The effect of prior sandblasting of the wire on the shear bond strength of two different types of lingual retainers.

PURPOSE: The aim of this study was to evaluate the effect of total surface sandblasting on the shear bond strength of two different retainer wires. The null hypothesis was that there is no difference in the bond strength of the two types of lingual retainer wires when they are sandblasted. MATERIALS AND METHODS: One hundred and sixty human premolar teeth were equally divided into four groups (n=40). A pair of teeth was embedded in self-curing acrylic resin and polished. Retainer wires were applied on the etched and rinsed surfaces of the teeth. Four retainers were used: group 1: braided retainer (0.010x0.028'', Ortho Technology); group 2: sandblasted braided retainer (0.010x0.028'', Ortho Technology); group 3: coaxial retainer (0.0215'' Coaxial, 3M) and group 4: sandblasted coaxial retainer (0.0215'' Coaxial, 3M). The specimens were tested using a universal test machine in shear mode with a crosshead speed of one mm/min. RESULTS: One-way analysis of variance (Anova) was used to determine the significant differences among the groups. There was no significant difference (P=0.117) among the groups according to this test. CONCLUSIONS: The null hypothesis was accepted. There was no statistically significant difference among the shear bond strength values of the four groups.