Evaluation of debris and smear layer removal efficacy of different irrigating solutions using the C-RCC irrigation system: An in vitro SEM study

Background: Conventional use of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetate (EDTA) for debris and smear layer removal may weaken dentin and prolong clinical procedures, prompting a search for safer, more efficient, and multifunctional irrigants. Thus, the present study aimed to evaluate debris and smear layer removal efficacy of different irrigating solutions using C-RCC irrigator. Materials and Methods: Eighty extracted single-rooted mandibular premolars were decoronated, instrumented with ProTaper Universal files, and randomly allocated into four groups ( n = 20): Group I-NaOCl-EDTA, Group II-NaOCl-Neem extract, Group III-Superoxidised water, and Group IV-Normal saline. Irrigation was performed using C-RCC irrigator. Samples were longitudinally sectioned and examined under scanning electron microscopic at × 500 and × 1000 magnification. Hulsmann’s scoring criteria were followed, and data were analyzed with Kruskal–Wallis and post hoc Dunn tests. Results: All irrigants except saline showed varying cleaning abilities. NaOCl–EDTA (debris = 1, smear layer = 1.25) and superoxidized water (debris = 1.2, smear layer = 1.45) demonstrated similar efficacy with statistically insignificant difference, although values were slightly higher for NaOCl–EDTA and both were significantly more effective than NaOCl–neem extract and saline. Coronal thirds showed better cleanliness than the middle and apical thirds. Conclusion: NaOCl–EDTA remained the most effective regimen. However, superoxidised water showed promise as a single, efficient irrigant.