Comparison of shear bond strength of different bonding materials bonded with primer and without primer - An in vivo study

Objective: To evaluate intra group and intergroup comparison between three different adhesives with and without primer. Materials and Methods: A total of 120 first premolars were selected randomly for in vivo study and are divided into six groupsGroup 1-(Transbond XT with Primer), Group 2 (Transbond XT without Primer), Group 3 (Orthofix with Primer), Group 4 (Orthofix without Primer), Group 5 (Flowable Composite with Primer), Group 6 (Flowable Composite without Primer). Metal brackets were bonded on teeth by using three different adhesives :Transbond XT, Orthofix and Flowable composite with and without primer. shear bond strength was assessed by modified testing machine with adhesive remnant index(ARI) score for different adhesives Results: Statistical analysis showed The mean shear bond strength of Transbond XT was maximum (9.773.09MPa) followed by that of Orthofix (8.752.04MPa) and minimum of Flowable composite (7.821.71MPa)and ARI suggested that the fracture occurred between composite and bracket interface. Conclusion: Transbond XT has the highest shear bond strength while the flowable composite has the least strength but it is more than the optimal strength required hence can be used in bonding. Orthofix showed shear bond strength equivalent to Transbond XT when used without primer. Keywords: Shear bond strength, Adhesive remnant index, Orthodontic adhesives.