM showed a significant increase in SMH. While R and R+ showed lower loss than SP and CD., Conclusions: All tested agents offered a degree of remineralization in both enamel and dentine with no significant difference between agents in enamel groups while R, R+, and TM offered better results in dentine groups., Clinical Significance: For dentine groups, similar findings were observed with superior tooth surface protection with the application of TM over other agents. Tooth surface remineralization was achieved when agents were either applied topically or brushed over the surface., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Alhamdan et al.)
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- 2024
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3. Saliva substitute mouthwash in nasopharyngeal cancer survivors with xerostomia: a randomized controlled trial.
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Marimuthu, Dayaabaran, Han, Kong Min, Mohamad, Mohd Shawal Firdaus, and Azman, Mawaddah
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ARTIFICIAL saliva , *NASOPHARYNX cancer , *RANDOMIZED controlled trials , *MOUTHWASHES , *CANCER survivors - Abstract
Objectives: Xerostomia is a prevalent sequelae among nasopharyngeal cancer (NPC) survivors; yet, effective treatment protocols have been elusive. This study was a prospective randomized clinical trial to compare the effects of saliva substitute mouthwash in nasopharyngeal cancer survivors with xerostomia, between two treatment arms, conducted in a tertiary center. Materials and methods: This study measured the effects within 4 weeks in relation to summated xerostomia inventory (SXI) and unstimulated whole saliva (UWS). Patients randomized into the interventional arm were prescribed an immunologically active saliva substitute (IASS), while patients in the control arm were prescribed a non-immunologically active mouthwash as placebo. Results: The study population consisted of 94 patients. There was a significant difference in SXI difference (p < 0.0001) and UWS difference (p < 0.0001) between control and interventional arms. No harmful side effects associated with the use of either mouthwash encountered throughout the study duration. Conclusion: IASS mouthwash significantly reduces subjective xerostomia scores measured using SXI and improves objective measurement of salivary flow using UWS among nasopharyngeal cancer survivors with xerostomia. Clinical relevance: IASS is significantly more effective in improving subjective and objective xerostomia measurements compared to non-immunologically active mouthwash. Additionally, this treatment is very safe, with superior side effect profiles. Trial registration: ClinicalTrials.gov Identifier: NCT04491435 [ABSTRACT FROM AUTHOR]
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- 2021
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4. Valoración de la rugosidad superficial de una resina fluida sometida a diferentes pH salivales.
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Gissela Amaya-Sánchez, Marjorie, Alejandra-Cabrera, and Del Carmen Armas-Vega, Ana
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To determine the surface roughness and color stability of a nanohybrid resin subjected to different salivary pH at different times. Materials and methods: experimental, comparative, in vitro study, in which 45 discs of EA2 nanohybrid resin (OPALLIS FGM) of 10 mm in diameter and 1 mm in thickness. They were randomly distributed in three groups (n = 15), each of the resin discs was subjected to an evaluation of its roughness by means of a digital roughness meter (TESTER SRT-6200) and color by colorimeter (Tooth Color Comparator). The discs according to their group were immersed in 18ml of artificial saliva modified with citric acid until obtaining saliva of pH 5, 6 and 7 respectively and placed in specific reservoirs maintained at 37 ° C, according to the specifications of the ANSI / ADA n0 standard. 66, after 168 and 504 hours of storage, a second and third evaluation was carried out. For the statistical analysis, the Friedman and Kruskal Wallis tests were used. Results: The three salivary pHs modified the surface roughness of the material used in a more evident way, pH 5, observing an increase in surface roughness with the time of exposure to substances with different pH analyzed (p <0.01), the color showed an evident increase of 4 tones in all the samples. Conclusions: The increase in roughness was proportional with time and inversely proportional with the pH, more evident with pH5. The color evaluation mechanism did not allow obtaining a conclusive data. [ABSTRACT FROM AUTHOR]
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- 2021
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5. Evaluación de la rugosidad superficial y estabilidad del color de una resina nanohíbrida sometida a diferentes pH salivales.
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Andrango-Herrera, Geovanna, Cabrera-Arias, Alejandra, and Armas-Vega, Ana
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Objective: To determine the surface roughness and color stability of a nanohybrid resin subjected to different salivary pH at different times. Materials and methods: experimental, comparative, in vitro study, in which 45 discs of EA2 nanohybrid resin (OPALLIS FGM) of 10 mm in diameter and 1 mm in thickness, and randomly distributed in three groups (n = 15). Each of the resin discs was subjected to an evaluation of its roughness by means of a digital roughness meter (TESTER SRT-6200) and color by colorimeter (Tooth Color Comparator). The discs according to their the group was immersed in 18ml of artificial saliva modified with citric acid until obtaining saliva of pH 5, 6 and 7 respectively, maintained at 37 ° C, according to the specifications of the ANSI / ADA No. 66 standard. After 168 and 504 hours of storage, a second and third evaluation, respectively, of roughness and color, was carried out. Statistical system using the Friedman and Kruskal Wallis test Results: The three salivary pHs modified the surface roughness of the material used in a more evident way, pH 5, observing an increase in surface roughness with the time of exposure to substances with different pH analyzed (p <0.01), the color showed an evident increase of 4 tones in all the samples, with an evident difficulty to analyze statistically. Conclusions: The increase in roughness was proportional with time and inversely proportional with the pH, more evident with pH5, the color evaluation mechanism did not allow obtaining a conclusive data. [ABSTRACT FROM AUTHOR]
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- 2021
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6. Análisis del proceso de degradación y comportamiento electroquímico de la aleación de magnesio AZ31 en saliva artificial
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Emmanuel Mena-Morcillo, Lucien Veleva, and Luis J. Espadas-Herrera
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az31 ,curvas de polarización ,eis ,resistencia a la polarización ,saliva artificial ,tratamiento en hf ,velocidad de degradación ,Mining engineering. Metallurgy ,TN1-997 - Abstract
En el presente trabajo se ha aplicado una combinación de pruebas de inmersión, técnicas de análisis de superficie y métodos electroquímicos para caracterizar el proceso de degradación de la aleación de magnesio AZ31 cuando ha sido expuesta a saliva artificial durante 28 días. La superficie de la aleación fue evaluada en dos condiciones: simple y con una capa de MgF2. Esta capa de conversión se formó sumergiendo el AZ31 en ácido fluorhídrico (HF). Las imágenes SEM revelaron diferencias en el ataque de corrosión de las dos condiciones de la superficie, específicamente en la vecindad de las partículas inter-metálicas de Al-Mn. Tanto el análisis EDS como XPS indicaron que la composición de las capas de corrosión formadas durante las pruebas de inmersión corresponde principalmente a Mg(OH)2 y Ca10(PO4)6(OH)2 para la muestra simple, mientras que para la superficie tratada el producto de corrosión principal fue MgCO3. El valor de resistencia a la polarización (Rp) estimado a partir de los experimentos EIS fue dos órdenes de magnitud mayor para las muestras tratadas con HF que para las muestras simples. Además, la velocidad de corrosión (CR) calculada a partir de las curvas de polarización potenciodinámica (PDP) fue menor para la superficie tratada con HF que para la superficie simple de AZ31. Todos los resultados han indicado que el tratamiento con HF en la superficie de aleación de magnesio AZ31 mejora significativamente su resistencia a la corrosión en saliva artificial.
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- 2020
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7. Surface roughness of two thermocured acrylic resins used in total dentures bases fabrication after artificial saliva challenge
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Claudia Patricia Lema Soto, Claudia Ortiz, and María Natalia Morera Rivera
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materiales dentales ,polimetil metacrilato ,saliva artificial ,Medicine ,Dentistry ,RK1-715 - Abstract
ntroduction: The thermocured acrylic resins are used as base material for teeth due to their aesthetic look, low water retention and solubility, relatively low toxicity, their repairability and their simple processing technique. Objective: To evaluate the super cial roughness of two denture-based acrylic resins exposed to artificial saliva. Methodology: In vitro study was performed, with 30 specimens of acrylic resins, divided into two groups Iv and Vr (n = 15), manufactured from a steel matrix; Two roughness measurements were performed: the initial and nal with the Mitutoyo Rogusimeter, to obtain the Ra (arithmetic mean), Rq (quadratic mean) and Rz(Mean). In between the initial and nal measurements, the specimens were submerged in arti cial saliva at 37 oC, for 60 days period. The data results were tabulated and statistically analyzed with the t-student and Anova tests. Results: Intergroup comparison was made in the baseline and nal values without showing statistical di erence for the Ra variables (1.9 ± 0.83 μm, 2.0 ± 0.72 μm); Rq (2.35 ± 1.01 μm; 2.7 ± 1.0 μm) and Rz (9.7 ± 5.3 μm, 12.7 ± 4.7 μm) for groups Iv and Vr respectively for baseline values; and Ra (0.58 ± 0.29μm, 0.68 ± 0.32μm), Rq (0.64 ± 0.25μm, 0.83 ± 0.39μm) and Rz (2.46 ± 0.88μm; ,03 ± 1.33μm) for nal values in groups Iv and Vr respectively, (p> 0.05). When comparing the intragroup changes in the surface roughness before and after the immersion in saliva, a statistically signi cant di erence was found for the values Ra, Rq, Rz (p
- Published
- 2018
8. SALIVA ARTIFICIAL EM GEL.
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CARMONA, Alessandra da Silva, DIAS, Leoni Adriana de Souza, and REBELO, Márcia de Araújo Rebelo
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ARTIFICIAL saliva , *XANTHAN gum , *MICROBIAL contamination , *CALCIUM chloride , *MAGNESIUM chloride , *ORAL hygiene products - Abstract
Saliva is one of the multifunctional fluid that contributes to the protection and lubrication of the oral mucosa, phonation, swallowing and oral health. The low production of saliva causes the individual to present intense pictures of dry mouth and hyposalivation, known as xerostomia. The main causes of xerostomia are smoking, alcoholism, excessive medication consumption, depression, stress, diabetes, autoimmune diseases, chemotherapy and radiotherapy. The aim of this study was to develop a salivary gel replacement to alleviate the symptoms caused by xerostomia. The formulation of artificial saliva was obtained by incorporating potassium chloride, sodium chloride, magnesium chloride, calcium chloride dihydrate, potassium phosphate, xylitol, methylparaben, monobasic, carboxymethylcellulose and xanthan gum. The thickeners were incorporated in different concentrations to produce daytime and nighttime artificial saliva. The artificial gel saliva was packed in its own package containing applicator nozzle. Viscosity characterization was performed in a rotational viscometer at 25ºC and 37ºC. The microbiological evaluation of the formulations was performed in a petri dish containing Mac Conkey Agar, Blood Agar and Sabouraund Agar. The results showed that the viscosity decreases as a function of thickener concentration and temperature increase. The formulations were free from microbiological contamination. Artificial gel saliva has adequate characteristics to alleviate dry mouth symptoms caused by xerostomia. [ABSTRACT FROM AUTHOR]
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- 2019
9. BOCA SECA EM IDOSOS: PROPOSTA DE UM NOVO SUBSTITUTO SALIVAR À BASE DE PRÓPOLIS.
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Luz Pedro, Rejane Eliete, Huttner, Eder Araújo, Palmeiro, Mariana Reuter, Sandini Linden, Maria Salete, Paulo De Carli, João, and Herberto Schneider, Rodolfo
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BEE products , *TOOTH demineralization , *SALIVARY glands , *DENTURES , *DENTAL caries , *ARTIFICIAL saliva , *ORAL mucosa - Abstract
Introduction: The elderly tends to dry the oral cavity, and it is linked to the atrophy of the oral mucosa and salivary glands. Objective: This study aims, through a literature review, to study xerostomia and the artificial substitutes currently used for saliva. Literature review: The health benefits of pharmacological properties with bee products are being studied because of their efficiencies, for the growing development of nutraceuticals and functional foods. Propolis and its extracts have numerous applications in the treatment of various diseases due to their antiseptic, anti-inflammatory, antioxidant, antibacterial, antifungal, anti-ulcer, anticancer, and immunomodulatory properties. In the dental field has attracted attention, reducing inflammation resulting from surgical procedures and as an antimicrobial agent in plaque control. Final considerations: Dry mouth symptoms (xerostomia and hyposialia) include taste disturbances, bad breath, intolerance to dental prostheses, increased risk of infection, including candidiasis and mucosal lesions, periodontal disease, tooth demineralization, tooth decay susceptibility and dental loss, especially in the elderly. Therefore, the importance in studying a new salivary substitute (APIS saliva) based on propolis, to soften and replace the lack of saliva in the oral cavity. [ABSTRACT FROM AUTHOR]
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- 2019
10. SALIVA ARTIFICIAL: UM ESTUDO DA LITERATURA SOBRE USO EM PACIENTES SUBMETIDOS A RADIOTERAPIA.
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DE SOUSA, JOMÁRIO BATISTA, NÓGIMO, IAKY TALLYSON ARAÚJO, BENTO, ADRÍCIA KELLY MARQUES, SANTANA, GABRIELA SOARES, BESERRA, MARIA MAYARA NASCIMENTO, DOS SANTOS, ZILA DANIERE DUTRA, DA SILVA, COSMO HELDER FERREIRA, CARNEIRO, SOFIA VASCONCELOS, MARTINS, LUIZ FILIPE BARBOSA, and RODRIGUES, ITALO SARTO CARVALHO
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Radiotherapy has a relevant clinical applicability; however, the region in which the neoplastic lesion is located is located in the vicinity of noble structures and plays an important role in oral homeostasis, such as oral mucosa, muscles, bone and the glands responsible for production of saliva. The objective of this study was to report the benefits of the use of artificial saliva in patients undergoing radiotherapy treatment in the head and neck region. This is a literature review from an electronic search in PubMed and Lilacs databases for health descriptors in the Portuguese and English languages from 2009 to 2018. Hyposalivation tables, alteration of salivary viscosity and sensation of dry mouth can affect these patients, characterizing xerostomia. Based on the survey, it is considered that artificial saliva as a means of intervention will restore to the patient improvements in the chewing and swallowing of food, reestablishing the balance of the oral cavity in the prevention of caries, lesions and opportunistic infections due to imbalance caused by hyposalivation of the individual affected by this complication. [ABSTRACT FROM AUTHOR]
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- 2019
11. Electrochemical analysis of the degradation of nitrided zirconia 3YTZP.
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Dorado-Bustamante, Kevin, Leal-Marin, Sara, and Estupiñán-Duran, Hugo
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ZIRCONIUM oxide , *ZIRCONIUM compounds , *ELECTROCHEMICAL analysis , *CRYSTAL structure , *MICROSTRUCTURE - Abstract
Zirconia is a material that is susceptible to changes in its structure from the tetragonal to the monoclinic phase caused by variations in temperature or by contact with water. One way of achieving the stability of the tetragonal phase at low temperatures is by incorporating anionic gaps in its crystal lattice through doping procedures with aliovalent anions such as nitrogen. Nitrogen replaces the oxygen in the crystal lattice, which stabilizes the tetragonal structure of zirconia at low temperatures. The aim of this research was to evaluate the degradation of nitrided zirconia 3Y-TZP after it was immersed in artificial saliva for 0, 7, 14, and 21 days. Interfacial processes such as oxide-formation were assessed simultaneously using the electrochemical impedance spectroscopy test. Additionally, morphological, topographic, and composition changes were analyzed in the degradation process using SEM-EDS and AFM. [ABSTRACT FROM AUTHOR]
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- 2018
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12. Rugosidad superficial de dos resinas acrílicas de termocurado para prótesis totales sometidas a saliva artificial.
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Lema Soto, Claudia Patricia, Ortiz, Claudia, and Morera Rivera, María Natalia
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Copyright of Acta Odontológica Colombiana is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2018
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13. The influence of protective varnish on the integrity of orthodontic cements
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Érika Machado Caldeira, Antonio de Moraes Izquierdo, Felipe Giacomet, Eduardo Franzotti Sant'Anna, and Antônio Carlos de Oliveira Ruellas
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Cimentos ortodônticos ,Saliva artificial ,Microdureza ,Dentistry ,RK1-715 - Abstract
OBJECTIVE: The aim of the present study was to assess the influence of saliva contamination over the structural strength and integrity of conventional glass-ionomer cements used for cementing orthodontic bands in the absence and presence of a surface-protecting varnish. METHOD: 48 samples were prepared by inserting 3 types of glass-ionomer cements into standardized metallic matrixes of 10 mm of diameter and 2 mm of depth. The cements used were: Meron (VOCO), Ketac-Cem (3M ESPE) and Vidrion C (DFL), all of which comprised groups A, B and C, respectively. Subgroups A1, B1 and C1 comprised samples with no surface protection, whereas subgroups A2, B2 and C2 comprised samples of which surface was coated with Cavitine varnish (SS White), after cement manipulation and application, in order to protect the cement applied. All samples were stored in artificial saliva for 24 hours at 37ºC. A Vickers diamond micro-durometer was used to produce indentations on the non-treated group (non-varnished) and the treated group (varnished). RESULTS: Varnished materials had significantly higher microhardness values in comparison to non-varnished materials. Ketac-Cem had the highest microhardness value among the varnished materials. CONCLUSION: Varnish application is necessary to preserve the cement and avoid enamel decalcification. Glass-ionomer cements should be protected in order to fully keep their properties, thus, contributing to dental health during orthodontic treatment.
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- 2013
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14. Saliva substitute mouthwash in nasopharyngeal cancer survivors with xerostomia: a randomized controlled trial
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Mohd Shawal Firdaus Mohamad, Mawaddah Azman, Dayaabaran Marimuthu, and Kong Min Han
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medicine.medical_specialty ,Side effect ,Nasopharyngeal cancer ,Hyposalivation ,Mouthwashes ,Placebo ,Xerostomia ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,stomatognathic system ,Randomized controlled trial ,Saliva substitute ,law ,Internal medicine ,medicine ,Humans ,Effective treatment ,Prospective Studies ,Survivors ,Saliva ,General Dentistry ,Mouth dryness ,business.industry ,Significant difference ,Nasopharyngeal Neoplasms ,030206 dentistry ,Radiation-induced toxicity ,stomatognathic diseases ,030220 oncology & carcinogenesis ,Saliva artificial ,Population study ,Original Article ,business - Abstract
Objectives Xerostomia is a prevalent sequelae among nasopharyngeal cancer (NPC) survivors; yet, effective treatment protocols have been elusive. This study was a prospective randomized clinical trial to compare the effects of saliva substitute mouthwash in nasopharyngeal cancer survivors with xerostomia, between two treatment arms, conducted in a tertiary center. Materials and methods This study measured the effects within 4 weeks in relation to summated xerostomia inventory (SXI) and unstimulated whole saliva (UWS). Patients randomized into the interventional arm were prescribed an immunologically active saliva substitute (IASS), while patients in the control arm were prescribed a non-immunologically active mouthwash as placebo. Results The study population consisted of 94 patients. There was a significant difference in SXI difference (p < 0.0001) and UWS difference (p < 0.0001) between control and interventional arms. No harmful side effects associated with the use of either mouthwash encountered throughout the study duration. Conclusion IASS mouthwash significantly reduces subjective xerostomia scores measured using SXI and improves objective measurement of salivary flow using UWS among nasopharyngeal cancer survivors with xerostomia. Clinical relevance IASS is significantly more effective in improving subjective and objective xerostomia measurements compared to non-immunologically active mouthwash. Additionally, this treatment is very safe, with superior side effect profiles. Trial registration ClinicalTrials.gov Identifier: NCT04491435
- Published
- 2020
15. Liberación de iones de aleaciones dentales no preciosas en la cavidad oral
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Elvar Quezada-Castillo, Wilder Aguilar-Castro, and Bertha Quezada-Alván
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Corrosion ,artificial saliva ,dental alloys ,Corrosión ,saliva artificial ,polarization curves ,General Physics and Astronomy ,General Materials Science ,productos de corrosión ,General Chemistry ,aleaciones dentales ,corrosion products ,curvas de polarización - Abstract
Dental alloys in the oral cavity release ions by corrosive action of saliva, which are deposited in the lower part of the mouth, others diffuse through the gums and most of them pass to the gastrointestinal system. In the present work, nine dental alloys frequently used in our country by people with low resources (316L stainless steel, low and high copper silver amalgams, Co-Cr and Ni-Cr alloys, Cu and Ti-6Al-4V base alloys). Its open circuit corrosion potential was measured, its potentiodynamic polarization curves were plotted and corrosion products were analyzed by EDAX, finding Hg, Ag, Ni, Co, Cu, Zn and Si ions, which can affect the health of users, so it is recommended that dentists and dental technicians inform patients who suffer from hypersensitivity do not use alloys containing potentially allergic metals. RESUMEN Las aleaciones dentales en la cavidad oral liberan iones por acción corrosiva de la saliva, los cuales se depositan en la parte inferior de la boca, otros se difunden a través de las encías y la mayor parte pasan al sistema gastrointestinal. En el presente trabajo se sometieron a ensayos de corrosión acelerada en saliva artificial nueve aleaciones dentales de uso frecuente en nuestro país por personas de bajos recursos (acero inoxidable 316L, amalgamas de plata de bajo y alto cobre, aleaciones Co-Cr y Ni-Cr, aleaciones base Cu y Ti-6Al-4V). Se midió su potencial de corrosión a circuito abierto, se trazaron sus curvas de polarización potenciodinámicas y se analizaron por EDAX los productos de corrosión encontrándose iones Hg, Ag, Ni, Co, Cu, Zn y Si, los cuales pueden afectar la salud de los usuarios, por lo que se recomienda a odontólogos y técnicos dentales informar a los pacientes que sufren de hipersensibilidad no usar aleaciones que contengan metales potencialmente alérgicos.
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- 2022
16. Avaliação das tensões liberadas por elásticos ortodônticos em cadeia: estudo in vitro Assessment of force decay in orthodontic elastomeric chains: an in vitro study
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Claudia Kochenborger, Dayanne Lopes da Silva, Ernani Menezes Marchioro, Diogo Antunes Vargas, and Luciane Hahn
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Elastômeros ,Materiais dentários ,Saliva artificial ,Elasticidade ,Elastics ,Synthetic elastics ,Elastomeric chain ,Dentistry ,RK1-715 - Abstract
INTRODUÇÃO: os materiais elastoméricos são considerados importantes fontes de força para a movimentação ortodôntica. OBJETIVO: avaliar a liberação de tensões de quatro marcas comerciais de elásticos ortodônticos em cadeia (Morelli, Ormco, TP e Unitek), em função do tempo, quando mantidas tensionadas por uma força inicial de 150g e imersas em saliva artificial a 37ºC. MÉTODOS: os elásticos em cadeia foram tensionados entre pinos de aço, fixados em uma placa de resina acrílica à distância de 15mm (Morelli e TP) e de 16mm (Unitek e Ormco), ambas medidas correspondendo a uma força de 150g. A leitura da quantidade de tensão liberada pelos elásticos foi realizada com um dinamômetro nos intervalos 30 minutos, 7, 14 e 21 dias. Os dados obtidos foram submetidos à análise de variância (ANOVA) (pINTRODUCTION: Elastomeric materials are considered important sources of orthodontic forces. OBJECTIVE: To assess force degradation over time of four commercially available orthodontic elastomeric chains (Morelli, Ormco, TP and Unitek). METHODS: The synthetic elastics were submerged in 37 ºC synthetic saliva and stretched by a force of 150 g (15 mm - Morelli and TP; 16mm - Unitek and Ormco). With a dynamometer, the delivered force was evaluated at different intervals: 30 minutes, 7 days, 14 days and 21 days. The results were subjected to ANOVA and Tukey's test. RESULTS: There was a force decay between 19% to 26.67% after 30 minutes, and 36.67% to 57% after 21 days of activation. CONCLUSIONS: TP elastomeric chains exhibited the smallest percentage of force decay, with greater stability at all time intervals tested. Meanwhile, the Unitek chains displayed the highest percentage of force degradation, and no statically significant difference was found in force decay between Ormco and Morelli elastomeric chains during the study period.
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- 2011
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17. Estudio de la biocompatibilidad de las aleaciones Ti-Nb y Ti-Mo con adición de indio
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Seguí Esquembre, Carmen
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Biocompatible ,Dental implant ,Cytotoxicity ,Hueso ,Diferenciación osteogénica ,Osseointegration ,Artificial saliva ,Osteogenic differentiation ,CIENCIA DE LOS MATERIALES E INGENIERIA METALURGICA ,Biological analysis ,Periimplantitis ,Peri-implantitis ,Bone ,Ti-15Mo-5In ,Citotoxicidad ,MG-63 ,Ti-35Nb-5In ,Grado en Ingeniería Biomédica-Grau en Enginyeria Biomèdica ,Osteointegración ,Implante dental ,Saliva artificial ,Módulo elástico ,Análisis biológico ,Elastic modulus ,HDPSC - Abstract
[ES] El titanio y sus aleaciones son los materiales más utilizados en el campo de la biomedicina y odontología para fabricar prótesis, componentes de las prótesis e implantes dentales ya que estos tienen una combinación favorable de propiedades mecánicas, físicas y químicas. En los últimos años la investigación en las aleaciones de base titanio ha estado en crecimiento constante, convirtiéndose en un sector muy competitivo, para buscar soluciones a los problemas que pueden dar los implantes utilizados actualmente, así como es la enfermedad periimplantaria. Mediante este trabajo se lleva a cabo la caracterización completa de la aleación Ti-15Mo-5In PM y Ti-35Nb-5In PM. Ambos presentan una estructura hexagonal compacta que permite la reducción de su módulo elástico y el acercamiento de este al del hueso, a diferencia de lo que ocurre con la aleación tan empleada Ti-6Al-4V, con un valor de módulo elástico que dista mucho del del hueso. Además, se realiza también la caracterización microestructural y mecánica de ambas aleaciones para conocer con exactitud sus propiedades. Por otro lado, se realiza en análisis de liberación de iones y el estudio de la resistencia a corrosión de las dos aleaciones en cuestión utilizando saliva artificial como electrolito. Ambas presentaron que se tratan de aleaciones biocompatibles y ninguna presentó ningún efecto tóxico. Además, se utilizaron las salivas con los restos de iones liberados como medio de contacto con las dos líneas celulares: las células madre de pulpa dental humana (hDPSC) y la línea de osteosarcoma humano MG-63. Esto hace posible el análisis de la posible citotoxicidad de estas y se mida el grado de viabilidad celular. Además, se realizan ensayos de diferenciación osteogénica de las células hDPSC y MG-63 para ver si se produce o no la diferenciación de estas en contacto con los discos de las aleaciones Ti-15Mo-5In PM y Ti-35Nb-5In PM. De este modo se consigue obtener un análisis tanto mecánico como biológico completo de las aleaciones ternarias. Como resultado, se concluye que tanto la aleación aleaciones Ti-15Mo-5In PM y Ti-35Nb-5In PM presentan resultados interesantes en todos los ensayos y también en los ensayos donde se ha utilizado el contacto con las células. Así pues, mediante este trabajo se anima a seguir investigando acerca de estas aleaciones que se consideran muy prometedoras en el campo biomédico., [EN] Titanium and its alloys are the most widely used materials in the field of biomedicine and dentistry to manufacture prostheses, components of prostheses and dental implants since they have a favorable combination of mechanical, physical and chemical properties. In recent years, research on titanium-based alloys has been in constant growth, becoming a very competitive sector, to seek solutions to the problems that currently used implants can cause, such as peri-implant disease. Through this work, the complete characterization of the Ti-15Mo-5In PM and Ti-35Nb-5In PM alloy is carried out. Both present a compact hexagonal structure that allows the reduction of their elastic modulus and its approach to that of bone, unlike what happens with the widely used Ti-6Al-4V alloy, with an elastic modulus value that is far from that of the bone. In addition, the microstructural and mechanical characterization of both alloys is also carried out to know exactly their properties. On the other hand, an ion release analysis and a study of the corrosion resistance of the two alloys in question was performed using artificial saliva as electrolyte. Both presented that they are biocompatible alloys and neither presented any toxic effect. In addition, saliva with the released ion remains were used as a means of contact with the two cell lines: human dental pulp stem cells (hDPSC) and the human osteosarcoma line MG-63. This makes possible the analysis of the possible cytotoxicity of these and the degree of cell viability is measured. In addition, osteogenic differentiation assays of hDPSC and MG-63 cells are carried out to see whether or not their differentiation occurs in contact with the discs of the Ti-15Mo-5In PM and Ti-35Nb-5In PM alloys. In this way it is possible to obtain a complete mechanical and biological analysis of the ternary alloys. As a result, it is concluded that both the alloys Ti-15Mo-5In PM and Ti-35Nb-5In PM present interesting results in all the tests and also in the tests where contact with cells has been used. Thus, this work encourages further research on these alloys that are considered very promising in the biomedical field.
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- 2021
18. Electrochemical behavior and pH stability of artificial salivas for corrosion tests Comportamento eletroquímico e estabilidade de pH de salivas artificiais para testes de corrosão
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Gláucia Maria Oliveira de Queiroz, Leandro Freitas Silva, José Tarcísio Lima Ferreira, José Antônio da Cunha P. Gomes, and Lúcio Sathler
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Saliva artificial ,Concentração de íons de hidrogênio ,Corrosão ,Fluoreto de sódio ,Saliva, artificial ,Hydrogen-ion concentration ,Corrosion ,Sodium fluoride ,Dentistry ,RK1-715 - Abstract
It is assumed that the compositions of artificial salivas are similar to that of human saliva. However, the use of solutions with different compositions in in vitro corrosion studies can lead dissimilar electrolytes to exhibit dissimilar corrosivity and electrochemical stability. This study evaluated four artificial salivas as regards pH stability with time, redox potentials and the polarization response of an inert platinum electrode. The tested solutions were: SAGF medium, Mondelli artificial saliva, UFRJ artificial saliva (prepared at the School of Pharmacy, Federal University of Rio de Janeiro, RJ, Brazil) and USP-RP artificial saliva (prepared at the School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, SP, Brazil). It was observed that pH variations were less than 1 unit during a 50-hour test. The SAGF medium, and the UFRJ and USP-RP solutions exhibited more oxidizing characteristics, whereas the Mondelli solution presented reducing properties. Anodic polarization revealed oxidation of the evaluated electrolytes at potentials below +600 mV SCE. It was observed that the UFRJ and USP-RP solutions presented more intense oxidation and reduction processes as compared to the Mondelli and SAGF solutions.Admite-se que as composições das salivas artificiais são semelhantes àquela da saliva humana. A utilização de soluções de composições distintas em estudos de corrosão in vitro, entretanto, pode fazer com que eletrólitos diferentes exibam diferenças no processo corrosivo e na estabilidade eletroquímica. Este estudo avaliou quatro salivas artificiais em relação a estabilidade do pH em função do tempo, potencial redox e resposta à polarização de um eletrodo de platina inerte. As soluções testadas foram: meio SAGF, saliva artificial Mondelli, saliva artificial UFRJ (preparada pela Faculdade de Farmácia da Universidade Federal do Rio de Janeiro, RJ, Brasil) e saliva artificial USP-RP (preparada pela Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, SP, Brasil). Foi observado que as variações de pH foram menores que 1 unidade durante as 50 horas de ensaio. O meio SAGF e as soluções UFRJ e USP-RP exibiram características mais oxidantes, enquanto a solução Mondelli apresentou propriedades redutoras. A polarização anódica mostrou oxidação dos eletrólitos avaliados a potenciais inferiores a +600 mV ECS. Foi observado que as soluções UFRJ e USP-RP são mais facilmente oxidadas e reduzidas se comparadas com as soluções Mondelli e SAGF.
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- 2007
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- View/download PDF
19. Análisis del comportamiento biológico de la aleación Ti-35Nb-7Zr-5Ta obtenida por colada
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Amigó Borrás, Vicente, Segovia López, Emilio Francisco, Mata Roig, Manuel, Universitat Politècnica de València. Departamento de Ingeniería Mecánica y de Materiales - Departament d'Enginyeria Mecànica i de Materials, Universitat Politècnica de València. Escuela Técnica Superior de Ingenieros Industriales - Escola Tècnica Superior d'Enginyers Industrials, Navarro Ventura, Beatriz, Amigó Borrás, Vicente, Segovia López, Emilio Francisco, Mata Roig, Manuel, Universitat Politècnica de València. Departamento de Ingeniería Mecánica y de Materiales - Departament d'Enginyeria Mecànica i de Materials, Universitat Politècnica de València. Escuela Técnica Superior de Ingenieros Industriales - Escola Tècnica Superior d'Enginyers Industrials, and Navarro Ventura, Beatriz
- Abstract
[ES] El titanio y sus aleaciones se utilizan en odontología para la fabricación de implantes, prótesis y componentes de prótesis debido a su combinación favorable de mecánica, física y propiedades químicas. En los últimos años, las investigaciones en este sector tan competitivo se han centrado en el desarrollo de nuevas aleaciones debido a la gran prevalencia de periimplantitis en los pacientes que emplean implantes dentales. Se han empezado a estudiar aleaciones de titanio que introducen niobio (Nb), zirconio (Zr) y/o tantalio (Ta). Esta aleación cuaternaria Ti-Nb-Zr-Ta se considera una de las más prometedoras por múltiples razones. La bibliografía se centra sobre todo en su análisis microestructural pero no se encuentran apenas ensayos in vitro. Mediante este trabajo se lleva a cabo una caracterización completa del material. Presenta una microestructura hexagonal compacta que permite la reducción de su módulo elástico y el acercamiento de este al del hueso, a diferencia de lo que ocurre con la aleación tan empleada Ti-6Al-4V, con un valor de módulo elástico que dista mucho del del hueso. Se analiza la caracterización microestructural y mecánica de la aleación Ti-35Nb-7Zr-5Ta (TNZT) para conocer en profundidad sus propiedades. Por su parte, los elementos de esta aleación son biocompatibles y parecen no presentar ningún efecto tóxico. Se realizan ensayos de liberación de iones de la aleación TNZT empleando saliva artificial como electrolito y se comparan, nuevamente, con datos de la aleación de titanio puro (Ti CP) y Ti-6Al-4V. Además, estas salivas que contienen los iones liberados son empleados como medio en contacto con dos líneas celulares: las células madre de pulpa dental humana (hDPSC) y la línea celular MG-63 de osteosarcoma humano. De este modo, se analiza la posible citotoxicidad de estas y se mide el grado de viabilidad celular que presentan. Otro factor que se pretende mejorar con el uso de la aleación TNZT es la relación entre la interfase hueso-implant, [CA] El titani i els seus aliatges s'utilitzen en odontologia per a la fabricació d'implants, pròtesis i components de pròtesis degut a la seua combinació favorable de mecànica, física i propietats químiques. En els últims anys, les investigacions en aquest sector tan competitiu s'han centrat en el desenvolupament de nous aliatges degut a la gran prevalença de periimplantitis en els pacients que empren implantes dentals. S'han començat a estudiar aliatges de titani que introduïxen niobi (Nb) , zirconi (Zr) i/o tàntal (Ta). Aquest aliatge quaternari Ti-Nb-Zr-Ta es considera un dels més prometedors per nombroses raons. La bibliografia se centra sobretot en el seu anàlisi microestructural però no es troben quasi assajos in vitro. Per mitjà d'este treball es du a terme una caracterització completa del material. Presenta una microestructura hexagonal compacta que permet la reducció del seu mòdul elàstic i l'acostament d'aquest al de l'os, a diferència del que ocorre amb l'aliatge tan emprat Ti-6Al-4V, amb un valor de mòdul elàstic que dista molt del de l'os. S'analitza la caracterització microestructural i mecànica de l'aliatge Ti35Nb-7Zr-5Ta (TNZT) per a conéixer en profunditat les seues propietats. Per altra banda, els elements d'este aliatge són biocompatibles i sembla no presentar cap efecte tòxic. Es realitzen assajos d'alliberament d'ions de l'aliatge TNZT emprant saliva artificial com a electròlit i es comparen, novament, amb dades de l'aliatge de titani pur (Ti CP) i Ti-6Al-4V. A més, estes salives que contenen els ions alliberats són empleades com a mitjà en contacte amb dos línies cel·lulars: les cèl·lules mare de polpa dental humana (hDPSC) i la línia cel·lular MG-63 d'osteosarcoma humà. D'aquesta manera, s'analitza la possible citotoxicitat d'aquestes i es mesura el grau de viabilitat cel·lular que presenten. Un altre factor que es es pretén millorar amb l'ús de l'aliatge TNZT és la relació entre la interfase os-implant per a promoure una futura osteointegrac, [EN] Titanium and its alloys are used in dentistry for the manufacture of implants, prosthetics, and prosthetic components due to their favorable combination of mechanical, physical, and chemical properties. In recent years, research in this highly competitive sector has focused on the development of new alloys due to the high prevalence of peri-implantitis in patients using dental implants. Titanium alloys that introduce niobium (Nb), zirconium (Zr) and / or tantalum (Ta) have begun to be studied. This Ti-Nb-Zr-Ta quaternary alloy is considered one of the most promising for multiple reasons. The bibliography focuses mainly on its microstructural analysis, but there are hardly any in vitro tests. Through this project a complete characterization of the material is carried out. It presents a compact hexagonal microstructure that allows the reduction of its elastic modulus and its approach to that of bone, unlike what happens with the widely used Ti-6Al-4V alloy, with an elastic modulus value that is far from the one of the bone. The microstructural and mechanical characterization of the Ti-35Nb-7Zr-5Ta (TNZT) alloy is analyzed to understand its properties in depth. On the other hand, the elements of this alloy are biocompatible and do not seem to present any toxic effect. Ion release tests of the TNZT alloy are performed using artificial saliva as electrolyte and are compared, again, with data from the pure titanium alloy (Ti CP) and Ti-6Al-4V. Furthermore, this saliva containing the released ions are used as a medium in contact with two cell lines: human dental pulp stem cells (hDPSC) and the human osteosarcoma cell line MG-63. In this way, the possible cytotoxicity of these is analyzed and the degree of cell viability they present is measured. Another factor that is intended to improve with the use of the TNZT alloy is the relationship between the bone-implant interface to promote future osseointegration. Thus, osteogenic differentiation assays of hDPSC and MG-63 ce
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- 2021
20. Estudio de la biocompatibilidad de las aleaciones Ti-Nb y Ti-Mo con adición de indio
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Amigó Borrás, Vicente, Milian Medina, Lara, Universitat Politècnica de València. Departamento de Ingeniería Mecánica y de Materiales - Departament d'Enginyeria Mecànica i de Materials, Universitat Politècnica de València. Escuela Técnica Superior de Ingenieros Industriales - Escola Tècnica Superior d'Enginyers Industrials, Seguí Esquembre, Carmen, Amigó Borrás, Vicente, Milian Medina, Lara, Universitat Politècnica de València. Departamento de Ingeniería Mecánica y de Materiales - Departament d'Enginyeria Mecànica i de Materials, Universitat Politècnica de València. Escuela Técnica Superior de Ingenieros Industriales - Escola Tècnica Superior d'Enginyers Industrials, and Seguí Esquembre, Carmen
- Abstract
[ES] El titanio y sus aleaciones son los materiales más utilizados en el campo de la biomedicina y odontología para fabricar prótesis, componentes de las prótesis e implantes dentales ya que estos tienen una combinación favorable de propiedades mecánicas, físicas y químicas. En los últimos años la investigación en las aleaciones de base titanio ha estado en crecimiento constante, convirtiéndose en un sector muy competitivo, para buscar soluciones a los problemas que pueden dar los implantes utilizados actualmente, así como es la enfermedad periimplantaria. Mediante este trabajo se lleva a cabo la caracterización completa de la aleación Ti-15Mo-5In PM y Ti-35Nb-5In PM. Ambos presentan una estructura hexagonal compacta que permite la reducción de su módulo elástico y el acercamiento de este al del hueso, a diferencia de lo que ocurre con la aleación tan empleada Ti-6Al-4V, con un valor de módulo elástico que dista mucho del del hueso. Además, se realiza también la caracterización microestructural y mecánica de ambas aleaciones para conocer con exactitud sus propiedades. Por otro lado, se realiza en análisis de liberación de iones y el estudio de la resistencia a corrosión de las dos aleaciones en cuestión utilizando saliva artificial como electrolito. Ambas presentaron que se tratan de aleaciones biocompatibles y ninguna presentó ningún efecto tóxico. Además, se utilizaron las salivas con los restos de iones liberados como medio de contacto con las dos líneas celulares: las células madre de pulpa dental humana (hDPSC) y la línea de osteosarcoma humano MG-63. Esto hace posible el análisis de la posible citotoxicidad de estas y se mida el grado de viabilidad celular. Además, se realizan ensayos de diferenciación osteogénica de las células hDPSC y MG-63 para ver si se produce o no la diferenciación de estas en contacto con los discos de las aleaciones Ti-15Mo-5In PM y Ti-35Nb-5In PM. De este modo se consigue obtener un análisis tanto mecánico como biológico completo de l, [EN] Titanium and its alloys are the most widely used materials in the field of biomedicine and dentistry to manufacture prostheses, components of prostheses and dental implants since they have a favorable combination of mechanical, physical and chemical properties. In recent years, research on titanium-based alloys has been in constant growth, becoming a very competitive sector, to seek solutions to the problems that currently used implants can cause, such as peri-implant disease. Through this work, the complete characterization of the Ti-15Mo-5In PM and Ti-35Nb-5In PM alloy is carried out. Both present a compact hexagonal structure that allows the reduction of their elastic modulus and its approach to that of bone, unlike what happens with the widely used Ti-6Al-4V alloy, with an elastic modulus value that is far from that of the bone. In addition, the microstructural and mechanical characterization of both alloys is also carried out to know exactly their properties. On the other hand, an ion release analysis and a study of the corrosion resistance of the two alloys in question was performed using artificial saliva as electrolyte. Both presented that they are biocompatible alloys and neither presented any toxic effect. In addition, saliva with the released ion remains were used as a means of contact with the two cell lines: human dental pulp stem cells (hDPSC) and the human osteosarcoma line MG-63. This makes possible the analysis of the possible cytotoxicity of these and the degree of cell viability is measured. In addition, osteogenic differentiation assays of hDPSC and MG-63 cells are carried out to see whether or not their differentiation occurs in contact with the discs of the Ti-15Mo-5In PM and Ti-35Nb-5In PM alloys. In this way it is possible to obtain a complete mechanical and biological analysis of the ternary alloys. As a result, it is concluded that both the alloys Ti-15Mo-5In PM and Ti-35Nb-5In PM present interesting results in all the tests and also i
- Published
- 2021
21. Uso do laser de 'C'O IND. 2' ('lambda'=10,6 'mu') na prevenção da carie e erosão dentarias
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Steiner-Oliveira, Carolina, 1981, Nobre dos Santos, Marinês, 1956, Aranha, Ana Celia Correa, Serra, Mônica Campos, Gavião, Maria Beatriz Duarte, Delbem, Alberto Carlos Botazzo, Universidade Estadual de Campinas. Faculdade de Odontologia de Piracicaba, Programa de Pós-Graduação em Odontologia, and UNIVERSIDADE ESTADUAL DE CAMPINAS
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Dental plaque ,Reações bioquímicas ,Microbiologia ,Placas dentárias ,Demineralization ,Microbiology ,Microradiography ,Streptococcus mutans ,Fluorides ,Biochemical reactions ,Desmineralização do dente ,Artificial saliva ,Saliva artificial ,Fluoretos ,Microrradiografia - Abstract
Orientador: Marines Nobre dos Santos Uchoa Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba Resumo: Os efeitos causados pelas modificações promovidas pela irradiação com laser de CO2 podem inibir a desmineralização dos tecidos dentários e podem ser potencializados quando associados ao fluoreto. Apesar de amplo uso do fluoreto e da redução da prevalência de cárie, essa doença ainda acomete grupos de alto risco. Por outro lado, tem sido observado um aumento da prevalência da erosão dentária. Os objetivos dessa tese, composta por 4 manuscritos, foram: (1) descrever as características do laser de CO2 e seus mecanismos de ação na inibição da desmineralização do esmalte; (2) desenvolver um modelo microbiológico, in vitro, de produção de lesão de cárie em dentina e testar duas hipóteses: (a) de que não há diferença na produção de cárie artificial em dentina utilizando um modelo microbiológico com regimes de 3 e 6 imersões ao dia em sacarose, avaliados por contagem bacteriana da dentina (UFC), análise microrradiográfica (AM) e análise de polissacarídeo insolúvel (API); (b) de que não há diferença no pH do biofilme antes e após sua imersão em sacarose; (3) avaliar, in vitro, a efetividade do laser de CO2 (? = 10,6 µm) pulsado, associado ou não ao fluoreto, na redução da desmineralização da dentina radicular usando um modelo microbiológico, avaliado por AM; (4) avaliar, in vitro, o efeito do mesmo laser, associado ou não ao fluoreto, na redução da desmineralização do esmalte e da dentina submetidos a um desafio erosivo, pela mensuração da perda de superfície e análise da concentração de cálcio, fósforo e fluoreto das soluções desmineralizadoras. Os dados foram analisados quanto à normalidade e testes apropriados foram realizados com nível de significância de 5%. No estudo 1, os efeitos do laser no esmalte, seu mecanismo de ação na redução da desmineralização, combinados ou não ao fluoreto, foram discutidos. No estudo 2, o pH do biofilme diminuiu imediatamente após a imersão em sacarose, mas aumentou novamente 5 min depois. Lesões em dentina foram produzidas com sucesso e a adição de sacarose mostrou as maiores perdas minerais, no entanto não diferiu entre os dois regimes de sacarose. A UFC não mostrou nenhuma diferença e a API dos tratamentos foram maiores que a do grupo controle. No estudo 3, os espécimes radiculares foram tratados ou não com laser de CO2 e com ou sem fluoreto antes ou após a irradiação com laser. O modelo microbiológico utilizado foi efetivo em produzir lesões dentinárias e as terapias combinadas mostraram as lesões dentinárias mais rasas. No estudo 4, espécimes de esmalte e dentina foram tratados com fluoreto, laser e fluoreto/laser e submetidos a um desafio erosivo. Os resultados de desgaste indicaram que o tratamento combinado interferiu com as perdas minerais do esmalte e da dentina, mesmo sem mostrar efeito sinérgico. Houve uma tendência de retenção de fluoreto no esmalte pelo tratamento combinado e também de liberação de menores quantidades de cálcio, fósforo e fluoreto para as soluções desmineralizadoras. Em conclusão, o mecanismo de ação do laser de CO2 na inibição da desmineralização do esmalte ainda não está completamente esclarecido e seu efeito pode ser aumentado quando associado ao fluoreto. O modelo microbiológico foi efetivo em produzir lesões de cárie dentinária. A irradiação da dentina radicular com laser inibiu a desmineralização dessa superfície apenas quando associado com o fluoreto; no entanto, não foi observado efeito sinérgico. O tratamento isolado com laser não foi capaz de prevenir a perda de superfície do esmalte e da dentina devido à erosão. Sua combinação com fluoreto mostrou alguma proteção, mas principalmente devido ao efeito do fluoreto. Não foi observada interação sinérgica significativa ou proteção duradoura com a terapia de laser. Abstract: The effects caused by the modifications promoted by the CO2 laser irradiation can inhibit the dental tissues demineralization and may be enhanced when associated with fluoride. Despite the widespread use of the fluoride and the reduction of the caries prevalence, this disease still occurs in the high risk groups. On the other hand, an increase of the dental erosion prevalence was observed. This thesis, comprised by 4 manuscripts, aimed: (1) to describe the CO2 laser characteristics and its action mechanisms in the enamel demineralization inhibition; (2) to develop an in vitro microbial model to produce dentin caries lesions and test two hypotheses - (a) that there is no difference in the artificial caries production in dentin using a microbial model with 3 and 6 sucrose bath immersions, as assessed by bacterial counts on the dentin (CFU), microradiographic analysis (TMR) and extracellular polysaccharide analysis (EPS); (b) that there is no difference in the biofilm pH before and after each sucrose bath; (3) to assess, in vitro, the effectiveness of a pulsed CO2 laser (? = 10.6 µm) associated or not with fluoride, in reducing the root demineralization using a microbial model, as assessed by TMR; (4) to assess, in vitro, the effect of the same laser, associated or not with fluoride, on the prevention of the enamel and dentin erosions by means of surface loss measurement and analysis of the calcium, phosphorus and fluoride concentrations in the demineralizing solutions. The data were checked for normality and appropriated tests were performed with a significance level of 5%. In study 1, the laser effects on the enamel and its action mechanisms in the demineralization reduction, combined or not with fluoride, were discussed. In study 2, the biofilm pH decreased immediately after the sucrose bath but increased again after 5 min. Dentin lesions were successfully produced, and the sucrose addition showed the highest mineral losses, even though there was no difference between the sucrose regimens. The CFU did not show any difference and the EPS from the treatment groups were higher than for the control. In study 3, root specimens were treated with/without CO2 laser and with/without fluoride prior or after the laser irradiation. The microbial model utilized was effective in developing dentin lesions and the combined therapies showed the shallowest dentin lesions. In study 4, specimens of enamel and root dentin were treated with fluoride, laser and fluoride/laser and submitted to an erosive challenge. The wear results indicated that the combined treatment interfered with the enamel or dentin surface losses, although no synergistic effect was observed. There was a trend for the combined treatment to retain more fluoride in enamel and release lower amounts of calcium and phosphorus into the demineralizing solutions. In conclusion, the CO2 mechanism action on the enamel demineralization reduction is still not elucidated and its effects can be increased when associated with fluoride. The microbial model was effective in producing dentin caries lesions. However, it did not reproduce the remineralizing phase of the caries process. Irradiation of the root dentin with laser inhibited the root surface demineralization only when associated with fluoride; however, no synergic effect was observed. The laser treatment alone was not able to prevent enamel or dentin surface losses due to erosion. Its combination with fluoride showed some protection, but mostly due to the fluoride effect. No significant synergistic interaction or lasting protection could be observed for the laser therapy. Doutorado Odontopediatria Doutor em Odontologia
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- 2021
22. Shear bond strength after dentin bleaching with 10% carbamide peroxide agents Resistência ao cisalhamento da dentina após clareamento com peróxido de carbamida a 10%
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Roberta Tarkany Basting, Patrícia Moreira de Freitas, Luiz André Freire Pimenta, and Mônica Campos Serra
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Clareamento de dente ,Dentina ,Saliva artificial ,Tooth bleaching ,Dentin ,Saliva, artificial ,Dentistry ,RK1-715 - Abstract
This in vitro study evaluated the shear bond strength (SBS) of dentin treated with two 10% carbamide peroxide bleaching agents 15 days after bleaching and storage in artificial saliva. Dentin fragments were randomly divided into 3 groups (n = 20) for the treatment with the two different bleaching agents (Rembrandt 10% or Opalescence 10%) or with a placebo agent, applied to the tooth surface for 8 hours a day. During the remaining time, the specimens were stored in artificial saliva. After 42 days, the fragments were stored in artificial saliva for 14 days. Another group (n = 20) was exposed to distilled and deionized water for 56 days. An adhesive system and microhybrid composite resin were used to prepare specimens for the SBS test. SBS tests were performed and the fractured surfaces were visually examined using a stereoscope at 30 X magnification. The analysis of variance (ANOVA) and SIDAK tests showed higher SBS values for dentin treated with Opalescence 10% than for dentin treated with Rembrandt 10% or placebo. Groups treated with Rembrandt 10%, Opalescence 10% or placebo did not differ from the group treated with distilled and deionized water. Ten percent carbamide peroxide agents or a placebo agent caused no differences in SBS of dentin after 15 days of storage in artificial saliva.Este estudo in vitro avaliou a resistência ao cisalhamento da dentina submetida ao tratamento com dois agentes clareadores contendo peróxido de carbamida a 10% depois de 15 dias de clareamento e armazenagem em saliva artificial. Fragmentos de dentina foram aleatoriamente distribuídos em 3 grupos (n = 20) para receber o tratamento com dois diferentes agentes clareadores (Rembrandt a 10% ou Opalescence a 10%) ou com um agente placebo, aplicados na superfície dental por 8 horas diárias. No restante do tempo, os espécimens permaneceram imersos em saliva artificial. Após o tratamento por 42 dias, os fragmentos foram armazenados em saliva artificial por 14 dias. Outro grupo (n = 20) somente recebeu a aplicação de água destilada e deionizada por 56 dias. Um sistema adesivo e uma resina composta microhíbrida foram utilizados para o preparo dos corpos-de-prova para o teste de cisalhamento. Após os ensaios, a superfície foi examinada visualmente com um estereoscópio com aumento de 30 X. A análise de variância (ANOVA) e o teste SIDAK mostraram que a dentina tratada com Opalescence a 10% apresentou maiores valores de resistência ao cisalhamento do que a tratada com o Rembrandt a 10% ou com o agente placebo. Os grupos tratados com Rembrandt a 10%, Opalescence a 10% ou agente placebo não diferiram do grupo que recebeu somente o tratamento com água destilada e deionizada. Agentes clareadores contendo peróxido de carbamida a 10% ou um agente placebo não alteraram a resistência ao cisalhamento da dentina após 15 dias de imersão em saliva artificial.
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- 2004
- Full Text
- View/download PDF
23. Análisis del comportamiento biológico de la aleación Ti-35Nb-7Zr-5Ta obtenida por colada
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Navarro Ventura, Beatriz
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Biocompatible ,Dental implant ,Cytotoxicity ,Biological analysis ,Os ,Citotoxicitat ,Mòdul elàstic ,Hueso ,Diferenciación osteogénica ,Osseointegration ,Implant dental ,Artificial saliva ,Osteogenic differentiation ,CIENCIA DE LOS MATERIALES E INGENIERIA METALURGICA ,Periimplantitis ,Peri-implantitis ,Bone ,Anàlisi biològic ,Diferenciació osteogènica ,Citotoxicidad ,MG-63 ,Grado en Ingeniería Biomédica-Grau en Enginyeria Biomèdica ,Ti-35Nb-7Zr-5Ta (TNZT) ,Osteointegración ,Implante dental ,Saliva artificial ,Osteointegració ,Módulo elástico ,Análisis biológico ,Elastic modulus ,HDPSC - Abstract
[ES] El titanio y sus aleaciones se utilizan en odontología para la fabricación de implantes, prótesis y componentes de prótesis debido a su combinación favorable de mecánica, física y propiedades químicas. En los últimos años, las investigaciones en este sector tan competitivo se han centrado en el desarrollo de nuevas aleaciones debido a la gran prevalencia de periimplantitis en los pacientes que emplean implantes dentales. Se han empezado a estudiar aleaciones de titanio que introducen niobio (Nb), zirconio (Zr) y/o tantalio (Ta). Esta aleación cuaternaria Ti-Nb-Zr-Ta se considera una de las más prometedoras por múltiples razones. La bibliografía se centra sobre todo en su análisis microestructural pero no se encuentran apenas ensayos in vitro. Mediante este trabajo se lleva a cabo una caracterización completa del material. Presenta una microestructura hexagonal compacta que permite la reducción de su módulo elástico y el acercamiento de este al del hueso, a diferencia de lo que ocurre con la aleación tan empleada Ti-6Al-4V, con un valor de módulo elástico que dista mucho del del hueso. Se analiza la caracterización microestructural y mecánica de la aleación Ti-35Nb-7Zr-5Ta (TNZT) para conocer en profundidad sus propiedades. Por su parte, los elementos de esta aleación son biocompatibles y parecen no presentar ningún efecto tóxico. Se realizan ensayos de liberación de iones de la aleación TNZT empleando saliva artificial como electrolito y se comparan, nuevamente, con datos de la aleación de titanio puro (Ti CP) y Ti-6Al-4V. Además, estas salivas que contienen los iones liberados son empleados como medio en contacto con dos líneas celulares: las células madre de pulpa dental humana (hDPSC) y la línea celular MG-63 de osteosarcoma humano. De este modo, se analiza la posible citotoxicidad de estas y se mide el grado de viabilidad celular que presentan. Otro factor que se pretende mejorar con el uso de la aleación TNZT es la relación entre la interfase hueso-implante para promover una futura osteointegración. Así pues, se realizan ensayos de diferenciación osteogénica de las células hDPSC y de las MG-63 como control y de adhesión celular de las mismas sobre discos metálicos de TNZT. De este modo, se hace una caracterización completa de esta aleación cuaternaria, no solo en cuanto a sus propiedades mecánicas sino también en cuanto a su análisis biológico. Finalmente, se concluye que la aleación TNZT presenta grandes resultados en todos los ensayos en los que se han utilizado en contacto con las células. Así pues, mediante este trabajo, se anima a seguir investigando acerca de la aleación TNZT, muy prometedora en el campo biomédico., [CA] El titani i els seus aliatges s'utilitzen en odontologia per a la fabricació d'implants, pròtesis i components de pròtesis degut a la seua combinació favorable de mecànica, física i propietats químiques. En els últims anys, les investigacions en aquest sector tan competitiu s'han centrat en el desenvolupament de nous aliatges degut a la gran prevalença de periimplantitis en els pacients que empren implantes dentals. S'han començat a estudiar aliatges de titani que introduïxen niobi (Nb) , zirconi (Zr) i/o tàntal (Ta). Aquest aliatge quaternari Ti-Nb-Zr-Ta es considera un dels més prometedors per nombroses raons. La bibliografia se centra sobretot en el seu anàlisi microestructural però no es troben quasi assajos in vitro. Per mitjà d'este treball es du a terme una caracterització completa del material. Presenta una microestructura hexagonal compacta que permet la reducció del seu mòdul elàstic i l'acostament d'aquest al de l'os, a diferència del que ocorre amb l'aliatge tan emprat Ti-6Al-4V, amb un valor de mòdul elàstic que dista molt del de l'os. S'analitza la caracterització microestructural i mecànica de l'aliatge Ti35Nb-7Zr-5Ta (TNZT) per a conéixer en profunditat les seues propietats. Per altra banda, els elements d'este aliatge són biocompatibles i sembla no presentar cap efecte tòxic. Es realitzen assajos d'alliberament d'ions de l'aliatge TNZT emprant saliva artificial com a electròlit i es comparen, novament, amb dades de l'aliatge de titani pur (Ti CP) i Ti-6Al-4V. A més, estes salives que contenen els ions alliberats són empleades com a mitjà en contacte amb dos línies cel·lulars: les cèl·lules mare de polpa dental humana (hDPSC) i la línia cel·lular MG-63 d'osteosarcoma humà. D'aquesta manera, s'analitza la possible citotoxicitat d'aquestes i es mesura el grau de viabilitat cel·lular que presenten. Un altre factor que es es pretén millorar amb l'ús de l'aliatge TNZT és la relació entre la interfase os-implant per a promoure una futura osteointegració. Així, doncs, es realitzen assajos de diferenciació osteogènica de les cèl·lules hDPSC i de les MG-63 com a control i d'adhesió cel·lular de les mateixes sobre discs metàl·lics de TNZT. D'aquesta manera, es fa una caracterització completa d'este aliatge quaternari, no sols quant a les seues propietats mecàniques sinó també quant al seu anàlisi biològic. Finalment, es conclou que l'aliatge TNZT presenta grans resultats en tots els assajos en què s'han utilitzat en contacte amb les cèl·lules. Així, doncs, per mitjà d'este treball, s'anima a continuar investigant sobre l'aliatge TNZT, molt prometedor en el camp biomèdic., [EN] Titanium and its alloys are used in dentistry for the manufacture of implants, prosthetics, and prosthetic components due to their favorable combination of mechanical, physical, and chemical properties. In recent years, research in this highly competitive sector has focused on the development of new alloys due to the high prevalence of peri-implantitis in patients using dental implants. Titanium alloys that introduce niobium (Nb), zirconium (Zr) and / or tantalum (Ta) have begun to be studied. This Ti-Nb-Zr-Ta quaternary alloy is considered one of the most promising for multiple reasons. The bibliography focuses mainly on its microstructural analysis, but there are hardly any in vitro tests. Through this project a complete characterization of the material is carried out. It presents a compact hexagonal microstructure that allows the reduction of its elastic modulus and its approach to that of bone, unlike what happens with the widely used Ti-6Al-4V alloy, with an elastic modulus value that is far from the one of the bone. The microstructural and mechanical characterization of the Ti-35Nb-7Zr-5Ta (TNZT) alloy is analyzed to understand its properties in depth. On the other hand, the elements of this alloy are biocompatible and do not seem to present any toxic effect. Ion release tests of the TNZT alloy are performed using artificial saliva as electrolyte and are compared, again, with data from the pure titanium alloy (Ti CP) and Ti-6Al-4V. Furthermore, this saliva containing the released ions are used as a medium in contact with two cell lines: human dental pulp stem cells (hDPSC) and the human osteosarcoma cell line MG-63. In this way, the possible cytotoxicity of these is analyzed and the degree of cell viability they present is measured. Another factor that is intended to improve with the use of the TNZT alloy is the relationship between the bone-implant interface to promote future osseointegration. Thus, osteogenic differentiation assays of hDPSC and MG-63 cells used as a control and cell adhesion of them on metallic TNZT discs are performed. In this way, a complete characterization of this quaternary alloy is made, not only in terms of its mechanical properties but also in terms of its biological analysis. Finally, it is concluded that the TNZT alloy presents great results in all the tests in which it has been used in contact with cells. Thus, through this work, further research is encouraged on the TNZT alloy, which is very promising in the biomedical field.
- Published
- 2021
24. Processamento por impressão 3D de próteses totais mandibulares
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Silva, Ana Margarida Verde Pereira Ramos da and Piedade, Ana Paula da Fonseca
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Próteses mandibulares ,Additive manufacturing ,Artificial saliva ,Mandibular prostheses ,Impressão 3D ,Saliva artificial ,Mechanical properties ,3D printing ,Propriedades Mecânicas ,Fabricação aditiva - Published
- 2020
25. Effect of xylitol varnishes on enamel remineralization of immature teeth: in vitro and in situ studies
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Vanessa Lira SIQUEIRA, Gabriela Santos BARRETO, Emilly Bezerra Vieira SILVA, Talita Vieira da SILVA, Denis Gomes do NASCIMENTO, André VERONEZI, Marcela Charantola RODRIGUES, Marília Afonso Rabelo BUZALAF, and Cristiane de Almeida Baldini CARDOSO
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food and beverages ,RK1-715 ,Dental Caries ,SALIVA ARTIFICIAL ,Cariostatic Agents ,carbohydrates (lipids) ,stomatognathic diseases ,stomatognathic system ,Dentistry ,Tooth Remineralization ,Humans ,Sodium Fluoride ,General Materials Science ,Fluorides, Topical ,Dental Enamel ,Xylitol - Abstract
We evaluated the efficacy of xylitol varnishes on the remineralization of newly erupted permanent and deciduous teeth in vitro and in situ. Human enamel specimens were randomly allocated to 8 groups (n = 15/group). Artificial caries lesions were produced and enamel alterations were quantified by surface/subsurface hardness and transverse microradiography. The blocks were then treated with the following varnishes: DuraphatTM; 20 wt% xylitol (146 μm) varnish; 20 wt% milled xylitol (80 μm) varnish, and placebo varnish, and removed after 6 h of immersion in artificial saliva. In vitro the blocks were subjected to pH-cycles for 8 days. In situ fifteen subjects wore palatal appliances containing four pre-demineralized and treated enamel specimens, for 5 days. Data were statistically analyzed by ANOVA/Tukey and Kruskal-Wallis/Tukey’s test (p < 0.05). The %SHR in both studies was significantly increased by xylitol and Duraphat™ varnishes when compared to placebo. Considering subsurface remineralization, only the xylitol varnishes were able to significantly reduce the enamel lesion. Xylitol varnishes can be promising alternatives to promote enamel remineralization of newly erupted permanent and deciduous teeth.
- Published
- 2020
26. Análisis del proceso de degradación y comportamiento electroquímico de la aleación de magnesio AZ31 en saliva artificial
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Mena-Morcillo, Emmanuel, Veleva, Lucien, and Espadas-Herrera, Luis J.
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lcsh:TN1-997 ,EIS ,eis ,saliva artificial ,HF treatment ,Tratamiento en HF ,curvas de polarización ,AZ31 ,Degradation rate ,Velocidad de degradación ,tratamiento en hf ,Artificial saliva ,Resistencia a la polarización ,Curvas de polarización ,resistencia a la polarización ,Saliva artificial ,Polarisation resistance ,Polarisation curves ,lcsh:Mining engineering. Metallurgy ,az31 ,velocidad de degradación - Abstract
This work applies a combination of immersion tests, surface analysis techniques, and electrochemical methods to characterise the degradation process of AZ31 magnesium alloy when it is exposed to artificial saliva for 28 days. The surface of the alloy was evaluated in two conditions: bare and with an MgF2 layer. This conversion layer was formed by soaking AZ31 in hydrofluoric acid (HF). SEM images revealed differences in the corrosion attack of the two surface conditions, specifically in the vicinity of Al-Mn intermetallic particles. Both EDS and XPS analysis indicated that the composition of the corrosion layers formed during immersion tests corresponds mainly to Mg(OH)2 and Ca10(PO4)6(OH)2 for the bare sample, whereas for the treated surface the principal corrosion product was MgCO3. The polarisation resistance (Rp) value estimated from EIS experiments was two orders of magnitude higher for the HF-treated samples than that of the bare samples. In addition, the corrosion rate (CR) calculated from the potentiodynamic polarisation (PDP) curves was lower for the HF-treated surface than for that of the bare AZ31 surface. All results indicate that the HF-treatment on AZ31 magnesium alloy surface improves significantly its corrosion resistance in artificial saliva. En el presente trabajo se ha aplicado una combinación de pruebas de inmersión, técnicas de análisis de superficie y métodos electroquímicos para caracterizar el proceso de degradación de la aleación de magnesio AZ31 cuando ha sido expuesta a saliva artificial durante 28 días. La superficie de la aleación fue evaluada en dos condiciones: simple y con una capa de MgF2. Esta capa de conversión se formó sumergiendo el AZ31 en ácido fluorhídrico (HF). Las imágenes SEM revelaron diferencias en el ataque de corrosión de las dos condiciones de la superficie, específicamente en la vecindad de las partículas inter-metálicas de Al-Mn. Tanto el análisis EDS como XPS indicaron que la composición de las capas de corrosión formadas durante las pruebas de inmersión corresponde principalmente a Mg(OH)2 y Ca10(PO4)6(OH)2 para la muestra simple, mientras que para la superficie tratada el producto de corrosión principal fue MgCO3. El valor de resistencia a la polarización (Rp) estimado a partir de los experimentos EIS fue dos órdenes de magnitud mayor para las muestras tratadas con HF que para las muestras simples. Además, la velocidad de corrosión (CR) calculada a partir de las curvas de polarización potenciodinámica (PDP) fue menor para la superficie tratada con HF que para la superficie simple de AZ31. Todos los resultados han indicado que el tratamiento con HF en la superficie de aleación de magnesio AZ31 mejora significativamente su resistencia a la corrosión en saliva artificial.
- Published
- 2020
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27. Análisis del proceso de degradación y comportamiento electroquímico de la aleación de magnesio AZ31 en saliva artificial
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Lucien Veleva, Luis J. Espadas-Herrera, and Emmanuel Mena-Morcillo
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Materials science ,eis ,020209 energy ,Alloy ,Intermetallic ,02 engineering and technology ,engineering.material ,Corrosion ,curvas de polarización ,chemistry.chemical_compound ,Hydrofluoric acid ,X-ray photoelectron spectroscopy ,resistencia a la polarización ,0202 electrical engineering, electronic engineering, information engineering ,Materials Chemistry ,Immersion (virtual reality) ,Physical and Theoretical Chemistry ,Magnesium alloy ,az31 ,Mining engineering. Metallurgy ,saliva artificial ,Metals and Alloys ,TN1-997 ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,chemistry ,tratamiento en hf ,engineering ,0210 nano-technology ,Layer (electronics) ,Nuclear chemistry ,velocidad de degradación - Abstract
En el presente trabajo se ha aplicado una combinación de pruebas de inmersión, técnicas de análisis de superficie y métodos electroquímicos para caracterizar el proceso de degradación de la aleación de magnesio AZ31 cuando ha sido expuesta a saliva artificial durante 28 días. La superficie de la aleación fue evaluada en dos condiciones: simple y con una capa de MgF2. Esta capa de conversión se formó sumergiendo el AZ31 en ácido fluorhídrico (HF). Las imágenes SEM revelaron diferencias en el ataque de corrosión de las dos condiciones de la superficie, específicamente en la vecindad de las partículas inter-metálicas de Al-Mn. Tanto el análisis EDS como XPS indicaron que la composición de las capas de corrosión formadas durante las pruebas de inmersión corresponde principalmente a Mg(OH)2 y Ca10(PO4)6(OH)2 para la muestra simple, mientras que para la superficie tratada el producto de corrosión principal fue MgCO3. El valor de resistencia a la polarización (Rp) estimado a partir de los experimentos EIS fue dos órdenes de magnitud mayor para las muestras tratadas con HF que para las muestras simples. Además, la velocidad de corrosión (CR) calculada a partir de las curvas de polarización potenciodinámica (PDP) fue menor para la superficie tratada con HF que para la superficie simple de AZ31. Todos los resultados han indicado que el tratamiento con HF en la superficie de aleación de magnesio AZ31 mejora significativamente su resistencia a la corrosión en saliva artificial.
- Published
- 2020
28. Comparative analysis of enamel microstructure exposed to a flavoured water in vitro
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Merlo, Diego Adrián, Lazo, Gabriel Eduardo, Abal, Adrián Alejandro, Belloni, Federico, Ingeniero, María José, Viskovic, María Cristina, Barceló, Miguel Andrés, Barrasa, Emanuel, Gómez Bravo, Francisco, Guzmán, María Pía, Motta, Guillermo Martín, Ogas, Cintia Soledad, Papasodaro, Jimena, Pérez, Diego, Pérez, Patricia Susana, Procopio Rodríguez, Melina Micaela, Saldías, Alejandro José, De Landaburu Martínez, Rosario, and Tanevitch, Andrea Matilde
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Odontología ,Esmalte Dental ,Desmineralización ,Agua saborizada ,Saliva Artificial - Abstract
El propósito de este trabajo fue comparar las variaciones morfológicas y químicas de la microestructura del esmalte por acción de un agua natural saborizada mediante dos regímenes de inmersión. Secciones longitudinales de coronas dentarias fueron incluidas en resina, desgastadas y pulidas en sentido longitudinal. Se utilizó un agua natural comercial sabor naranja. Un grupo de muestras se sumergieron en el agua durante 12 minutos y otro se ciclaron en saliva artificial 4 veces por día, 5 minutos cada inmersión en la bebida, durante 14 días. Se realizaron observaciones al ESEM (SeMFi-LIMF. FI- UNLP) y determinaciones de espectrometría de energía dispersiva de calcio y fósforo, antes y después de la exposición al agua en amos grupos. Se analizó el esmalte radial y con bandas de Hunter Schreger. Se evidenciaron alteraciones en la morfología de los prismas en ambos grupos y variaciones en la composición elemental. En las muestras sumergidas durante 12minutos la relación calcio/fósforo disminuyó, mientras que en las cicladas 14 días aumentó. Concluimos que el agua produce pérdida mineral y la saliva artificial podría favorecer el depósito de minerales. Se considera necesario continuar profundizando el estudio de estos aspectos., The purpose of this work was to compare the morphological and chemical variations of the enamel microstructure by the action of a natural flavored water through two immersion regimes. Longitudinal sections of dental crowns were embedded in resin, worn and polished in the longitudinal direction. A commercial natural water orange flavored was used. One group of samples was immersed in water for 12 minutes and another was cycled in artificial saliva four times a day, five minutes each immersion in the drink, for 14 days. Observations were made at ESEM (SeMFi-LIMF. FI-UNLP) and determinations of calcium and phosphorus energy dispersive spectrometry, before and after exposure to water in both groups. Hunter Schreger band and radial enamel were analyzed. Alterations in the morphology of the prisms were evidenced in both groups and variations in the elemental composition. In the samples submerged for 12 minutes, the calcium/phosphorus ratio decreased, while in those cycled for 14 days it increased. We conclude that water produces mineral loss and artificial saliva could stimulate the deposit of minerals. It is considered necessary to continue deepening the study of these aspects., Facultad de Odontología
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- 2020
29. Assessment of surface roughness and the distribution of mechanical stress on the palate by different pacifiers
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Freitas, Camila Nobre de, 1990, Castelo, Paula Midori, 1978, Barbosa-Martins, Luiz Filipe, Castilho, Aline Rogéria Freire de, Steiner-Oliveira, Carolina, Bussadori, Sandra Kalil, Universidade Estadual de Campinas. Faculdade de Odontologia de Piracicaba, Programa de Pós-Graduação em Odontologia, and UNIVERSIDADE ESTADUAL DE CAMPINAS
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Disinfection ,Sucção ,Chupetas ,Finite element analysis ,Saliva artificial ,Desinfecção ,Saliva, artificial ,Análise de elementos finitos ,Suction ,Pacifiers - Abstract
Orientador: Paula Midori Castelo Ferrua Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba Resumo: O uso prolongado de chupetas traz efeitos deletérios à criança, podendo prejudicar o crescimento e desenvolvimento das estruturas orofaciais e da oclusão. O objetivo deste estudo foi avaliar a distribuição das tensões mecânicas de três diferentes geometrias de chupetas sobre o palato (Artigo 1) e o efeito de dois métodos de desinfecção física (calor) sobre a rugosidade superficial de chupetas de silicone (Artigo 2). O Artigo 1 descreve a distribuição da tensão principal máxima e do deslocamento em magnitude de três diferentes tipos de bicos de chupetas de silicone: convencional (A), ortodôntica (B) e Super Soothie TM (C). As imagens dos três bicos de chupetas foram adquiridas por escaneamento 3D. A estrutura do palato foi recriada por tomografia computadorizada de um crânio seco de uma criança com ~3 anos de idade, enquanto a estrutura da língua foi reconstruída por meio de software usando dados disponíveis na literatura. As propriedades mecânicas do material da chupeta foram determinadas por meio do ensaio de tração à ruptura em Máquina de Teste Universal- EMIC DL500, onde 15 amostras padronizadas foram removidas de cada tipo de chupeta (A, B e C). A força máxima de língua foi obtida pela avaliação de 8 crianças com ~3anos de idade pelo instrumento IOPI. Posteriormente, os três sistemas foram discretizados em elementos finitos e a força aplicada sobre os modelos para a simulação. Observou-se que o bico B apresentou os maiores valores de tensão máxima distribuída sobre o palato, seguido da chupeta A. A chupeta B estimulou um deslocamento em magnitude maxilar para frente e para os lados, enquanto a A promoveu uma deformação para cima, favorecendo um palato mais atrésico. Os dois tipos de chupeta tendem ao movimento de giro no plano sagital, gerando tensões na região de incisivos e podendo resultar em mordida aberta anterior. O bico C apresentou uma melhor distribuição das tensões sobre o palato, permitindo a distribuições de tensões mais favorável sobre a maxila, para frente e para os lados sem influência na inclinação dos dentes incisivos superiores. O artigo 2 apresenta a variação na rugosidade superficial de três tipos de chupetas convencional (A), ortodôntica (B) e Super Soothie¿ (C); n=20 cada) quando submetidas a processos de desinfecção por calor. A rugosidade superficial e morfologia microscópica foram avaliadas ao baseline, 15 e 30 dias após desinfecção com água fervente e micro-ondas (7 e 5 min, respectivamente), utilizando-se perfilômetro e microscópio eletrônico de varredura. Ao baseline, foi encontrada maior rugosidade superficial na chupeta C em relação à A e B. Foi observado um efeito de interação tempo*chupeta, ou seja, um aumento da rugosidade superficial após a desinfecção dependente do tipo de chupeta, sendo maior para a chupeta C aos 15 e 30 dias (p
- Published
- 2020
30. Estudio y evaluación de la biocompatibilidad de aleaciones binarias de Titanio procesadas por pulvimetalurgia
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Amigó Borrás, Vicente, Mata Roig, Manuel, Universitat Politècnica de València. Departamento de Ingeniería Mecánica y de Materiales - Departament d'Enginyeria Mecànica i de Materials, Universitat Politècnica de València. Escuela Técnica Superior de Ingenieros Industriales - Escola Tècnica Superior d'Enginyers Industrials, Masiá Vargas, Lidia, Amigó Borrás, Vicente, Mata Roig, Manuel, Universitat Politècnica de València. Departamento de Ingeniería Mecánica y de Materiales - Departament d'Enginyeria Mecànica i de Materials, Universitat Politècnica de València. Escuela Técnica Superior de Ingenieros Industriales - Escola Tècnica Superior d'Enginyers Industrials, and Masiá Vargas, Lidia
- Abstract
[ES] El titanio es uno de los elementos metálicos más abundantes de la naturaleza, que tiene importantes propiedades y características que lo hacen único y ampliamente demandado en el sector industrial. En particular, las aleaciones de titanio son las protagonistas en el sector biomédico, ya que, al presentar un módulo bajo de elasticidad, baja conductividad térmica y eléctrica, y una alta resistencia a la corrosión, son las seleccionadas para la fabricación de implantes y prótesis biomédicas. Sin embargo, se ha de tener cuidado con su manipulación porque es altamente reactivo cuando está en presencia de oxígeno, teniendo asociados unos riesgos considerables. En este trabajo, las aleaciones de titanio de las que se estudia su biocompatibilidad han sido procesadas por vía pulvimetalúrgica. Esta técnica es la más común para obtener y diseñar composiciones que pueden ser difíciles de obtener por metalurgia convencional, disminuyendo la cantidad de residuos del material durante el procesamiento e impidiendo que los elementos de aleación sean segregados (garantizando la homogeneidad de la microestructura). Se trata pues con aleaciones formadas por la mezcla elemental y el aliado mecánico de los polvos de los elementos de aleación, cuyas propiedades mecánicas han sido determinadas por una prueba de dureza y flexión de tres puntos; mientras que la caracterización microestructural se ha analizado mediante la microscopía electrónica de barrido. La biocompatibilidad es un término relativo que cubre muchos conceptos, y que indica la capacidad de un material para realizar una función biológica sin producir una reacción a un cuerpo extraño. Entonces, las aleaciones han sido sometidas a una prueba de resistencia a la corrosión, junto con una prueba de liberación de iones con saliva artificial durante 732 horas. Luego, para ver el efecto de los resultados de las pruebas anteriores y empleando una línea celular de osteosarcoma humano (MG63), se ha hecho una determinación de la toxi, [CA] El titani es un dels elements metàl·lics més abundants de la naturalesa, que posseeix unes importants propietats i característiques que el fan únic i àmpliament demandat en el sector industrial. Concretament, els aliatges de titani son els protagonistes en el sector biomèdic ja que al presentar un baix mòdul d’elasticitat, baixa conductivitat tèrmica i elèctrica, i una elevada resistència a la corrosió, son els seleccionats per a la fabricació d’implants i pròtesis biomèdiques. No obstant, es deu de tindre en conter amb la seua manipulació ja que és altament reactiu quan es troba en presencia d’oxigen , ocasionant uns riscos considerables. En aquest treball, els aliatges de titani dels quals s’estudia la seua biocompatibilitat, han sigut processades per via pulvimetal·lúrgica. Aquesta tècnica es la més comú per a l’obtenció i disseny de composicions que puguin ser difícils d’obtenir mitjançant la metal·lúrgia convencional, disminuint la quantitat de deixalles del material durant el processat i evitant que els elements d’aliatge es segreguen (garantint la homogeneïtat de la microestructura). Es tracta amb aliatges resultats de la mescla elemental i aliat mecànic dels pols dels elements d’aliatge, les propietats mecàniques dels quals s’han determinat per una prova de duresa i de flexió a tres punts; mentre que la caracterització microestructural ha sigut analitzada per microscòpia electrònica d’escombrat. La biocompatibilitat, es un terme relatiu que engloba molts conceptes, i que indica la capacitat d’un material de realitzar una funció biològica sense produir una reacció a cos estrany. Aleshores, per estudiar-lo, primerament, s’han sotmès els aliatges a una prova de resistència a la corrosió junt a una d’alliberament d’ions amb saliva artificial durant 732 hores. A continuació, per veure l’efecte dels resultats de les proves anteriors i fent ús d’una línia cel·lular d’osteosarcoma humà (MG-63), s’ha realitzat una determinació de la toxicitat amb el reactiu MTS, [EN] Titanium is one of the most abundant metal elements of nature, which has important properties and characteristics that make it unique and widely demanded in the industrial sector. Specifically, the titanium alloys are the protagonists in the biomedical sector as by presenting a low modulus of elasticity, low thermal and electrical conductivity, and a high resistance to corrosion, are those selected for the manufacture of implants and biomedical prostheses. However, their manipulation is complicated because it is highly reactive when it is in the presence of oxygen. In this work, the titanium alloys have been processed by powder metallurgical route. This technique is the most common to obtain and design compositions that can be difficult to obtain by conventional metallurgy, amount of material waste during processing and preventing the alloy elements from being segregated (guaranteeing the homogeneity of the microstructure). They are alloys formed by the elementary mixture and the mechanical alloy of the powders of the alloy elements, whose mechanical properties have been determined by a three-point hardness and flexural test; while the microstructural characterization has been analyzed by scanning electron microscopy. Biocompatibility is a relative term that covers many concepts, and that indicates the ability of a material to perform a biological function without producing a reaction to a foreign body. Then, the alloys have been subjected to a corrosion resistance test, and an ion release test with artificial saliva for 732 hours. Then, to see the effect of the results of the previous tests and using a human osteosarcoma cell line (MG-63), a toxicity determination was made with the MTS reagent, and subsequently a 5-hour and 72-hour cell adhesion and proliferation test was performed respectively. Therefore, the results of the study of the different titanium alloys characterized by the presence of an alloy element in each case, allow to determine whether they be
- Published
- 2019
31. Corrosion of galvanic pairs of dental alloys copper base with silver amalgams in artificial saliva
- Author
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Quezada-Castillo, Elvar, Aguilar-Castro, Wilder, and Quezada-Alván, Bertha
- Subjects
Corrosion ,curva de polarización ,artificial saliva ,Corrosión ,saliva artificial ,galvanic pair ,par galvánico ,aleación dental ,dental alloy ,polarization curve - Abstract
Galvanic corrosion is a metal dissolution process that occurs when two metals of different electrochemical potential are immersed in an electrolyte causing electrical currents between the metals through the conducting medium. To restore lost or damaged teeth, different alloys are used, leaving the mouth exposed to electrical currents that circulate through saliva and dental fluids. In the present work, the potentials and densities of corrosion currents of galvanic pairs of silver amalgams and copper base dental alloys were determined simultaneously using potenciodynamic methods, finding that the most resistant to corrosion are the pairs formed by silver amalgams of high copper and Cu -Zn alloys, and that the corrosion products released in greater quantity in the electrolytic medium are formed by Hg, Cu, Zn and Ni ions. RESUMEN La corrosión galvánica es un proceso de disolución metálica que se produce cuando dos metales de distinto potencial electroquímico se sumergen en un electrolito originando corrientes eléctricas entre los metales a través del medio conductor. Para restaurar las piezas dentales perdidas o deterioradas se usan diferentes aleaciones quedando la boca expuesta a corrientes eléctricas que circulan a través de la saliva y los fluidos dentarios. En el presente trabajo se determinaron simultáneamente, los potenciales y densidades de corrientes de corrosión de pares galvánicos de amalgamas de plata y aleaciones dentales base cobre usando métodos potenciodinámicos, encontrando que los más resistentes a la corrosión son los pares formados por amalgamas de plata de alto cobre y aleaciones Cu – Zn, y que los productos de corrosión liberados en mayor cantidad en el medio electrolítico están formados por iones Hg, Cu, Zn y Ni.
- Published
- 2019
32. Resistência à Fratura de Três Resinas Acrílicas em Diferentes Condições de pH
- Author
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Vieira, Maria Francisca Machado and SÁ, JULIANA MANUELA BARBOSA DE
- Subjects
Fratura ,Polimetilmetacrilato ,Resinas acrílicas ,Termopolimerizáveis ,Saliva artificial ,pH salivar ,Prótese removível ,Resistência ao impacto - Abstract
A análise das caraterísticas das resinas acrílicas nomeadamente a sua resistência à fratura requer bastante importância. Através destes estudos é possível selecionar os melhores materiais no sentido de satisfazer as necessidades dos pacientes e também proporcionar-lhes uma melhor qualidade de vida. O principal objetivo deste trabalho é avaliar qual a força necessária para fraturar bases de próteses de três marcas diferentes de resina acrílica e comparar qual das três marcas se mostrou mais resistente. Secundariamente será avaliar a influência do pH oral nos valores de resistência à fratura. Foi realizada uma análise de três marcas de resinas acrílicas diferentes, “RS vertex®”, “Triplex hot®” e “Megacryl®”. Elaboraram-se 10 bases de prótese de cada marca submetendo-as a diferentes condições de pH (pH 7 e pH 4) através do uso de saliva artificial durante 1 mês. Após esta exposição foi testada a resistência das resinas acrílicas por meio de utilização da Máquina de teste Dental CS® utilizada em testes de fadiga. A pesquisa bibliográfica foi realizada através da recolha de artigos nas bases de dados PubMed, Ebsco, ResearcheGate e Google académico tendo-se selecionado um total de 33 artigos e 2 livros, por possuírem os critérios de inclusão definidos. Perante a análise dos resultados observamos que existem diferenças na resistência à fratura nas três marcas de resina acrílica. A marca “Megacryl®” é a mais resistente e a marca “Triplex hot®” a menos resistente. Também observamos que o pH diminuiu a resistência à fratura das marcas “Megacryl®” e “RS Vertex®”.
- Published
- 2019
33. Estudio y evaluación de la biocompatibilidad de aleaciones binarias de Titanio procesadas por pulvimetalurgia
- Author
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Masiá Vargas, Lidia
- Subjects
Biocompatibilitat ,MTS ,Corrosion resistance ,Resistència a la corrosió ,Microestructura ,Toxicitat ,Pròtesis biomèdiques ,Biomedical prostheses ,Biològica ,Cell adhesion and proliferation ,Powder metallurgy ,Hardness ,Artificial saliva ,CIENCIA DE LOS MATERIALES E INGENIERIA METALURGICA ,Element d¿aliatge i biomaterials ,Alloys ,Biomaterials ,Alliberament d¿ions ,Microstructure ,Keywords: Titanium ,Flexió ,Toxicity ,Metal ,Biomèdic ,Implant ,Característiques ,Titani ,MG-63 ,Biological ,Biomedicine ,Characteristics ,Titanium [Keywords] ,Grado en Ingeniería Biomédica-Grau en Enginyeria Biomèdica ,Aliatges ,Adhesió i proliferació cel·lular ,Ion release ,Alloy element ,Saliva artificial ,Biocompatibility ,Metàl·lics ,Duresa ,Pulvimetal·lúrgia ,Flexion - Abstract
[ES] El titanio es uno de los elementos metálicos más abundantes de la naturaleza, que tiene importantes propiedades y características que lo hacen único y ampliamente demandado en el sector industrial. En particular, las aleaciones de titanio son las protagonistas en el sector biomédico, ya que, al presentar un módulo bajo de elasticidad, baja conductividad térmica y eléctrica, y una alta resistencia a la corrosión, son las seleccionadas para la fabricación de implantes y prótesis biomédicas. Sin embargo, se ha de tener cuidado con su manipulación porque es altamente reactivo cuando está en presencia de oxígeno, teniendo asociados unos riesgos considerables. En este trabajo, las aleaciones de titanio de las que se estudia su biocompatibilidad han sido procesadas por vía pulvimetalúrgica. Esta técnica es la más común para obtener y diseñar composiciones que pueden ser difíciles de obtener por metalurgia convencional, disminuyendo la cantidad de residuos del material durante el procesamiento e impidiendo que los elementos de aleación sean segregados (garantizando la homogeneidad de la microestructura). Se trata pues con aleaciones formadas por la mezcla elemental y el aliado mecánico de los polvos de los elementos de aleación, cuyas propiedades mecánicas han sido determinadas por una prueba de dureza y flexión de tres puntos; mientras que la caracterización microestructural se ha analizado mediante la microscopía electrónica de barrido. La biocompatibilidad es un término relativo que cubre muchos conceptos, y que indica la capacidad de un material para realizar una función biológica sin producir una reacción a un cuerpo extraño. Entonces, las aleaciones han sido sometidas a una prueba de resistencia a la corrosión, junto con una prueba de liberación de iones con saliva artificial durante 732 horas. Luego, para ver el efecto de los resultados de las pruebas anteriores y empleando una línea celular de osteosarcoma humano (MG63), se ha hecho una determinación de la toxicidad con el reactivo MTS, y posteriormente se ha realizado un ensayo de adhesión celular y proliferación, de 5 horas y 72 horas respectivamente. Por lo tanto, los resultados del estudio de las diferentes aleaciones de titanio caracterizadas por la presencia de un elemento de aleación en cada caso permiten determinar si se comportan como verdaderos biomateriales o resultan nocivos para un medio biológico., [CA] El titani es un dels elements metàl·lics més abundants de la naturalesa, que posseeix unes importants propietats i característiques que el fan únic i àmpliament demandat en el sector industrial. Concretament, els aliatges de titani son els protagonistes en el sector biomèdic ja que al presentar un baix mòdul d’elasticitat, baixa conductivitat tèrmica i elèctrica, i una elevada resistència a la corrosió, son els seleccionats per a la fabricació d’implants i pròtesis biomèdiques. No obstant, es deu de tindre en conter amb la seua manipulació ja que és altament reactiu quan es troba en presencia d’oxigen , ocasionant uns riscos considerables. En aquest treball, els aliatges de titani dels quals s’estudia la seua biocompatibilitat, han sigut processades per via pulvimetal·lúrgica. Aquesta tècnica es la més comú per a l’obtenció i disseny de composicions que puguin ser difícils d’obtenir mitjançant la metal·lúrgia convencional, disminuint la quantitat de deixalles del material durant el processat i evitant que els elements d’aliatge es segreguen (garantint la homogeneïtat de la microestructura). Es tracta amb aliatges resultats de la mescla elemental i aliat mecànic dels pols dels elements d’aliatge, les propietats mecàniques dels quals s’han determinat per una prova de duresa i de flexió a tres punts; mentre que la caracterització microestructural ha sigut analitzada per microscòpia electrònica d’escombrat. La biocompatibilitat, es un terme relatiu que engloba molts conceptes, i que indica la capacitat d’un material de realitzar una funció biològica sense produir una reacció a cos estrany. Aleshores, per estudiar-lo, primerament, s’han sotmès els aliatges a una prova de resistència a la corrosió junt a una d’alliberament d’ions amb saliva artificial durant 732 hores. A continuació, per veure l’efecte dels resultats de les proves anteriors i fent ús d’una línia cel·lular d’osteosarcoma humà (MG-63), s’ha realitzat una determinació de la toxicitat amb el reactiu MTS, i després un assaig d’adhesió i proliferació cel·lular, de 5 hores i 72 hores respectivament. Per tant, els resultats de l’estudi dels diferents aliatges de titani caracteritzats per la presencia d’un element d’aliatge en cada cas, permeten determinar si aquests es comporten com a vertaders biomaterials o resulten perjudicials per al medi biològic., [EN] Titanium is one of the most abundant metal elements of nature, which has important properties and characteristics that make it unique and widely demanded in the industrial sector. Specifically, the titanium alloys are the protagonists in the biomedical sector as by presenting a low modulus of elasticity, low thermal and electrical conductivity, and a high resistance to corrosion, are those selected for the manufacture of implants and biomedical prostheses. However, their manipulation is complicated because it is highly reactive when it is in the presence of oxygen. In this work, the titanium alloys have been processed by powder metallurgical route. This technique is the most common to obtain and design compositions that can be difficult to obtain by conventional metallurgy, amount of material waste during processing and preventing the alloy elements from being segregated (guaranteeing the homogeneity of the microstructure). They are alloys formed by the elementary mixture and the mechanical alloy of the powders of the alloy elements, whose mechanical properties have been determined by a three-point hardness and flexural test; while the microstructural characterization has been analyzed by scanning electron microscopy. Biocompatibility is a relative term that covers many concepts, and that indicates the ability of a material to perform a biological function without producing a reaction to a foreign body. Then, the alloys have been subjected to a corrosion resistance test, and an ion release test with artificial saliva for 732 hours. Then, to see the effect of the results of the previous tests and using a human osteosarcoma cell line (MG-63), a toxicity determination was made with the MTS reagent, and subsequently a 5-hour and 72-hour cell adhesion and proliferation test was performed respectively. Therefore, the results of the study of the different titanium alloys characterized by the presence of an alloy element in each case, allow to determine whether they behave as true biomaterials or are harmful to a biological environment.
- Published
- 2019
34. Measurement of erosive potential of candies dissolved in water and artificial saliva
- Author
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Ana Keila Soares, Beatriz Helena Eger Schmitt, Brenda Bonvini, Maria Mercês Aquino Gouveia Farias, and Silvana Marchiori de Araújo
- Subjects
Saliva ,candies ,lcsh:Medicine ,Titratable acid ,Orange (colour) ,Standard solution ,law.invention ,concentração de íons de hidrogênio ,03 medical and health sciences ,0302 clinical medicine ,law ,balas ,030212 general & internal medicine ,Food science ,saliva, artificial ,acidity ,Dissolution ,Flavor ,Tooth erosion ,saliva artificial ,Chemistry ,Erosão dentária ,lcsh:R ,030206 dentistry ,General Medicine ,Glass electrode ,lcsh:RK1-715 ,hydrogen-ion concentration ,Distilled water ,lcsh:Dentistry ,acidez - Abstract
Resumo Introdução O consumo excessivo e frequente de balas ácidas pode estar associado à etiologia da erosão dental. Objetivo Mensurar e comparar o pH e a acidez titulável de balas dissolvidas em água e saliva artificial. Material e método Foram utilizadas as balas Tic Tac® sabores laranja, cereja/maracujá e morango, agrupadas em dois grupos: G-1: balas dissolvidas em água; G-2: balas dissolvidas em saliva artificial. As balas foram trituradas e, do pó resultante de cada sabor, foram pesadas duas amostras de 20 g, sendo então dissolvidas em 120 mL de água destilada ou 120 mL de saliva artificial. Destas soluções, obtiveram-se três amostras de 30 mL para cada um dos sabores, permitindo a leitura em triplicata do pH e da acidez titulável. O pH foi mensurado utilizando-se um potenciômetro e eletrodo combinado de vidro, previamente calibrado com soluções padrão pH 7,0 e pH 4,0. Para a verificação da acidez titulável, adicionaram-se alíquotas de 100 μL NaOH 1M, até o pH alcançar 5,5. Submeteram-se os resultados à Análise de Variância (ANOVA). As comparações das médias foram realizadas pelo Teste Tukey, em um nível de 5% de significância (p
- Published
- 2016
35. Electrochemical analysis of the degradation of nitrided zirconia 3Y-TZP
- Author
-
Dorado-Bustamante, Kevin, Leal-Marin, Sara, Estupiñán-Duran, Hugo, Dorado-Bustamante, Kevin, Leal-Marin, Sara, and Estupiñán-Duran, Hugo
- Abstract
Zirconia is a material that is susceptible to changes in its structure from the tetragonal to the monoclinic phase caused by variations in temperature or by contact with water. One way of achieving the stability of the tetragonal phase at low temperatures is by incorporating anionic gaps in its crystal lattice through doping procedures with aliovalent anions such as nitrogen. Nitrogen replaces the oxygen in the crystal lattice, which stabilizes the tetragonal structure of zirconia at low temperatures. The aim of this research was to evaluate the degradation of nitrided zirconia 3Y-TZP after it was immersed in artificial saliva for 0, 7, 14, and 21 days. Interfacial processes such as oxide-formation were assessed simultaneously using the electrochemical impedance spectroscopy test. Additionally, morphological, topographic, and composition changes were analyzed in the degradation process using SEM-EDS and AFM., La circonia es un material susceptible a cambios en su estructura de la fase tetragonal a monoclínica, ocasionados por cambios en la temperatura o contacto con agua. Una manera de alcanzar la estabilidad de la fase tetragonal a bajas temperaturas es a través de la incorporación de vacancias aniónicas en su estructura cristalina por medio de procedimientos de dopado con aniones aliovalentes como el nitrógeno. El nitrógeno reemplaza el oxígeno en la estructura cristalina y estabiliza la estructura tetragonal de la circonia a bajas temperaturas. El objetivo de este trabajo fue evaluar la degradación de la circonia 3Y-TZP nitrurada a través de su inmersión en saliva artificial por 0, 7,14 y 21 días, evaluando los procesos interfaciales como la formación de óxidos a través de espectroscopia por impedancia electroquímica. Adicionalmente se analizó la morfología, topografía y cambios de composición en el proceso de degradación empleando SEM-EDS y AFM.
- Published
- 2018
36. Electrochemical analysis of the degradation of nitrided zirconia 3Y-TZP
- Author
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Dorado Bustamante, Kevin, Leal Marin, Sara, Estupiñán Durán, Hugo Armando, Dorado Bustamante, Kevin, Leal Marin, Sara, and Estupiñán Durán, Hugo Armando
- Abstract
Zirconia is a material that is susceptible to changes in its structure from the tetragonal to the monoclinic phase caused by variations in temperature or by contact with water. One way of achieving the stability of the tetragonal phase at low temperatures is by incorporating anionic gaps in its crystal lattice through doping procedures with aliovalent anions such as nitrogen. Nitrogen replaces the oxygen in the crystal lattice, which stabilizes the tetragonal structure of zirconia at low temperatures. The aim of this research was to evaluate the degradation of nitrided zirconia 3Y-TZP after it was immersed in artificial saliva for 0, 7, 14, and 21 days. Interfacial processes such as oxide-formation were assessed simultaneously using the electrochemical impedance spectroscopy test. Additionally, morphological, topographic, and composition changes were analyzed in the degradation process using SEM-EDS and AFM., La circonia es un material susceptible a cambios en su estructura de la fase tetragonal a monoclínica, ocasionados por cambios en la temperatura o contacto con agua. Una manera de alcanzar la estabilidad de la fase tetragonal a bajas temperaturas es a través de la incorporación de vacancias aniónicas en su estructura cristalina por medio de procedimientos de dopado con aniones aliovalentes como el nitrógeno. El nitrógeno reemplaza el oxígeno en la estructura cristalina y estabiliza la estructura tetragonal de la circonia a bajas temperaturas. El objetivo de este trabajo fue evaluar la degradación de la circonia 3Y-TZP nitrurada a través de su inmersión en saliva artificial por 0, 7,14 y 21 días, evaluando los procesos interfaciales como la formación de óxidos a través de espectroscopia por impedancia electroquímica. Adicionalmente se analizó la morfología, topografía y cambios de composición en el proceso de degradación empleando SEM-EDS y AFM
- Published
- 2018
37. Valoración clínica de una nueva saliva artificial en forma de spray para los pacientes con boca seca.
- Author
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Silvestre, F. J., Minguez, M. P., and Suñe-Negre, J. M.
- Abstract
Copyright of Medicina Oral, Patologia Oral y Cirugia Bucal is the property of Medicina Oral SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2009
38. Síntesis y caracterización in vitro del hidrogel a base de un aceite esencial de Cinnamomum zeylanicum. Una propuesta para el tratamiento de la estomatitis subprotésica
- Author
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Medina, Henry, Ramírez, Carla, Bustillos R., Lorena, González, Anajulia, Rojas, Luis B., Aparicio Z., Rosa L., and Ortiz, Reinaldo
- Subjects
Estomatitis subprotética ,Cinnamomum zeylanicum ,Fitoterapia ,Revistas ,Hidrogel ,Trabajos de Investigación [Revista Odontológica de los Andes] ,Revista Odontológica de Los Andes ,Saliva Artificial ,Denture stomatitis ,Hydrogel ,Medicina y Salud ,Facultad de Odontología ,Controlled release ,Phytotherapy - Abstract
La estomatitis subprotésica es una patología frecuente relacionada con el uso de prótesis dental. En su tratamiento, la fitoterapia tiene poca evidencia científica. El objetivo de este trabajo fue determinar in vitro la adhesión, solubilidad y liberación controlada de un hidrogel a base del aceite esencial de Cinnamomun zeylanicum (canela) en una solución de saliva artificial; con el propósito futuro de ser utilizado como fitoterapia en la estomatitis subprotésica. Se realizó: 1. Extracción del aceite esencial por el método de hidrodestilación e identificación de sus compuestos esenciales. 2. Elaboración del hidrogel. Se analizó el aceite esencial por el método de cromatografía de gases acoplado a espectrometría de masas (CG-EM), identificando como compuestos principales monoterpenos y sesquiterpenos y 16 compuestos fueron determinados, siendo mayoritarios cinnamaldehído (57,48 %); eugenol (12,36 %); ß-cariofileno (10,97 %). La adhesión del hidrogel se probó sobre placas acrílicas de termocurado y se determinó: solubilidad y liberación controlada en saliva artificial a través de espectrometría de UV-Visible, utilizando el programa UV WintLab como base de datos. Los resultados se manejaron a través de gráficos, demostrando que la saliva artificial y suero fisiológico son buenos medios para la liberación del hidrogel; observándose una meseta en ambos casos alrededor de los 80 minutos. Al unir estos medios con el hidrogel hubo buena adhesión del hidrogel en las placas acrílicas, homogeneidad en la mezcla, solubilidad y liberación controlada en saliva. Denture stomatitis is a common condition related to the use of dental prosthesis. Regarding its treatment, phytotherapy has little scientific evidence published. The aim of the study was to determine in vitro adhesion, solubility and controlled release of a hydrogel based on essential oil of Cinnamomun zeylanicum (cinnamon) in artificial saliva solution; the further purpose was to propose this gel as phytotherapy for denture stomatitis. Researchers performed: (1) The extraction of the essential oil by the method of distillation and identification of its essential compounds and (2) preparation of the hydrogel. Essential oil was analyzed by the method of gas chromatography coupled with mass spectrometry (GC-MS), identifying monoterpenes and sesquiterpenes as main compounds; other 16 compounds were determined, being the majority cinnamaldehyde 57,48 %); eugenol (12.36 %) and β-caryophyllene (10.97 %). Adhesion of the hydrogel was tested on thermic acrylic plates to determine solubility and controlled release in artificial saliva through UV-Visible spectrometry by using the UV WintLab as the database. The results were presented in graphics showing that artificial saliva and physiological solution are a good way for the hydrogel release; observing a plateau in both cases for around 80 minutes. Good adhesion of hydrogel on acrylic plates was observed by joining these solutions with hydrogel; it was also observed homogeneity in the mixture, solubility and controlled release in saliva. 22-33 semestral
- Published
- 2018
39. Rugosidad superficial de dos resinas acrílicas de termocurado para prótesis totales sometidas a saliva artificial
- Author
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Claudia Patricia Ortiz, María Natalia Morera Rivera, and Claudia Patricia Lema Soto
- Subjects
Baseline values ,polymethyl methacrylate ,Saliva ,Low toxicity ,Chemistry ,saliva artificial ,General Medicine ,materiales dentales ,artificial saliva ,Animal science ,polimetil metacrilato ,visual_art ,61 Ciencias médicas ,Medicina / Medicine and health ,visual_art.visual_art_medium ,In vitro study ,dental materials ,Acrylic resin ,Arithmetic mean - Abstract
Introducción: las resinas acrílicas de termocurado son utilizadas como material de base para dentaduras por su estética, baja sorción acuosa y solubilidad en agua, relativa baja de toxicidad, reparabilidad y técnica de procesamiento simple. Objetivo: evaluar la rugosidad super cial de dos resinas acrílicas de base de dentadura expues- tas a saliva arti cial. Metodología: se realizó un estudio in vitro, con 30 especímenes de resinas acrílicas, dividido en dos grupos Ivoclar (Iv) y Veracryl (Vr) (n = 15), fabri- cados con una matriz de acero, se realizaron dos mediciones de rugosidad inicial y nal con el Rugosímetro Mitutoyo, para obtener la Ra (media aritmética), Rq (media cuadrática), Rz (media). Entre las mediciones, inicial y final, los especímenes fueron sumergidos en saliva artificial a 37 oC, por un período de 60 días. Los datos fueron tabulados y analizados estadísticamente. Resultados: fue realizada comparación intergrupal en los valores de línea base y nal, sin evidenciar diferencia estadística para las variables de Ra en micrómetros (1.9 ± 0.83; 2.0 ± 0.72); Rq (2.35 ± 1.01; 2.7 ± 1.0) y Rz (9.7 ± 5.3; 12.7 ± 4.7), para los grupos Iv y Vr, respectivamente, las unidades de medición para todas son micras (μm). Para valores de línea base: Ra (0,58 ± 0,29; 0,68 ± 0,32), Rq (0,64 ± 0,25; 0,83 ± 0,39) y Rz (2,46 ± 0,88; 3,03 ± 1,33), para valores nales en los grupos Iv y Vr, respectivamente, (p0.05). Al comparar los cambios intragrupo en la rugosidad superficial antes y después de la inmersión en saliva, fue encontrada una diferencia signi cativamente estadística para los valores Ra, Rq, Rz (p0,05). Conclusiones: existe disminución de rugosidad super cial para ambos grupos al ser sumergidos en saliva artificial. ntroduction: The thermocured acrylic resins are used as base material for teeth due to their aesthetic look, low water retention and solubility, relatively low toxicity, their repairability and their simple processing technique. Objective: To evaluate the super cial roughness of two denture-based acrylic resins exposed to artificial saliva. Methodology: In vitro study was performed, with 30 specimens of acrylic resins, divided into two groups Iv and Vr (n = 15), manufactured from a steel matrix; Two roughness measurements were performed: the initial and nal with the Mitutoyo Rogusimeter, to obtain the Ra (arithmetic mean), Rq (quadratic mean) and Rz(Mean). In between the initial and nal measurements, the specimens were submerged in arti cial saliva at 37 oC, for 60 days period. The data results were tabulated and statistically analyzed with the t-student and Anova tests. Results: Intergroup comparison was made in the baseline and nal values without showing statistical di erence for the Ra variables (1.9 ± 0.83 μm, 2.0 ± 0.72 μm); Rq (2.35 ± 1.01 μm; 2.7 ± 1.0 μm) and Rz (9.7 ± 5.3 μm, 12.7 ± 4.7 μm) for groups Iv and Vr respectively for baseline values; and Ra (0.58 ± 0.29μm, 0.68 ± 0.32μm), Rq (0.64 ± 0.25μm, 0.83 ± 0.39μm) and Rz (2.46 ± 0.88μm; ,03 ± 1.33μm) for nal values in groups Iv and Vr respectively, (p 0.05). When comparing the intragroup changes in the surface roughness before and after the immersion in saliva, a statistically signi cant di erence was found for the values Ra, Rq, Rz (p 0.05). Conclusions: There is a decrease in superficial roughness for both groups when immersed in artificial saliva.
- Published
- 2018
40. Diseño de alimentos lácteos con capacidad saciante. Relación entre estructura, procesamiento oral y percepción
- Author
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Fiszman Dal Santo, Susana, Hernando Hernando, Mª Isabel, Universitat Politècnica de València. Instituto Universitario de Ingeniería de Alimentos para el Desarrollo - Institut Universitari d'Enginyeria d'Aliments per al Desenvolupament, Morell Esteve, Pere, Fiszman Dal Santo, Susana, Hernando Hernando, Mª Isabel, Universitat Politècnica de València. Instituto Universitario de Ingeniería de Alimentos para el Desarrollo - Institut Universitari d'Enginyeria d'Aliments per al Desenvolupament, and Morell Esteve, Pere
- Abstract
Tesis por compendio, This thesis studies how to increase the expected satiating ability in dairy products analyzing the effect of the incorporation of certain ingredients. The study of food reformulation with high expected satiating ability contributes to moderate size meal choice and to regulate food intake. In this thesis, two factors influencing the satiating ability perception of semi-solid foods have been mainly studied: a) the increase in oral processing time that produces prolonged orosensory signals, and b) the increase in protein content. The increase in oral processing time is produced by, for example, higher consistencies, mouth-coating or creaminess sensations. These features can be modified by the addition of hydrocolloids. Native starch, modified starch, ¿-carrageenan and guar gum were added to increase the viscosity and consistency of milkshakes. Rheological characterization of the products revealed very different behavior patterns depending on the type of hydrocolloid. The addition of saliva in the studies showed modified sensory perceptions, so its inclusion is desirable and more realistic. The addition of hydroxypropyl methylcellulose (HPMC) and the effect of milk solids and cream in milk-based desserts was also studied. In addition to HPMC dominant effect on the temporality of perceptions, the presence of fat globules or milk solids modulated such perceptions. Yogurt was selected to increase protein content, adding twice the original amount of protein from different milk fractions, and starch. Yogurt with milk powder addition was the most accepted sample and it was closer to the 'ideal' characteristics of a satiating yogurt according to consumers, with a series of sensory attributes that contribute to the feeling of expected satiety. On the other hand, in vitro oral digestion showed that physically modified starch granules remain unchanged after the attack of ¿-amylase, and would be responsible for its consistency and creaminess. In addition, it was found that the sen, La presente tesis estudia cómo aumentar las expectativas de la capacidad saciante en productos lácteos analizando el efecto de la incorporación de determinados ingredientes. El estudio de la reformulación de alimentos con alta expectativa sobre su capacidad saciante contribuye a moderar la elección de las raciones de alimentos y a regular la ingesta. En la presente tesis se han estudiado principalmente dos de los factores que más influyen en la percepción de capacidad saciante de alimentos semisólidos: a) el aumento en el tiempo de procesado oral que produce saciedad debido a una prolongación de las señales orosensoriales, y b) el alto contenido en proteínas. El aumento del tiempo de procesado oral lo producen, por ejemplo, mayores consistencias, recubrimiento oral o sensaciones de cremosidad, que son características que se pueden modificar por adición de hidrocoloides. Se emplearon almidón nativo y modificado, goma guar y ¿-carragenato para aumentar la viscosidad y consistencia de batidos lácteos. La caracterización reológica de los productos reveló patrones de comportamiento muy diferentes dependiendo del tipo de hidrocoloide. La adición de la saliva en los estudios demostró modificar las percepciones sensoriales, por lo que su inclusión resulta recomendable y más realista. Se estudió también la adición de hidroxipropilmetilcelulosa (HPMC) y el efecto de dos componentes normales en productos lácteos (sólidos lácteos y nata). Además del efecto dominante del HPMC en la temporalidad de las percepciones, la presencia de glóbulos de grasa o sólidos de la leche modularon dichas percepciones. Para aumentar el contenido en proteína se seleccionó como alimento el yogur, al que se añadió el doble de la cantidad de proteína de distintas fracciones lácteas y almidón. El yogur con el doble de leche en polvo fue globalmente el más aceptado y más cercano a las características "ideales" según los consumidores, con una serie de atributos sensoriales que contribuyen a la sensación, La present tesi estudia com augmentar les expectatives de la capacitat saciant en productes lactis analitzant l'efecte de la incorporació de determinats ingredients. L'estudi de la reformulació d'aliments amb alta expectativa sobre la seua capacitat saciant contribueix a moderar l'elecció de les racions d'aliments i a regular la ingesta. En la present tesi s'han estudiat principalment dos dels factors que més influeixen en la percepció de capacitat saciant d'aliments semisòlids: a) l'augment en el temps de processat oral que produeix sacietat a causa d'una prolongació dels senyals orosensorials, i b) l'alt contingut en proteïnes. L'augment del temps de processat oral el produeixen, per exemple, majors consistències, recobriment oral o sensacions de cremositat, que són característiques que es poden modificar per addició d'hidrocol·loïdes. S'emprà midó natiu i modificat, goma guar i ¿-carragenat per augmentar la viscositat i consistència de batuts lactis. La caracterització reològica dels productes revelà patrons de comportament molt diferents depenent del tipus d'hidrocol·loïde. L'addició de la saliva en els estudis demostrà modificar les percepcions sensorials, per la qual cosa la seua inclusió resulta recomanable i més realista. S'estudià també l'addició d'hidroxipropilmetilcel·lulosa (HPMC) i l'efecte de dos components normals en productes lactis (sòlids lactis i nata). A més de l'efecte dominant del HPMC en la temporalitat de les percepcions, la presència de glòbuls de greix o sòlids de la llet van modular les citades percepcions. Per augmentar el contingut en proteïna es va seleccionar com a aliment el iogurt, a què s'afegí el doble de la quantitat de proteïna de diverses fraccions làcties i midó. El iogurt amb el doble de llet en pols fou globalment el més acceptat i més pròxim a les característiques "ideals" segons els consumidors, amb una sèrie d'atributs sensorials que contribueixen a la sensació de sacietat esperada. D'altra banda, la digestió oral in vitro
- Published
- 2017
41. Diseño de alimentos lácteos con capacidad saciante. Relación entre estructura, procesamiento oral y percepción
- Author
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Morell Esteve, Pere, FISZMAN DAL SANTO, SUSANA, Hernando Hernando, Mª Isabel, and Universitat Politècnica de València. Instituto Universitario de Ingeniería de Alimentos para el Desarrollo - Institut Universitari d'Enginyeria d'Aliments per al Desenvolupament
- Subjects
proteína láctea ,análisis sensorial ,almidón modificado físicamente ,tribología ,TECNOLOGIA DE ALIMENTOS ,saliva artificial ,flash profiling ,capacidad saciante ,food and beverages ,cuestionario CATA ,procesado oral ,yogur ,procesamiento oral ,batido ,digestión oral in vitro ,capacidad saciante esperada ,alimentos lácteos ,reología ,postre lácteo ,microestructura ,dominancia temporal de las sensaciones - Abstract
This thesis studies how to increase the expected satiating ability in dairy products analyzing the effect of the incorporation of certain ingredients. The study of food reformulation with high expected satiating ability contributes to moderate size meal choice and to regulate food intake. In this thesis, two factors influencing the satiating ability perception of semi-solid foods have been mainly studied: a) the increase in oral processing time that produces prolonged orosensory signals, and b) the increase in protein content.The increase in oral processing time is produced by, for example, higher consistencies, mouth-coating or creaminess sensations. These features can be modified by the addition of hydrocolloids. Native starch, modified starch, ¿-carrageenan and guar gum were added to increase the viscosity and consistency of milkshakes. Rheological characterization of the products revealed very different behavior patterns depending on the type of hydrocolloid. The addition of saliva in the studies showed modified sensory perceptions, so its inclusion is desirable and more realistic. The addition of hydroxypropyl methylcellulose (HPMC) and the effect of milk solids and cream in milk-based desserts was also studied. In addition to HPMC dominant effect on the temporality of perceptions, the presence of fat globules or milk solids modulated such perceptions. Yogurt was selected to increase protein content, adding twice the original amount of protein from different milk fractions, and starch. Yogurt with milk powder addition was the most accepted sample and it was closer to the 'ideal' characteristics of a satiating yogurt according to consumers, with a series of sensory attributes that contribute to the feeling of expected satiety. On the other hand, in vitro oral digestion showed that physically modified starch granules remain unchanged after the attack of ¿-amylase, and would be responsible for its consistency and creaminess. In addition, it was found that the sensation of astringency was undesirable; tribological studies allowed to interpret yogurt sensory characteristics. The lubricity of some samples did not reflect the difference in astringency between samples indicating that this was not a purely tactile perception caused by an increase in friction. The addition of physically modified starch significantly reduced friction coefficients values due to soluble starch polymers and starch granules preservation.All the strategies allowed to gain understanding on how to reformulate food increasing its satiating ability perception. Such strategies could be extrapolated to other food categories, what broadens the scope of the results obtained in this thesis., La presente tesis estudia cómo aumentar las expectativas de la capacidad saciante en productos lácteos analizando el efecto de la incorporación de determinados ingredientes.El estudio de la reformulación de alimentos con alta expectativa sobre su capacidad saciante contribuye a moderar la elección de las raciones de alimentos y a regular la ingesta. En la presente tesis se han estudiado principalmente dos de los factores que más influyen en la percepción de capacidad saciante de alimentos semisólidos: a) el aumento en el tiempo de procesado oral que produce saciedad debido a una prolongación de las señales orosensoriales, y b) el alto contenido en proteínas.El aumento del tiempo de procesado oral lo producen, por ejemplo, mayores consistencias, recubrimiento oral o sensaciones de cremosidad, que son características que se pueden modificar por adición de hidrocoloides. Se emplearon almidón nativo y modificado, goma guar y ¿-carragenato para aumentar la viscosidad y consistencia de batidos lácteos. La caracterización reológica de los productos reveló patrones de comportamiento muy diferentes dependiendo del tipo de hidrocoloide. La adición de la saliva en los estudios demostró modificar las percepciones sensoriales, por lo que su inclusión resulta recomendable y más realista. Se estudió también la adición de hidroxipropilmetilcelulosa (HPMC) y el efecto de dos componentes normales en productos lácteos (sólidos lácteos y nata). Además del efecto dominante del HPMC en la temporalidad de las percepciones, la presencia de glóbulos de grasa o sólidos de la leche modularon dichas percepciones. Para aumentar el contenido en proteína se seleccionó como alimento el yogur, al que se añadió el doble de la cantidad de proteína de distintas fracciones lácteas y almidón. El yogur con el doble de leche en polvo fue globalmente el más aceptado y más cercano a las características "ideales" según los consumidores, con una serie de atributos sensoriales que contribuyen a la sensación de saciedad esperada. Por otro lado, la digestión oral in vitro mostró que los gránulos de almidón procedentes de almidón físicamente modificado permanecen inalterados después del ataque de la ¿-amilasa de la saliva, y serían los responsables de la mayor consistencia y cremosidad.Adicionalmente, se encontró que la sensación de astringencia resultaba negativa; los estudios tribológicos permitieron interpretar las características sensoriales. Las propiedades lubricantes de algunas muestras no reflejaron la diferencia de astringencia sensorial indicando que ésta no era una percepción puramente táctil causada por un aumento en la fricción. La adición de almidón modificado físicamente redujo significativamente los valores de los coeficientes de fricción relacionados con los polímeros de almidón solubles y la conservación de gránulos en el almidón.Todas las estrategias abordadas permitieron comprender y ahondar en los conocimientos que conducen a cómo reformular un alimento para aumentar la percepción de saciedad. Dichas estrategias son extrapolables a otras categorías de alimentos lo que amplía el alcance de los resultados obtenidos en la presente tesis., La present tesi estudia com augmentar les expectatives de la capacitat saciant en productes lactis analitzant l'efecte de la incorporació de determinats ingredients.L'estudi de la reformulació d'aliments amb alta expectativa sobre la seua capacitat saciant contribueix a moderar l'elecció de les racions d'aliments i a regular la ingesta. En la present tesi s'han estudiat principalment dos dels factors que més influeixen en la percepció de capacitat saciant d'aliments semisòlids: a) l'augment en el temps de processat oral que produeix sacietat a causa d'una prolongació dels senyals orosensorials, i b) l'alt contingut en proteïnes.L'augment del temps de processat oral el produeixen, per exemple, majors consistències, recobriment oral o sensacions de cremositat, que són característiques que es poden modificar per addició d'hidrocol·loïdes. S'emprà midó natiu i modificat, goma guar i ¿-carragenat per augmentar la viscositat i consistència de batuts lactis. La caracterització reològica dels productes revelà patrons de comportament molt diferents depenent del tipus d'hidrocol·loïde. L'addició de la saliva en els estudis demostrà modificar les percepcions sensorials, per la qual cosa la seua inclusió resulta recomanable i més realista. S'estudià també l'addició d'hidroxipropilmetilcel·lulosa (HPMC) i l'efecte de dos components normals en productes lactis (sòlids lactis i nata). A més de l'efecte dominant del HPMC en la temporalitat de les percepcions, la presència de glòbuls de greix o sòlids de la llet van modular les citades percepcions.Per augmentar el contingut en proteïna es va seleccionar com a aliment el iogurt, a què s'afegí el doble de la quantitat de proteïna de diverses fraccions làcties i midó. El iogurt amb el doble de llet en pols fou globalment el més acceptat i més pròxim a les característiques "ideals" segons els consumidors, amb una sèrie d'atributs sensorials que contribueixen a la sensació de sacietat esperada. D'altra banda, la digestió oral in vitro mostrà que els grànuls de midó procedents de midó físicament modificat romanen inalterats després de l'atac de l'¿-amilasa de la saliva, i serien els responsables de la major consistència i cremositat.Addicionalment, es trobà que la sensació d'astringència resultava negativa; els estudis tribològics permeteren interpretar les característiques sensorials. Les propietats lubricants d'algunes mostres no reflectiren la diferència d'astringència sensorial indicant que esta no era una percepció purament tàctil causada per un augment en la fricció. L'addició de midó modificat físicament reduí significativament els valors dels coeficients de fricció relacionats amb els polímers de midó solubles i la conservació de grànuls en el midó.Totes les estratègies abordades permeteren comprendre i aprofundir en els coneixements que condueixen a com reformular un aliment per augmentar la percepció de sacietat. Les citades estratègies són extrapolables a altres categories d'aliments, cosa que amplia l'abast dels resultats obtinguts en la present tesi., Morell Esteve, P. (2017). Diseño de alimentos lácteos con capacidad saciante. Relación entre estructura, procesamiento oral y percepción [Tesis doctoral no publicada]. Universitat Politècnica de València. doi:10.4995/Thesis/10251/89093., TESIS
- Published
- 2017
42. Caraterização da microdureza da superfície do esmalte erodido, antes e depois da aplicação de um verniz de flúor
- Author
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Guia, Marta Alexandra da Silva, Manso, Ana Cristina, Carvalho, Patrícia Maria Almeida, and Carmo, Joana do
- Subjects
Verniz de flúor ,Microdureza de Vickers ,Saliva artificial ,Erosão do esmalte - Abstract
Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz Objetivos: Avaliar a capacidade remineralizadora da saliva artificial e do verniz de flúor através dos testes de microdureza de Vickers e da Microscopia Eletrónica de Varrimento (MEV). Materiais e Métodos: 8 molares humanos, foram cortados no sentido axial em hemifaces e divididos aleatoriamente em 4 grupos: Grupo A (n=8), exposição a água desionizada; Grupo B (n=8), exposição a água desionizada e verniz de flúor; Grupo C (n=8), exposição a saliva artificial; Grupo D (n=8), exposição a saliva artificial e verniz de flúor. Todos os grupos foram sujeitos a uma exposição diária (3x20 minutos num intervalo de 2 horas e 40minutos) de desmineralização com Redbull®, a 37ºC e 30 rpm. Após cada um dos ciclos, os espécimenes foram lavados com água desionizada e foi renovada a solução de exposição. 6 espécimenes de cada grupo foram submetidos ao teste da Microdureza Vickers; os outros 2 espécimenes de cada grupo, foram observados ao Microscópio Eletrónico de Varrimento, JEOL JSM 70001F. A análise estatística foi efetuada através de um teste ANOVA one-way e post hoc escolheu-se o teste de Bonferroni devido ao reduzido tamanho amostral. 95% Confidence Interval para um nível de significância de p < 0.05. Resultados: Os valores médios obtidos para cada grupo (Grupo A – 502,63±50,24 HV; Grupo A.1 – 577,43±43,36 HV; Grupo B – 650,16±14,45 HV; Grupo B.1 – 646,56±19,74 HV; Grupo C – 436,12±40,84) revelam um aumento da microdureza aquando da utilização de saliva artificial e verniz de flúor em comparação com o esmalte são. Foi observada uma desorganização na orientação dos prismas de esmalte no grupo A aquando da comparação com os restantes grupos, onde havia a utilização de saliva artificial e verniz de flúor. Conclusões: Tanto o verniz de flúor como a saliva artificial aumentam a dureza do esmalte erodido.
- Published
- 2016
43. Estratégias para o alívio da sede: revisão integrativa da literatura
- Author
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Lígia Fahl Fonseca, Aline Korki Arrabal Garcia, Patricia Aroni, and Cristina Maria Galvão
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Cuidados de Enfermagem ,Temperatura Baixa ,Low Temperature ,Saliva Artificial ,03 medical and health sciences ,0302 clinical medicine ,Artificial Saliva ,Medicine ,030212 general & internal medicine ,General Nursing ,lcsh:RT1-120 ,Atención de Enfermería ,lcsh:Nursing ,030504 nursing ,Frío ,business.industry ,SEDE ,Ice ,Hielo ,Sed ,Nursing Care ,Gelo ,0305 other medical science ,business ,Thirst - Abstract
RESUMO Objetivo: analisar as estratégias utilizadas para minorar a sede do paciente hospitalizado. Método: revisão integrativa, para a qual as bases de dados PubMed, LILACS, CINAHL e o conjunto de referências organizadas pelo Grupo de Estudo e Pesquisa da Sede foram selecionadas para a busca dos estudos primários, com os descritores: thirst, ice, cold, intervention, nursingcare, artificialsaliva. Resultados: a amostra da revisão foi composta de 10 estudos primários. As estratégias encontradas foram: baixa temperatura utilizando gaze congelada, lascas de gelo e água fria, mentol associado a estratégias frias, goma de mascar, acupressão, uso de canudo fino, substituto salivar e ingestão precoce de líquidos. Conclusão: a temperatura apresentou-se como estratégia predominante e efetiva para minorar a sede de pacientes cirúrgicos, em cuidado intensivo e em tratamentos de hemodiálise. RESUMEN Objetivo: analizar las estrategias utilizadas para saciar la sed del paciente hospitalizado. Método: revisión integrativa, sobre estudios primarios seleccionados de las bases de datos PubMed, LILACS, CINAHL y del conjunto de referencias elaboradas por el Grupo de Estudio e Investigación de la Sed, con los descriptores: thirst, ice, cold, intervention, nursing care, artificial saliva. Resultados: la muestra de la revisión se compuso de 10 estudios primarios. Las estrategias halladas fueron: baja temperatura utilizando gasa congelada, hielo molido y agua fría, mentol asociado a estrategias frías, goma de mascar, acupresión, uso de sorbete delgado, sustituto salival e ingestión precoz de líquidos. Conclusión: la temperatura se presentó como estrategia predominante y efectiva para saciar la sed en pacientes quirúrgicos, en cuidados intensivos y en tratamientos de hemodiálisis. ABSTRACT Objective: to analyze the strategies used to relieve the thirst of hospitalized patients. Method: an integrative review, for which the databases PubMed, LILACS, CINAHL and the group of references organized by the Group for Study and Research of Thirst were selected for the search of primary studies, with the keywords: thirst, ice, cold, intervention, nursing care, artificial saliva. Results: the review sample was composed of ten primary studies. The strategies found were: low temperature using frozen gauze, ice chips, and cold water, menthol associated with cold strategies, chewing gum, acupressure, and the use of a thin straw, substitute saliva, and early fluid ingestion. Conclusion: the temperature was presented as a predominant and effective strategy to relieve the thirst for surgical patients in intensive care and hemodialysis treatment.
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- 2016
44. COMPARISON OF THERAPY EFFECT OF LASER AND ARTIFICIAL SALIVA ON STIMULATION OF SALIVATION
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Tolić, Barbara and Cigić, Livia
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Low-Level Light Therapy ,BIOMEDICINE AND HEALTHCARE. Dental Medicine. Oral Medicine ,Kserostomija ,Xerostomia ,Saliva Artificial ,BIOMEDICINA I ZDRAVSTVO. Dentalna medicina. Oralna medicina ,Umjetna slina ,Niskoenergetska laserska terapija - Abstract
Cilj: Glavni cilj istraživanja je ispitati postoji li razlika u količini izlučene sline u pacijenata koji su koristili umjetnu slinu u odnosu na one čije su velike žlijezde slinovnice tretirane niskoenergetskim laserom kroz 10 uzastopnih tretmana, i to neposredno nakon (Qs i Qss 2) ili mjesec dana od završetka terapije (Qs i Qss 3) u odnosu na početno mjerenje (Qs i Qss 1). Materijali i metode: U istraživanju je sudjelovalo 39 ispitanika kojima je sijalometrijom dokazana suhoća usta (Qs˂2.0 ml/5min). Ispitnu skupinu čini 14 ispitanika koji su podvrgnuti terapiji velikih žlijezda slinovnica niskoenergetskim laserom kroz 10 uzastopnih tretmana dok kontrolnu skupinu čini 25 osoba, koje su prema uputama, više puta dnevno kontinuirano koristile preparat umjetne sline (Caphosol otopina). Rezultati: Rezultati ovog istraživanja pokazali su kako je porast količine izlučene nestimulirane sline (Qs) mjeren 10 dana nakon završetka laser terapije u ispitnoj skupini bio nešto manji u odnosu na kontrolnu skupinu koja je svo to vrijeme koristila preparat umjetne sline. Nešto manja razlika zabilježena je u porastu količine izlučene stimulirane sline (Qss), ali također u korist kontrolne skupine. Stariji ispitanici (iznad 70 godina) pokazuju nešto veći porast u Qs-u i Qss-u neposredno nakon završetka laser terapije odnosno 10 dana od početka korištenja umjetne sline, da bi te vrijednosti nakon mjesec dana bilježile pad. Suprotno tome, mlađi ispitanici pokazuju linearni porast u količini izlučene stimulirane i nestimulirane sline kroz vrijeme. Pacijenti koji ne uzimaju lijekove koji utječu na suhoću usta očekivano bilježe veće početne rezultate i dugoročno veći, linearni napredak kroz vrijeme u količini izlučene nestimulirane (Qs) i stimulirane (Qss) sline. Zaključak: Rezultati ovog istraživanja pokazali su kako je porast u količini izlučene nestimulirane i stimulirane sline nakon mjesec dana od završetka laser terapije ipak veći u ispitanika kontrolne skupine koja je svo vrijeme koristila umjetnu slinu prema uputama, nekoliko puta dnevno., Objective: The main aim of this research is to explore if there is a difference in saliva secretion between patients who were using artificial saliva, and those treated with low-level laser on major salivary glandes through ten consecutive treatments, and soon after (Qs and Qss 2) or one month after therapy was over (Qs and Qss 3) in ratio of first measurment (Qs and Qss 1). Materials and methods: The reaserch contained 39 patients, diagnosed with xerostomia using sialometry test (Qs < 2.0 ml/5min). The tested group contained 14 patients who were treated with low-level laser on major salivary glandes, through ten consecutive treatments, while control group contained 25 patients, who were using artificial saliva (Caphosol) several times a day according to manufacturers guide of product instructions. Results: Results of this research indicate that increase of measured quantum of non stimulated saliva (Qs) secretion in time of ten days after laser therapy, in tested group, was slightly lower in rate of control group who was using artificial saliva through all time. Slightly lower difference was observed in increasing of salivation of stimulated saliva (Qss), but also in favour of control group. Older patients (above 70 years) were showing slightly higher Qs and Qss rate soon after laser therapy was over, regarding ten days of using artificial saliva. After one month, measurment of Qs and Qss salivation quantum rate were decreasing. Younger patients (under 70 years) were showing linear increase in quantum of salivation of stimulated and non stimulated saliva through time. Patients who were not using medication, that can cause mouth dryness, expectedly scored better results and long term better linear progression through time, in order of measured quantum salivation of nonstimulated (Qs) and stimulated (Qss) saliva. Conclusion: Results of this research indicate that increase of measured quantum salivation of non stimulated and stimulated saliva, after one month of finished laser therapy, were higher in control group patients who were using artificial saliva the whole time, according to manufacturers guide of product instructions several times a day.
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- 2016
45. Assessment of force decay in orthodontic elastomeric chains: an in vitro study
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Diogo Antunes Vargas, Claudia Kochenborger, Dayanne Lopes da Silva, Ernani Menezes Marchioro, and Luciane Hahn
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Elastômeros ,Orthodontics ,Elastics ,Chemistry ,Materiais dentários ,Elasticidade ,Significant difference ,Saliva artificial ,Elastomeric chain ,Oral Surgery ,Synthetic elastics - Abstract
INTRODUÇÃO: os materiais elastoméricos são considerados importantes fontes de força para a movimentação ortodôntica. OBJETIVO: avaliar a liberação de tensões de quatro marcas comerciais de elásticos ortodônticos em cadeia (Morelli, Ormco, TP e Unitek), em função do tempo, quando mantidas tensionadas por uma força inicial de 150g e imersas em saliva artificial a 37ºC. MÉTODOS: os elásticos em cadeia foram tensionados entre pinos de aço, fixados em uma placa de resina acrílica à distância de 15mm (Morelli e TP) e de 16mm (Unitek e Ormco), ambas medidas correspondendo a uma força de 150g. A leitura da quantidade de tensão liberada pelos elásticos foi realizada com um dinamômetro nos intervalos 30 minutos, 7, 14 e 21 dias. Os dados obtidos foram submetidos à análise de variância (ANOVA) (p
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- 2011
46. Efeito do clareamento do consultório sobre a sorção de um compósito de baixa contração
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Abreu, Mariana Mota, Ferreira, Reinaldo de Souza, Mota, Cristiane Soares, Abreu, Mariana Mota, Ferreira, Reinaldo de Souza, and Mota, Cristiane Soares
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Saliva artificial ,Resinas Compostas ,Dentes de Dentes ,Saúde ,Odontologia - Abstract
O presente estudo teve como objetivo avaliar a influência do clareamento dental sobre a sorção salivar de uma resina de baixa contração baseada em silorano (Filtek TM P90, 3M ESPE), quando comparada a uma resina baseada em dimetacrilatos ( Filtek TM Z250, 3M ESPE). Dez corpos de prova (CP) de cada resina composta foram confeccionados apartir de uam matriz metálica bipartida ( 5mm x 1mm). Os CP foram fotoativados com unidade LED (1.400mW/cm²). Todos os CP forma imersos em saliva artificial por 1 mês e metade deles doi submetida semanalmente a protocolo de tratamento clareador (TC) de consultório com gel de peróxido de hidrogênio 35% (Whitegold, Dentsply Brasil). Dessa forma, foram formados 4 grupos (n=5): (G1) Z250, sem TC; (G2) Z250 com TC; (G3) P90 sem TC; e (G4) P90 com TC. Avaliação da sorção foi realizada através de pesagens em balança analítica de precisão, de acordo com a ISO 4049/2000. Os dados foram analisados pleos estes ANOVA2- fatores e de comprações múltiplas Student Newman Keuls (p=0,05). A ordem dos valores de sorção foi: G2>G4>G1>G3, sem diferença estatística entre eles. Os fatores compósito (p=0,2117) e meio (p=0,1584) não exerceram influência significativa sobre os valores de sorção. Conclui-se que o clareamento dental não afetou os valores de sorção dos compósitos avaliados e não houve diferença de comportamento entre os diferentes compoósitos em ambos os meios testados. The aim of the present study was to evaluate the influence of dental bleaching on the salivary sorption of a low shrinkage dental composite based on silorane monomer (FiltekTM P90, 3M ESPE, EUA) in relation to a methacrylate-based composite (FiltekTM Z250, 3M ESPE, EUA). Ten specimens of each material were fabricated in sectioned customized metaçlic mold ( 5mm x h 1mm). The composites were photo activated with a LED unit (1.400mW/cm²). All specimens were immersed in artificial saliva for 1 month and half of them was weekly submitted to an in -office bleaching protocol (BP) with 35% hydrogen peroxide (Whitegold, Dentsply Brasil). So, four groups (n=5) were analyzed: (G1) Z250 with BP; (G2) Z250 with BP; (G3) P90 no BP; and G(4) P90 with BP. the measurements of sorption behavior were made by weighing in anaaytical balance, according to ISO 4049/2000. Data were analyzed by 2-factor ANOVA and Student-Newman -Keuls post-hoc test (p=0.05). The sorption behavior was: G2> G4> G1> G3, and medium (p = 0.1584) did not show significant influence on the sorption's values. It was concluded that the bleaching treatment did not affect the values of sorption of the composites evaluated ande there was no difference in sorption behavior between different composites in both media tested.
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- 2014
47. The influence of protective varnish on the integrity of orthodontic cements
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Antônio Carlos de Oliveira Ruellas, Felipe Giacomet, Eduardo Franzotti Sant'Anna, Erika Machado Caldeira, and Antonio de Moraes Izquierdo
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Materials science ,Time Factors ,Orthodontic Brackets ,Surface Properties ,Cimentos ortodônticos ,Varnish ,Dentistry ,Orthodontics ,Protective Agents ,Hardness ,Artificial saliva ,Materials Testing ,Humans ,Saliva contamination ,Microdureza ,Cement ,Treated group ,Polycarboxylate Cement ,Bone decalcification ,Enamel paint ,business.industry ,Dental health ,Glass-ionomer cements ,Temperature ,Saliva, Artificial ,lcsh:RK1-715 ,Microhardness ,Glass Ionomer Cements ,visual_art ,lcsh:Dentistry ,visual_art.visual_art_medium ,Saliva artificial ,Equipment Contamination ,Stress, Mechanical ,Oral Surgery ,Diamond ,Zinc Oxide ,business ,Magnesium Oxide - Abstract
OBJECTIVE: The aim of the present study was to assess the influence of saliva contamination over the structural strength and integrity of conventional glass-ionomer cements used for cementing orthodontic bands in the absence and presence of a surface-protecting varnish. METHOD: 48 samples were prepared by inserting 3 types of glass-ionomer cements into standardized metallic matrixes of 10 mm of diameter and 2 mm of depth. The cements used were: Meron (VOCO), Ketac-Cem (3M ESPE) and Vidrion C (DFL), all of which comprised groups A, B and C, respectively. Subgroups A1, B1 and C1 comprised samples with no surface protection, whereas subgroups A2, B2 and C2 comprised samples of which surface was coated with Cavitine varnish (SS White), after cement manipulation and application, in order to protect the cement applied. All samples were stored in artificial saliva for 24 hours at 37ºC. A Vickers diamond micro-durometer was used to produce indentations on the non-treated group (non-varnished) and the treated group (varnished). RESULTS: Varnished materials had significantly higher microhardness values in comparison to non-varnished materials. Ketac-Cem had the highest microhardness value among the varnished materials. CONCLUSION: Varnish application is necessary to preserve the cement and avoid enamel decalcification. Glass-ionomer cements should be protected in order to fully keep their properties, thus, contributing to dental health during orthodontic treatment. OBJETIVO: avaliar a influência da contaminação salivar na resistência estrutural e integridade de cimentos de ionômero de vidro convencionais utilizados para cimentação de bandas ortodônticas na ausência e na presença de um verniz protetor de superfície. MÉTODOS: quarenta e oito corpos de prova foram confeccionados a partir de três cimentos ortodônticos, com auxílio de matrizes metálicas padronizadas com 10mm de diâmetro e 2mm de altura. Os cimentos utilizados foram: Meron (Voco), Ketac-Cem (3M ESPE) e Vidrion C (DFL), compondo os grupos A, B e C, respectivamente. Metade dessas amostras não recebeu nenhum tipo de proteção superficial, constituindo os subgrupos A1, B1 e C1, enquanto, os subgrupos A2, B2 e C2 tiveram suas superfícies isoladas com verniz Cavitine (SS White) após manipulação e aplicação do cimento, com intuito de proteger a superfície do cimento. As amostras foram armazenadas em saliva artificial por 24 horas a 37ºC. Foi realizado um ensaio de microdureza (Vickers) para avaliação da dureza de superfície do grupo não-tratado (sem isolamento) e do grupo tratado (agente protetor). RESULTADOS: os materiais previamente isolados com o verniz obtiveram valores de microdureza significativamente maiores que os não-isolados. O cimento Ketac-Cem apresentou, estatisticamente, a maior microdureza entre os materiais protegidos. CONCLUSÃO: o isolamento com verniz mostrou-se necessário para preservação do cimento e, consequentemente, de sua capacidade de evitar possíveis desmineralizações dentárias. Os cimentos de ionômero de vidro devem ser protegidos para manutenção de sua integridade, contribuindo para saúde dental durante o tratamento ortodôntico.
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- 2013
48. Estratégias para o alívio da sede: revisão integrativa da literatura
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Aline Korki Arrabal Garcia, Lígia Fahl Fonseca, Patricia Aroni, and Cristina Maria Galvão
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Sed ,Hielo ,Atención de Enfermería ,Frío ,Saliva Artificial ,Nursing ,RT1-120 - Abstract
RESUMO Objetivo: analisar as estratégias utilizadas para minorar a sede do paciente hospitalizado. Método: revisão integrativa, para a qual as bases de dados PubMed, LILACS, CINAHL e o conjunto de referências organizadas pelo Grupo de Estudo e Pesquisa da Sede foram selecionadas para a busca dos estudos primários, com os descritores: thirst, ice, cold, intervention, nursingcare, artificialsaliva. Resultados: a amostra da revisão foi composta de 10 estudos primários. As estratégias encontradas foram: baixa temperatura utilizando gaze congelada, lascas de gelo e água fria, mentol associado a estratégias frias, goma de mascar, acupressão, uso de canudo fino, substituto salivar e ingestão precoce de líquidos. Conclusão: a temperatura apresentou-se como estratégia predominante e efetiva para minorar a sede de pacientes cirúrgicos, em cuidado intensivo e em tratamentos de hemodiálise.
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49. Resistencia compresiva vidrio ionómero Ionofil Molar® y Vitremer® según tiempo de exposición en saliva artificial
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Hernández González, R, Moraga Castillo, R, Velásquez Castilla, M, and Gutiérrez Flores, F
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artificial saliva ,Cemento de vidrio ionómero ,saliva artificial ,Glass ionomer cement ,compressive strength ,resistencia compresiva - Abstract
Objetivo: El conocimiento sobre las propiedades mecánicas de los materiales dentales es fundamental para una correcta indicación y funcionamiento en la cavidad oral, permitiéndole al profesional optar por el que presente mejor comportamiento durante la masticación. El objetivo de este estudio fue evaluar la resistencia a la compresión de Ionofil Molar® y Vitremer®, según tiempo de exposición en saliva artificial. Materiales y Métodos: Se prepararon 5 muestras para cada material evaluadas a los tiempos 0, 168 y 504 horas en saliva artificial a 37° C, según las especificaciones propuestas por la norma ANSI/ADA n°66. La resistencia a la compresión se determinó sometiendo las muestras a cargas en un equipo de ensayo de fuerzas Instron® a una velocidad de carga de 1 mm/min. Se realizó una prueba de homogeneidad de varianzas, la normalidad se determinó mediante Kolmogorov-Smirnov, y posteriormente un ANOVA. Se realizó el test de Tukey para determinar si existió diferencia significativa entre variables. Resultados: La resistencia compresiva de Vitremer no presentó diferencias estadísticamente significativas en el tiempo (p=0.282), a diferencia de Ionofil Molar, que sí presentó diferencias entre los distintos tiempos (p=0.011). Además en las muestras sin sumergir, no hubo diferencia estadísticamente significativa entre materiales (p=0.091), en cambio sí existió diferencia al cabo de una y tres semanas de exposición (p=0). Conclusión: El vidrio ionómero Vitremer presenta mayor resistencia compresiva a lo largo del tiempo, sin presentar alteraciones significativas en el tiempo al ser inmerso en saliva, a diferencia del Ionofil Molar que disminuyó significativamente su resistencia en las mismas condiciones. Objective: Understanding the mechanical properties of dental materials is essential for proper indication and a correct functioning in the oral cavity, as it allows the dentist to choose the material that presents better performance during mastication. The aim of this study was to evaluate the compressive strength of Ionofil Molar and Vitremer, according to the exposure time in artificial saliva. Materials: 5 samples were prepared for each material evaluated at 0, 168 and 504 hours in artificial saliva at 37º Celsius, according to the specifications suggested by ANSI/ADA specification No 66. The compressive strength was determined by subjecting the samples to an Instron strength-testing machine at a load speed of 1 mm/min. A test of homogeneity of variance was conducted; normality was determined by Kolmogorov-Smirnov, and ANOVA. Tukey’s test was performed to determine if significant differences existed between variables. Results: Vitremer compressive strength did not show statistically significant differences over time (p=0.282), unlike Ionofil Molar, which did present differences between times (p=0.011). Besides, there were no statistically significant differences in the samples without submerging (p=0.091), unlike after one to three weeks of exposure, were a difference did exist (p=0). Conclusion: Vitremer has greater compressive strength over time, without showing significant changes in time after being immersed in saliva, unlike Ionofil Molar, whose resistance decreased significantly under the same conditions.
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- 2013
50. Evaluation of the microstructure, hardness and corrosion resistance of welded joints of a Ni-Cr alloy obtained by different welding processes
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Matos, Irma Cunha, Miranda, Mauro Sayão de, Diniz, Marilia Garcia, Sampaio, Carlos Antonio Freire, Sampaio Filho, Hélio Rodrigues, Bastos, Ivan Napoleão, Dias, Katia Regina Hostilio Cervantes, and Borges, Márcio Antônio Paraizo
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Corrosion ,Nickel alloy ,Dental alloy ,Juntas soldadas ,Corrosão ,Artificial saliva ,Electrochemical characterization ,CIENCIAS DA SAUDE::ODONTOLOGIA [CNPQ] ,Saliva artificial ,Caracterização eletroquímica ,Ligas odontológicas ,Wlded joints ,Ligas de Níquel - Abstract
Submitted by Boris Flegr (boris@uerj.br) on 2021-01-07T14:57:00Z No. of bitstreams: 1 TESE_FINAL_IRMA_CUNHA_MATOS.pdf: 6190027 bytes, checksum: a0fdf7182073e55750ce6c260d5a5c5e (MD5) Made available in DSpace on 2021-01-07T14:57:00Z (GMT). No. of bitstreams: 1 TESE_FINAL_IRMA_CUNHA_MATOS.pdf: 6190027 bytes, checksum: a0fdf7182073e55750ce6c260d5a5c5e (MD5) Previous issue date: 2013-02-20 This study evaluated and compared the electrochemical behavior of the base metal (BM) of a nickel-chromium dental alloy with welded joints obtained by brazing processes (BRA) and Tungsten Inert Gas (TIG), when immersed in artificial saliva at pH 2.5 and 5.5. Microhardness, microstructural characterization by means of optical microscopy, scanning electron microscopy (SEM) and semi-quantitative chemical analysis by Energy Dispersive Spectroscopy (EDS), were performed in the groups BM, TIG, BRA and in joints weld by laser (LAS). The BM showed a matrix rich in nickel and chromium, distributed in a typical dendritic arrangement, with inclusions of silicon and titanium, and porosities. LAS and TIG welds reveled a microstructure more refined than the BM, however, the same chemical composition and distribution of its elements. BRA showed marked differences in their microstructure, chemical composition and distribution of the elements in relation to BM. Vickers microhardness (HV), corrosion potential (Ecorr) and corrosion current density (jcorr) were statistically analyzed with ANOVA and Tukey test (p
- Published
- 2013
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