Evaluation of effect of three different dental unit waterline antimicrobials on the shear bond strength to dentin – An ex vivo study

BACKGROUND: In restorative treatment dental unit water is used while irrigating the cavity and also in the use of composite restorations to flush away the etchant to place bonding agent. These antimicrobials may influence the bond strength of the dentine bonding agent to the dentine. AIM AND OBJECTIVE: To evaluate the effect of three different dental units waterline antimicrobials on the shear bond strength of dentin. MATERIALS AND METHODS: Sixty freshly extracted human teeth were taken and the occlusal surfaces were sectioned to obtain a flat dentin surface. Then the teeth were randomized into 4 groups depending on the antimicrobial used: Group 1(Distilled water), Group 2 (Alpron), Group 3 (CitriSil), and Group 4 (Chlorhexidine). The dentine surface was prepared for bonding and composite resin was placed in two increments of 2 mm each. The specimens were stored in distilled water, thermo cycled after 7 days shear test was performed by using the universal testing machine. RESULT: No significant difference between Group 1 and Group 2 with regard to shear bond strength. There was a significant difference in the SBS of Group 1 and Group 3 and Group 4. The SBS of group 2 was higher than Group 3 and Group 4 and the difference was statistically significant. CONCLUSION: Citrisil and Chlorhexidine groups showed affected bond strength whereas Alpron did not vary with bond strength.