Evaluating the shear bond strength of rebonded ceramic brackets after using three different techniques for adhesive removal: an in-vitro study

Abstract

Objective: The main purpose of the study was to compare the shear bond strength of the rebonded ceramic bracket after using different techniques for removal of the adhesive from the debonded brackets base to find the most favorable method for recycling ceramic brackets. The Research Question of the study was that In recycling of ceramic brackets, would removal of the adhesive from the debonded brackets base using Er,Cr:YSGG laser versus using carbide bur and sandblasting, enhance the shear bond strength of the rebonded ceramic bracket? Materials and Methods: Sixty premolar teeth were randomly divided into 4 equal groups (n = 15) then embedded in resin blocks with their crowns exposed. Sixty upper premolar ceramic orthodontic brackets were used in this study and were divided into 4 equal groups (n = 15) according to different adhesive resin removal protocols; Control Group (New brackets), Laser Group, Sandblast Group, and Handpiece Group. Then ceramic brackets were rebonded and the shear bond strength of the rebonded brackets was evaluated using a universal testing machine. All collected data were statistically analyzed.Results: The highest statistically significant shear bond strength mean value was revealed between control group (13.2302MPa) and handpiece (carbide bur) as it has showed the smallest mean (6.1863MPa). While there was no statistically significant difference between Control group vs Laser group and Sandblast group. Conclusion: Er,Cr:YSGG laser and Sandblasting were efficient for reconditioning of mechanically retentive ceramic brackets.