Effect of refrigerant spray on orthodontic composite resin-bracket debond strength and associated adhesive remnant index

Abstract

This study evaluated effects of refrigerant spray and crosshead speed on orthodontic composite resin shear debond strength and Adhesive Remnant Index (ARI) after bond failure. Orthodontic brackets were bonded to forty paired extracted mandibular third molars. Pairs were divided into experimental and control groups, with and without refrigerant spray prior to debond, respectively. Each group was further divided into two subgroups based on crosshead speed of 1 or 10 mm/min. Bracket shear debond strength was tested with a universal testing machine and ARI scores assessed. Results showed no statistically significant difference for shear debond strength or ARI score as a function of refrigerant spray usage. Statistically significant differences were shown for shear debond strength and ARI score as a function of crosshead speed. As crosshead speed increased, shear debond strength and ARI score both increased. These results indicate that application of refrigerant spray prior to bracket debonding is not beneficial.