Purpose: To evaluate whether the application of an enamel etchant (Etch-37 BAC) and a desensitizer (PrepEze desensitizer) which contain the antibacterial agent benzalkonium chloride (BAC) affects the bond strength of the orthodontic resin Transbond XT. Materials and Methods: Eighty-five extracted premolars were used. They were divided into four groups: 1. Transbond XT, 2. Etch-37 BAC/Transbond XT, 3. PrepEze/Transbond XT, 4. Etch-37 BAC/PrepEze/Transbond XT. Shear bond strength was measured using a universal testing machine with a crosshead speed of 1 mm/min. The adhesive remnant on the tooth after debonding was quantified using image analysis equipment. Results: No significant differences were found in shear bond strength when Transbond XT was bonded with the conventional etchant or with Etch-37 BAC (p > 0.008). PrepEze decreased the shear bond strength and the amount of adhesive remnant on the tooth after debonding significantly (p < 0.008). The amount of adhesive remnant on the tooth surface diminished significantly when the enamel was etched with Etch-37 BAC (p < 0.008). Conclusions: The bond strength values obtained with the application of Etch-37 BAC are similar to those obtained with a conventional etchant. However, the application of PrepEze significantly decreased the bond strength of Transbond XT.

Keywords: antibacterial bonding systems, shear bond strength, bracket bonding