Influence of proanthocyanidins combined with ethanol-wet bonding on the bonding quality of fibre posts to root dentine.

This study evaluated the influence of a bonding approach using proanthocyanidins (PAs) combined with ethanol-wet bonding (EWB) and a hydrophobic adhesive on the bonding quality of fibre posts. After endodontic treatment and post-space preparation, 72 single-rooted extracted human teeth were etched, thoroughly rinsed, and then treated using the following procedures (n = 24 teeth per group): group 1, no pretreatment; group 2, pretreatment with absolute ethanol three times, for 30 s each time; or group 3, pretreatment with absolute ethanol solution containing 5% PAs three times, for 30 s each time. Six teeth per group were dried according to a dry and a wet drying protocol and then observed using field emission-scanning electron microscopy. The remaining 18 teeth in each group were cemented with fibre posts: All-Bond 3 and Duo-Link cement were used for group 1; and hydrophobic adhesive and Duo-Link cement were used for groups 2 and 3. Push-out bond strength, failure mode, and nanoleakage were evaluated immediately and after collagenase treatment. Higher push-out bond strength and less nanoleakage were observed in the two ethanol-pretreatment groups, regardless of storage conditions. Teeth pretreated with PAs + ethanol exhibited significantly higher push-out bond strength after collagenase treatment than did teeth pretreated with ethanol alone. Within the limits of this study, the bonding approach of PAs combined with EWB and a hydrophobic adhesive synergistically improved the durability of fibre post bonds.