Influence of chlorhexidine digluconate on bond strength durability of a self-etching adhesive system

ABSTRACT

Introduction and objective: The aim of this study was to evaluate in vitro the effect of 2% chlorhexidine on bond strength durability of a self-etching adhesive system (ClearFill SE Bond). Material and methods: Forty bovine incisors' crowns had their labial surfaces abraded to dentin exposure, in order that the standard adhesion area reached 4 mm in diameter. Subsequently, they were divided into four groups, according to the treatments performed on the surfaces and storage time G1 - adhesive system without chlorhexidine for 24 hours (control group); G2 - adhesive system without chlorhexidine for 6 months (control group); G3 - adhesive system with chlorhexidine for 24 hours (experimental group); G4 - adhesive system with chlorhexidine for 6 months (experimental group). After dentin surface treatments, cylinders of composite resin (Z350) were constructed. Then, the specimens were stored in distilled water according to each group design and storage time. Following, the four groups were subjected to shear bond strength test, at a crosshead speed of 0.5 mm / min. The obtained values were subjected to statistical analysis. Results: The results indicated a significant decrease of bond strength in the group treated with chlorhexidine followed by 24-hour storage when compared to control group. However, there was no significant difference in 6-month storage between the experimental and control groups (p>0.05). Conclusion: The application of 2% chlorhexidine was deleterious for bond strength after 24-hour storage.