What to do after bracket debonding? Laboratory study

Ariane Fernanda Carvalho, Mauro Carlos Agner Busato, Francielle Carneiro Hirata, Giovani Ceron Hartmann, Priscilla Do Monte Ribeiro Busato.

Objective: To compare in vitro the shear bond strength of metallic brackets and adhesive remnant index after rebonding with the use of new brackets or two new recycling methods. Methods: Orthodontic brackets were bonded to the buccal surface of 45 bovine teeth, which were sheared in a universal EMIC test machine. Next, three groups were created: Group 1- new brackets; Group 2- brackets recycled with multilaminated drill; Group 3 - brackets recycled with aluminum oxide. Shear and adhesive strength values were obtained again. Each enamel surface was classified according to the Adhesive Remnant Index (ARI) scores. Intra- group and intergroups comparisons were per- formed, with statistical tests specific for each variable. Results: Analyzing the bond strength, it was verified that there was a statistically significant difference between the groups. The results of ARI in the different groups showed statistical difference (p < 0.05). The groups with reconditioned brackets presented a pattern of failures with predominance of scores 2 and 3. The intragroup comparison of bond strength showed a trend of increase in resistance in the new bracket bonding group, whereas in the reconditioning groups there was a maintenance of bond strength. Conclusion: There was a trend towards increased strength in group 1. Bond strength of new and reconditioned brackets with aluminum oxide blasting was better than drill reconditioning. The ARI results showed that there was a difference between groups, with a greater amount of adhesive remnants when there was recycling.

Keywords: Shear strength. Braces. Orthodontics.

How to cite: Carvalho AF, Busato MCA, Hirata FC, Hartmann GC, Busato PMR. O braquete descolou: o que fazer? Estudo laboratorial. Rev Clín Ortod Dental Press. 2019 Out-Nov;18(5):100-9.

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