Dentin resistence to acids promoted by the glass ionomer cements

Introdução: as principais características dos CIVs são: liberação de flúor, biocompatibilidade, adesividade aos tecidos dentais duros e expansão térmica linear próxima à dentina.Objetivo: avaliar a capacidade dos cimentos de ionômero de vidro de promover à dentina maior resistência frente aos ácidos e microrganismos presentes na cavidade oral, discutindo a suposta bioatividade desse material relacionada ao substrato dentinário em diversas situações. Revisão de literatura: são inúmeras as opções e possibilidades de indicação dos CIVs, porém, a situação clínica deve ser avaliada com critério para escolher o material mais viável e aquele que ofereça o maior número de vantagens. Conclusões: os CIVs apresentam adesividade a estrutura dental, proporcionam vedamento marginal, reduzem a microinfiltração e/ou a passagem de nutrientes para os microorganismos que porventura possam estar presentes na cavidade. Devido à liberação de fluoretos, os CIVs apresentam potencial remineralizador ou paralisador mesmo em dentina cariada.Introduction: the main characteristics of GICs are: fluoride release, biocompatibility, adhesion to dental hard tissues and linear thermal expansion similar the dentin. Aim: this literature review, based on the work currently available, evaluated the ability of glass ionomer cements to promote greater dentin resistance against acids and microorganisms presents in the oral cavity, discussing the supposed bioactivity of this material related to dentinary substrate in various situations. Literature review: there are countless options and possibilities for indication of GICs, however, the clinical situation must be evaluated on the criteria for selecting the material most viable and one that offers the greatest number of advantages. Conclusion: it was concluded that the GICs exhibit adhesion to tooth structure, providing marginal sealing, reduce microleakage and / or the passage of nutrients to the microorganisms who may be present in the cavity. Due to the release of fluoride, GICs have potential remineralizing paralyzing or even in carious dentin

Bond strength of adhesive systems with different solvents to dry and wet dentin

Aim: This study evaluates bond strength between dentin and composite using adhesives with different solvents to dry and wet dentin. Materials and methods: Ninety bovine incisors were used; the vestibular surfaces were worn by the exposure of an area with a diameter of 4 mm of dentin. The specimens were divided into 6 groups, according to the type of adhesive used and hydratation stals: Group SB-wet: Single Bond 2 in wet dentin, Group SBdry: Single Bond 2 in dry dentin, Group SL-wet: Solobond M in wet dentin, Group SL-dry: Solobond M in dentin dry. Group XPwet: XP Bond in wet dentin, Group XP-dry: XP Bond in dentin dry. They were cut to obtain specimens in the shape of stick with 1 × 1 mm and subjected to microtensile test in universal testing machine with a cross speed of 1mm/min. The data were analyzed with ANOVA and Tukey's tests (5%). Results: ANOVA showed significant differences for surface treatment and interaction, but no difference was found for adhesive factor. The Tukey's test showed that the samples with wet dentin shown higher values of bond strength. Conclusion: The adhesive did not influence in the bond strength. The groups with wet dentin showed higher values of bond strength than groups with dry dentin

Effect of antioxidant agents on bond strength of composite to bleached enamel with 38% hydrogen peroxide

This study evaluated the effect of antioxidant agents on microtensile bond strengths (mTBS) of composite to bleached enamel. Fifteen freshly extracted human third molars were selected and randomly assigned to 6 groups (n = 5): (NB) enamel not bleached, (B) bleached enamel, (BR7) bleached enamel and restored 7 days later, (BSA) bleached enamel+sodium ascorbate, (BMC) bleached enamel+malvidin chloride, (BPC) bleached enamel+pelargonidin chloride. The groups were bleached with 38% hydrogen peroxide (HP - Opalescence Xtra Boost) and restored with Single Bond+Filtek Z350. The specimens were thermocycled and submitted to a microtensile load at 1 mm/min crosshead speed. The data were evaluated by ANOVA and Tukey test at 5% of significance. The mean and standard-deviation for all groups were: NB: 30.95(±11.97)a; BSA: 30.34(±8.73)a, BPC: 22.81(6.00)b, BR7: 21.41(±6.12)b, B: 14.10(±4.45)c, BMC: 13.25(±6.02)c. Sodium ascorbate reversed the bond strengths to enamel immediately after bleaching.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Streptococcus Mutans Group And Lactobacillus Counts In Proximal Amalgam And Resin Composite Restorations: An In Vivo Study

 Aim & Objectives: This study assesses the quantity of streptococcus mutans group and lactobacillus in interproximal contact of posterior teeth with proximal amalgam and resin composite restorations. Methods: Twenty patients were divided into two groups (n=10) according to the type of restorative material they presented: amalgam (AM) or resin composite (RC). In the same patient, one interproximal Class II amalgam or resin composite restoration and one interproximal contact without restorations (control group – C) were studied. The material was collected from the interproximal with the aid of a piece of sterilized dental thread, and stored in phosphate buffered saline solution.  The material was seeded on plates containing Mitis Salivarius Bacitracin Sucrose agar and Rogosa agar culture medium and incubated at 37°C for 48-72h. The colony forming units (Log10 CFU/mL) were counted and the data were submitted to the Student’s-t test (5%).  Results: There was significant difference between Groups C and AM (p=0.019) with regard to lactobacillus count. For streptococcus mutans group, there was significant difference between Groups C and RC (p=0.015). Conclusion: There is significantly greater growth of streptococcus mutans group in RC Class II restorations  and lactobacillus in AM restorations when compared with interproximal contact without the presence of restorations