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Made available in DSpace on 2022-04-29T08:32:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Introduction: Fixed orthodontic appliances create areas of stagnation for dental biofilms and make it difficult to clean the teeth; therefore, there is a risk of developing incipient caries lesions during the orthodontic treatment. The objective of this study is to determine if the combination of 2 different therapies, phototherapy by blue light (BL) and the antimicrobial 0.12% chlorhexidine (CHX) on enamel, orthodontic brackets, and elastics, would reduce or inhibit mature Streptococcus mutans biofilms and their regrowth on these substrates 24 hours after the application of the treatment; and if this treatment would interfere with bracket adhesion to the enamel. Methods: Biofilms of S. mutans UA159 were formed for 5-days over samples composed of a bovine enamel, orthodontic bracket, and orthodontic elastic. Then, the specimens were treated with 0.89% NaCl for 1 minute, BL for 12 minutes (72 J/cm2), 0.12% CHX for 1 minute, and BL for 12 minutes, followed by 0.12% CHX for 1 minute (BL+CHX). Biofilm was evaluated by colonies forming units and dry weight immediately after treatments and 24 hours after treatments (regrowth). The pH of the spent media was measured on the fifth and sixth days. Biofilm formation on the samples after the treatments and regrowth was visually evaluated by confocal laser scanning microscopy. Shear bond strength (SBS) between bracket and enamel was evaluated using a universal testing machine at a crosshead speed of 1 mm/min. After bonding, specimens were thermocycled (500× at 5-55°C), treated, and thermocycled again. Results: After 5 days of biofilm formation, BL+CHX significantly reduced the bacterial viability on enamel compared with NaCl (P = 0.004) and BL (P = 0.014). For bracket and elastic, all the treatments resulted in similar bacterial viability (P ≥0.081). In the regrowth, CHX and BL+CHX significantly reduced the bacterial viability in the enamel compared with the NaCl (P ≤0.015) and BL (P ≤0.013). For bracket, BL+CHX significantly reduced the bacterial viability compared with NaCl (P = 0.008) and BL (P = 0.009). For the elastic, BL+CHX eliminated the biofilms from the substrate. CHX and BL+CHX significantly reduced the bacterial viability 24 hours after treatment for all substrates (P ≤0.05). The media pH significantly increased when samples were treated with CHX and BL+CHX (P ≤0.001). Confocal laser scanning microscopy images visually showed an abundant quantity of red cells in the samples treated with BL+CHX. There was no difference in the SBS between the treatments (P ≥0.932). Conclusions: The association between BL and CHX reduced S. mutans biofilm and its regrowth on an in vitro orthodontic model and did not influence the bonding strength between bracket and enamel. Department of Cariology Operative Dentistry and Dental Public Health Indiana University School of Dentistry Department of Orthodontics and Pediatric Dentistry School of Dentistry at Araraquara UNESP São Paulo State University Department of Biomedical Sciences and Comprehensive Care Indiana University School of Dentistry Department of Orthodontics and Pediatric Dentistry School of Dentistry at Araraquara UNESP São Paulo State University

Enamel and dentin are susceptible to acids from food sources leading to dental erosion, a global problem affecting millions of individuals. Particulate hydroxyapatite (HAP) on the tooth surface can influence the effects of acid attacks. Standardized bovine enamel and dentin samples with artificial saliva are used in an in vitro cyclic demineralization–remineralization protocol to analyze the structural changes experienced by tooth surfaces using high-resolution scanning electron microscopy and to evaluate the potential of a HAP-based oral care gel in the protection of teeth from erosive attacks. The interfaces between HAP particle and enamel HAP crystallites are investigated using focused ion beam preparation and transmission electron microscopy. The results show that erosion with phosphoric acid severely affects enamel crystallites and dentin tubules, while artificial saliva leads to remineralization effects. The HAP-gel forms a microscopic layer on both enamel and dentin surfaces. Upon acid exposure, this layer is sacrificed before the native tooth tissues are affected, leading to significantly lower degrees of demineralization compared to the controls. This demonstrates that the use of particulate HAP as a biomaterial in oral care formulations can help protect enamel and dentin surfaces from erosive attacks during meals using a simple and effective protection principle.

O clareamento dos dentes pode ser realizado de várias maneiras, em consultório, no âmbito caseiro ou com a utilização de produtos OTC (Over-the-Counter). Dentre esses produtos, existem os dentifrícios clareadores que prometem clarear e prevenir o manchamento dentário. Objetivos: (1) investigar o potencial clareador e abrasivo de diferentes dentifrícios no esmalte; e (2) avaliar o efeito do dentifrício Oral-B 3D White Perfection® (Oral-B) na prevenção do escurecimento. Materiais e Métodos: amostras de esmalte bovino foram pigmentadas e escovadas por 14 dias com água (controle negativo) ou com diferentes produtos: Colgate Total 12® (controle), Oral-B, Sensodyne Branqueador Extra Fresh® (Sensodyne) ou Colgate Luminous White Advanced® (Colgate). Oral-B foi testado antes e após pigmentação. As amostras foram avaliadas quanto à cor (espectrofotômetro) e rugosidade superficial (rugosímetro). Para cálculo de alteração de cor (ΔDE00) se utilizou o sistema CIEDE2000. Os dados foram analisados com os testes Kruskal-Wallis, SNK e Mann-Whitney (ɑ=5%). Resultados: O controle negativo apresentou a menor ΔE00 (p, Tooth whitening can be performed at the dental office, at-home or upon the use of OTC (Over-the-Counter) products. Among the latter, there are whitening toothpastes that promise to bleach and to prevent tooth staining. Objectives: (1) to investigate the bleaching and abrasive potential of different whitening dentifrices to enamel; and (2) to evaluate the effect of Oral-B 3D White Perfection® (Oral-B) toothpaste in preventing staining. Materials and Methods: Bovine enamel samples were stained and brushed for 14 days with water (negative control) or with different products: Colgate Total 12® (control), Oral-B, Sensodyne Branqueador Extra Fresh® (Sensodyne), and Colgate Luminous White Advanced® (Colgate). Oral-B was also tested before and after staining. The samples were tested by their color (spectrophotometer) and surface roughness (profilometer). Color change (ΔDE00) was calculated using the CIEDE2000 color system. The data were analyzed using Kruskal-Wallis, SNK, and Mann-Whitney tests (ɑ=5%). Results: The negative control showed the lowest ΔE00 (p

Objective: To evaluate color and roughness of bovine enamel exposed to dentifrices, dental bleaching with 35% hydrogen peroxide (HP), and erosion/staining by red wine. Methods: Bovine enamel blocks were exposed to: artificial saliva (control), Oral-B Pro-Health (stannous fluoride with sodium fluoride, SF), Sensodyne Repair & Protect (bioactive glass, BG), Colgate Pro-Relief (arginine and calcium carbonate, AR), or Chitodent (chitosan, CHI). After toothpaste exposure, half (n=12) of the samples were bleached (35% HP), and the other half were not (n=12). The color (CIE L*a* b*, ΔE), surface roughness (Ra), and scanning electron microscopy were evaluated. Color and roughness were assessed at baseline, post-dentifrice and/or -dental bleaching, and after red wine. The data were subjected to analysis of variance (ANOVA) (ΔE) for repeated measures (Ra), followed by Tukey´s test. The L*, a*, and b* values were analyzed by generalized linear models (a=0.05). Results: The HP promoted an increase in Ra values; however, the SF, BG, and AR did not enable this alteration. After red wine, all groups apart from SF (unbleached) showed increases in Ra values; SF and AR promoted decreases in L* values; AR demonstrated higher ΔE values, differing from the control; and CHI decreased the L* variation in the unbleached group. Conclusion: Dentifrices did not interfere with the bleaching efficacy of 35% HP. However, dentifrices acted as a preventive agent against surface alteration from dental bleaching (BG, SF, and AR) or red wine (SF). Dentifrices can decrease (CHI) or increase (AR and SF) staining by red wine.

Purpose This study investigated the influence of professional mechanical tooth cleaning (PMTC) pastes on the surface texture of different subject materials. Methods Two one-step PMTC pastes, Clinpro Cleaning Paste for PMTC (CP) and PRG Pro-Care Gel (PG), and multiple-step PMTC pastes, Merssage Regular (MR), Merssagge Fine (MF), and Merssage Plus (MP), were used. For comparison, PMTC was performed using distilled water without paste (DW). The subjected materials used were bovine enamel (ENA) and dentin (DEN), a resin composite (FSU), and lithium disilicate (IEC). The prepared specimens were polished using a #2000-grit silicon carbide paper. PMTC was performed using a brush at 1,000 rpm for 15 s. Results The surface roughness (Ra) values of the specimens before and after PMTC were measured by laser scanning microscopy. The Knoop hardness number (KHN) of the subjected material was obtained. The types of PMTC pastes and subject materials had a significant influence on the Ra values and KHN. For the majority of subject materials, the descending order of Ra values after PMTC was MR > MF > CP > PG > MP > DW. The descending order of KHN of the materials was IEC > ENA > FSU > DEN. Conclusion Although one-step PMTC pastes appeared to be effective, it is important to consider the subject material during PMTC.

Made available in DSpace on 2021-06-25T10:18:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Biofilms were developed from human saliva on bovine enamel discs in four experimental conditions to investigate dental caries development: feast and famine (M1), abundance and scarcity (M2), three meals daily (M3), and three meals plus two snacks daily (M4). The main difference between these models was the diet for microbial growth. The evaluations included verifying the pH of the spent culture media and analyzing the enamel discs for demineralization (microhardness and roughness) and biofilms (biomass, viable populations of mutans streptococci, and total microbiota). Two major behaviors were observed: M1 and M2 promoted an acidic environment, while M3 and M4 maintained pH values closer to neutral. The demineralization process was slower in the neutral groups but more pronounced in M3, while a greater increase in microbiota and biomass was observed over time for both neutral groups. Thus, the M3 model was better at mimicking the oral environment that leads to demineralization. Department of Dental Materials and Prosthodontics São Paulo State University (Unesp) School of Dentistry School of Dentistry University Santo Tomas Department of Dental Materials and Prosthodontics São Paulo State University (Unesp) School of Dentistry

Objective: to evaluate the effects of topical application of strontium on bond strength in orthodontics in vitro by using Instron universal testing machine . Materials and Methods: forty eight bovine enamel specimens were randomly allocated to four groups (n =12). Specimens of group I were not demineralized and were not pretreated, but served as controls. The other specimens were demineralized by using Featherstone pH cycling technique to form artificial carious lesions. Samples from group II were only demineralized. The other samples were pretreated with strontium chloride solution(Srcl2) for 5 minutes. Teeth in groups III were treated with Srcl2 solution before acid-etching. Teeth in groups IV were treated with Srcl2 after acid-etching. The brackets were then bonded .The brackets' SBS was measured and the adhesive remnant was assessed using adhesive remnant index (ARI). Analyses were done for SBS values between the four groups using One-Way ANOVA test followed by Post Hoc Tukey’s analysis between each two groups .Fisher’s exact test was used to evaluate differences in ARI scores between the groups. Results: srcl2treated group before acid etching )showed the highest mean SBS value when compared to other groups (Mean ± SD =24.7±7.4 MPa). There was insignificant difference between the four groups as regarding ARI scores (p=0.406). Conclusion: The topical application of srcl2 did not compromise the bond strength of orthodontic brackets to demineralized bovine enamel.

The purpose of this study was to clarify the effects of fabrication method of restorative resin-based composites on its wear using enamel as antagonist teeth. Wear evaluation was performed via two-body wear test using hemispherical samples of restorative resin-based composite (abrader specimen) fabricated through direct restoration method, indirect restoration method, and CAD/CAM, and bovine enamel (substrate specimen). As a result, there was a difference in wear volume between resin-based composite and bovine enamel depending on the fabrication method. Resin composite used for indirect restoration method showed more wear in both the abrader and substrate specimens. Resin composite used for CAD/CAM crowns showed greater wear volume in the abrader specimen. In conclusion, results clarified that fabrication method of restorative resin-based composite has an influence on the wear of the resin composite itself and enamel as antagonist teeth.

Controversy exists regarding the effectiveness of delayed toothbrushing in decreasing erosive tooth wear (ETW). The purpose of this systematic review and meta-analysis was to assess the effects of delayed toothbrushing on ETW. This systematic review and meta-analysis was conducted according to the PRISMA statement and registered in PROSPERO (CRD42020200463). PubMed, Embase, and Web of Science databases were systematically searched with no publication year limits. Screening and data extraction were performed independently by two reviewers. In situ and in vitro studies comparing ETW after delayed and immediate toothbrushing following an erosive attack were included. Review Manager software 5.3 (The Cochrane Collaboration, Oxford, UK) was used for statistical analyses. Heterogeneity was assessed with the Cochran Q test and I2 statistics. Of the 565 potentially relevant studies, 26 full-text articles were assessed for eligibility. Twelve articles were included in the systematic review, and 11 were included in the qualitative analyses. No significant difference in the ETW of human enamel was observed between delayed and immediate toothbrushing (P = 0.13), whereas significantly less ETW of bovine enamel was observed after delayed toothbrushing (P

Purpose: To evaluate the effect of Actilux-activated whitening toothpaste and Marine salts powder on color change and microhardness of bovine enamel. Methods: Thirty intact bovine incisors were used in this study to produce enamel specimens. The specimens were randomly distributed into three groups (n= 10) according to the tested whitening agents as follows: Group I: BW; BlanX LED White Shock (Actilux-activated), Group II: MS; Marine salts whitening powder and Group III: CR; Crest regular fluoridated toothpaste. The specimens were stained using black tea solution for 5 days. Each specimen was brushed twice daily for 8 then 15 days. The color was assessed according to CIE (Lab) color system using a VITA Easyshade spectrophotometer. The microhardness was assessed using Digital Display Vickers Microhardness Tester at baseline, after staining, after 8 days, and 15 days brushing. Data were tabulated and statistically analyzed. Results: After 8 days brushing, BW showed the highest mean (ΔE) while MS and CR both showed lower mean (ΔE). BW and MS showed the highest mean (ΔE) after 15 days brushing with no statistically significant difference between them. After 15 days; BW showed the highest mean microhardness followed by MS while CR showed the lowest mean microhardness. Conclusion: Both Actilux-activated toothpaste combined with LED device and Marine salts powder were effective in tooth whitening as well as increasing enamel microhardness. The whitening efficacy and microhardness is time dependent.

Objective To compare the effect of two bleaching systems (bleaching gel and whitening strips) on the color change, roughness, and microhardness of enamel and two resin composites. Material and methods Two cavities were prepared on bovine enamel specimens (n = 16) and restored with two composites: a nano-hybrid [Herculite Ultra (HU)] and a micro-hybrid composite [TPH Spectra (TS)]. Baseline color (CIE L*a*b*), roughness (μm), and microhardness (kgf/mm2) were measured using a spectrophotometer, optical profilometer, and Vickers microhardness (VHN) tester, respectively. The specimens were stained with coffee for 14 days, and randomized into two bleaching groups: gel and strips (n = 8), then submitted to a 10-day bleaching/staining test. Color, roughness, and microhardness were re-measured. The outcomes were analyzed using two-way ANOVA and Fisher’s-PLSD test (α = 0.05). Results Gel significantly improved the color (ΔE 4.9–8.3) and increased the roughness (Ra 0.04–0.08 μm) of all substrates (p

Background Vinegar has been recognized as an effective antimicrobial agent for long. This study intended to elucidate the effect of commercially available vinegar on in situ pellicle formation and existing 24-h biofilms. Methods In situ biofilm formation took place on bovine enamel slabs mounted in individual splints and exposed intraorally over 3 min and 24 h, respectively. After 5 s rinsing with vinegar, all samples were analyzed via fluorescence microscopy (FM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In addition, salivary samples were collected and analyzed via FM. Samples with water rinsing served as controls. Results Vinegar caused destruction of the pellicle. Compared to the control group, vinegar rinsing reduced the outer globular layer of the pellicle (p p p Conclusion This in situ study reveals that rinsing with vinegar for only 5 s alters the pellicle layer resulting in subsurface pellicle formation. Furthermore, vinegar rinsing will destruct mature (24-h) biofilms, and significantly reduce the viability of planktonic microbes in saliva, thereby decreasing biofilm formation.

This study evaluates the effects of resin infiltrant composition and caries histological zone on the hydrolytic degradation of resininfiltrated artificial bovine enamel caries (RI-AEC). Different resin infiltrants were tested (n=26 per group): Icon (G1); TEGDMA 60%, UDMA 20%, and HEMA 20% (TUH); TEGDMA 80% and HEMA 20% (TH); and TEGDMA 75% and Bis-EMA 25% (TB). Following caries infiltration, samples were cut perpendicularly, and transverse microhardness were analyzed (at two histological zones: surface layer and lesion body) before and after 21 days of water immersion. TB presented lower decrease in microhardness (due to hydrolytic degradation) than the other groups, with a large effect size (Hedge's G from 0.83 to 1.19) and high power (84 to 99%). Neither histological zone nor its interaction with resin infiltrant composition significantly affected the outcome. In conclusion, resin composition affected microhardness of RI-AEC upon water immersion, and TB was the least affected.

Made available in DSpace on 2022-04-29T08:29:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-09-01 Background: Tooth whitening protocols with low concentration hydrogen peroxide (HP) appear to minimize the microstructural effect on teeth. In addition, light sources have been used to enhance bleaching efficiency. This study evaluated the color change and microhardness of a protocol with 6% HP photoactivated by LED/laser in comparison with 35% HP. Methods: Twenty bovine incisors were randomized in two groups: 6% HP + LED/laser and 35% HP (n=10). Teeth were submitted to staining using dark tea. Three whitening sessions were carried out according to the manufacturer's instructions. Enamel microhardness (VHN) and color change evaluation (∆L*, ∆a*, ∆b*, ∆E00 [CIEDE2000], and WID) before 24 hours and 7 days after the last whitening session were performed. Two-way repeated ANOVA and Bonferroni post-test was used (α = 0.05). Results: Both groups showed perceptible color changes, being more pronounce for 35% HP. Differences were observed for ∆a*, ∆b* and ∆E00 (p≤0.027), except for ∆L* (p>0.05). Differences were also found in the comparison among the evaluation times within the same group (p≤0.027), except for ∆a* results (p>0.05). WID showed that 35% HP exhibited high whiteness values. Regarding microhardness, the groups did not show significant differences (p>0.05). However, 35% HP showed decreased values after 7 days of the last whitening session compared to the baseline (p≤0.027). Conclusions: 6% HP + LED/laser promoted perceptible color change, but not comparable with 35% HP. No differences on enamel microhardness were observed between the whitening protocols. However, 35% HP showed decreased hardness after 7 days of whitening compared to baseline. Department of Restorative Dentistry School of Dentistry Araraquara São Paulo State University - UNESP Department of Restorative Dentistry School of Dentistry Araraquara São Paulo State University - UNESP

This study was performed to investigate the influence of pre-etching area and functional monomers in orthodontic adhesive pastes on enamel bond strength. Bovine enamel was partially pre-etched with phosphoric acid for 30 s over areas with a diameter of 1.0, 2.0 or 3.0 mm, and metal brackets were then bonded with or without functional monomers in the orthodontic adhesive paste. For the baseline groups, the whole adherent area was pre-etched. The shear bond strength (SBS) and adhesive remnant index (ARI) were determined. The adhesive paste/enamel interfaces were observed by scanning electron microscopy (SEM). Although the adhesive paste with functional monomers showed higher SBS than the functional monomer-free adhesive paste in all groups, there were no significant differences in SBS between them regardless of the pre-etched area. The SBS increased with increasing pre-etched area in both orthodontic adhesive pastes. In SEM images of adhesive paste/enamel interfaces, although adhesive with functional monomers showed excellent adaptation, the functional monomer-free adhesive paste showed gap formation at the interface. These findings suggested that the pre-etching area greatly influenced bond strength, regardless of the presence or absence of the functional monomer in the orthodontic adhesive paste.

Objective: This study aimed to clarify the effect of trace elements on enamel erosion due to citric acid eliminating other factors that can affect enamel erosion. Method: Forty enamel specimens were obtained by embedding bovine enamel blocks into a quick cure resin. Half of the enamel surface of the specimens was covered with nail varnish. The specimens were randomly divided into control (Ct), zinc (Zn), iron (Fe), and copper (Cu) groups and immersed in 1% citric acid solution, 1% citric acid solution with 10 mmol/L zinc, 1% citric acid solution with 10 mmol/L iron, or 1% citric acid solution with 10 mmol/L copper, respectively, at 37°C for 5 h. After immersion, the demineralized lesion depth was measured using transverse microradiography (TMR) and compared between groups using one-way analysis of variance and Tukey’s test. Results: The lesion depth was significantly higher in the Zn (218.9 ± 88.5 μm) group than that in the Ct group (116.3 ± 22.1 μm) (p < 0.01). Conclusion: It was suggested that zinc has decalcification properties when consumed with citric acid, while iron and copper don’t have such properties.

Aim To compare the effect after bleaching with 35% hydrogen peroxide with and without calcium gluconate on surface microroughness in an in vitro study on the bovine enamel. Materials and methods The study had an in vitro experimental design. The following groups were formed: group I: MV (mesiovestibular) enamel, group II: V (vestibular) enamel, and group III: DV (dystovestibular) enamel, undergoing treatment with Whiteness HP Blue (H2O2 at 35% with calcium gluconate), Whiteness HP Maxx: H2O2 at 35% (without calcium gluconate), and physiological serum. A Surftest SJ-210 digital roughness meter (Mitutoyo) was used to evaluate microroughness. Results The highest mean microroughness was found in group II (V) with 0.23 ± 0.13 μm and 0.17 ± 0.02 μm for Whiteness HP Blue and Whiteness HP Maxx, respectively. The post hoc analysis of surface microroughness subjected to H2O2 with and without calcium gluconate showed that there were only statistically significant differences between Whiteness HP Blue and the control (p = 0.032). Conclusion There were no significant differences in surface microroughness on comparing the Whiteness HP Maxx group with the control group and the Whiteness HP Blue group. Clinical significance The clinical importance of this study was that it allowed us to know the direct impact that bleaching agents with and without calcium have on dental structures.

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.

Background : The gold standard for quantifying mineral loss of enamel is transverse microradiography (TMR) and is complimented by the non-destructive quantitative light induced fluorescence (QLF) which measures changes in autofluorescence. Fluorescence loss has been shown to correlate with mineral loss. Building upon the established method, the use of hyperspectral fluorescence imaging (HI) allows the capture of a broader range of wavelengths to quantify fluorescence changes more accurately. Method : Bovine Enamel was demineralised within the dual constant depth film fermenter over 14 days and analysed using TMR, QLF and HI. The mineral change values were compared using Pearson's Correlation Coefficient. Results : The analysis showed a statistically significant correlation that was equal between TMR and HI (r=0.844) and TMR and QLF (r=0.844), but weaker between QLF and HI (r=0.811). Conclusions : The correlations indicate that HI is a promising valid non-destructive method for quantifying mineral loss from bovine enamel that is as accurate as QLF and complements TMR.

Objective The purpose of the present study was to assess the anti-erosive potential of the acquired enamel pellicle formed in situ under the influence of periodic milk or cream treatment. Methods The pellicle was formed on bovine enamel specimens in the oral cavity at buccal and palatal sites of upper molars in 6 subjects, using removable acrylic splints. During 6-h of intraoral exposure, splints were removed from the oral cavity every 25 min, treated with milk or cream for 5 min, and subsequently re-inserted into the oral cavity. After 6 h, pellicle covered specimens were immersed in citric acid (0.1 or 1.0 %) for 1 min, and processed for measurement of surface microhardness, determination of calcium release by atomic absorption spectroscopy, scanning and transmission electron microscopy. Statistical analysis was performed with SAS. Results Statistical analysis did not indicate major differences between erosive surface alterations on enamel specimens covered by pellicles treated with cream or milk, and those covered by control pellicles. In addition, TEM analysis did not reveal any differences concerning the ultrastructure of the different pellicle treatments during acid exposure. All pellicles were dissolved in part after exposure to 0.1 % citric acid and were nearly completely removed after treatment with 1.0% citric acid. Conclusions It is concluded that periodic treatment with milk or cream during pellicle formation in situ does not improve the protective potential of the acquired enamel pellicle against erosion. Clinical significance Modification of the pellicle by consumption of milk or cream prior to an acidic challenge cannot sufficiently protect enamel from erosion.

Made available in DSpace on 2022-05-01T06:31:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Objective: To evaluate the efficacy of different fluoride varnishes on white spot lesions (WSL) remineralization. Material and Methods: Polished bovine enamel specimens were obtained (n = 60) and had their initial surface Knoop microhardness (SMH) determined. WSL were created and the SMH was measured again. Then, specimens were allocated into six groups: C – Control (without varnish); BF – Bifluorid 12 (6% NaF + 6% CaF2); DP – Duraphat (5% NaF); PF – Profluorid (5% NaF); FP - Fluor Protector (0.2% NaF + 0.9% difluorsilane); CW - Clinpro White Varnish (5% NaF + 5% TCP). After varnishes application, specimens were immersed in artificial saliva for 24 h. Then, pH-cycling was performed for 8 days and SMH was measured. Data were analyzed by one-way ANOVA and Tukey’s test. Results: Non-significant differences were observed among the groups at baseline (p = 0.187) and after WSL formation (p = 0.999). After treatments, significant differences were observed among the groups (p = 0.001). Mean % of alteration (SD) and results of Tukey test were: C- 92.40 (12.10)a; PF- 88.66 (10.66)a; FP- 85.90 (14.49)ab; BF- 67.85 (17.86)bc; CW- 66.60 (18.48)c; DP- 58.62 (8.69) c. Conclusion: Bifluorid 12, Clinpro White Varnish, and Duraphat showed higher efficacy than artificial saliva in promoting the remineralization of WSL, nevertheless, none of the treatments were able to recover sound enamel baseline microhardness. São Paulo State University (Unesp) Institute of Science and Technology Department of Restorative Dentistry Department of Prosthodontics University Center Funvic – UniFunvic São Paulo State University (Unesp) Institute of Science and Technology Department of Restorative Dentistry

Background: Little is known about the effect of the type of splint material, heat-cured PMMA (HC) or chemical-cured PMMA (CC) on the wear of opposing tooth surfaces. Objective: The aim of this in vitro study was to evaluate two-body wear of dentin, enamel, glass-ceramic or one of four resin composites when opposing splint materials, namely ProBase HC and CC. Methods: The two-body wear of bovine dentine, bovine enamel, glass-ceramic IPS e.max CAD (EMAX) and four composites (Filtek Z250 [Z250], Clearfil AP-X [AP-X], Clearfil Majesty Posterior [CMP], Filtek Supreme XTE [FSE]) opposing three antagonists (HC and CC and stainless steel as control) were evaluated in the ACTA wear machine. In addition, all the surfaces were evaluated with scanning electron microscopy. Results: The highest average wear was observed in the case of dentin. The lowest average wear was found EMAX. In every case—except for EMAX—the wear rate was higher with HC than with CC (all differences being statistically significant). Conclusions: The level of wear of enamel, dentin and various resin composites was higher in contact with HC than in CC, the wear of dentin being the highest. In the case of a patient with no or little tooth wear or whose teeth are restored with composite material or glass-ceramic, the splint HC might be preferred because of its better durability. However, when the splint is in contact with opposing dentin preservation of the dentin, CC might be the best choice.

Objective To evaluate the volume loss after air abrasion with alumina particles with different morphology on bovine enamel and luting composite resin. Methods Air abrasion was performed on 12 unscathed bovine teeth and 72 luting composite resin discs with 85 μm round-shaped and 50 μm sharp-edged alumina particles applied for 20 s, 40 s and 60 s (n = 12). Air abrasion was standardized by uniform areas of 2 mm diameter, a pressure of 0.25 MPa and a distance of 3 mm. The volume loss was determined by using a laboratory scanner. Results Air abrasion with round-shaped alumina particles was mostly not measurable with the laboratory scanner, while sharp-edged alumina air abrasion resulted in significant loss of enamel. The median of volume loss by sharp-edged alumina particles ranged from 0.78 mm3 (20 s) to 2.52 mm3 (60 s). In contrast to round-shaped alumina the removal caused by sharp-edged alumina increased significantly with increasing application times (p ≤ 0.05). For air abrasion on luting composite resin the median of the removed volume ranged from 2.25 mm3 (20 s) to 6.18 mm3 (60 s), while round-shaped alumina showed a range from 0.45 mm3 (20 s) to 1.40mm3 (60 s). The round-shaped alumina produced a statistically significant lower volume loss than sharp-edged alumina for all three air abrasion times. Significance The 85 μm round-shaped alumina particles removed less composite resin than 50 μm sharp-edged alumina particles but barely any enamel, making it an option for removing composite resin residues from enamel.

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.

The antimicrobial and anticaries effects of CaneCPI-5 were evaluated. Ninety bovine enamel samples were treated for 60 s with either phosphate-buffered-saline (PBS), 0.12% chlorhexidine (CHX), 0.05 mg ml

Background One of the most unfavorable side effects of fixed orthodontic treatment is white spot lesions (WSLs). Although the most important approach is prevention of WSLs, it is also essential to evaluate the efficacy of the remineralization agents. However, there is no concurrence in the literature with respect to the remineralization process of these agents. The objective of the present study was to evaluate the effects of different fluoride varnishes, enamel matrix protein, and self-assembling peptide derivatives with varying chemical compositions on remineralization of artificially created WSLs in vitro using quantitative light-induced fluorescence (QLF). Methods Artificial WSLs were created on bovine enamel samples using acidic buffer solution (pH 5, 10 days). Specimens were randomly allocated to six groups (n = 10/group): (1) Emdogain (Straumann, Basel, Switzerland), (2) Curodont Repair (Credentis AG, Switzerland), (3) Duraphat (Colgate-Palmolive, New York, NY), (4) Clinpro XT (3 M ESPE, Pymble, New South Wales, Australia), (5) Enamel Pro Varnish (Premier Dental Products, PA, USA), and (6) control (untreated). The agents were applied to the WSLs according to the manufacturers’ instructions. Fluorescence loss (ΔF), lesion area (area), and impact (ΔQ) values of enamel surfaces were quantified by QLF-D BiluminatorTM (Inspektor-Pro, Amsterdam, The Netherlands) at baseline and after 7, 14, and 21 days of application of the respective materials. Results ΔF value presented a significantly decreasing trend throughout the 21 days for all groups except the Duraphat and Enamel Pro varnishes. The changes between 14th and 21st days of the Clinpro XT varnish application were significantly higher than Emdogain, Curodont, and Enamel Pro. The Curodont group showed higher lesion area changes between the first and second week in comparison to the Emdogain, Clinpro XT, and Enamel Pro groups, whereas Clinpro XT assured the highest reduction from the second to the third week of the observation period. Conclusions The fluorescence loss was significantly reduced with enamel matrix protein, self-assembling peptide, and light-curable fluoride varnishes in the analysis for 21 days. Curodont and Clinpro XT were effective in diminishing the fluorescence loss and lesion area compared to the Duraphat, Enamel Pro fluoride varnishes, and Emdogain in different time points.

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.

To evaluate the action of photoinitiators on the microtensile resistance of adhesive systems and resins composed in bovine enamel. Forty dental fragments, with flat and smooth enamel surfaces, obtained from the coronary buccal face of healthy bovine incisors, were randomly assigned to 4 experimental groups (n = 10) according to the different adhesive systems and composite resins used: Group 1- Ambar APS + Vittra APS; Group 2- Ambar APS + Opallis; Group 3- Ambar + Vittra APS; Group 4- Ambar + Opallis. After composite restoration, the samples were sectioned to obtain toothpicks that were subjected to the microtensile test (1.0 mm/min). The data obtained were subjected to statistical analysis. The Kruskal-Wallis test revealed no significant differences between groups (p

Objective To investigate the effect of different types of manual toothbrushes and brushing loads on the progression of erosive tooth wear (ETW) on enamel. Methods Bovine enamel specimens (n = 10) were submitted to a 5-day erosive-abrasive cycling model (0.3 % citric acid for 5 min, artificial saliva for 60 min, 4x/day). Toothbrushing was carried out 2x/day for 15 s, according to the toothbrushes tested (ultra-soft (a): Curaprox 5460; ultra-soft (b): Sensodyne Repair & Protect; soft (a): Colgate Slim Soft; soft (b): Oral-B Indicator Plus; medium: Johnson’s Professional; hard: Tek) and brushing loads (1.5 N, 3 N). Surface loss (SL, in μm) was assessed by optical profilometry on conclusion of the cycling. Some of the toothbrush characteristics were evaluated. Data were statistically analyzed (α = 0.05). Results For the 1.5 N load, the hard brush showed the highest SL value, with statistical significance. The other toothbrushes did not differ significantly, except that ultra-soft (a) caused significantly higher SL than ultra-soft (b). For the 3 N load, hard and soft (a) exhibited the highest SL. Soft (b) and medium had the lowest SL value, with statistical significance. Only soft (a) and ultra-soft (b) showed significant difference between loads, with lower SL for the load of 1.5 N. None of the toothbrush characteristics were significantly correlated with SL. Conclusions Although different degrees of enamel surface loss were observed with use of the different toothbrushes, no association was found between the toothbrush characteristics and SL. Depending on the toothbrush, the force of brushing was capable of modulating the ETW of enamel. Based on the brushing loads usually applied by healthy individuals, hard brushes are not recommended for use by patients with ETW. Clinical significance The use of hard bristle brushes is not recommended for use by individuals who exert healthy forces when brushing their teeth. The toothbrush characteristics are of secondary importance in terms of causing enamel loss in ETW.