Comparison of Shear Bond Strength of Composite Resin-Dentin after Different Rinsing Times of Dentin Cut with a Suggested Surfactant as a Coolant

Suitable preparation of dentin and removal or modification of smear layer is effective on high bond strength. The aim of this study was to determine the best shear bond strength of composite resin-dentin after different rinsing times of dentin cut with a suggested surfactant as a coolant. In this in vitro experimental study, 96 premolar teeth were randomly divided into 8 groups. In groups 1 and 2, water coolant was used and Excite® and Adhese® bondings were used respectively. In the other groups a suggested surfactant as a coolant was used. In groups 3, 4 and 5, after 5, 10 and 15 seconds rinsing with water, Excite® bonding was used without etching. In groups 6, 7 and 8, after 5, 10 and 15 seconds rinsing with water, Adhese® bonding was used according to manufacturer’s instructions. Composite cylinders were made and after thermocycling, shear bond strength was tested. Data were analyzed using ANOVA and Duncan. Mean bond strength of all groups were significantly different (P=0.001) and were higher in groups 1, 3 and 4. The difference between bond strength of group 1 (8.37MPa) and group 2 (4.71) was significant (P=0.019). t-test showed no significant difference in shear bond strength between group 1 (8.37MPa) and group 2 (8.18MPa, P=0.904). The type of adhesive is effective on shear bond strength. Use of surfactant as a coolant followed by dentine rinsing with water spray for 5 seconds, leads to bond strength similar to conventional method with excite bonding while extending rinsing time, results in decreased bond strength.