Abstract
Objective: The objective of this study was to evaluate the effect of sodium ascorbate on resin composite bond strength. Methods: Forty human premolars were used, which were divided into 4 groups: C – (control) unbleached teeth submitted to a restorative procedure; S – teeth bleached with 35% hydrogen peroxide and stored in artificial saliva for 48 hours; AS – teeth bleached with 35% hydrogen peroxide and irrigated with a 10% sodium ascorbate solution for 10 minutes; AG – teeth bleached with 35% hydrogen peroxide and immersed in 10% sodium ascorbate for 3 hours. After restoration, the samples were section and microtensile bond strength tests were performed in a universal test machine (Emic) at a speed of 1mm/min. The data were evaluated and submitted to the ANOVA and Tukey statistical tests (5% significance level). Results: Group C presented the highest bond strength value, differing statistically from Groups S and AG, however, without statistical difference in comparison with Group AS. Conclusion: Keeping teeth that have been bleached with 35% hydrogen peroxide in saliva for 48 hours is insufficient to recover bond strength. However, the use of 10% sodium ascorbate for 10 minutes may promote adequate bond strength, allowing immediate restoration of the teeth.
Highlights
As the contemporary pattern of beauty, widely disseminated by the media, extols the attractiveness of “white teeth”, dental bleaching has become a routine treatment in dental offices, as is the case with several other esthetic procedures
The reduction in bond strength has been attributed to the presence of residual oxygen within the tooth structure [5,7] preventing polymerization of the adhesive monomers, alteration in mineral and protein content [8,9] and the capacity of the bleaching agent to influence the formation of resin tags, structures responsible for micromechanical bond of resin composites to tooth structure
The data obtained in the microtensile bond strength test were analyzed (Table 1), and the mean and standard deviation were calculated for each group (Table 2)
Summary
As the contemporary pattern of beauty, widely disseminated by the media, extols the attractiveness of “white teeth”, dental bleaching has become a routine treatment in dental offices, as is the case with several other esthetic procedures. In spite of its advantages, bleaching continues to promote several adverse effects, such as: Cytotoxic effects on pulp tissue cells [1], increase in intra-pulp temperature [2] dentin sensitivity, release of oxygen during the first 24 hours [3], reduction in microhardness [4], reduction in shear strength [5], greater microleakage in resin composite restorations [3], and lower resin composite bond strength to the tooth structure [3,6]. When the bond technique is performed immediately after conclusion of the dental bleaching session, the absence of tags or formation of shorter tags has been observed [10,11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
