Effects of catalase, 2% chlorhexidine gel and 1% sodium hypochlorite on the microtensile bond strength of teeth bleached with 35% hydrogen peroxide

Resumo

Introduction and objective: Dental bleaching is an effective,
relatively simple and noninvasive technique. The aim of this study
was to evaluate the effects of catalase, 2% chlorhexidine gel, and 1%
sodium hypochlorite on the microtensile bond strength to enamel of
bovine teeth submitted to internal and external bleaching with 35%
hydrogen peroxide. Material and methods: Sixty bovine incisors
were used. They had their debris removed, washed in tap water and
stored frozen. The samples were divided into five experimental groups
according to the treatment applied after bleaching (n = 12): 1 − control/no
bleaching (C); 2 − catalase (CA); 3 − 2% chlorhexidine gel (CG); 4 − 1%
sodium hypochlorite (SH); 5 − distilled water (DW). For microtensile
test, samples were prepared into blocks of enamel/resin, which were
sectioned to obtain hourglass-like specimens. Bond strength was
calculated in MPa and data analyzed statistically by Anova (p < 0.05).
Results: Microtensile bond strength means decreased in comparison to
control group, but no statistically significant difference between groups
was found. Conclusion: The substances used after dental bleaching
did not result in statistically significant microtensile bond strength
means of the tested groups.