Comparative Efficacy of Sequential Chelation, Continuous Chelation, and Triton® All-In-One Irrigation Protocols for Removing Accumulated Hard-Tissue Debris: A Micro-CT Study

Objectives To use micro-computed tomography (micro-CT) to evaluate residual accumulated hard-tissue debris (AHTD) and changes in root canal volume after three irrigation protocols: NaOCl followed by EDTA, Triton® All-In-One, and NaOCl combined with Dual Rinse® HEDP. Materials and Methods Thirty-six extracted single-rooted human teeth with a single canal were allocated equally to three groups (n = 12). Canals were prepared with ProTaper Ultimate to FX (35/.12) and irrigated with 5.25% NaOCl followed by 17% EDTA (group A), Triton® All-In-One (group B), or 5.25% NaOCl/HEDP® (group C). Pre- and post-treatment micro-CT scans were acquired at an isotropic resolution of 8.92 µm. AHTD was quantified as absolute volume and as a percentage of canal volume. Groups were compared using Kruskal-Wallis tests and ANCOVA. Results Median residual AHTD volumes were 0.38 mm³ in group A, 0.41 mm³ in group B, and 0.31 mm³ in group C (p = 0.370). AHTD normalized to post-treatment canal volume was 7.23%, 6.67%, and 5.00%, respectively (p = 0.559). No significant differences were found in adjusted post-treatment canal volume (p = 0.599) or in absolute or percentage changes in canal volume. Conclusions No statistically significant differences were detected among the protocols, and none completely prevented AHTD accumulation. The favorable trend observed with NaOCl/HEDP requires confirmation in larger studies. Clinical Relevance Under the conditions tested, none of the three irrigation protocols provided a statistically demonstrable advantage in reducing AHTD.