Influence of dentin biomodification with epigallocatechin-3-gallate on the bond strength of self-etch adhesive: Twelve-month results

To evaluate the effectiveness of dentin biomodification with epigallocatechin-3-gallate (EGCG) on the resin-dentin bonds over time. Twenty seven extracted human third molars were prepared to expose a flat dentin surface and divided into 3 groups (n=9). Dentin surfaces were dried and treated with 20µL aliquots of either distilled water (control); 2% chlorhexidine digluconate solution (CHX) or 0.1% EGCG aqueous solution. Solutions were rubbed for 60s followed by bonding with Adper Easy One, and 5-mm-thick resin crown build-up. Bonded teeth were stored in distilled water for 24h and then longitudinally sectioned to obtain bonded sticks. One-third of the specimens were immediately subjected to a microtensile bond strength test in tension at 0.5 mm/min, while the remaining specimens were tested after six and twelve months of storage in distilled water at 37°C. Data were analyzed with Two-way ANOVA and Holm–Sidak method. After 24h of storage, mean bond strength values were not significantly different among all groups (p>0.05). Bond strengths of EGCG and CHX remained stable after 6 and 12 months. (p>0.05). To conclude, pretreatment with EGCG or CHX preserved the bonding of Adper Easy One to dentin after six and twelve months of storage.