Effect of 10% sodium bicarbonate on bond strength of enamel and dentin after bleaching with 38% hydrogen peroxide

Abstract

IntroductionBy-products of hydrogen peroxide degradation released during dental bleaching influence the polymerization of adhesive systems and composite resins, causing a reduction in shear bond strength to the tooth.Objectivethe aim of this article was to evaluate the effect of 10% sodium bicarbonate (SB), applied for different lengths of time, on the shear bond strength to enamel and dentin after bleaching.Material and methodEnamel and dentin blocks were divided into groups (n=10): (1) control: no bleaching; (2) immediate: bleaching immediately followed by restoration; (3) 14-day: bleaching, restoration 14 days later; (4) SB for 10 minutes: bleaching, SB gel for 10 minutes, immediately followed by restoration; (5) SB for 20 minutes: bleaching, SB gel for 20 minutes, immediately followed by restoration. A 38% hydrogen peroxide gel (Opalescence Boost/Ultradent) was used. After application of the adhesive system, composite resin cylinders were mounted on the surface of the substrates in order to test shear bond strength. Result: ANOVA and Tukey tests showed significantly higher mean enamel bond strength values for the 14-day follow-up group and without significant differences for control group. Mean bond strength values obtained for the other groups were intermediate. When testing dentin, the Tukey test revealed a significantly higher mean bond strength value for the 14-day follow-up group when compared with application of SB for 20 minutes.ConclusionSB gel applied was unable to reverse the low bond strength to enamel and dentin after bleaching treatment.

Bonding strength of ceramic laminates to dental enamel after bleaching treatment

“…Failure mode analysis demonstrated most adhesive type failures. This corroborates the findings of Darzé et al (2015), who also observed a predominance of adhesive failures in their studies, when using hydrogen peroxide.…”