Bond Strength of Adhesives to Dentin Surface Treated with Chlorhexidine

The aim of this study was to evaluate the shear bond strength (SBS) of two types of adhesives (total and self-etch) to dentin surface treated with 2% of chlorhexidine (CHX) conditioner. A total of 72 freshly extracted human sound premolar teeth were selected, washed and cleaned, and then divided randomly into three main groups; each tooth cusp was cut off until the first layer of dentin under the groove between the two cusps was exposed (superficial dentin). Then, 48 teeth were randomly selected to be used in Group I (control group) and Group II (n = 24 each). The remaining 24 teeth were selected to be used in Group III which were cut off until the deep dentine between the first layer of exposed dentin and pulp horn was exposed. Then, adhesives were applied on the exposed dentin in Group I without application of CHX intermediate. In Group II, 2% CHX was applied to the superficial dentin surface for 1 min and washed away before application of adhesives. In Group III, 2% CHX was applied to deep dentin surface for 1 min and washed away before applying adhesives. Instron machine was used to assess the SBS. Data were analyzed using one-way ANOVA and Tukey's post-hoc test. The control group showed the higher mean SBS than the two groups as well as, bonding to superficial dentin in Group I and Group II showed higher mean bond strength when compared with deep dentin in both self-etch and total-etch groups. In general, self-etch showed higher bond strength than total etched adhesives. Bond strength of adhesives without using CHX was the highest compared with using CHX as dentine surface conditioner. However, self-etch was stronger than total etch, and also adhesives were weakest in deep than superficial dentin.