A Comparative Study of Shear Debonding Strengh Between New Brackets, Air-Abrasion and Recycled Brackets: An <i>In Vitro</i> Analysis

Abstract

The aim of this study was to compare the shear bonding strength between new brackets, recycled brackets by the Ortho-Cycle Co. and sandblasted brackets along with a sterilization process after being debonded. Thus, 60 human bicuspids extracted for orthodontics purposes were divided into 3 groups to bond the brackets. Group 1: new brackets. Group 2: these brackets were removed from Group 1, they were sandblasted and placed in the ultrasound and sterilized. Group 3: these brackets were recycled by the Ortho-Cycle Co. The brackets were debonded using the Instron Universal Test machine and the results were recorded. Then the brackets were inspected using an optical microscope and a scanning electron microscope to perform the Adhesive Remnant Index. The group of recycled brackets had the highest mean value of 7.55 MPa, then, the new brackets group with a mean value of 7.24 MPa. And finally the minor value was for the sandblasted brackets with a mean value of 6.43 MPa. The results of this study shows that the three groups of brackets studied had not statistical significant differences in their mean values in their resistance to debonding and that the three groups of brackets fulfill the requirements to be bonded to the teeth.