(PR60) Effects of Dentin Surface Cleaning on Bonding of Self-etch Adhesive to Root Canal Sealer-contaminated Dentin

Abstract:

Objectives: To compare sealer cleaning methods in the bonding of a self-etch adhesive to root canal sealer-contaminated dentin.

Methods: Forty-nine extracted molars were divided into seven groups. Dentin surfaces were exposed and covered with an epoxy resin-based sealer (AH-Plus) or zinc oxide eugenol-based sealer (ZOE). Three cleaning methods were examined: dry cotton pellet, 70% ethanol-saturated pellet or a surfactant-based cleaner (Katana Cleaner, Kuraray Noritake; KC). Normal dentin was the control. The dentin was subsequently bonded with a two-step self-etching adhesive and restored with composite. Microtensile bond strength (MTBS) testing was performed. Teeth from each group were used for scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The pulpal floor of the teeth was covered with sealer and cleaned. The percentage of zinc or zirconium on the dentin was detected to indicate residual sealer.

Results: The MTBS for uncontaminated dentin control was 46.4±7.3 MPa; MTBS decreased significantly for the dry cotton group (29.6±4.2 MPa for AH-Plus, 24.7±4.7 MPa for ZOE, p< 0.05). Both ethanol and KC restored bonding performance, with no significant difference from the control. Significantly lower MTBS was observed for the ZOE/ethanol subgroup (38.9±5.1 MPa) as compared to Katana and ethanol. Cleaner surfaces and less zirconium or zinc was revealed by SEM/ESDX after cleaning with ethanol or KC, compared to dry cotton-wiped dentin.

Conclusions: Katana Cleaner decontaminated root canal sealer-smeared dentin surfaces effectively and restored the bonding performance of a self-etch adhesive to dentin.