[Show abstract][Hide abstract] ABSTRACT: ABSTRACT
Objective: The purpose of this investigation was to compare the shear bond strength of four different esthetic brackets in combination with a commonly used bonding system as well as to assess bracket failure with vertical forces.
Methods: Four of the most common ceramic brackets were used in this study: Clarity by 3M/Unitek, Ice by Ormco, InVu by TP Orthodontics, and Radiance by American. Each company provided 70 upper right incisor brackets and they were tested with the same light-cured bonding system (Transbond XT). Bonding procedures were performed on four equal groups of 70 bovine teeth. Shear bond strength tests were performed on an Instron machine at 5 minutes and at 24 hours after the teeth were bonded. Data were analyzed by two-way analysis of variance (StatView) at the 0.05 level of significance. Means were compared using Fisher's PLSD intervals.
Results: There were no bracket failures or enamel damage evident upon debonding the four groups of ceramic brackets. Five minutes after bonding, Ice and InVu showed significantly higher bond strength than Radiance and Clarity, p< 0.01, while bond strength for Radiance was significantly lower than for all other brackets 24 hours after bonding.
Conclusions: Bond strengths were different among the different brackets and at different time intervals; and bond strengths for all brackets were significantly higher 24 hours after bonding than at 5 minutes.
Esthetic brackets, ceramics, bovine teeth
Materials sources: 3M Unitek, Ormco, TP Orthodontics and American Orthodontics