The purpose of this study was to compare and evaluate the clinical bond failure rate and accuracy of bracket placement of two indirect bonding materials and transfer trays. A split mouth technique was used in this study in which twenty patients were randomly divided into four groups: Group A – Polyvinyl siloxane / Sondhi™ Rapid-Set (3M unitek), Group B - Polyvinyl siloxane / custom IQ (Reliance orthodontics), Group C - Thermal glue / Sondhi™ Rapid-Set (3M unitek) & Group D - Thermal glue / custom IQ ( Reliance orthodontics).
A total of 326 brackets were bonded and bond failure of brackets involved only first time failures during the tray removal, initial arch wire placement and thereafter three consecutive appointments (30,60 and 90 days). Accuracy of bracket placement was measured with modified digital/vernier caliper. Vertical and horizontal measurements were taken both on the models and intraorally in the patients and were evaluated for accuracy.
CONCLUSION:
The findings of the study showed Polyvinyl Siloxane / Sondhi Rapid Set had maximum bond failure rate (25.4%) when compared with other groups. The bond failure rate was higher during the transfer tray removal (7.6%) which gradually declined in consecutive appointments. Thermal glue transfer tray and Custom IQ (Reliance orthodontics) resin proved to be superior with minimum bond failure. Mandibular second premolars (22.2%) and lower incisors (17.7%) showed increased bond failure rates.
Indirect bonding was accurate in vertical dimension and fourth quadrant showed least accuracy. Thermal glue / Sondhi Rapid set (3M unitek) group was efficient in accurate transfer of the brackets.
Thermal Glue found to be an inexpensive and a better transfer tray material when compared to Polyvinyl Siloxane. Thermal Glue tray reinforced with 19 gauge wire proved to be more effective. In case of malocclusions it was recommended to section the tray to minimize bond failure.
Modified Digital vernier caliper can be a reproducible and convenient method for measuring bracket placement accuracy. These findings need to be confirmed in future studies with larger samples over a longer period of time
