In vitro and in vivo comparison of the indirect bonding resins

The aim of this study is to evaluate the shear bond strengths of the chemically-cured and light-cured indirect bonding resins by in vitro and in vivo. For the in vitro study, 75 extracted premolars were divided into three groups. First group was the control group of the study and these were bonded with direct bonding with the light-cured resin (Transbond XT, 3M, Unitek). In the indirect group II and group III, teeth were fixed to the typodonts to imitate indirect bonding, the brackets bonded to the study models with light-cured resin (Transbond XT, 3M, Unitek). In indirect group II, clinical rezin was chemically-cured resin (Transbond IDB, 3M, Unitek) resin and in indirect group III, the clinical resin was light-cured flowable resin (Transbond Supreme LV, 3M, Unitek). The shear bond strenghts and the ARI scores were evaluated; the comparisons between the groups were made. For the in vivo study, twenty patients were bonded with a split-mouth approach: Left half of the upper arch and right half of the lower arch were bonded with chemically-cure resin (Transbond IDB, 3M, Unitek) and right half of the upper arch and left half of the lower arch were bonded with light-cured flowable resin (Transbond Supreme LV, 3M, Unitek). The laboratory resin was light-cured resin (Transbond XT 3M, Unitek) for all of the patients. These quadrants were rotated clockwise with each patient for the randomization. The number and the date of the bracket failure recorded for twelve months. The data obtained from the study were evaluated statistically by analysis of variance, Tukey tests and Weibull Survival analysis. Mean SBS values (MPa) were 17.6± 6.6, 13.1±4.7 and 15.1±5.9 for the control direct group I and for the indirect groups II and III, respectively. There were no significant difference between indirect group III and direct group (P>0,05); whereas there were significant difference between indirect group II and direct group (P=0.019, P<0.05). In vivo evaluation, no statistically significant differences were found in total bond failure rate between the groups (P>0,05). Conclusion: Chemically-cured indirect bonding resin (Transbond IDB, 3M, Unitek) and light-cured flowable resin (Transbond Supreme LV, 3M, Unitek) have sufficient bond strengths in vitro and adequate clinical performance in vivo.