IN-VITRO PEEL SHEAR BOND STRENGTH EVALUATION OF ORTHODONTIC BRACKET BASE DESIGN/

Objectives: The adhesive capacity of 17 different bracket types was ev aluated in an in vitro peel/shear test. Methods: Silane-treated metal bars were used as substrates with all bonding being performed using th e orthodontic adhesive Concise. The effect of aluminium oxide air abra sion on the bonding performance of recycled metal bracket bases was ev aluated. Morphological examination of the bracket bases was carried ou t under scanning electron microscopy. Statistics analysis included one -way ANOVA with Tukey's Studentized Range Test, two-way ANOVA and Weib ull analysis. Results: Mean peel/shear bond strength values range from 13.9 MPa for Allure Accu Arch, a ceramic bracket type, to 1.6 MPa for the plastic bracket CeramaFlex Advant Edge. Allure Accu Arch performe d the best of all the ceramic brackets. However, bracket wing fracture was observed. The metal brackets Mini masters and Omni Arch showed no significant difference in bond strength compared with the ceramic bra cket Allure Accu Arch (P<0.01). Conclusion: The type of the bracket ba se determines its adhesive capacity. Sandblasting the base of recycled metal brackets had no uniform effect. (C) 1997 Elsevier Science Ltd.