RESUMO
OBJECTIVE: To determine the influence on shear bond strength and bond failure location of four cleaning methods for orthodontic bracket custom bases. DESIGN: In vitro laboratory study. MATERIAL AND METHODS: Eighty bovine teeth were divided at random into four groups. The bracket custom bases were cleaned with different methods: group 1 with methyl methacrylate monomer, group 2 with acetone, group 3 with 50 µm aluminium oxide particles and group 4 with detergent. The brackets were indirectly bonded onto the teeth with the Sondhi Rapid-Set self-curing adhesive. The maximum required shear bond strength to debond the brackets was recorded. The bond failure location was evaluated using the Adhesive Remnant Index (ARI). One-way analysis of variance (ANOVA) analysis (P<0·05) was used to detect significant differences in the bond strength. Kaplan-Meier survival plots and log-rank test were done to compare the survival distribution between the groups. The Kruskal-Wallis test (P<0·05) was used to evaluate the differences in the ARI scores. RESULTS: The mean bond strengths in groups 1, 2, 3 and 4 were 23·7±5·0, 25·3±5·1, 25·6±3·7 and 25·7±4·2 MPa, respectively. There were no significant statistically differences in either the bond strength or the ARI score between the groups. CONCLUSION: The four custom base-cleaning methods presented the same efficiencies on indirect bond of the brackets; thus, practitioners can choose the method that works best for them.