Influence of erosive challenge in deciduous teeth undergoing restorative procedures with different adhesive protocols : an in vitro study

Objetivo: Avaliar a influência do desafio erosivo na interface dente-restauração de dentes decíduos submetidos a diferentes protocolos adesivos (sistemas convencionais e autocondicionantes, contendo ou não flúor). Métodos: Neste estudo, in vitro, 40 molares decíduos foram cortados mésio-distalmente, incluídos em resina de poliestireno e polidos. Após a realização de preparo cavitário padronizado (2x2 mm), as amostras foram randomizadas e divididas de acordo com o sistema adesivo a ser aplicado: G1 (Adper Single Bond 2®, 3M ESPE), G2 (Universal Single Bond®, 3M ESPE), G3 (Optibond FL®, Kerr) e G4 (Bond Force®, Tokuyama). As cavidades hibridizadas foram restauradas com resina composta (Filtek Z350). Metade das amostras foi submetida a ciclos de desafio erosivo e abrasivo (grupo teste) e a outra metade (grupo hígido) permaneceu imersa em saliva artificial durante o período experimental (n= 10). Para o desafio erosivo, as amostras foram imersas em 30 ml de Coca-Cola® (pH= 2,6) durante 1 minuto a 25 °C, sob agitação constante, 4 vezes ao dia por 5 dias. As amostras foram escovadas uma vez ao dia usando pasta dental fluoretada (Colgate Total 12) e saliva artificial. Para a análise de microinfiltração, as amostras foram imersas em solução tamponada de azul de metileno 2% durante 1 hora, seccionadas longitudinalmente, analisadas e avaliadas quantitativamente pela extensão da penetração do corante ao longo da interface dente-restauração em microscópio óptico com aumento de 40X. O teste de microdureza foi realizado com endentações de 50g por 5s em esmalte a 25, 50 e 100 μm da superfície erodida e a 25, 75 e 125 μm da interface adesiva. Na análise estatística utilizou-se o teste não-paramétrico Kruskal Wallis para os dados de microinfiltração e 2-way ANOVA para os dados de análise da microdureza (p=0,05). Resultados: Com relação à microinfiltração, 7,5% das amostras não mostraram infiltração do corante, 30% apresentaram corante somente em esmalte e 62,5% mostraram infiltração do corante além da junção amelo-dentinária. Não foram observadas diferenças estatísticas na microdureza em nenhuma das diferentes profundidades (p≥0,05), bem como na microinfiltração (p=0,413) para todos os grupos experimentais avaliados. Conclusão: O desafio erosivo não comprometeu a microdureza, tampouco a microinfiltração marginal dos dentes decíduos restaurados com sistemas adesivos convencionais e autocondicionantes, com ou sem flúor.Aim: To evaluate the influence of erosive challenge in the tooth-restoration interface of deciduous teeth submitted to different bonding protocols (etch-and-rinse and self-etching adhesives, containing or not fluoride). Methods: In this in vitro study, 40 deciduous molars were cut mesio-distally, embedded in polystyrene resin, grinded and polished. Samples were randomly divided according to the adhesive system: G1 (Adper Single Bond 2®, 3M ESPE), G2 (Universal Single Bond®, 3M ESPE), G3 (Optibond FL®, Kerr) and G4 (Bond Force®, Tokuyama). After conducting standardized cavity preparations (2x2 mm), adhesive systems were applied and the samples were restored with composite resin (Filtek Z350). Half of the samples were submitted to erosive and abrasive cycles (test group), and the other half (sound group) remained immersed in artificial saliva during the experimental phase (n=10). For the erosive challenge, samples were immersed in 30 ml of Coca-Cola® (pH=2,6) for 1 minute at 25°C, under constant shaking, 4 times per day for 5 days. The samples were brushed once a day using fluoridated toothpaste (Colgate Total 12) and artificial saliva. For microleakage analysis, samples were immersed in 2% methylene blue during 1 hour, cross-sectioned, and analyzed by measuring the extent of dye penetration along the restoration-tooth interface under stereomicroscope at 40 X magnification. Cross-sectional microhardness (CSMH) was performed with 50g/5s indentations in enamel at 25, 50 and 100 μm from the eroded surface and at 25, 75 and 125μm from the adhesive interface. Statistical analysis was completed using Kruskal Wallis non-parametric test for microleakage and non-parametrical ANOVA for microhardness data (significance level set at 0.05). Results: Considering the microleakage, in 7.5% of the samples, no dye infiltration were observed, in 30% dye was observed only at enamel and in 62.5% the dye infiltrated through amelo-dentin junction. No significant differences were observed neither on CSMH at different depths (p≥ 0.05) nor in microleakage (p=0.413) in all experimental groups. Conclusions: The erosive challenge does not jeopardize the microhardness neither the marginal microleakage of deciduous teeth restored with etch-and-rinse and self-etching adhesives, containing or not fluoride

Effect of erosive challenges on deciduous teeth undergoing restorative procedures with different adhesive protocols - an in vitro study

<div><p>ABSTRACT Objective: To evaluate the effect of erosive challenges on the tooth- restoration interface of deciduous teeth treated with different adhesive protocols. Material and Methods: Deciduous molars were cut mesiodistally, then embedded, abraded and polished (n=80). Samples were randomly divided according to the adhesive system used into: G1 (Adper Single Bond2®, etch-and-rinse), G2 (Universal Single Bond®, self-etching), G3 (OptibondFL®, etch-and-rinse with Fluoride) and G4 (BondForce®, self-etching with Fluoride). After standardized cavity preparation (2 mm diameter x 2 mm depth), adhesive systems were applied and samples were restored (composite resin Z350®). Half of the samples were exposed to erosive/abrasive cycles (n = 10, each adhesive group), and the other half (control group; n = 10) remained immersed in artificial saliva. For microleakage analysis, samples were submersed in methylene blue and analyzed at 40x magnifications. Cross-sectional microhardness (CSMH) was carried out (50 g/5 s) at 25 μm, 50 μm, and 100 μm from the eroded surface and at 25 μm, 75 μm, and 125 μm from the enamel bond interface. Results: Regarding microleakage, 7.5% of the samples showed no dye infiltration, 30% showed dye infiltration only at the enamel interface, and 62.5% showed dye infiltration through the dentin-enamel junction, with no difference between groups (p≥0.05). No significant difference was observed in CSMH at different depths (two-way ANOVA, p≥0.05). Conclusions: We did not observe significant changes in microleakage or CSMH after erosive/abrasive challenges in deciduous teeth treated with different adhesive protocols (etch-and-rinse and self-etching adhesives, with and without fluoride).</p></div