“Comparative evaluation of shear bond strength and surface topographical changes seen on enamel using gingivally offset premolar bracket and conventional orthodontic bracket –scanning electron microscopy (sem) study

Aim: This study is done to evaluate the shear bond strength of gingivally offset premolar brackets with conventional brackets and to compare the enamel surface topographical changes (using scanning electron microscope) after debonding the brackets using EDI index. Materials and methods: The study included 30 mandibular premolars divided randomly into two groups. These teeth mounted on acrylic blocks were bonded with conventional standard brackets and gingivally offset brackets which represents GROUP I and GROUP II. Results and discussion: Mean shear bond strength of conventional premolar bracket is 13.2 MPa and that of gingivally offset premolar bracket is 15.7 MPa with a standard deviation of 1.39 and 2.16 respectively. The EDI scores are higher with gingivally offset premolar brackets. Conclusions: Gingivally offset premolar brackets have superior shear bond strength and causes greater enamel damage than conventional bracket.