The Comparison of Shear Bond Strength of Orthodontic Brackets on Different Tooth Surfaces Bonded by Indirect Bonding Technique Using DT3C Device

Background and aim: This in-vitro study was conducted to evaluate and compare the shear bond strength (SBS) of brackets bonded by indirect technique in labial and lingual fixed orthodontic appliance mechanotherapy using a DT3C device.
Material and methods: The sample of 240 humans extracted premolars were randomly divided into three groups of 80 teeth each- Group-I(direct bonding of brackets on the labial surface), Group II (Indirect bonding on the labial surface), and Group III (Indirect bonding on the lingual surface) and each group were etched with 3M etchants, and for bonding, Transbond XT was used. For group I, direct bonding was done following standard protocol. For Group II, indirect bonding was done using a customized transfer tray. For Group III, indirect bonding was done using a DT3C device and a customized transfer tray to transfer brackets on to teeth surface. Instron universal testing machine moving at a speed of 0.5 mm/min was used to measure SBS for the three groups. Data obtained were subjected to statistical analysis using SPSS software (Windows version 17.0) statistical analysis.
Results: Highest shear bond strength was found in Group III (16.87 ±0.39 MPa), followed by Group II (14.56 ±0.48 MPa) and least for Group I (12.45±0.29 MPa). On comparison, a statistically significant difference (P<0.001) was observed in the bond strengths of all the groups evaluated.
Conclusions: Shear bond strength was highest for indirect bonding on the lingual surface, indirect bonding on the labial surface, and least for direct bonding on the labial surface.