Divergent chemical and mechanical dentin responses to an all-in-one endodontic irrigant

This study evaluated chemical and mechanical changes in root dentin after exposure to Triton, a new all-in-one continuous chelation solution, compared with conventional sequential irrigation, using Raman spectroscopy and Vickers microhardness testing. Forty human canine roots were decoronated, sectioned longitudinally, and divided into four groups (n = 10): 2.5% NaOCl + 5% EDTA + 2.5% NaOCl, Triton, 2.5% NaOCl + 10% citric acid + 2.5% NaOCl, and distilled water. Microhardness and Raman spectra were measured before and after irrigation. Surface microhardness reduction (%SMHR) and absolute percentage change in the phosphate/amide III ratio were calculated. Data were analyzed using Welch's ANOVA, Games-Howell post hoc test, and paired t-tests (α = 0.05). Both outcomes showed significant intergroup differences (p < 0.001). The highest microhardness reduction was observed in the citric acid group (37.98 ± 14.29%), followed by the NaOCl-EDTA-NaOCl group (28.50 ± 11.94%), Triton group (14.99 ± 7.53%), and distilled water group (2.70 ± 0.74%). Raman analysis showed the greatest phosphate/amide III ratio change in the Triton group (54.92 ± 9.26%), followed by the citric acid group (9.59 ± 5.79%), NaOCl-EDTA-NaOCl group (5.93 ± 3.41%), and distilled water group (2.71 ± 1.81%). Triton and citric acid groups showed consistent ratio increases, indicating deproteinization, whereas the NaOCl-EDTA-NaOCl group exhibited bidirectional shifts, suggesting concurrent deproteinization and demineralization. The negligible change in the distilled water group reflected expected measurement variability. Triton caused the greatest chemical alteration but less microhardness reduction than conventional protocols, suggesting lower surface softening than conventional sequential protocols; however, because this study only evaluated surface microhardness and chemical composition, its deproteinizing effect and its actual impact on bulk mechanical properties warrant further investigation.