Comparison of the Effects of Laser Irradiation and Conventional Acid Etching on the Surface Characteristics and Bond Strength of Bonded Molar Tubes—an In Vitro Study

Abstract

Introduction: The aim of study is to determine if laser irradiated enamel may be a viable alternative to acid etching for orthodontic bonding of molar tubes. Method: Sixty extracted permanent molars were divided into 3 groups of 20 each. Group I was irradiated with Er:YAG laser for 15 s, group II with Er;Cr:YSGG laser for 15 s, and group III was etched with 37% phosphoric acid. Ten samples from each group were observed under scanning electron microscope and later all 60 samples were bonded with molar tubes. Molar tubes were debonded and shear bond strength was recorded. Adhesive remnant index was measured under electron microscope (2000×). Results: Shear bond strength with Er:YAG laser etching was significantly higher than with acid etching and Er;Cr:YSGG laser etching. Er:YAG laser etching, and Er;Cr:YSGG laser etching showed Type III etching pattern with microcracks while acid etching showed Type I etching pattern. Adhesive remnant index was significantly higher for Er:YAG laser etching as compared to conventional acid etching. Conclusion: Er:YAG and Er;Cr:YSGG laser etching is a viable alternative to acid etching for bonding of bondable molar tubes.