Comparision of the shear bond strength of orthodontic brackets to restorated teeth by methacrylate based and silorane based composite with different surface treatment

This study compared shear bond strength of metal brackets to the teeth restored with silorane and methacrylate-based composites after different surface treatments.
Subjects and After cavity preparation on the buccal surfaces of 112 acrylic central teeth and etching; the specimens were restored with Filtek Z-250 (methacylate base) or Filtek P-90 (silorane base) composites. Surface treatments were done by the diamond bur槈 etch, diamond bur槈 etch눩媝, air abrasion and air abrasion눩媝. The brackets were bonded to the teeth and after thermal cycles; shear bond strength of the brackets to composites were calculated by the universal testing machine. Data were analyzed with one-sided ANOVA and Tukey test was used for paired comparison regarding surface treatments. Non parametric Kruscal-Wallis test was used for evaluation of ARI index.
The mean shear bond strength of brackets to teeth restored with Filtek Z-250 after treatments of diamond bur槈 etch, diamond bur槈 etch눩媝, air abrasion and air abrasion눩媝 were 16.36±5.32,13.11±4.08,12.74±5.21and 13.16±3.82 MPa respectively. The values for the Filtek P-90 were 11.7±3.54, 8.2±3.25, 10.41±2.25 and 10.56±3.04 MPa. In all treatment methods, adequate bond strengths created between the brackets and composite surfaces. On the Filtek P-90, bond strength for diamond bur槈 etch was significantly more than diamond bur槈 etch눩媝 (P Bond strength of the brackets to the silorane in relation to methacrylate was lower but acceptable. For this reason and due to lower remaining adhesive after debonding; the bonding of brackets to the teeth restored with silorane was acceptable in all methods.