The effect of zinc oxide-eugenol temporary restorations on bond strength of a composite resin

Introduction: Effect of zinc oxide-eugenol (ZO-E) on bond strength of composite is equivocal. The aim of the present study was to determine if ZO-E affects shear bond strength. Methods: For the purposes of the study, extracted human molar teeth were ground so that composite rods could be bonded to dentine. In group 1, dentine was not exposed to ZO-E. In group 2, ZO-E was applied to dentine for 10 days prior to acid etching and bonding the composite. A universal testing machine was used to determine the composite’s shear bond strength. Data were analyzed using t-test. Results: Mean score of shear bond strengths were 137.15 (± 46.82) and 140.08 (± 40.39) N for groups 1 and 2, respectively, with no statistically significant difference. Majority of samples in Group 1 (74% vs. 65%) had “clean breaks” where the composite fractured without any dentine attached, while the rest of the samples had some dentine attached.