Influence of antioxidants on bond strength of bleached dental substrates

The search for esthetic has led many patients to the dental office, becoming the whitening of vital teeth a noninvasive alternative when compared to microabrasion, veneers and crowns, besides providing high success rate for the treatment of discolored teeth. However, there is a necessity to wait for 14-21 days to carry out new restorations after bleaching, since the oxidizing effect on dental tissues can cause structural changes in the enamel and reduction of bond strength. This time interval often does not match the expectations of patients, causing dissatisfaction. In view of this, studies have been conducted in order to minimize or even cancel the adverse effect of residual oxygen, enabling the post-bleaching performance of adhesive restorations safely and effectively, reducing the waiting time. One of the alternatives has been the use of antioxidant agents. Thus, this study aimed to review the literature in relation to the antioxidant agents used as well as their effectiveness in bond strength of restorative dental materials to the bleached substrates. This review was performed by searching for scientific articles in databases such as Scielo, PubMed / Medline and Cochrane Library, without limitation of date. It was included in the study, researches involving the themes "Tooth whitening", "Bleaching agents", "Enamel", "Dentin", "Antioxidants" and "Tensile Strength", searching to analyze its clinical and scientific relevance. The assessments that did not fit the main subject and adjacent items evaluated were excluded from the review. It can be concluded that the use of antioxidant compounds, such as 10% sodium ascorbate (gel and solution), proanthocyanidins, catalase, 10% green tea and alpha-tocopherol, have shown effectiveness in reversion of the bond strength values to bleached enamel when applied for 10 minutes (ascorbate solution and proanthocyanidins), 20 minutes (catalase), 60 minutes (green tea, gel ascorbate and alpha-tocopherol), after bleaching.