Optimised clinical protocol for root canal obturation using single cone and hydraulic cement sealer

INTRODUCTION: This study aimed to establish an optimised clinical protocol based on matching the root canal preparation, irrigation and obturation by choosing an adequate that prepared the dentin and reduced the microbial load followed by a root canal obturation that maintained the seal. METHODS: A split tooth model was used to assess the irrigation and obturation quality. Three irrigation sequences including sodium hypochlorite, EDTA and HEDP with water used as a control. Four commercial sealers (AH Plus, BioRoot RCS, BioRoot Flow and TotalFill) were used to obturate the root canal using single cone obturation technique. The ultrastructure and chemical properties of the dentin and sealers and the dentin-sealer interface were assessed before and after obturation and contact with the irrigation sequences using scanning electron microscopy, energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. Microbiological analysis by direct contact test and minimum inhibitory concentration was undertaken with and without dentin contact. All results were analysed using a two-way ANOVA and Tukey post hoc tests (p < 0.05). RESULTS: Irrigation with HEDP resulted in less erosion of dentin and a larger mineral concentration zone at the interface of hydraulic cements with dentin. Furthermore, continuous chelation with HEDP improved the antimicrobial properties of the hydraulic cement sealers. All sealers exhibited a reduction in their antimicrobial effectiveness when in contact with irrigated dentin. CONCLUSIONS: The irrigation techniques affected the interfacial characteristics and antimicrobial properties of root canal sealers, indicating that a selection of appropriate irrigation protocols for clinical practice is required to optimize treatment outcomes.