Effect of Different Etching Time on Bond Strength of Composite Resin to Dentin

Aim: The aim of this study is to evaluate the bond strength of composite resin to dentin surface with various etching protocol.

Methodology: Three sample groups, each consisting of ten permanent mandibular first molar teeth were established. The buccal surfaces of the samples were grinded with the help of straight fissured diamond abrasive removing enamel layer. Samples of Group A, B and C were etched for 15, 30 and 60 seconds respectively, with 37% phosphoric acid. All the samples were washed for 1 min and then dried. Samples were bonded for 15 seconds and restored with composite resin and cured. Samples were subjected under universal testing machine for bond failure.

Results: Bond strength was found to be much higher in group B than in group C and A with a confidence of more than 98.828% (P value: 0.0675).

Conclusion: Within the limitations of this in vitro study; it can be concluded that 30 seconds of etching time gave better bond strength due to longitudinal tubules which influenced the dentin hybridization process in the sense of forming more resin tags that, in turn, contributed to bond strength.