Abstract
Purpose To evaluate the effect of different chlorhexidine concentrations on bond strength of resin composite to normal and canes-affected dentin using a self-etch primer adhesive Methods Thirty canons human molars were ground to expose flat dentin surfaces containing canes-affected surrounded by normal dentin The teeth were divided into three groups One group received no chlorhexidine pretreatment (control) The second and third groups received 2% or 5% chlorhexidine pretreatments, respectively before applying the self-etch primer adhesive (Clearfil SE Bond) Resin composite was applied to caries-affected dentin and to normal dentin on the same tooth with the aid of polyethylene tubes (0 9 mm diameter and 0 7 mm height) For micro-shear bond strength testing, each tooth was secured in a specially designed attachment jig to hold the specimens to the universal testing machine Load was applied by the testing machine through a wire loop adjusted to the bonded interface at a crosshead speed of 0 5 mm/minute Micro-shear bond strength was calculated and mode of failure was examined with a x40 stereomicroscope Results Statistical analysis revealed insignificant differences between control, 2% and 5% chlorhexidine pretreatment for normal as well as for canes-affected dentin groups Also, there were insignificant differences in bond strength values between normal and canes-affected dentin for each treatment modality Adhesive failure was the most common mode of failure (Am J Dent 2010,23 217-222)