Methods: Sixty extracted maxillary premolars were divided into 2 groups (n=30), such as T group (Transbond XT, Scotchbond-3M ESPE) and F group (Fuji Ortho LC, GC Corporation). Debonding was performed after 24 hours of bonding. After each debonding, 10 teeth of each group were examined for the enamel morphology by the SEM at the magnification of 700x. The other teeth were applied the twice (n=10) and three times (n=10) of debonding procedures.
Results: In T group, the prismatic and peripheral prismatic enamel were damaged after the first debonding. Moreover, some remnant adhesives left in the enamel prism were observed after the second debonding sequence. The surface roughness of T group was apparently diminished with the repeated bonding. In F group, the enamel surface was less damage compared with the T group after the first debonding.
Conclusions: In present study, F group less damage to the enamel structures compared with T group. The more times of bonding repetition intend the more damage on the enamel surface. To prevent the bond failure, we should pay attention to the adhesion method for the bondable retainer.