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We evaluated bacterial endotoxin adhesion, superficial micromorphology and mechanical properties of latex and non-latex intermaxillary orthodontic elastics.To quantify the adhered bacterial endotoxin, elastics were divided into 5 groups: experimental (n = 12) latex and non-latex elastics, previously contaminated by an endotoxin solution, negative control (n = 6) latex and non-latex elastics without contamination, and positive control (n = 6) stainless steel specimens (metallic replicas), contaminated by an endotoxin solution. In parallel, the structural micromorphology (n = 6) and surface roughness of latex and non-latex intermaxillary orthodontic elastics were assessed using confocal laser microscopy. Force degradation (g) and deformation of the internal diameter change (mm) were also evaluated. Structural micromorphology, surface roughness (µm), force degradation (g) and internal diameter (mm) change were evaluated at time 0 and after 24 and 72 h in a deformation test. Data were analyzed by the Shapiro-Wilk, Kruskal-Wallis, Dunn, ANOVA and Bonferroni tests (α = 5%).Endotoxin adhered similarly to both types of elastics with scores of 3 ( 1.0 EU/mL). The surface microstructure of both types of elastics showed irregularities and porosities at all times. Initially, the latex elastics had a higher surface roughness (p 0.001) than the non-latex ones. After 24 h loading, surface roughness of the latex elastics was significantly reduced (p 0.001), while after 72 h, the values were similar for both types (p 0.05). The non-latex elastics had significantly higher force generation values (p 0.05) at 0, 24 and 72 h compared with the latex elastics, although there was a significant reduction (p 0.001) in force over time for both elastics. Despite similar initial values, non-latex elastics had a significantly larger internal diameter (p 0.001) after the loading periods of 24 and 72 h compared with the latex elastics.Both elastics showed high affinity with endotoxin and microstructural irregularities of their surface. The non-latex elastics generated higher force values but demonstrated greater deformation of the internal diameter after loading.ZIELSETZUNG: Wir untersuchten die bakterielle Endotoxinadhäsion, die oberflächliche Mikromorphologie und die mechanischen Eigenschaften von latexhaltigen und nicht-latexhaltigen intermaxillären kieferorthopädischen Elastics.Zur Quantifizierung des anhaftenden bakteriellen Endotoxins wurden die Elastics in 5 Gruppen eingeteilt: experimentelle (n = 12) Latex- und Nicht-Latex-Elastics, die zuvor mit einer Endotoxinlösung kontaminiert worden waren, Negativkontrolle (n = 6) Latex- und Nicht-Latex-Elastics ohne Kontamination und Positivkontrolle (n = 6) Edelstahlproben (metallische Nachbildungen), die mit einer Endotoxinlösung kontaminiert waren. Parallel dazu wurden die strukturelle Mikromorphologie (n =6 ) und die Oberflächenrauheit von intermaxillären Elastics aus Latex und aus Nicht-Latex mittels konfokaler Lasermikroskopie untersucht. Ebenfalls bewertet wurden der Kraftabbau (g) und die Verformung des Innendurchmessers (mm). Die strukturelle Mikromorphologie, die Oberflächenrauheit (µm), der Kraftabbau (g) und die Änderung des Innendurchmessers (mm) wurden zum Zeitpunkt 0 sowie nach 24 und 72 h in einem Verformungstest bewertet. Die Daten wurden mit den Tests Shapiro-Wilk, Kruskal-Wallis, Dunn, ANOVA und Bonferroni (α = 5%) analysiert.Das Endotoxin haftete an beiden Arten von Elastics in ähnlicher Weise mit Scores von 3 ( 1,0 EU/ml). Die Oberflächenmikrostruktur beider Arten von Elastics zeigte zu jedem Zeitpunkt Unregelmäßigkeiten und Porositäten. Zu Beginn wiesen die Latex-Elastics eine höhere Oberflächenrauheit auf (p 0,001) als die Nicht-Latex-Elastics. Nach 24 h Belastung war die Oberflächenrauheit der Latex-Elastics deutlich geringer (p 0,001), während nach 72 h die Werte für beide Typen ähnlich waren (p 0,05). Die Nicht-Latex-Elastics wiesen nach 0, 24 und 72 h signifikant höhere Werte für die Krafterzeugung auf (p 0,05) als die Latex-Elastics, auch wenn die Kraft bei beiden Elastics im Laufe der Zeit signifikant abnahm (p 0,001). Trotz ähnlicher Ausgangswerte wiesen die Nicht-Latex-Elastics nach den Belastungszeiten von 24 und 72 h einen signifikant größeren Innendurchmesser (p 0,001) auf als die Latex-Elastics.Beide Elastics zeigten eine hohe Affinität zu Endotoxin und mikrostrukturelle Unregelmäßigkeiten auf ihrer Oberfläche. Die latexfreien Elastics erzeugten höhere Kraftwerte, wiesen aber nach der Belastung eine größere Verformung des Innendurchmessers auf.

Investigate the effect of erosive challenge with hydrochloric acid (HCl) on the surface of five different restorative materials.Ten plates of five restorative materials (Admira Fusion, Activa BioActive-Restorative, Charisma, Equia Forte HT Fil/EF, Filtek Universal Restorative/FU) were obtained. Half of the plate surfaces was covered with an adhesive tape, creating a control area, and the other side was submitted to the HCl (0.06 M HCl; pH 1.2; at 37 °C; for 30 h). Plates with control and HCl-treated areas were analyzed regarding the surface roughness (Sa), roughness profile (Rv), surface loss (SL), microhardness (MI), and gloss (GL) (n = 10). Surface morphology was analyzed by SEM and chemical elements were identified by EDX (n = 5). Data were evaluated by ANOVA and Tukey's test (α = 0.05).Most materials were not affected by HCl. FU showed the lowest Sa and Rv, and the highest GL after HCl. On the other hand, EF presented the highest Sa, Rv, and SL, and the lowest GL. The MI of materials was not changed after HCl. Topographical and chemical alterations were observed after HCl only for EF.The composites showed minor surface changes after HCl, which was not observed for the glass ionomer cement (EF). FU presented the best performance regarding the parameters evaluated.The effects of erosive challenge with HCl on composites were minimal, while the glass ionomer cements might not be indicated as restorative material for patients with gastroesophageal reflux disease.

Introduction Structural defects created by endodontic treatment are the most common cause of major dental failures. This study analyzed levels of stress produced by endodontic instruments during the root canal treatment by Photoelastic Analysis of Stress. Methods Twenty-four human premolars were randomly divided into four groups (n=6) according to instrumentation protocol: ProTaper Next (GPT), One Shape (GOS), Wave One Gold (GWO), and TF Adaptive (GTF). The evaluation of the photoelastic model was performed at four- dental zones: dental-crown region, cervical third of root, middle third of root and apical third of root). Silicone molds were prepared (2mmx15mm) and pinjets were used inside the root canals to fixate teeth. Photoelastic resin (2:1ratio) was poured into the silicone molds to form photoelastic models. A transmission polariscope was used to analyze the positions of interest and recorded with a digital camera. Tardy's method was used to quantify the fringe order(n) and calculate the maximum stress value(τ) at each selected point. Data were analyzed with a two-way ANOVA, Tukey's test(p Results All groups showed a significant increase in the level of stress created during biomechanical preparation of the root canals. In the quantitative analysis, there was no statistically significant difference among the groups(p> 0.05). In the qualitative analysis, GPT and GTF instruments achieved greater levels of stresses compared to GWO and GOS instruments. At the beginning of instrumentation, stresses were concentrated at the coronary level, and the end of instrumentation at the middle and apical root level. Conclusions All endodontic systems resulted in accumulation of stress along the dental structure. Stress was found in different concentrations along the tooth and at different levels.

Background: The objective of this study was to evaluate wear and surface roughness of in vivo irradiated human enamel and dentin after abrasive challenge. Methods: Using teeth donated by healthy patients or with head and neck cancer who received radiotherapy (RT) or chemoradiotherapy (CRT), 42 enamel and dentin specimens were made, divided into three groups: control, RT and CRT (n = 14 in each group, both for enamel and dentin). The specimens were submitted to an in vitroexperimental abrasive using a brushing machine and wear and surface roughness were evaluated. Results: In enamel specimens, wear profile values of CRT and RT groups were not different from control (p-value >0.05). The RT group presents lower step values than CRT and control groups (p-value p-value >0.05). In dentin specimens, no significant difference in wear profile and step was observed in all groups (p-value >0.05). However, CRT and RT groups present higher values in final surface roughness (p-value Conclusion: The exposure to ionizing radiation (associated or not to chemotherapy) influenced the surface roughness of dentin and the wear (step) of enamel after the in vitro abrasive challenge. Trial registration: Ethical procedures were approved by the FORP/USP Research Ethics Committee (CAAE: 61308416.4.0000.5419) and Hospital do Câncer de Barretos/Fundação Pio XII (CAAE: 61308416.4.3001.5437). Clinical relevance: Considering probable effects of ionizing radiation on teeth structure, understanding the behaviour of enamel and dentin under physiological processes is important to prevent and treat adverse oral side effects related to radiotherapy.

Introduction: The aim of this study was to perform a scoping review to systematically map the research done in the role of epigenetic factors on enamel development. Methods: Articles that reported relevant data among the role of epigenetics on enamel development/formation or enamel defects were selected. The data from the included studies were compiled and organized. The search strategy retrieved a total of 263 titles and abstract. Upon exclusion, only 53 articles were eligible for full article assessment. Results: After the selection process, only 12 articles were included in the scoping review. The first studies were published in 2010, while the most recent studies were published in 2021. The studies have different aims and designs and none of them evaluated human population. Conclusion: Future studies in this subject are recommended to unravel the role of epigenetic factors in normal and abnormal enamel development as well as in the development enamel defect.

We aimed to optimize the mechanical and biological properties of a conventional methacrylate-based dental polymer by loading it with double- and triple-walled carbon nanotubes as growth (DTWCNTG).A formulation of bisphenol A-glycidyl methacrylate and triethylene glycol dimethacrylate (mass ratio = 2:1) was mixed with DTWCNTG at concentrations of 0.0% (control), 0.001%, 0.005%, and 0.010%. The concentrations were physicochemical and morphologically evaluated, and antibacterial activity was assessed by seeding a Streptococcus mutans strain (ATCC 25175) on the experimental polymeric surfaces. Cellular survival and osteodifferentiation were evaluated in epithelial (HaCat) and preosteoblast cells (MC3T3-E1).The 0.001% DTWCNTG concentration yielded higher compressive strength, elastic modulus, flexural strength, flexural modulus, water sorption, and solubility than the control. The degree of conversion and color did not significantly change with a low amount of DTWCNTG incorporated into the polymer. Antibacterial activity significantly improved when tested on the 0.001% DTWCNTG discs. No groups showed cytotoxicity in a short-term analysis and adding DTWCNTG favored MC3T3-E1 mineralization over the control, particularly in the 0.001% formulation.The micro-addition of 0.001% DTWCNTG confers mechanical resistance, antimicrobial properties, and bioactivity to methacrylate-based polymers without significantly compromising color. Incorporating DTWCNTG improved dental composite properties and could be a biomodified material for minimally invasive procedures.

The aim of this study was to evaluate the color stability and the surface roughness of different composites brushed with toothpastes presenting different levels of abrasivity. Thirty discs of each material were obtained using michohybrid composites (Brilliant NG and Charisma Diamond) and a nanocomposite (Filtek Z350XT). The initial color (CIELab) and surface roughness (confocal laser scanning microscopy) of resin discs were evaluated. Afterwards, 10 specimens per group were brushed with the following dentifrices: Maximum Cavity Protection, Sensodyne Repair & Protect and Colgate Sensitive Pro-Relief. Brushing was performed with an electric toothbrush equipped with soft bristle head, with standard power and weight, for 30 minutes. Every 30 seconds, 1.0 ml of the slurry was injected between the bristles of the brush and the specimen. After abrasive challenge, the samples had their color and roughness reevaluated. Data were submitted to the Kruskal-Wallis test (color change) or the t-test (surface roughness). The level of significance was 5%. Results: Brushing did not significantly change the color of the composites tested in the study herein . On the other hand, the surface roughness of the composites was significantly affected by the abrasive challenge, regardless of the toothpaste used. The surface roughness change was similar for all the composites. The abrasive challenge with the toothpastes Maximum Cavity protection, Sensodyne Repair & Protect and Colgate Sensitive Pro-Relief was not able to significantly change the color of the composite resins. Nevertheless, the abrasive challenges significantly altered the surface roughness of all the evaluated composites. However, the changes in surface roughness were statistically similar in the microhybrid and nanofilled composites. Keywords: Composites Resins. Dentifrices. Color. ResumoO objetivo deste estudo foi avaliar a estabilidade de cor e a rugosidade superficial de diferentes resinas compostas escovadas com dentifrícios de diferentes níveis de abrasividade. Trinta discos de cada material foram obtidos utilizando compósitos micro-híbridos (Brilliant NG e Charisma Diamond) e um nanocompósito (Filtek Z350XT). A cor inicial (CIELab) e a rugosidade superficial (microscopia confocal de varredura a laser) dos discos de resina foram avaliadas. Em seguida, 10 amostras por grupo foram escovadas com os dentifrícios Máxima Proteção Anticáries, Sensodyne Repair & Protect e Colgate Sensitive Pro-Alívio. A escovação foi realizada com uma escova elétrica com cabeça de cerdas macias, com potência e peso padronizados, durante 30 minutos. A cada 30 segundos, 1,0 ml da pasta era injetada entre as cerdas da escova e a amostra. Após o desafio abrasivo, as amostras tiveram sua cor e rugosidade reavaliadas. Os dados foram submetidos ao teste de Kruskal-Wallis (alteração de cor) ou ao teste t (rugosidade da superfície) (α=5%). A escovação não alterou significativamente a cor dos compósitos. Por outro lado, a rugosidade superficial dos compósitos foi significativamente afetada pelo desafio abrasivo, independentemente do dentifrício utilizado. A alteração da rugosidade superficial foi semelhante para todos os compósitos. O desafio abrasivo com a Máxima Proteção Anticáries, o Sensodyne Repair & Protect e o Colgate Sensitive Pro-Alívio não foi capaz de alterar significativamente a cor das resinas. Diferentemente, os desafios abrasivos alteraram significativamente a rugosidade superficial de todos os compósitos avaliados. No entanto, as mudanças na rugosidade foram estatisticamente semelhantes nos compósitos micro-híbridos e nanoparticulado. Palavras-chave: Resinas Compostas. Dentifrícios. Cor.

Introduction: The purpose of this study was to evaluate the effects of different concentrations of chitosan solution used as a final rinse after root canal treatment on the shear bond strength of composite resin to enamel and coronary dentin. Materials and Methods: Sixty-four enamel/dentin fragments were taken from the cervical-third of bovine teeth. The specimens were randomly divided into four groups according to the irrigation protocol (0.2% chitosan, 0.5% chitosan, 1% chitosan, and 17% ethylenediaminetetraacetic acid [EDTA]-control) and in two subgroups according to the substrate (enamel or dentin). Each specimen was fixed in a metallic clamping device and composite resin (Single Bond/z350) was inserted in two increments and polymerized for 20s. The microshear bond strength was performed, and the adhesive interface was analyzed by three-dimensional laser confocal scanning microscopy. The data were analyzed using a two-way ANOVA and Tukey's test (α = 5%). Results: For the irrigation protocol, bond strength was significantly higher for all chitosan solutions compared to the 17% EDTA-control solution. All chitosan solutions, 0.2%, 0.5% and 1.0%, were statistically similar to each other (P > 0.05). For the substrate, enamel showed greater bond strength and was significantly different from dentin (P < 0.05). For interaction factor, 1% chitosan solution presented bond strength values statistically superior to the 17% EDTA control solution (P < 0.05) in dentin. The adhesive fracture was the most prevalent for all groups. Conclusion: The irrigation protocol on the root canal treatment does not affect the enamel bond strength and 1% chitosan solution improved dentin bond strength. Bond strength was higher for enamel than for coronary dentin.

To evaluate the efficiency of photobiomodulation therapy (PBMT) in the midpalatal suture (MPS) and pain sensation in patients undergoing rapid palatal expansion (RPE). Thirty-four individuals with the diagnosis of skeletal maxillary hypoplasia were divided in two groups: laser (n = 18) and control (n = 16). Treatment plan consisted of the use of the Hyrax expander in all patients. Subjects in the laser group were irradiated with diode laser (980 nm, 0.3 W) in six spots bilaterally distributed along the MPS for 10 s during the active phase of treatment and after overcorrection (passive phase of RPE). Control group received sham irradiations with the laser in standby mode to characterize the placebo effect. Digital occlusal radiographs were performed at different time-points for bone formation evaluation in both groups. The effects of laser irradiation on pain were assessed by the visual analog scale (Wong-Baker Faces Pain Scale). Bone formation between groups was not significantly different (p = 0.2273). At 3 months, bone formation was not yet complete in both groups. Pain sensation was similar between groups (p = 0.3940). However, pain was significantly higher for the first 7 days of treatment compared with the 14th day. PBMT did not accelerate bone regeneration in the MPS and pain sensation was similar.

The objective of this in vitro study was to evaluate the influence of remineralizing agents on the surface roughness of eroded tooth enamel. Forty incisive bovines were selected and sectioned to obtain specimens of 4mm X 4mm, resulting in a surface area of 16,00mm², with a thickness of 2.50mm. The specimens were immersed in lemon juice, twice a day, over 5 days, and randomly divided into the following 4 groups: G1 = No treatment; G2 = 1.23% APF; G3 = Fluoride Varnish 5% and G4 = Regenerated. The surface roughness of the specimens was analyzed by means of confocal laser scanning microscopy. The obtained data were submitted to ANOVA after attend the homogeneity (Levene´s) and normality tests (Kolmogorov-Smirnov). All tests were statistically significant at 5% (α=0.05). The results showed that there was no statistically significant difference on the enamel roughness surface area between groups in the experimental region and the founded values were higher at the experimental when compared to the control region, however, without differences between the groups in each region. It was concluded that the remineralizing agents were not able to reduce the surface roughness of the studied groups. Keywords: Tooth Erosion. Dental Enamel. Fluorine. Tooth Remineralization. Resumo O objetivo deste estudo in vitro foi avaliar a influência de agentes remineralizantes na rugosidade da superficial do esmalte dental erodido. Quarenta bovinos incisivos foram selecionados e seccionados para obter espécimes de 4 mm x 4 mm, resultando em uma área superficial de 16,00 mm², com espessura de 2,50 mm. As amostras foram imersas em suco de limão, duas vezes ao dia, durante 5 dias, e divididas aleatoriamente nos 4 grupos seguintes: G1 = Sem tratamento; G2 = Flúor gel 1,23%; G3 = Verniz fluoretado 5% e G4 =Regenerate. A rugosidade superficial das amostras foi analisada por microscopia confocal de varredura a laser. Os dados obtidos foram submetidos à ANOVA após os testes de homogeneidade (Levene) e normalidade (Kolmogorov-Smirnov). Todos os testes foram estatisticamente significantes a 5% (α = 0,05). Os resultados mostraram que não houve diferença estatisticamente significante na rugosidade de área do esmalte entre os grupos na região experimental e os valores encontrados foram maiores na experimental quando comparados à região controle, no entanto, sem diferenças entre os grupos em cada região. Concluiu-se que os remineralizantes não foram capazes de reduzir a rugosidade da superfície dos grupos estudados. Palavras-chave: Erosão Dentária. Esmalte dentário. Flúor. Remineralização Dentária.

Background: Laser irradiation modifies the topography and composition of dentin surface aiming to increase the retention of bonded posts. Objective: To assess the effect of dentin irradiation with ...

Background: Nowadays, observed a growing rate of teeth affected by molar incisor hypomineralization (MIH). These teeth can present persistent inflammation of the pulp, increasing the dentin hypersensitivity and consequently, directly affecting the cleaning of the affected tooth and contributing to the progression of caries lesions. Aims: This study aims to compare the use of diode laser (DL) irradiation (970nm) with the application of a glass ionomer-based sealant (GIC) for the most clinically and cost-effective strategy for the management of first permanent molars affected with MIH. Methods: This is a two-arm, parallel-group, patient randomized superiority-controlled trial, children present MIH molars will be selected and treated either with the application of DL or with the application of GIC-based sealants. Baseline and follow-up evaluations will be assessed through clinical examination and analysis of dental impressions that will be carried out of the affected teeth. The outcomes evaluated will be: 1) presence of post-eruptive breakdown and/or atypical dentin caries lesions, 2) retention rate of sealants 3) parent’s satisfaction, 4) children’s hypersensitivity 5) child-self-reported discomfort 6) impact on the quality of life and 7) the incremental cost-effectiveness. Evaluations will be performed by one trained evaluator after one week, and 1, 6, 12, 18, and 24 months. Multilevel statistical analyzes will be conducted to establish the ability of DL treatment compared to sealing, in joining to plausible factors associated with this efficacy. Discussion: We expect that this study contributes to the best scientific proof concerning the most cost-effective treatment for permanent molars affected with MIH.

The aim of the present in vivo study was to evaluate the bacterial contamination of sports mouthguards, surface roughness, and the efficacy of chlorhexidine gluconate spray in the disinfection of these devices. A randomized, blinded cross-over clinical trial was performed with twenty 9 to 13 years old children who practiced martial arts and participated in all phases of the study. They were instructed to wear mouthguards 3 alternated days a week for 1 hour and, after use, to spray sterile tap water or chlorhexidine 0.12%. The mouthguards were analyzed by MTT assay, Checkerboard DNA-DNA hybridization, and confocal laser microscopy prior and after use for 2 weeks. Data were analyzed by Wilcoxon and t-Student, and Pearson correlation tests, with 5% significance level. Were observed that mouthguards of the control group were more contaminated with cariogenic microorganisms than those of the chlorhexidine group (p

Dental alloys are widely used in fabrication of removable partial dentures, particularly as a dental framework. The present study aimed at studying the effect of the commercial mouthwashes on the corrosion behavior of the Co−Cr dental casting alloy. Corrosion behavior was investigated in alcohol-free and alcohol-containing mouthwashes added to artificial saliva solutions at room temperature by electrochemical tests recorded the open circuit potential (OCP) and current density, after the surface analysis of the samples was performed. During the early 250s, the OCP values showed significant changes, with the exception of one test group containing alcohol, where potential decreased continuously during the test, which also recorded the highest current density, different from the other groups. It was observed that the presence of alcohol increased the current density and the corrosion process in this alloy and the mouthwashes had more aggressive action in specimens submitted to solutions with alcohol in the composition.

An ideal aesthetic standard consists of facial and smile harmony. Discolored teeth generally cause an imbalance in facial aesthetics, leading to low self-esteem and disturbance in social relationships. Causes of teeth discoloration are classified as intrinsic or extrinsic. Bleaching is considered a safe and effective treatment for discolored nonvital teeth and can be associated with restorative treatment to properly correct the dental color and maximize the aesthetic results. This paper aims to present two case reports of single discolored nonvital anterior teeth and the protocol used to reestablish the dental harmony of these patients by bleaching and direct composite resin restoration. To exert minimally invasive dentistry is very important to preserve tooth structure and reduce the risk of fracture. Internal bleaching, although may not be sufficient to reestablish the aesthetic in some cases, it is important to minimize dental preparation to perform an indirect or direct restoration. Dentists must take into account the patients expectations, dominate the restorative technique and know the dental materials to properly be able to restore function and aesthetics and consequently improve life quality and social relationships. RESUMO Um padrão estético ideal consiste na harmonia facial e do sorriso. Dentes descoloridos geralmente causam um desequilíbrio na estética facial, levando a baixa auto-estima e interferência nas relações sociais. As causas da descoloração dos dentes são classificadas como intrínsecas ou extrínsecas. O clareamento é considerado um tratamento seguro e eficaz para os dentes não vitais escurecidos e pode ser associado ao tratamento restaurador para corrigir adequadamente a cor dental e maximizar os resultados estéticos. O objetivo deste trabalho é apresentar dois relatos de casos de dentes anteriores não vitais escurecidos e o protocolo utilizado para restabelecer a harmonia dentária desses pacientes por meio de clareamento e restauração direta em resina composta. Para exercer uma Odontologia minimamente invasiva é muito importante preservar a estrutura dentária e reduzir o risco de fratura. O clareamento interno, embora possa não ser suficiente para restabelecer a estética em alguns casos, é importante para minimizar o preparo dental para realizar uma restauração indireta ou direta. Os dentistas devem levar em consideração as expectativas dos pacientes, dominar a técnica restauradora e conhecer os materiais dentários para poder restaurar adequadamente a função e a estética e, consequentemente, melhorar a qualidade de vida e as relações sociais.

The aim of this study was to evaluate the effect of Er, Cr: YSGG laser irradiation in the physics properties of the different dentin bonding systems (DBS) applied in dentin substrate.This study presented two variation factors: laser, divided into two levels (Er, Cr: YSGG [L] and Control - not irradiated [C]) and DBS divided into four levels (AdperTM Scotchbond Multipurpose [MP], AdperTM Single Bond 2 [SB], ClearfilTM SE Bond [CSE], ScotchbondTM Universal Adhesive [SU]). The response variables were water sorption/solubility (mg/mm3) [WS/WSB], degree of conversion (%) [DC], microtensile bond strength (MPa) [MS] and scanning electron microscopy [SEM] for descriptive analysis. After application of DBS over dentin substrate and before curing, in the L groups the irradiation was performed over the primer on MP and CSE and after primer/adhesive on SB and SU. After 7 days, the specimens were cut to obtain squared-shape blocks for WS/WSB, slices for one-year DC/MEV and sticks for one-year MS. The data was analyzed by two-way ANOVA, followed by Tukey test for multiple comparisons (p

This study evaluated the effects of four over-the-counter (OTC) bleaching products on the properties of enamel. Extracted human molars were randomly assigned into four groups (n = 5): PD: Poladay (SDI), WG: White Teeth Global (White Teeth Global), CW: Crest3DWhite (Procter & Gamble), and HS: HiSmile (HiSmile). The hydrogen peroxide (H2 O2 ) content in each product was analyzed via titration. Twenty teeth were sectioned into quarters, embedded in epoxy resin, and polished. Each quarter-tooth surface was treated with one of the four beaching times: T0: control/no-bleaching, T14: 14 days, T28: 28 days, and T56: 56 days. Materials were applied to enamel surfaces as recommended. Enamel surfaces were examined for ultramicrohardness (UMH), elastic modulus (EM), superficial roughness (Sa), and scanning electron microscopy (SEM). Ten additional teeth were used to evaluate color and degree of demineralization (DD) (n = 5). Data were statistically tested by two-way ANOVA and Tukey's tests (α = 5%). Enamel surfaces treated with PD and WG presented UMH values significantly lower than the controls (p

The objective of this in vitro study was to evaluate the influence of the Er,Cr:YSGG laser associated or not to a desensitizing agent in the treatment of erosive lesions. Forty specimens with dimensions of 4mm x 4mm and 3mm thickness were divided into 4 groups (n = 10): G1- no treatment; G2- 5% fluoride varnish; G3- Er,Cr: YSGG; G4 - fluoride varnish + laser. The specimens were immersed in erosive drink 3 times a day for 1 minute with an average interval of 2 hours between cycles for a period of 10 days. The treatments were performed according to the groups and the surface roughness and the wear profile were analyzed by scanning confocal microscopy. The normality (Kolmogorov-Smirnov) and homogeneity (Levene's) of the tests were evaluated. After these analyzes, the surface roughness data were submitted to the statistical analysis of Variance Analysis (ANOVA). All tests adopted a significance level of 5% (α = 0.05). At the representative images of the wear profile, the morphology of bovine dental enamel in its control and eroded areas were compared and qualitatively discussed. As regard surface roughness, there was no statistically significant difference between the groups. The qualitative analysis of the loss of volume showed that all experimental groups showed significant superficial morphology differences. Considering the limitations of an in vitro study, it can be concluded that the treatments performed were not able to treat dental erosion satisfactorily, indicating the need for more treatment sessions. Keywords: Tooth Erosion. Dental Enamel. Fluoride. YSGG Laser. ResumoO objetivo desse estudo in vitro foi avaliar a influência do laser Er,Cr:YSGG associado ou não a um agente dessensibilizante no tratamento de lesões erosivas. Foram confeccionados 40 espécimes com dimensões de 4mm x 4mm e 3mm de espessura, divididos em 4 grupos (n=10): G1- nenhum tratamento; G2- verniz fluoretado 5%; G3- aplicação do laser Er,Cr:YSGG; G4- verniz fluoretado + laser. Os espécimes foram imersos em bebida erosiva, 3 vezes por dia, durante 1 minuto, com intervalo médio de 2 horas entre os ciclos, por um período de 10 dias. Os tratamentos foram realizados de acordo com os grupos e que foram analisados a rugosidade superficial e o perfil de desgaste por meio de microscopia confocal de varredura. Avaliou-se a normalidade (Kolmogorov-Smirnov) e homogeneidade (Levene’s) dos dados. Após estas análises, os dados de rugosidade superficial foram submetidos ao teste estatístico de Análise de Variância (ANOVA). Todos os testes adotaram nível de significância de 5% (α=0,05). Através da obtenção das imagens representativas do perfil desgaste, a morfologia do esmalte dental bovino em suas áreas controle e erodida foram comparadas e qualitativamente discutidas. Quanto à rugosidade superficial, não houve diferença estatisticamente significativa entre os grupos. A análise qualitativa da perda de volume mostrou que todos os grupos experimentais apresentaram diferenças significativas na morfologia superficial. Considerando as limitações de um estudo in vitro pode-se concluir que os tratamentos realizados não foram capazes de tratar a erosão dentária de forma satisfatória, indicando a necessidade de mais sessões de tratamento. Palavras-chave: Erosão dentária. Esmalte dental. Flúor. Laser de YSGG.

SUMMARY Objectives: This study evaluated the effect of toothbrushing with a dentifrice on gloss, roughness profile, surface roughness, and wear of conventional and bulk-fill resin-based composites. Methods and Materials: Gloss and surface roughness of resin-based composites (RBCs; Admira Fusion X-tra, Aura Bulk Fill, Filtek Bulk Fill Flowable, Filtek Bulk Fill Posterior Restorative, Filtek Supreme Ultra, Herculite Ultra, Mosaic Enamel, SDR flow+, Sonic Fill 2, Tetric EvoFlow Bulk Fill and Tetric EvoCeram Bulk Fill) were analyzed before and after brushing; the roughness profile and wear were also determined after toothbrushing. Representative three-dimensional images of the surface loss and images comparing the unbrushed and brushed surfaces were also compared. Analysis of variance and Tukey post hoc tests were applied (α=0.05) to the gloss, surface roughness, roughness profile, and surface loss data. Pearson's correlation test was used to determine the correlation between gloss and surface roughness, surface loss and percentage of gloss decrease after brushing, and surface loss and surface roughness after brushing. Results: For all RBCs tested after 20,000 brushing cycles, the gloss was reduced and the surface roughness increased (p Conclusions: Toothbrushing with a dentifrice reduced the gloss, increased the surface roughness, and caused loss at the surface of all the RBCs tested. Considering all the properties tested, Mosaic Enamel exhibited excellent gloss retention and a low roughness profile and wear, while Admira Fusion X-tra exhibited the greatest decrease in gloss, the highest roughness profile, and the most wear.

Purpose: This study evaluated the micro shear bond strength of resin cement to an yttria-stabilized zirconia ceramic and the survival probability of zirconia abutments and crowns after different surface treatments through a fatigue test. Materials and Methods: The study was divided into two parts. For part 1, 95 zirconia disks were divided into five groups (n = 19): control, untreated, airborne particle abrasion with Al2O3 particles before sintering, airborne particle abrasion with Al2O3 particles after sintering, silicatization before sintering, and silicatization after sintering. Three samples of each group were used for evaluation of surface roughness by confocal laser scanning microscopy and afterward were prepared for surface microstructural analysis by scanning electron microscopy. Ten samples of each group were subjected to micro shear bond strength testing, and the interfaces of the remaining six were examined by scanning electron microscopy. In part 2, 70 external hex zirconia abutments and copings were made by computer-aided design/computeraided manufacturing (n = 14). Marginal fit of abutment/coping was measured in a confocal laser scanning microscope. Afterward, a fatigue test was carried out with progressive load of 80 up to 320 N (40 N steps), 5 Hz frequency, and 20,000 cycles at each step. Thermal cycling was simultaneously performed (5 degrees C to 55 degrees C). Results: The group treated after sintering with SiO achieved statistically higher micro shear bond strength (P

Purpose To determine the effects of tooth brushing on the surface roughness (Sa) and morphology, maximum relative depth (Rv), gloss (GU), and microhardness (MH) of four esthetic restorative materials and enamel. Materials and methods A light-curing composite resin (Filtek Supreme Ultra [FSU], 3M ESPE), two hybrid resin/ceramic CAD/CAM materials (Lava Ultimate [LAV], 3M ESPE, and VITA Enamic [VEN], VITA Zahnfabrik), and a CAD/CAM feldspathic ceramic (VITA Blocs Mark II [VMA], VITA Zahnfabrik) were evaluated. Bovine enamel (ENA) was used as a control group. All surfaces were polished in accordance with the manufacturer's instructions. Samples were analyzed before and after brushing (30,000 cycles) regarding Sa and Rv using a 3D laser-measuring microscope. GU was evaluated every 10,000 tooth brushing cycles. MH was also measured before and after tooth brushing. The surfaces were observed using scanning electron and laser measuring microscopies to determine the wear patterns. Data were analyzed by paired t test, one-way or two-way repeated measures analysis of variance, and Tukey test (α = .05), depending on the method performed. Results The Sa increased significantly after brushing for all materials, except for VMA, which showed the opposite effect. ENA and VEN showed higher Rv than VMA. After 30,000 tooth brushing cycles, VMA showed the highest GU, while FSU showed the lowest. Also, little surface topography changes were observed for VMA. MH did not change significantly after 30,000 brushing cycles, except for LAV. Conclusion Brushing caused surface alterations in all tested materials except for feldspathic ceramic. The changes were more evident in resin-based materials.

This study evaluated how Er,Cr:YSGG laser, associated or not with 5% fluoride varnish, influences the surface roughness and volume loss of bovine root dentin submitted to erosive and/or abrasive wear. One hundred and twenty dentin specimens were divided into the groups: without preventive treatment (WPT), 5% fluoride varnish (FV); Er,Cr:YSGG laser irradiation (L), and varnish combined with laser (FV + L). The specimens (n = 10) were subdivided into: 1 = erosion (E); 2 = abrasion (A); and 3 = erosion followed by abrasion (E + A). The erosive solution used was a soft-drink (pH = 2.42 at 4ºC) applied in 5-min cycles twice a day for 10d. Abrasive wear involved brushing for 60s with an electric brush (1,600-oscillations/s) at a load of 2.0N. Surface roughness and volume loss were evaluated using a laser scanning confocal microscope. Roughness data were submitted to one-way ANOVA and Tukey post-hoc test. For volume loss, the Kruskal-Wallis and Dunn’s post-hoc tests were used (α = 5%). The lowest values of roughness were found in the control areas of all subgroups (p > 0.05). In the experimental area, the [(WPT) + (E+A)] subgroup had a significantly higher roughness (5.712 ± 0.163 μm 2 ) than the other subgroups (p < 0.05). The L and (FV + L) groups had statistically similar roughness, regardless of the type of wear. The (FV + L) group had the lowest volume loss, regardless of the type of wear performed: [(FV + L) + (E)] = 7.5%, [(FV + L) + (A) = 7.3%, and [(FV + L) + (E + A)] = 8.1%. The subgroup [(WPT) + (E + A)] had the highest volume loss (52.3%). The proposed treatments were effective in controlling dentin roughness. Laser irradiation can be an effective method to increase root dentin resistance after challenges and limit problems related to non-carious lesions.

Objetivo: Avaliar a ação do ácido clorídrico gasoso sobre o esmalte humano e bovino e comparar o padrão de desmineralização desses substratos expostos ao agente erosivo gasoso. Métodos: Oito espécimes de esmalte bovino e oito de esmalte humano foram obtidos (4 × 4 × 2 mm), metade da superfície foi protegida com resina composta e a outra metade exposta ao ácido clorídrico gasoso (gHCl), pH 2 a 37 °C, por 3 min, 8 vezes ao dia, durante 12 dias, e em intervalos os espécimes foram mantidos em saliva artificial. Os espécimes foram analisados quanto ao perfil de desgaste, rugosidade superficial e microdureza (antes e após a exposição ao ácido). Os dados foram analisados estatisticamente por ANOVA de uma via. Resultados: Os dados não mostraram diferença significativa entre o esmalte bovino e humano para todas as propriedades analisadas – microdureza (98,1 ± 5,2, 96,9 ± 4,8), perfil de desgaste (11,5 ± 2,8, 11,4 ± 3,6) e rugosidade (2,6 ± 0,3, 3,3 ± 0,3), respectivamente. Nas imagens, observou-se que gHCl pode causar erosão do esmalte em ambos os grupos. Conclusão: O ácido clorídrico gasoso causa erosão do esmalte de forma semelhante em bovinos e humanos. Objective: To evaluate the action of gaseous hydrochloric acid on human and bovine enamel and compare the demineralization pattern of these substrates exposed to the gaseous erosive agent. Methods: Eight bovine enamel and eight human enamel specimens were obtained (4 × 4 × 2 mm), half surface was protected with composite resin and the other half was exposed to gaseous hydrochloric acid (gHCl), pH 2 at 37 °C, for 3 min, 8 times a day, for 12 days, and in intervals the specimens were maintained in artificial saliva. The specimens were analyzed according to wear profile, surface roughness and microhardness (before and after acid exposition). Data were statistically analyzed by one-way ANOVA. Results: Data showed no significant difference between bovine and human enamel for all properties analyzed – microhardness (98.1 ± 5.2, 96.9 ± 4.8), wear profile (11.5 ± 2.8, 11.4 ± 3.6) and roughness (2.6 ± 0.3, 3.3 ± 0.3), respectively. In images, we observed that gHCl could cause enamel erosion in both groups. Conclusion: Gaseous hydrochloric acid causes similar enamel erosion on bovine and humans.

This in vitro study evaluated the effect of the beam homogeneity of a multiple-peak light-curing unit on the surface microhardness and the effect of toothbrushing wear on the microhardness, surface roughness, roughness profile, volume loss, and gloss retention of incremental and bulk-fill resin-based composites (RBCs). A LED light-curing unit (VALO) with four LEDs at the tip end (405, 445, 465A, and 465B nm emission peak) was used according to each manufacturer-recommended time to obtain disks (n=10) of six RBCs: Estelite Sigma Quick, Charisma Classic, Tetric EvoCeram Bulk Fill, Filtek Z250, Filtek Supreme Ultra, and Filtek Bulk Fill. Microhardness values were obtained according to each LED positioning of the light-curing unit on the top surface of the RBCs and were analyzed before and after toothbrushing regarding microhardness, surface roughness, roughness profile, volume loss, and gloss retention. Microhardness was considered homogeneous on the top surface regardless of the type of RBC or wavelength tested (p>0.05). Overall, toothbrushing did not reduce the microhardness of the RBCs but influenced the gloss values for most RBCs (p0.05). In conclusion, different wavelengths of the LED did not affect the top surface microhardness, regardless of the RBCs tested; and bulk-fill composites presented similar surface changes (microhardness, surface roughness, roughness profile, volume loss, and gloss retention) when compared to conventional composites after toothbrushing. Resumo Este estudo in vitro avaliou a homogeneidade do feixe de um fotopolimerizador de múltiplos picos na microdureza superficial e o efeito da escovação na microdureza, rugosidade superficial, perfil de rugosidade, perda de volume e retenção do brilho de compósitos a base de resina (RBCs) incrementais ou bulk-fill. Um fotopolimerizador LED (VALO) com quatro LEDs na ponteira (405, 445, 465A e 465B nm de pico de emissão) foi usado de acordo com o tempo recomendado por cada fabricante para obtenção de discos (n=10) de seis RBCs: Estelite Sigma Quick, Charisma Classic, Tetric EvoCeram Bulk Fill, Filtek Z250, Filtek Supreme Ultra e Filtek Bulk Fill. Os valores de microdureza foram obtidos seguindo o posicionamento de cada LED na superfície superior das amostras e foram analisados antes e após a escovação quanto a microdureza, rugosidade superficial, perfil de rugosidade, perda de volume e retenção do brilho. A microdureza foi considerada homogênea no topo da superfície, independentemente do tipo de RBCs ou comprimento de onda testados (p>0.05). No geral, a escovação não reduziu a microdureza das RBCs, mas influenciou o brilho para a maioria das RBCs (p0.05). Em conclusão, os diferentes comprimentos de onda do LED não alteraram a microdureza do topo da superfície, independentemente das RBCs testadas; e as resinas bulk-fill apresentaram alterações superficiais similares (microdureza, rugosidade superficial, perfil de rugosidade, perda de volume e manutenção do brilho) quando comparadas às resinas convencionais após a escovação.

This study aimed to analyze the interaction of a MDP-based universal dentin bonding system (DBS) with Er, Cr: YSGG laser irradiation, measuring the microtensile bond strength to dentin over a six-month period. The experimental design involved three factors: DBS (Adper Scotchbond Universal; Clearfil SE Bond, Adper Scotchbond Multipurpose and Adper Single Bond 2), laser (Control and Er, Cr: YSGG), and time (initial- 7 days and 6 months). Eighty dentin samples from molars were prepared (n=10) with laser irradiation after primer and DBS application. After 7 days, were subjected to micro tensile bond strength test. The data were analyzed by three-way ANOVA and Tukey tests (p

To evaluate the effects of stomach and duodenal fluid on enamel surfaces, simulating the action of refluxed liquid in patients with duodenogastric reflux.Forty bovine incisors were used to obtain enamel fragments. Only half of the enamel surface was exposed to erosive challenges; the samples were then randomly divided into the following four groups (n = 10): G1: HCl; G2: HCl + pepsin; G3: HCl + ox bile + NaHCO3; and G4: HCl + pancreatin + NaHCO3. The specimens were placed in 37°C solutions, six times per day, for 20 s, over a period of 5 days and then analysed for morphology, surface roughness and the step formed on the dental enamel using confocal laser microscopy. The data were analysed using the Kruskal-Wallis and Dunn's test (p0.05).Both analyses revealed a higher step and surface roughness for the G3 group (5.6 μm ± 1.69, 2.2 μm ± 1.61), which were statistically significant compared with the G1 and G2 groups (3.9 μm ± 1.5 μm; 1.0 μm ± 0.18; 3.7 μm ± 1.45; and 0.9 μm ± 0.12) (p0.05); only the step in the G4 group (4.9 μm ± 1.8 μm) was similar to that of the G3 group (p0.05). Morphological analysis showed greater structural loss in the G3 and G4 groups.Bile and pancreatin, in combination with hydrochloric acid, may promote a greater loss of structure, increased surface roughness and loss of enamel prismatic anatomy.

The purpose of this study was to investigate whether different surface treatments, executed before and after the sintering process, affect the surface characteristics (roughness and morphology) and shear bond strength of computer-aided design–computer-aided manufacturing (CAD–CAM) milled zirconia luted with self-adhesive resin cement onto human dentin. Sixty-four rectangular zirconia slabs (6 × 8.5 × 2.3 mm thickness) were prepared using the CAD–CAM system and randomly distributed into two groups according to the moment of treatment, before and after sintering, and four subgroups according to the surface treatment (n = 8): C (untreated; control), AO (aluminum oxide air abrasion), GB (glass beads air abrasion), and HA (etching with hydrofluoric acid). The samples were evaluated using a confocal laser microscope to assess the surface roughness and morphology. For the shear bond strength test, the milled zirconia was cemented onto dentin slabs using self-adhesive resin cement and submitted to the test in a universal testing machine. Data were submitted to a two-way ANOVA and Tukey test (p

Root-filled teeth that received fiber posts most frequently fail at the adhesive interface between resin cement and dentin. The objective of this study is to evaluate the effect of Er:YAG laser and/or sodium ascorbate (SA) on bond strength, microhardness of dentin, and penetration depth of cement into dentinal tubules. Forty-eight bovine incisor roots were endodontically treated, post spaces were prepared and equally divided into four groups (n = 12): G1-distilled water (control); G2-10% SA (10 min); G3-Er:YAG laser (150 mJ/4 Hz/40 s), and G4-Er:YAG laser + 10% SA. Glass fiber posts were cemented and roots sectioned into slices. In the first slice, the push-out bond strength (MPa) and failures were analyzed by confocal laser scanning microscope (CLSM). The second slice was subjected to microhardness test (KHN) and CLSM to assess the cement penetration. ANOVA and Tukey test were used for bond strength and microhardness data and Kruskal-Wallis and Dunn tests for the cement penetration (α = .05). The SA-treated samples had higher bond strength (10.02 ± 5.45a), similar to Er:YAG laser (9.91 ± 4.62a) and Er:YAG laser + SA (8.09 ± 4.07a). The least values (P .05) were found on control (4.02 ± 2.39b). Significant differences were observed on root thirds (P .05): cervical middle apical. There was a predominance of adhesive failures. The microhardness test revealed no differences between groups (P .05). The experimental groups (G2, G3, and G4) had highest penetration into dentinal tubules when compared to the control (G1). Dentin pretreatments with Er:YAG laser or SA improved bond strength of cement-post-dentin interfaces; however, no synergistic effect of both treatments combined was observed.

Evaluate if etching protocols affect superficial/internal microstructural integrity of CAD/CAM ceramic materials.Sixty blocks (3×3×3mm) of IPS/Empress-LEU, IPS/e.max-LDC (Ivoclar-Vivadent) and Enamic-PIC (VITA) were used. Lateral surfaces from each block were isolated with Teflon strip and petroleum jelly to keep them untouched. Specimens were distributed into 6 groups (n=10): 1. no treatment (C); 2. hydrofluoric acid (HF) 5%, 20s (HF5%20s); 3. HF5%60s; 4. HF10%20s; 5. HF10%60s; 6. Monobond EtchPrime (MBEP). Surface roughness (Sa) and 3D profile were obtained using a confocal-laser-optical-microscope (LEXT OLS 4000, Olympus), while element ratios (Si/K for LEU and LDC; Si/C for PIC) were recorded using energy dispersive spectroscopy (EDS). Superior (treated) and lateral (non-treated) surfaces were analyzed using scanning electron microscopy (SEM) (JSM 5600 LV, JEOL). Etching depth was measured on lateral surfaces. Data were submitted to ANOVA-One-Way and Tukey test (α=0.05).For LEU, only HF10% treatments produced statistically different roughness values and Si/K ratios compared to C group. Regarding LDC and PIC, groups HF5%60s and HF10% showed higher roughness values than C group. In the case of PIC, all treatments (except MBEP) produced lower Si/C ratios than C group. All treatments (except MBEP) produced higher etching depth values than C group for all materials, being HF10%60s the highest (LEU:403.2±11.4μm; LDC:617.4±75.7; PIC:291.6±6.5μm). HF10% produced more aggressive etching morphology patterns on superior and lateral surfaces (SEM). Treatments MBEP and HF5%20s, produced the least aggressive structural alterations. Acid etching produces superficial and internal alterations on ceramics' structural configuration.Aggressive etching protocols of glass-ceramics may cause internal material loss, consequently, milder etching is recommended to treat those materials before adhesion procedures.

Patients undergoing radiotherapy treatment present more susceptibility to dental caries and the use of an orthodontic device increases this risk factor due to biofilm accumulation around the brackets. The objective of this study was to evaluate the shear bond strength to irradiated permanent teeth of orthodontic brackets bonded with conventional glass ionomer cement and resin-modified glass ionomer cement due to the fluoride release capacity of these materials. Ninety prepared human premolars were divided into 6 groups (n=15), according to the bonding material and use or not of radiation: CR: Transbond XT composite resin; RMGIC: Fuji Ortho LC conventional glass ionomer cement; GIC: Ketac Cem Easymix resin-modified glass ionomer cement. The groups were irradiated (I) or non-irradiated (NI) prior to bracket bonding. The specimens were subjected to a fractioned radiation dose of 2 Gy over 5 consecutive days for 6 weeks. After the radiotherapy, the brackets were bonded on the specimens with Transbond XT, Fuji Ortho LC and Ketac Cem Easymix. After 24 h, the specimens were subjected to shear bond strength test. The image of enamel surface (classified by Adhesive Remnant Index - ARI) was also evaluated and its frequency was checked among groups/subgroups. The shear bond strength variable was evaluated with ANOVA and Tukey’s post-hoc test. GIC group showed the lowest adhesion values among the groups (p0.05). As for the ARI, the CR-I group showed the highest material retention on enamel surface among the irradiated groups. RMGIC group showed the highest values for shear bond strength and presented ARI acceptable for clinical practices. Resumo Pacientes submetidos a tratamento radioterápico apresentam maior suscetibilidade à cárie dentária e o uso de aparelho aumenta esse fator de risco devido ao acúmulo de biofilme dental ao redor dos bráquetes. Assim, o objetivo deste estudo foi avaliar a resistência ao cisalhamento de bráquetes ortodônticos colados com cimento de ionômero de vidro convencional (CIV) e o modificado por resina (CIVMR), devido à capacidade de liberação de flúor desse material em dentes permanentes irradiados. Noventa pré-molares humanos foram divididos em 6 grupos (n=15), de acordo com o materila de colagem e com o uso ou não de radiação: RC: Transbond XT; CIVMR: Fuji Ortho LC; RMGIC: Ketac Cem Easymix. Os grupos for irradiados (I) ou não-irradiados (NI) previamente à colagem dos bráquetes. Os espécimes foram submetidos a doses fracionadas de radiação de 2 Gy/dia, durante 5 dias consecutivos, por 6 semanas. Depois da termociclagem e radioterapia, os bráquetes foram colados sobre os espécimes com Transbond XT, Fuji Ortho LC e Ketac Cem Easymix. Depois de 24 h, os espécimes foram sumetidos ao teste de resistência ao cisalhamento. A imagem da superfície do esmalte (classificado pelo Índice de Remanescente Adesivo-IRA) também foi avaliada. O IRA foi distribuido em tabelas de contingência e analisado quanto à frequência entre grupos/subgrupos. O teste de resistência ao cisalhamento foi avaliado por ANOVA e pós-teste de Tukey. CIVMR apresentou os menores valores de adesão entre os grupos (p0,05). Quanto ao IRA, RC-I apresentou maior retenção de compósito na superfície do esmalte do que os demais subgrupos. CIVMR pode ser utilizado para colagem de bráquetes metálico e apresentou IRA aceitável para práticas clínicas.

To evaluate the effect of the bleaching with 35% hydrogen peroxide either activated or not by a 970nm diode laser on the chemical stability and dentin surface morphology of intracoronary dentin.Twenty-seven slabs of intracoronary dentin specimens (3×3mm) were distributed into three groups (n=9), according to surface treatment: HP - 35% hydrogen peroxide (1×4'), DL - 970nm diode laser (1×30"/0,8W/10Hz), HP+DL - 35% HP activated with 970nm diode laser (1×30"/0,8W/10Hz leaving the gel in contact to the surface for 4' after activation). Three Raman spectra from each fragment were obtained to calculate the mean intensity of peaks of inorganic component (a.u.), organic collagen content (a.u.), and the ratio of inorganic/organic content, before and after treatment. Analyses of the samples by confocal laser microscopy were performed to evaluate the surface roughness, percentage of tubules, perimeter and area percentage of tubules, before and after treatment. Data were analyzed by Kruskal-Wallis, Dunn's, and Wilcoxon test (P0.05).Data analysis showed that HP+DL did not change the inorganic content peaks 8.31 [29.78] or the inorganic/organic ratio 3.37 [14.67] (P0.05). Similarly, DL did not affect the chemical stability of the dentin surface (P0.05). However, HP significantly increased inorganic content peaks 10.87 [22.62], as well as the inorganic/organic ratio 6.25 [27.78] (P0.05). Regarding the morphological alterations, all surface treatments increase tubules exposure; HP treatment significantly increases perimeter and area percentage; and HP+DL increases surface roughness.Bleaching HP combined with DL offers an improvement in terms of intracoronal dentin surface protection, yielding better maintenance of dentin chemical stability and morphology.

O acúmulo de biofilme sobre a superfície dental pode gerar diversas complicações para a cavidade bucal, além de acometer a saúde geral do indivíduo. Assim, o objetivo deste trabalho foi avaliar in vivo a capacidade do emprego da irradiação com laser de Diodo no biofilme bacteriano dental maduro na inativação dos micro-organismos presentes. Foram selecionados 12 voluntários com acúmulo de biofilme sobre a superfície vestibular dos dentes. O presente estudo foi fatorial, com período de realização da irradiação em 2 níveis (controle/sem irradiação e após a irradiação) e o tipo de tratamento em 2 níveis (irradiação de laser de Diodo com 660 e 970 nm). Foram testados 4 sítios de cada voluntário, divididos aleatoriamente em 2 grupos/4 subgrupos experimentais. Inicialmente, foram coletadas 2 amostras iniciais do biofilme. Cada amostra foi inserida em um tubo Eppendorf correspondente contendo o fluido de transporte reduzido (RTF). Em seguida, previamente à irradiação, foi aplicada uma dose do fotossensibilizador azul de metileno sobre toda a superfície vestibular com um tempo de pré-irradiação de 5 minutos. A irradiação foi realizada sobre a superfície vestibular na forma de varredura. As amostras irradiadas foram coletas e dispersadas em um tubo Eppendorf correspondente. As amostras foram diluídas em RTF e semeadas em meio de cultura MM10 Sacarose Ágar em duplicata. Após 7 dias em anaerobiose à 37°C, foram contadas as unidades formadoras de colônias (UFC) de cada amostra sobre a superfície da placa. Foi realizada a comparação da quantidade de UFC/mg antes e após os tratamentos. Os dados foram analisados pelos testes de Wilcoxon e Mann Whitney com =0,05. Pode-se observar que ambos os tratamentos realizados foram capazes de diminuir estatisticamente (p

The objective of this study was to evaluate the antibacterial effect and the ultrastructural alterations of diode laser with different wavelengths (808nm and 970nm) and its association with irrigating solutions (2.5% sodium hypochlorite and 2% chlorhexidine) in root dentin contaminated by a five days biofilm. Thirteen uniradicular teeth were sectioned into 100 dentin intraradicular blocks. Initially, the blocks were immersed for 5min in 17% EDTA and washed with distilled water for 5min, then samples were sterilized for 30min at 120°C. The dentin samples were inoculated with 0.1mL of E. faecalis suspension in 5mL BHI (Brain Heart Infusion) and incubated at 37°C for 5days. After contamination, the specimens were distributed into ten groups (n=10) according to surface treatment: GI - 5mL NaOCl 2.5%, GII - 5mL NaOCl 2.5%+808nm diode (0.1W for 20s), GIII - 5mL NaOCl 2.5%+970nm diode (0.5W for 4s), GIV - 808nm diode (0.1W for 20s), GV - 970nm diode (0.5W for 4s), GVI - CHX 2%, GVII - CHX 2%+808nm diode (0.1W for 20s), GVIII - CHX 2%+970nm diode (0.5W for 4s), GIX - positive control and GX - negative control. Bacterial growth was analyzed by turbidity and optical density of the growth medium by spectrophotometry (nm). Then, the specimens were processed for analysis ultrastructural changes of the dentin surface by SEM. The data was subject to the One-way ANOVA test. GI (77.5±12.1), GII (72.5±12.2), GIII (68.7±8.7), GV (68.3±8.7), GVI (62.0±5.5) and GVII (67.5±3.3) were statistically similar and statistically different from GIV (58.8±25.0), GVIII (59.2±4.0) and control groups (p

The treatments for dentin hypersensitivity (DH) may change the surface roughness of the root dentin, which can lead to biofilm accumulation, increasing the risk of root caries. The aim was to compare the surface roughness of root dentin after different treatments of DH and the biofilm formation on those surfaces. After initial surface roughness (Sa) assessment, 50 bovine root fragments received the following treatments (n = 10): G 1—no treatment; G2—5% sodium fluoride varnish; G3—professional application of a desensitizing dentifrice; G4—toothbrushing with a desensitizing dentifrice; and G5—diode laser application (908 nm; 1.5 W, 20 s). The Sa was reevaluated after treatments. Afterward, all samples were incubated in a suspension of Streptococcus mutans at 37 °C for 24 h. The colony-forming units (CFU) were counted using a stereoscope, and the results were expressed in CFU/mL. The one-way ANOVA and the Tukey’s tests compared the roughness data and the results obtained on the bacterial adhesion test (α = 5%). G2 (2.3 ± 1.67%) showed similar Sa variation than G1 (0.25 ± 0.41%) and G5 (5.69 ± 0.99%), but different from group G3 (9.05 ± 2.39%). Group 4 showed the highest Sa variation (30.02 ± 3.83%; p

This in vitro study aimed at evaluating the influence of Nd:YAG irradiation and chlorhexidine (CHX) application on immediate and long-term bond strength of a self-etching adhesive system to dentin. Thirty fragments of dentin were randomly divided into three groups according to the treatment to be applied to the dentin surface prior to applying the self-etching adhesive system (n = 10): CHX:2% CHX application (60 s); Nd: YAG (100 mJ/20 Hz for 20 s); and NT: no treatment. The adhesive system (Clearfil SE Bond, Kuraray) was applied according to the manufacturer’s instructions, and composite resin restorations were made on the dentin. After 24 h, at 37 °C, the resin-tooth blocks were sectioned perpendicular to the adhesive interface in the form of sticks (0.8 mm2 of adhesive area), and randomly subdivided into two groups according to the microtensile bond strength (μTBS) test periods: immediately or 6 months after storage in distilled water. The data were reported in MPa and submitted to two-way ANOVA for randomized blocks, followed by Tukey’s test (α = 0.05). The group irradiated with an Nd:YAG laser presented the lowest bond strength means, regardless of the μTBS test period (24 h or 6 months) (p 0.05), nor did time influence bond strength (p > 0.05). Immediate and long-term bond strength was negatively affected by Nd:YAG irradiation, a condition not observed with 2% CHX solution application.

Made available in DSpace on 2020-12-12T01:49:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-04-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The aim was to assess the effects of 1% peracetic acid (PAA) as a single endodontic irrigant on microhardness, roughness, and erosion of root canal dentin, compared with 2.5% sodium hypochlorite (NaOCl) and with 2.5% NaOCl combined with 17% EDTA. Forty human, single-rooted tooth hemisections were submitted to Knoop microhardness test, before and after the following irrigation protocols: PAA = 1% PAA; NaOCl = 2.5% NaOCl; NaOCl-EDTA-NaOCl = 2.5% NaOCl +17% EDTA +2.5% NaOCl; and SS = saline. Another 40 roots were instrumented, irrigated with the same protocols, and sectioned longitudinally. The roughness analysis was performed on the mesial section using a confocal laser scanning microscope, whereas erosion was analyzed on each third of the distal section, using a scanning electron microscope. The data were analyzed using ANOVA and Tukey post-tests, and Kruskal-Wallis and Dunn post-tests (α =.05). The PAA and NaOCl-EDTA-NaOCl groups showed no significant differences (p >.05); both promoted reduction in microhardness and increase in roughness, compared with the NaOCl and SS groups (p .05). There was also no difference among the groups regarding the apical third (p >.05). PAA used as a single endodontic irrigant caused reduction in root canal dentin microhardness and increase in roughness in a similar way to NaOCl-EDTA-NaOCl; however, PAA caused less erosion than NaOCl-EDTA-NaOCl. Department of Restorative Dentistry Araraquara School of Dentistry São Paulo State University - UNESP Department of Restorative Dentistry Ribeirão Preto School of Dentistry São Paulo University - USP Department of Restorative Dentistry Araraquara School of Dentistry São Paulo State University - UNESP

Objective: Saliva is the most important biological factor to protect against erosive tooth wear (ETW). Gastroesophageal reflux disease (GERD) patients have an increased risk of ETW due to the frequent presence of intrinsic acids in the oral cavity. Remarkably, not all GERD patients suffer from ETW, which might be due to differences in the composition of the saliva. Methods: This study compared the proteomic profile of saliva in patients (1) with GERD and ETW (basic erosive wear examination, BEWE, score ≥9; GE group) and (2) with GERD without ETW (BEWE = 0; GNE group) using shotgun label-free quantitative proteomic analysis nLC-ESI-MS/MS. The ability of hemoglobin (Hb) to protect against initial enamel erosion caused by a daily 10-s immersion of enamel specimens in 0.01 M HCl (pH 2.3) for 3 days was evaluated in vitro for proof of concept. Surface hardness change was used as response variable. Results: The differential expression of Hb subunits was significantly increased in the GNE group versus the GE group, in particular the Hb α-subunit that showed a >22-fold increase. Expressions of serum albumin (4.5-fold) and isoforms of cytoskeletal keratin type II (>3-fold) were also increased in the GNE group. Proteinase inhibitors, such as α1-antitrypsin and α2-macroglobulin, were only identified in the GNE group. In vitro, Hb (1.0 and 4.0 mg/mL) significantly reduced initial enamel erosion compared to a negative control after 3 days. Conclusions: Our results indicate that many proteins, with special emphasis on Hb, may be involved in the resistance of GERD patients to the occurrence of ETW. These proteins may be candidates for inclusion in dental products to protect against ETW.