This study was done to compare the tensile bond strength of three different generation bonding agents to dentin using one composite resin and scanning electron microscopic study (SEM) of hybrid layer.

In this study 36 non carious human molar teeth were selected. 30 teeth were used for evaluating tensile bond strength and were divided in to three groups. Six teeth were used for hybrid layer evaluation also divided into three groups. Group 1 specimens 10 teeth were etched with 37% phosphoric acid and Scotch bond multipurpose adhesive was applied. Group 2 specimens 10 teeth were etched with 37% phosphoric acid and 3M Single bond was applied. Group 3 specimens 10 teeth were treated with Prompt-L-Pop. Composite material (3M- Hybrid-Z100) was applied incrementally and cured for 40 seconds each. Specimens were then stored in distilled water before testing. Two teeth from each group were cross-sectioned to obtain 1mm thick dentin disks for SEM evaluation. Adhesives were applied as mentioned above. Composite was applied over these discs and light cured for 40 seconds. Samples were stored in distilled water at 37°c for two weeks; these disks were fractured with chisel for cross-sectional viewing

Dentin conditioning with single bond (5th Generation) revealed better bond strengths as compared to scotch bond multipurpose (4th generation) and Prompt-L-Pop (6th generation). SEM evaluation of hybrid layer reveals that Single bond has shown a thicker hybrid layer comparing to other adhesives.