Influence of several root canal disinfection methods on pushout bond strength of self-etch post and core systems

Abstract

Aim: To determine the effect of four root canal disinfection protocols (2.5% sodium hypochlorite, 0.2% chlorhexidine gluconate, gaseous ozone and Nd : YAG laser) on the pushout bond strength of a self-etch post and core system.

Methodology: Sixty anterior single-rooted permanent human teeth were used. Root canals were instrumented with ProTaper instruments (Dentsply Maillefer; Ballaigues, Switzerland). Roots were divided into four groups (n = 15 each) according to the final disinfection protocol: sodium hypochlorite, chlorhexidine gluconate, gaseous ozone and Nd:YAG laser. Fibre-reinforced composite post preparations were created in previously filled root canals, and posts cemented according to the manufacturer's instructions. Roots were then uniformly sectioned and prepared for the pushout bond strength testing in a universal testing machine. One-way anova with post hoc Scheffe test was used for statistical analysis. SEM imaging of one sample from each group was made.

Results: The only significant difference (P = 0.004) was observed between sodium hypochlorite irrigation, which was associated with the lowest bond strength, and Nd:YAG laser irradiation, which provided the highest bond strength. There was no difference between root canal pre-treatment with sodium hypochlorite, gaseous ozone and chlorhexidine, nor between gaseous ozone, chlorhexidine and Nd : YAG laser.

Conclusion: Sodium hypochlorite irrigation was associated with the lowest bond strength values and Nd : YAG laser irradiation with the highest bond strength values for a self-etch post and core system bonded to root canal dentine.

Keywords: Nd : YAG laser; chlorhexidine; gaseous ozone; glass-fibre post; pushout bond strength; sodium hypochlorite.