Comparison of Chlorhexidine Effect on Tensile Bond Strength to the Dentin of Two Step Self-etch Adhesives with and without Fluoride

Pre-treatment of the tooth surface with chlorhexidine may decrease the harmful effects of the residual bacteria in the cavity. This study determined the effects of chlorhexidine and chlorhexidine and fluoride on the microtensible bond strength of two-stage self-etch adhesives to the dentin.
Subjects and In this in vitro trial, 20 extracted human molars were cut and after dentin exposure; were assigned to 4 groups. With or without the application of chlorhexidine, self-etch adhesives of Clearfil SE Bond and Clearfil Liner Bond F were applied to the dentin surface and the teeth were restored with composite. The teeth were stored at 37 °C and 100% moisture for 1 week and received 5000 thermal cycles. Sections with the dimensions of 1×1×10 mm were obtained from teeth. The sections glued to the jig of the microtensile testing machine and their microtensile bond strengths were recorded.
No significant differences were found in terms of microtensile bond strengths with and without the application of chlorhexidine for the Clearfil SE Bond (17.88±5.73 vs. 20.53±4.22 MPa) and Clearfil Liner Bond F adhesives (32.09±9.48 vs. 32.03±6.93 MPa). The analysis of variance and Tukey test was used to analyze relationships among variables.
Due to the antimicrobial properties of chlorhexidine and insignificant effects of its application on the microtensile bond strength; it was recommended to be used with the two-step self-etch adhesives in clinical conditions.