In vitro peel/shear bond strength of orthodontic adhesives

Objectives: The purpose of this study was to evaluate the in vitro peel/shear bond strength of a selection of orthodontic bracket adhesives to human premolar teeth. Methods: Twenty-two commercially available bracket adhesives were used to bond the same bracket type (Miniature Twin, 3M Unitek, Monrovia, CA, USA) on 264 intact human premolar teeth and then adhesively tested to failure. Peel/shear bond strength values were calculated in newtons and megapascals. The site of bond failure was scored according to the Adhesive Remnant Index. Statistics included one-way analysis of variance and Tukeyʹs Studentized Range test together with Weibull analysis. The latter is a survival analysis able to describe the performance of a material. Results: The mean bond strengths varied from 9.9 MPa for Concise to 4.1 MPa for Heliosit Orthodontic. The overall F-test showed a significant difference (P < 0.0001). No significant differences in bond strength were found between Concise, AccuBond, Imperva Dual, Transbond XT, Kurasper and Spectrum. Conclusion: Concise and AccuBond are among the materials of choice for bonding fixed orthodontic appliances to teeth. These materials combine high bond strength with a reliable bond that is easily and quickly debonded.