Human Biology Comparison of Shear Bond Strength and Surface Structure Between Acid Etching and Air-Abrasion Techniques

Aim: To compare shear bond strength and surface structure between acid etching and air-abrasion techniques Materials and Methods: Sixty three extracted human premolar teeth were taken, divided into three groups and mounted with color codings. Group l was acid etched with 37 % phosphoric acid. Group ll and lll –air abrasion was done with 50µ & 90µ Al2O3 particles respectively. After enamel preparation, from each group one tooth was selected for surface roughness study by scanning electron microscope (SEM). The other sixty teeth were selected to evaluate shear bond strength by Instron universal testing machine. Results: Group I showed significantly higher shear bond strength (10.1 ± 3.6 Mpa) than Group II and Group III. In SEM study Group l etching pattern showed peripheral dissolution of the prisms. The enamel removal of Group ll was more regular, uniform and less as compared to Group lll. Adhesive remnant index showed that no adhesive material was left on the tooth surface of Group ll & lll as compared to Group l after debonding. Conclusion: From the present study it was concluded that air abrasion can be used as an adjunct to acid etching but by itself it is not a potent enamel preparation agent