Practical training using BEWE aimed at improving the diagnosis ability of erosive tooth wear for dental students-A randomized trial.

INTRODUCTION: Erosive tooth wear (ETW) has been gaining attention due to its high prevalence. However, ETW clinical diagnosis is difficult and may go unnoticed by many professionals. The present study aimed to develop, implement and evaluate a theoretical-practical training using active methodologies in the development of undergraduate students' skills for the diagnosis of ETW compared to the traditional teaching method. MATERIALS AND METHODS: This randomized controlled study involved two parallel groups: control group (n = 22), with learning based only on theoretical content and test group (n = 24), learning by theoretical-practical activity mediated by monitors/tutors. The theoretical class covered the current concepts of ETW, aetiology, diagnosis, use of the BEWE index, prevention and treatment. The practical training included exercises and discussions based on the diagnosis using BEWE scores of a collection of images and extracted teeth. To evaluate the efficacy of the teaching-learning methods, a theoretical multiple-choice questionnaire and a practical test using images and extracted teeth were applied. The outcome was the number of correct answers. Groups were compared by Mann-Whitney (theoretical knowledge) and T tests (practical ability in diagnosis) (p < .05). RESULTS: There was no significant difference between groups in the theoretical evaluation (p = .866). The test group showed higher ability to diagnose ETW lesions compared to the control group in the practical tests (p = .001). The performance of ETW diagnosis was similar when images were used in comparison to extracted teeth (p = .570). CONCLUSION: The practical activity associated with theoretical classes can be a promising strategy to improve the development of undergraduate students' skills in the diagnosis of ETW.

Are S-PRG composites able to resist against erosive and abrasive challenges and protect surrounding enamel in situ?

OBJECTIVES: This study evaluated the resistance of S-PRG (Surface Pre-Reacted Glass-ionomer) composites and other restorative materials against erosive and abrasive challenges and their protective effect on enamel adjacent to the restorations. MATERIALS AND METHODS: Bovine enamel blocks were prepared and randomized into 12 groups, including 6 types of material, each of them subjected to erosion_e or erosion+abrasion_ea: Beautifil II (S-PRG); Beautifil Bulk Restorative (S-PRG); Filtek Z250 XT; Filtek Bulk Fill; EQUIA Forte; Riva Light Cure. Cavities were prepared in the middle of enamel blocks and restored with the materials. Initial profiling measurement was performed on the material and on adjacent enamel (100, 200, 300, 600 and 700 µm from the restoration margin). Palatal intraoral appliances with the restored enamel blocks were used by the volunteers (n = 10). During 5 days appliances were immersed in 2.5 % citric acid for 2 min; 6 × /day (erosion_e). For ea condition, blocks were brushed for 1 min after each acid immersion. Final profile assessment was performed. Data were analysed by two and three way ANOVA followed by Tukey's test (p < 0.05). RESULTS: Material wear: Riva Light Cure showed the highest wear followed by EQUIA Forte and then all resin composites, including the ones with S-PRG (p = 0.000). Enamel wear: there was significant interaction among type of restorative material, wear condition and distance (p = 0.014), enamel around materials showed similar wear (p = 0.983) and the enamel subjected to ea exhibited highest wear (p = 0.000). CONCLUSION: SPRG based composites showed resistance against erosive and abrasive challenges but were not able to protect enamel adjacent to the restorations. CLINICAL SIGNIFICANCE: S-PRG composites exhibit resistance to material wear comparable to resin composites. However, they have shown an inability to effectively protect the adjacent enamel under in situ erosive-abrasive conditions, despite the presence of mineral-loss-preventing ions surrounding materials.

Acquired pellicle engineering with the association of cystatin and vitamin E against enamel erosion.

OBJECTIVE: Evaluate CaneCPI-5 associated with Vitamin E in acquired enamel pellicle (AEP) engineering to prevent dental erosion. METHODS: 180 human enamel specimens were divided into 12 groups and treated with the following solutions: Cane+VitT and Cane+VitS- CaneCPI-5 + Vit E; Vit+CaneT and Vit+CaneS- Vit E + CaneCPI-5; VitT and VitS- Vit E; CaneT and CaneS- CaneCPI-5; ControlT and ControlS - AmF/NaF/SnCl2; WaterT and WaterS- Deionized water. Groups' name followed by "T" were first treated (200 µl; 2 min) and then incubated in human saliva (200 µl; 1 h) to form the AEP. For groups followed by "S", the AEP was formed and then treatment was applied. The erosive challenge consisted of immersion in 1% citric acid (1 min, 1x/day, for 3 days). The percentage of superficial hardness loss (%SHL) and the relative surface reflection intensity (%SRI) were subjected to normality and homogeneity tests, Shapiro-Wilk and Levene tests, respectively. Subsequently, the data were analyzed using two-way ANOVA, Tukey's test and Pearson's correlation (p < 0.005). RESULTS: For%SHL and%SRI, water controls showed significantly lower protective capacity. Cane+VitT, Cane+VitS, and Vit+CaneS presented the lowest%SHL, and VitT and VitS did not differ from Vit+CaneT, but they were different from the other groups (p = 0.002). The greatest%SRI was found for the Cane+VitT, Vit+CaneT, VitT, Cane+VitS, Vit+CaneS, and VitS groups, which did not significantly differ. CaneT and ControlT, showed similar reflections compared to CaneS and ControlS. CONCLUSION: CaneCPI-5 and Vitamin E demonstrated a synergistic protective effect against initial erosion. CLINICAL SIGNIFICANCE: The results open up new possibilities for preventive approaches against erosion through the acquired pellicle engineering, with the combination of CaneCPI-5 and Vitamin E, which demonstrated to be more effective than commercial stannous mouthwash. Further research is warranted to explore the potential of this combination in diverse clinical settings.

Erosion-inhibiting and enamel rehardening effects of different types of saliva.

OBJECTIVES: The objective of this study was to assess the effects of in situ saliva compared to in vitro human saliva, with or without mucin, on inhibiting erosion and promoting enamel rehardening. DESIGN: Bovine enamel blocks were randomly distributed into groups (n = 23): Gsitu (human saliva in situ), Gvitro (collected human saliva) and GvitroM (collected human saliva with mucin). The enamel blocks underwent a 2-hour period for the formation of salivary pellicle, based on the assigned groups. Subsequently, they were subjected to three erosive cycles, each of them consisting of an erosive challenge (immersion in 0.65 % citric acid, pH 3.5, 1 min) and saliva exposure (immersion in situ or in vitro saliva for 2 h). Microhardness measurements were performed at each cycle, after each experimental step (erosive challenge and exposure to saliva). RESULTS: After the first demineralization, in vitro saliva groups presented greater hardness loss, with no statistical difference between GVitroM and GVitro. After the third erosive demineralization the in situ saliva resulted in less hardness loss compared to the first demineralization. In relation to surface hardness recovery, there was no difference among types of saliva but there was a decrease in hardness as the cycles progressed. CONCLUSION: Saliva groups had different behaviors between the first and third demineralization, being similar after the third cycle in terms of hardness loss. Regarding hardness recovery, all saliva promoted enamel gain, but there was a gradual decrease with the progression of the cycles.

Effect of 10% Proanthocyanidin gel on demineralized organic matrix degradation: ELISA method / Efeito do gel de Proantocianidina a 10% na degradação da matriz orgânica desmineralizada: método ELISA

Objective: This study evaluated Proanthocyanidin protective effect on dentin subjected to erosion and its inhibition on degradation of the demineralized organic matrix (DOM). Material and Methods: The tested groups were: G1 - 10% Proanthocyanidin gel (test group), G2 - 1.23% NaF (positive control 1), G3 - 0.012% Chlorhexidine (positive control 2) and G4 ­ Placebo (negative control with no active compound) and two methodologies were performed: contact profilometry and ICTP ELISA method. To quantify dentin wear, profilometry was performed. Data were submitted to Analysis of Variance followed by Fisher's LSD Test. To assess the collagen degradation, ICTP ELISA method was performed. Data were submitted to the Kruskal-Wallis followed by the Dunn ́s test. Simple linear regression and Pearson Correlation test were also performed (p<0.05). Results: The profilometry showed significantly lower wear of G1 when compared to other groups and G2, G3 and G4, which did not present significant difference among them. In the ICTP ELISA analysis, G1 and G4 did not show significant differences and the same happened between G2 and G3. However, G1 and G4 had lower values of collagen degradation compared to groups G2 and G3. Data showed that degraded DOM is a significant predictor to explain the values obtained through the ICTP ELISA. Conclusions: The results allow to verify that 10% proanthocyanidin provided less tooth wear and decreased degradation of the DOM, suggesting a good ability to prevent dentin erosion. The regression analysis also suggests that contact profilometry is a good strategy to quantify dentin wear (AU)

Objetivo: Este estudo avaliou o efeito protetor da proantocianidina na dentina submetida à erosão e sua inibição na degradação da matriz orgânica desmineralizada (MOD). Material e Métodos: Os grupos testados foram: G1 - gel de Proantocianidina 10% (grupo teste), G2 - NaF 1,23% (controle positivo 1), G3 - Clorexidina 0,012% (controle positivo 2) e G4 - Placebo (controle negativo sem princípio ativo) e duas metodologias foram realizadas: perfilometria de contato e método ICTP ELISA. Para quantificar o desgaste da dentina, a perfilometria foi realizada. Os dados foram submetidos à Análise de Variância seguida do Teste LSD de Fisher. Para avaliar a degradação do colágeno, foi realizado o método ICTP ELISA. Resultados: Os dados foram submetidos ao teste de Kruskal-Wallis seguido do teste de Dunn. Regressão linear simples e teste de correlação de Pearson também foram realizados (p<0,05). A perfilometria mostrou desgaste significativamente menor do G1 quando comparado aos outros grupos e G2, G3 e G4, que não apresentaram diferença significativa entre si. Na análise ICTP ELISA, G1 e G4 não apresentaram diferenças significativas e o mesmo ocorreu entre G2 e G3. No entanto, G1 e G4 apresentaram valores menores de degradação do colágeno em relação aos grupos G2 e G3. Os dados mostraram que a MOD degradada é um preditor significativo para explicar os valores obtidos pelo ICTP ELISA. Conclusão: Os resultados permitem verificar que a proantocianidina a 10% proporcionou menor desgaste dentário e diminuição da degradação da MOD, sugerindo uma boa capacidade de prevenir a erosão dentinária. Também sugere que a perfilometria de contato é uma boa estratégia para quantificar o desgaste da dentina (AU)

Vitamin E: A potential preventive approach against dental erosion-an in vitro short-term erosive study.

OBJECTIVES: This study evaluated the in vitro effect of different components of palm oil on enamel in a short-term erosive challenge. METHODS: The acquired enamel pellicle (AEP) was previously formed in situ for 2 h. Subsequently, the bovine enamel blocks were treated in vitro according to following solutions: G1-palm oil; G2-85% tocotrienol solution; G3-oily vitamin E; G4-oily vitamin A; G5-deionized water (negative control); G6-stannous-containing solution (Elmex® Erosion Protection Dental Rinse) (positive control). After application of the treatment solutions (500 µl, 30 s), the blocks were immersed in 0.5% citric acid (pH 2.4) during 30 s (initial erosion). The response variable was the percentage of surface hardness loss. Data were analyzed by one-way ANOVA and Fisher's Test (p < 0.05). RESULTS: The positive control (G6), palm oil (G1) and oily vitamin E (G3) groups presented the lowest percentage of surface hardness loss, and were statistically different from the negative group (G5) (p < 0.05), and no differences were found between these three groups. The 85% tocotrienol solution (G2) and oily vitamin A groups (G4) were not different to the negative control group. CONCLUSIONS: Stannous-containing positive control (Elmex® Erosion Protection), palm oil and oily Vitamin E were able to protect enamel against the erosive challenge performed in this in vitro study. In addition, vitamin E is probably the key ingredient of palm oil responsible for preventing enamel erosion. CLINICAL SIGNIFICANCE: Vitamin E presented similar preventive effect to a commercial mouthwash stannous-containing solution (Elmex® Erosion Protection) against initial erosion and, it can be considered as a promising natural alternative for the formulations of solutions aiming to prevent erosive tooth wear.

Proanthocyanidin protects the enamel against initial erosive challenge when applied over acquired pellicle.

PURPOSE: Concurrently with the growing interest in CAD-CAM systems, several new materials of different chemical nature have become available. As an alternative to ceramics, numerous polymer-based materials have recently been proposed for permanent prosthetic restorations. Aim of this study was to test the CAD-CAM polymer-based materials available on the market, comparing mean flexural strength, Weibull characteristic strength and Weibull modulus. METHODS: Seven types of polymer-based blocks were tested: Lava Ultimate, 3M; Brilliant Crios, Coltene; Cerasmart, GC; Block HC, Shofu; Katana Avencia, Noritake; Grandio Blocs, Voco; Tetric CAD, and Ivoclar-Vivadent. Specimens were cut out from blocks, finished, polished, and tested in a three-point bending test apparatus until failure (n=30). Flexural strength, Weibull characteristic strength, and Weibull modulus were calculated. Flexural strength data were statistically analyzed. ANOVA on Ranks was applied, followed by the Dunn's test for post hoc comparisons (P= 0.05). RESULTS: Flexural strength values (MPa) were measured (mean±standard deviation). Different letters in parentheses label statistically significant differences: Grandio Blocs 266±24(a), Brilliant Crios 259±21(ab); Tetric CAD 254±15(ab); Katana Avencia 241±29(bc); Cerasmart 221±24(cd); Lava Ultimate 196±23(de); Block HC 139±10(e). All the tested materials had flexural strengths greater than 100 MPa, thereby satisfying the requirements of ISO standards for polymer-based materials. For all the tested materials the Weibull characteristic strength was greater than 100 MPa. Weibull modulus ranged between 21.20 (Tetric CAD) and 9.09 (Katana Avencia). CLINICAL SIGNIFICANCE: Even though all the CAD-CAM polymer-based materials marketed in blocks tested in the present study satisfy the requirements of ISO standard for polymer-based materials, their flexural resistance differs significantly. The data presented in the study may be helpful to clinicians for selecting the most appropriate materials for each clinical case.

In situ effect of a proanthocyanidin mouthrinse on dentin subjected to erosion.

BACKGROUND: Proanthocyanidin has been shown to be efficient in inhibiting matrix metalloproteinases. OBJECTIVE: The aim of this in situ study was to evaluate the protective effect of Proanthocyanidin-based mouthrinses either with naturally acidic or with a neutral pH applied on dentin subjected to erosion. METHODOLOGY: Eight volunteers wore one palatal device in two phases (7 days washout) with 16 samples per group (n=8). The groups under study were: First Phase/ G1 - 10% proanthocyanidin mouthrinse (pH 7.0, Experimental group 1 - Purified Grape Seeds Oligomeric Proanthocyanidins), G2 - 10% proanthocyanidin mouthrinse (pH 3.0, Experimental group 2 - Purified Grape Seeds Oligomeric Proanthocyanidins). Second Phase/ G3 - 0.12% chlorhexidine mouthrinse (pH 7.0, Positive control group), G4 - no previous treatment (Negative control group). Each device was subjected to 3 erosive cycles (5 minutes) per day for 5 days. Treatments with different mouthrinses were applied once after the second erosive challenge (5 minutes). Profilometry was used to quantify dentin loss (µm). RESULTS: Data were analyzed by repeated measures of ANOVA followed by Fisher's test (p<0.05). G1 (1.17±0.69) and G3 (1.22±0.25) showed significantly lower wear values with no statistical difference between them. G2 (2.99±1.15) and G4 (2.29±1.13) presented higher wear values with no significant differences between them. CONCLUSION: The 10% proanthocyanidin mouthrinse (pH 7.0) could be a good strategy to reduce dentin wear progression.

In situ effect of a proanthocyanidin mouthrinse on dentin subjected to erosion

Abstract Proanthocyanidin has been shown to be efficient in inhibiting matrix metalloproteinases. Objective The aim of this in situ study was to evaluate the protective effect of Proanthocyanidin-based mouthrinses either with naturally acidic or with a neutral pH applied on dentin subjected to erosion. Methodology Eight volunteers wore one palatal device in two phases (7 days washout) with 16 samples per group (n=8). The groups under study were: First Phase/ G1 - 10% proanthocyanidin mouthrinse (pH 7.0, Experimental group 1 - Purified Grape Seeds Oligomeric Proanthocyanidins), G2 - 10% proanthocyanidin mouthrinse (pH 3.0, Experimental group 2 - Purified Grape Seeds Oligomeric Proanthocyanidins). Second Phase/ G3 - 0.12% chlorhexidine mouthrinse (pH 7.0, Positive control group), G4 - no previous treatment (Negative control group). Each device was subjected to 3 erosive cycles (5 minutes) per day for 5 days. Treatments with different mouthrinses were applied once after the second erosive challenge (5 minutes). Profilometry was used to quantify dentin loss (µm). Results Data were analyzed by repeated measures of ANOVA followed by Fisher's test (p<0.05). G1 (1.17±0.69) and G3 (1.22±0.25) showed significantly lower wear values with no statistical difference between them. G2 (2.99±1.15) and G4 (2.29±1.13) presented higher wear values with no significant differences between them. Conclusion The 10% proanthocyanidin mouthrinse (pH 7.0) could be a good strategy to reduce dentin wear progression.

Uso de infiltrante no tratamento de lesão cariosa incipiente em região com envolvimento estético / Infiltrant use to treat incipient carious lesions in region with aesthetic involvement

Dentre os tratamentos disponíveis para as lesões cariosas incipientes em superfícies livres, a técnica de infiltração de cárie utilizando resinas compostas fluidas representa uma abordagem que vem se destacando como uma excelente alternativa. Devido às suas particularidades, estabelece uma barreira dentro da lesão reforçando sua estrutura enfraquecida, tornando-a ácido-resistente e impedindo a sua progressão a um estágio de cavitação. Assim o objetivo deste trabalho é apresentar o tratamento empregando infiltrante em um caso clínico de um paciente cuja queixa principal eram as manchas brancas que comprometiam a harmonia do seu sorriso. Ao exame clínico, observaram-se lesões iniciais de cárie com aspecto de mancha branca. O tratamento proposto foi o de orientação de higiene bucal, além de neutralização das lesões incipientes através do tratamento das manchas brancas com auxílio do infiltrante. Após profilaxia e isolamento absoluto, foi realizada a aplicação do agente infiltrante com aplicação de ácido clorídrico 15% (Icon Etch - DMG) por 2 minutos, lavagem por 30 segundos, aplicação de álcool absoluto (Icon Dry - DMG), secagem por 30 segundos e, posteriormente, aplicação do agente infiltrante (Icon Infiltrant - DMG) durante 3 minutos, seguido de fotoativação por 40 segundos. Foi feita nova aplicação do agente infiltrante com espera de 1 minuto seguida de fotoativação por 40 segundos. Procedeu-se então ao acabamento e polimento. Após o término do tratamento, foi constatada a estabilização da atividade de cárie e a redução significativa das manchas brancas, o que melhorou a aparência do sorriso do paciente, que demonstrou satisfação imediata e após os 10 meses de acompanhamento do caso (AU).

Among the treatments available for incipient carious lesions on free surfaces, the caries infiltration technique using fluid composite resins represents an approach that has been highlighted as an excellent alternative. Due to its particularities, it establishes a barrier in the lesion by reinforcing its weakened structure, making it acid-resistant and preventing its progression to a cavitation stage. Thus, the aim of this case report is to present the treatment using infiltrant in a clinical case of a patient whose main complaint was white spot lesions that compromised the harmony of his smile. Clinical examination revealed initial caries lesions with white spot appearance. The proposed treatment was oral hygiene guidance and also incipient lesions neutralization through white spots treatment with the aid of infiltrant agent. After prophylaxis and absolute isolation, the infiltrant agent was applied with 15% hydrochloric acid (Icon Etch - DMG) for 2 minutes, rinsing for 30 seconds, application of absolute alcohol (Icon Dry - DMG), drying for 30 seconds and, after that, infiltrant agent (Icon Infiltrator - DMG) was applied for 3 minutes, followed by photoactivation for 40 seconds. Infiltrant agent new application was performed with 1-minute-wait followed by photoactivation for 40 seconds. Finishing and polishing were then carried out. After the treatment end stabilization of caries activity and significant reduction of white spots were observed, which improved the patient's smile appearance, who showed immediate and after 10 month case follow up of satisfaction (AU).

Effect of different concentrations and application times of proanthocyanidin gels on dentin erosion.

PURPOSE: To analyze the effect of different concentrations and application times of proanthocyanidin gels on dentin before an erosive challenge in order to evaluate if there is a dose-response or application time-response relationship in the use of these gels for erosion prevention. METHODS: 80 bovine root dentin blocks were randomly and equally divided into 10 groups and treated according to the two factors under study (purified grape seed proanthocyanidin gel concentration and time of application): 0.05P1: 0.05% proanthocyanidin gel during 1 minute; 0.05P5: 0.05% proanthocyanidin gel during 5 minutes; 1P1: 1% proanthocyanidin gel during 1 minute; 1P5: 1% proanthocyanidin gel during 5 minutes; 5P1: 5% proanthocyanidin gel during 1 minute; 5P5: 5% proantho-cyanidin gel during 5 minutes; 10P1: 10% proanthocyanidin gel during 1 minute; 10P5: 10% proanthocyanidin gel during 5 minutes; Control 1: placebo gel during 1 minute; and Control 5: placebo gel during 5 minutes. The gels were applied over dentin blocks once before the first erosive challenge. After that, the blocks were subjected to three erosive cycles per day, during 5 days. Profilometry was used to quantify the dentin loss (µm). Data were analyzed by two-way ANOVA and Fisher's test (P< 0.05). RESULTS: Statistical analysis showed that there was no significant difference between the application times. The different concentrations of proanthocianidin gels presented similar results (P> 0.05). All tested gels resulted in significantly less wear when compared to the placebo gel. CLINICAL SIGNIFICANCE: Grape seed proanthocyanidin gels could be considered as a promising therapy to diminish erosive dentin wear because it may interact with the exposed collagen, enhancing the demineralized organic matrix stabilization, which acts as a barrier against the diffusion of the acids from erosion.

Effect of Proanthocyanidin-enriched extracts on the inhibition of wear and degradation of dentin demineralized organic matrix.

OBJECTIVES: The aim of this study was to evaluate the effect of Cranberry and Grape seed-enriched extract gels in inhibiting wear and degradation of demineralized organic matrix (DOM). DESIGN: 225 dentin specimens obtained from bovine incisors were randomly allocated into 5 groups (n=45): 10% Grape seed extract gel (GSE), 10% Cranberry extract gel (CE), 0.012% Chlorhexidine gel (CX), 1.23% NaF gel (F), and no active compound gel (P, placebo). Before the treatments, samples were demineralized by immersion in 0.87M citric acid, pH 2.3 (36h). Then, the studied gels were applied once over dentin for 1min. Next, the samples were immersed in artificial saliva containing collagenase obtained from Clostridium histolyticum for 5days. The response variable for dentin wear was depth of dentin loss measured by profilometry and for collagen degradation was hydroxyproline determination. Data were analyzed by ANOVA followed by Tukey's test and Pearson Correlation Test (p<0.05). RESULTS: Grape seed extract significantly reduced dentin wear compared to the other groups (p<0.05). Cranberry extract and Chlorhexidine did not differ statistically and were able to reduce wear when compared to NaF and placebo treatments. The hydroxyproline analysis showed that there was no significant difference among groups for all treatments (p<0.05). Correlation analysis showed a significant correlation between the amount of degraded DOM evaluated by profilometry and the determination of hydroxyproline. CONCLUSION: Cranberry extract was able to reduce the dentin wear and collagen degradation, likely due to the proanthocyanidin content and its action. Therefore, Cranberry could be suggested as an interesting natural-based agent to prevent dentin erosion.

Effect of vegetable oils applied over acquired enamel pellicle on initial erosion.

OBJECTIVE: The prevalence of dental erosion has been recently increasing, requiring new preventive and therapeutic approaches. Vegetable oils have been studied in preventive dentistry because they come from a natural, edible, low-cost, and worldwide accessible source. This study aimed to evaluate the protective effect of different vegetable oils, applied in two concentrations, on initial enamel erosion. MATERIAL AND METHODS: Initially, the acquired pellicle was formed in situ for 2 hours. Subsequently, the enamel blocks were treated in vitro according to the study group (n=12/per group): GP5 and GP100 - 5% and pure palm oil, respectively; GC5 and GC100 - 5% and pure coconut oil; GSa5 and GSa100 - 5% and pure safflower oil; GSu5 and GSu100 - 5% and pure sunflower oil; GO5 and GO100 - 5% and pure olive oil; CON- - Deionized Water (negative control) and CON+ - Commercial Mouthwash (Elmex® Erosion Protection Dental Rinse, GABA/positive control). Then, the enamel blocks were immersed in artificial saliva for 2 minutes and subjected to short-term acid exposure in 0.5% citric acid, pH 2.4, for 30 seconds, to promote enamel surface softening. The response variable was the percentage of surface hardness loss [((SHi - SHf) / SHf )×100]. Data were analyzed by one-way ANOVA and Tukey's test (p<0.05). RESULTS: Enamel blocks of GP100 presented similar hardness loss to GSu100 (p>0.05) and less than the other groups (p<0.05). There was no difference between GP5, GC5, GC100, GSa5, GSu100, GSa100, GSu5, GO5, GO100, CON- and CON+. CONCLUSION: Palm oil seems to be a promising alternative for preventing enamel erosion. However, further studies are necessary to evaluate a long-term erosive cycling.

Susceptibility of bovine dental enamel with initial erosion lesion to new erosive challenges.

This in vitro study evaluated the impact of initial erosion on the susceptibility of enamel to further erosive challenge. Thirty bovine enamel blocks were selected by surface hardness and randomized into two groups (n = 15): GC- group composed by enamel blocks without erosion lesion and GT- group composed by enamel blocks with initial erosion lesion. The baseline profile of each block was determined using the profilometer. The initial erosion was produced by immersing the blocks into HCl 0.01 M, pH 2.3 for 30 seconds, under stirring. The erosive cycling consisted of blocks immersion in hydrochloric acid (0.01 M, pH 2.3) for 2 minutes, followed by immersion in artificial saliva for 120 minutes. This procedure was repeated 4 times a day for 5 days, and the blocks were kept in artificial saliva overnight. After erosive cycling, final profile measurement was performed. Profilometry measured the enamel loss by the superposition of initial and final profiles. Data were analyzed by t-test (p<0.05). The result showed no statistically significant difference between groups (GS = 14.60±2.86 and GE = .14.69±2.21 µm). The presence of initial erosion on bovine dental enamel does not enhance its susceptibility to new erosive challenges.

Effect of vegetable oils applied over acquired enamel pellicle on initial erosion

Abstract Objective The prevalence of dental erosion has been recently increasing, requiring new preventive and therapeutic approaches. Vegetable oils have been studied in preventive dentistry because they come from a natural, edible, low-cost, and worldwide accessible source. This study aimed to evaluate the protective effect of different vegetable oils, applied in two concentrations, on initial enamel erosion. Material and Methods Initially, the acquired pellicle was formed in situ for 2 hours. Subsequently, the enamel blocks were treated in vitro according to the study group (n=12/per group): GP5 and GP100 - 5% and pure palm oil, respectively; GC5 and GC100 - 5% and pure coconut oil; GSa5 and GSa100 - 5% and pure safflower oil; GSu5 and GSu100 - 5% and pure sunflower oil; GO5 and GO100 - 5% and pure olive oil; CON− - Deionized Water (negative control) and CON+ - Commercial Mouthwash (Elmex® Erosion Protection Dental Rinse, GABA/positive control). Then, the enamel blocks were immersed in artificial saliva for 2 minutes and subjected to short-term acid exposure in 0.5% citric acid, pH 2.4, for 30 seconds, to promote enamel surface softening. The response variable was the percentage of surface hardness loss [((SHi - SHf) / SHf )×100]. Data were analyzed by one-way ANOVA and Tukey's test (p<0.05). Results Enamel blocks of GP100 presented similar hardness loss to GSu100 (p>0.05) and less than the other groups (p<0.05). There was no difference between GP5, GC5, GC100, GSa5, GSu100, GSa100, GSu5, GO5, GO100, CON− and CON+. Conclusion Palm oil seems to be a promising alternative for preventing enamel erosion. However, further studies are necessary to evaluate a long-term erosive cycling.

Penetration of resin-based materials into initial erosion lesion: A confocal microscopic study.

The application of resin-based materials is an alternative of treatment for eroded lesions. Nevertheless, there are no studies about the penetration of these materials into eroded lesion, which might affect its adhesion. Therefore, this study evaluated the penetration of four resin-based materials, with and without enamel etching. By using an in vitro protocol, types of treatment were studied at five levels (AdheSE(®) , Tetric N-Bond(®) , Single Bond 2(®) , Helioseal Clear(®) , Icon(®) ) and types of enamel etching in two levels (with and without). Materials were stained with 0.02 mg/mL ethanolic solution of tetramethylrhodamine isothiocyanate. Bovine enamel samples (4 × 4 mm) were immersed in 0.01 M HCl, pH 2.3, for 30 seconds to produce initial eroded lesions. Afterward, the materials were applied on half of sample enamel surface following the manufacturer's instructions. On the other half of sample, the materials were applied without etching the enamel. Materials penetration into the enamel was assessed by Confocal Laser Scanning Microscopy on reflection and fluorescence modes. The penetration depth (PD) was measured using ImageJ software. Data were analyzed by two-way ANOVA and Tukey test (P < 0.05). Regardless of the material, etched enamel resulted in higher PD than non-etched (P < 0.05). Icon(®) showed the highest PD in enamel followed by Helioseal Clear(®) (P < 0.05), with significant difference between them (P < 0.05) and no difference was found among AdheSE(®) , Tetric N-Bond(®) , and Single Bond 2(®) (P > 0.05). It can be concluded that prior enamel etching increased the materials penetration into eroded enamel and the Icon(®) -infiltrant presented highest penetration.

Effect of cranberry and proanthocyanidin in the inhibition of wear and dentin demineralized organic matrix degradation / Efeito do cranberry e da proantocianidina na inibição do desgaste da degradação da matriz orgânica da dentina desmineralizada

A literatura reconhece que uma das estratégias mais efetivas na minimização da perda de tecido dentinário promovido por agentes erosivos é a manutenção da sua matriz orgânica, visto que esta atua como barreira de difusão aos ácidos. Contudo, o colágeno tende a ser degradado por metaloproteinases da matriz (MMPs) e tem sido cada vez mais frequente a busca por agentes que possam inibir este processo. Existem indícios de que o Cranberry e a proantocianidina podem inibir as MMPs, porém estes agentes não foram adequadamente avaliados na erosão dentária. Assim, o objetivo desta dissertação foi avaliar o papel do extrato de Cranberry e da proantocianidina aplicados como gel tópico na inibição da degradação da matriz orgânica da dentina desmineralizada e consequentemente na minimização do desgaste da dentina submetida à erosão. Para isso, dois estudos foram conduzidos (artigo 1 e 2). O primeiro avaliou o efeito de diferentes concentrações (placebo, 0,05%, 1%, 5% e 10%) e tempos de aplicação (1 e 5 minutos) da proantocianidina na dentina submetida à ciclagem erosiva in vitro. Após a aplicação dos géis, os blocos de dentina foram submetidos a 3 ciclos de des-remineralização por dia, durante 5 dias. A perfilometria foi utilizada para quantificar a perda de dentina. Neste estudo, a proantocianidina não mostrou um efeito dose e tempo/ resposta, mas os resultados deste trabalho sugerem a sua eficácia na redução dos efeitos deletérios da erosão na dentina, uma vez que géis de diferentes concentrações de proantocianidina foram capazes de promover menor desgaste da dentina quando comparado com os géis placebo. O segundo estudo avaliou o efeito de diferentes géis (proantocianidina, clorexidina, Cranberry, NaF e placebo) na inibição do desgaste e degradação da matriz orgânica desmineralizada (DOM). Antes do tratamento, as amostras foram desmineralizadas por imersão em ácido cítrico (36 h a 4ºC). Os diferentes géis foram aplicados sobre a dentina durante 1 minuto. Em seguida, as amostras foram imersas em saliva artificial contendo colagenase do Clostridium histolyticum, durante 5 dias. A variável de resposta foi de profundidade de perda de dentina medida por meio de perfilometria. Os resultados deste estudo mostraram que o grupo Cranberry foi capaz de reduzir o desgaste da dentina e a degradação do colágeno, mas a proantocianidina obteve os melhores resultados, confirmando a sua eficácia na prevenção da erosão da dentina.(AU)

The literature recognizes that one of the most effective strategies in minimizing the dentin tissue loss by erosive agents is the maintenance of its organic matrix, because this acts as a diffusion barrier to acid. However, the collagen tends to be degraded and has been increasingly used to search for agents that inhibit this process. There is evidence that the Cranberry and proanthocyanidin can inhibit matrix metalloproteinases (MMPs) which degrade the dentin collagen, but these agents have not been adequately evaluated in dental erosion. The aim of this dissertation was to analyze the role of Cranberry extract and proanthocyanidin applied as a local gel for inhibiting the dentin demineralized organic matrix degradation and hence minimizing wear of dentin subjected to erosion. To this end, two studies were conducted (article 1 and 2). The first evaluated the effect of different concentrations (placebo, 0.05%, 1%, 5% e 10%) and application time (1 and 5 minutes) of proanthocyanidin gels on dentin erosion. After gels application, the dentin blocks were subjected to 3 erosive cycles per day, during 5 days. Profilometry was used to quantify the dentin loss. In this case, proanthocyanidin not have shown a dose and time-response effect, but the results of this study suggests its efficacy on decreasing the deleterious effects of erosion on the dentin, since different proanthocyanidin gels were able to promote lower dentin wear when compared with the placebo gels. The second study evaluated the effect of different gels (proanthocyanidin, chlorexidine, Cranberry, NaF e placebo) in inhibition wear and demineralized organic matrix (DOM) degradation. Before the treatment, samples were demineralized by immersion in citric acid (0,87 M, 36 h). Then, the studied gels were applied once on dentin for 1 minute. Next, the samples were immersed in artificial saliva containing collagenase obtained from Clostridium histolyticum for 5 days. The response variable was depth of dentin loss measured by profilometry. The results of this study showed that Cranberry was able to reduce the dentin wear and collagen degradation, but the proanthocyanidin obtained the best results, confirming its effectiveness in preventing dentin erosion.(AU)