Effect of adjunctive application of epigallocatechin-3-gallate and ethanol–wet bonding on adhesive–dentin bonds

Abstract

ObjectivesTo determine the effect of the combined use of epigallocatechin-3-gallate (EGCG) and ethanol–wet bonding (EWB) on resin–dentin bonds. MethodsSixty molars were sectioned, polished, and randomly divided into six groups (n=10) according to the following pretreatments: group 1, water–wet bonding (WWB); group 2, WWB with 0.02% (w/v) EGCG; group 3, WWB with 0.1% EGCG; group 4, EWB; group 5, EWB with 0.02% EGCG; and group 6, EWB with 0.1% EGCG. An etch-and-rinse adhesive was then used, followed by the resin composites building. The microtensile bond strength (MTBS), failure modes and interfacial nanoleakage were separately determined after 24h water storage or 10,000 runs of thermocycling. ResultsBoth pretreatment method (P<0.05) and thermocycling (P<0.05) significantly influenced bond strength and nanoleakage. Irrespective of thermocycling, the 0.02% EGCG/ethanol (group 5) pretreated adhesive–dentin interfaces showed higher MTBS than the control group (P<0.05). Nanoleakage expression of all groups increased after thermocycling (P<0.05) except group 5. Adhesive failure was the main fracture pattern in all groups. ConclusionThis study showed that pretreatment with 0.02% EGCG/ethanol solutions can effectively improve immediate bond strength and bond stability of etch-and-rinse adhesives on dentin. Clinical significanceThe adjunctive application of EGCG and EWB provides a new strategy for dentists to obtain the desired bond effectiveness during adhesive restoration in clinical practice.