Evaluation of the shear bond strength of different ceramic bracket base designs

The purpose of this study was to compare the Ceramaflex bracket with a traditional ceramic orthodontic bracket with regard to shear bond strength and bond failure location. Forty newly extracted human premolars were randomly divided into two groups. Twenty Ceramaflex brackets (TP Orthodontics Inc, LaPorte, Ind) and 20 Transcend 6000 brackets (Unitek Corp, Monrovia, Calif) were bonded to the teeth using the same bonding system (Right On, TP Orthodontics Inc, LaPorte, Ind). A Zwick Universal Test machine (Zwick Gm bH & Co, Ulm, Germany) was used to determine the shear bond strength for each bracket. After debonding, the teeth and brackets were examined under 10x magnification. After debonding, the amount of resin material adhering to the enamel surface was assessed according to the Adhesive Remnant Index (ARI). The results of this study suggest that Ceramaflex brackets have a significantly lower bond strength than traditional ceramic brackets. On the other hand, the bond failure location of the Ceramaflex bracket was consistently more favorable, i.e., occurring at the ceramic bracket-polycarbonate base.