Comparative Evaluation of Shear Bond Strength of Three Dental Adhesives under Dry and Wet Bonding Conditions: An In Vitro Study

Background: The old concept of total-etch/dry bonding has been superseded by total-etch/wet bonding, and later on by the self-etch systems. Manufacturers have introduced single bottle systems to be used in total-etch, self-etch, or selective-etch modes under both dry and moist conditions. The aim of this study was to evaluate shear bond strengths of three different dental adhesives under dry and wet bonding conditions, using etch-and-rinse and self-etch protocols. Materials and Methods: A total of 60 extracted human mandibular molars were decoronated perpendicular to the long axis to expose flat coronal dentin surface embedded in acrylic resin. The teeth were randomly allocated into 4 experimental groups depending on bonding agent used: Group-I: AdperTM Single Bond 2 (Wet bonding); Group-II: AdperTM Easy Bond (Dry bonding); Group-III: Single Bond UniversalTM (Dry bonding); and Group-IV: Single Bond UniversalTM (wet bonding), with 15 teeth per group (n = 15). Composite cylinders of 3 mm height were built and subjected to shear bond strength testing using a Universal testing machine. Data was analyzed statistically by ANOVA followed by post-hoc Tukey test. Results: Group-I (AdperTM Single Bond 2; total-etch/wet bonding) showed the highest shear bond strength followed in order by Group-IV (Single Bond UniversalTM; total-etch/wet bonding); Group-III (Single Bond UniversalTM; self-etch/dry bonding); and Group-II (AdperTM Easy Bond; self-etch/dry bonding). Group-I (AdperTM Single Bond 2) showed statistically significant difference (P < 0.001), with higher shear bond strength than Groups II, III or IV. Conclusion: A higher shear bond strengths may be attained with AdperTM Single Bond 2 (Group-I) used under wet bonding conditions.