Chx stabilizes the resin/demineralized dentin interface

The aim of this study was to evaluate the effect of 2% chlorhexidine diglueonate (CHX) on microtensile bond strength (μTBS) between an adhesive system and under 3 dentin conditions. For that, this study evaluated the adhesive interface at initial, after 6 months and 1 year of storage. Forty-eight human third molars were prepared and randomly divided into 3 groups, according to dentin substrates: Sound dentin (Sd), caries-infected dentin (Ci) and caries-affected dentin (Ca). The groups were subdivided into two according to the dentin pre-treatment: Application of 2% CHX or without pre-treatment (control). The dentin surfaces were etched with 35% phosphoric acid gel and bonded with Adper Single Bond 2 (3M ESPE) adhesive system according to manufacturer's instructions. Subsequently, the specimens were stored in deionized water at 37°C for 24h, 6 months and 1 year. Two additional teeth were used to analyze the bonding interfaces by SEM. Data was submitted to three-way ANOVA in a split plot design and Tukey's test (α = 0.05). The results showed that Ci decreased μTBS values when compared to Ca and Sd, regardless storages time or treatment. Stored samples for 6 months and 1 year decreased the pTBS for the control group, but no difference was found between storages time for the CHX group. As a conclusion, the 2% CHX application after etching showed improved dentin bond strength in the storage time, regardless of the substrates evaluated