Rebonding of unused brackets with different orthodontic adhesives
Dental Press Journal of Orthodontics
Objective: To compare in vitro shear bond strength (SBS) of different orthodontic adhesives in bonding and repeatedly rebonding metal brackets, and to evaluate the bond failure site with the adhesive remnant index (ARI). Methods: Specimens consisted of 90 extracted human first premolars, randomly divided into three groups (n=30). The adhesives Alpha Plast (AP), Concise™ (CO) and Transbond™ XT (TB) were used in each group. Three SBS tests were performed, i.e., one at T 0 (initial) and the other
... ial) and the other two at T 1 and T 2 (first and second rebondings, respectively), observing a 24-hour interval. The tests were performed in a Shimadzu AG-I (10kN) SBS testing machine, at a speed of 0.5 mm/min. Results : SBS data were subjected to ANOVA, Tukey's test and Bonferroni test (p<0.05). For the ARI, the Kruskal Wallis test was performed, followed by the Dunn test. The results revealed that at T 0 groups AP and CO showed SBS values that were near, but above TB values; and at T 1 and T 2 , the highest SBS values were observed for the AP group, followed by the CO and TB groups. Conclusion: Statistically significant differences were found in SBS between groups AP, CO and TB during bonding and repeated rebondings of unused metal brackets, with group AP achieving the highest SBS value. Regarding ARI, adhesive AP exhibited bond failure at the enamel-adhesive interface, with a higher enamel fracture frequency.