Catechin-doped universal adhesive system: Physicochemical characterization and resin-dentin bonding stability

Abstract

Objectives

To evaluate the influence of EGCG on the physicochemical properties of a universal adhesive and the stability of the resin-dentin interfaces.

Methods

An experimental adhesive was obtained by adding 0.1 % EGCG w/w to Single Bond Universal. Adhesive specimens were assayed following ISO recommendations for flexural strength, water sorption and solubility experiments. The degree of conversion (DC) was analyzed by FTIR. Data were statistically analyzed using a T-test (p < 0.05). Subsequently, the teeth were randomly allocated to four groups (n = 9): controls (ER and SE) and experimentals (ER-EGCG and SE-EGCG), prepared to bonding and sectioned to obtain bonded sticks to test in the universal machine immediately, after 6 and 12 months. Mean μTBS values were subjected to two-way ANOVA and Student-Newman-Keuls test (p < 0.05). Dentin micropermeability and interfacial nanoleakage were assessed using a confocal-laser scanning microscope and scanning electron microscope.

Results

EGCG-dopped adhesive showed higher values of modulus of elasticity (ME) (p < 0.05) and lower values of WS (p < 0.05). After 24 h, mean bond strength values were not significantly different among all groups (p > 0.05). The SE-EGCG showed higher mean bond strength value when compared to control at 12 months of storage (p < 0.05). CLSM technique and nanoleakage expression showed better results in SE groups.

Conclusion

EGCG does not affect the physicochemical properties of SBU and presents a positive effect on bond strength when used in the SE strategy, which could improve the durability of the dentin-resin bond over time.

Clinical significance

EGCG incorporated into a universal adhesive for inhibition of hybrid layer degradation does not present a negative effect on the physicochemical properties of the adhesive system.