Influence of apical diameter and instrument taper on apical debris extrusion during root canal instrumentation: An in vitro study

Abstract

Context: Apical debris extrusion can result in complications leading to unfavorable clinical outcomes. Aim: This in vitro study aimed to ascertain the influence of apical size and variation of instrument taper on the apical extrusion of debris. Setting and Design: Forty roots from sixty recently extracted human permanent mandibular molars were selected. The apical diameter was measured using an image analysis program and divided into two groups: mesial roots for narrower canals (N) (n = 20) and distal roots for wider canals (W) (n = 20). These were further subdivided based on preparation size and instrument taper as #25/0.04 and #25/0.06 for narrower and #30/0.04 and #30/0.06 for wider canals. Materials and Methods: The canals were prepared using Hero Shapers, with double distilled water as irrigant. The extruded debris was collected using the Myers and Montgomery method. Statistical Analysis Used: The mean weight of extruded debris was analyzed using the Kolmogorov-Smirnov test. The Mann-Whitney test compared the differences in the weight of debris between different tapers and different canal widths. The level of significance was set at P ≤ 0.05. Results: Narrow canals prepared using #25/0.06 showed significantly more debris extrusion when compared to #25/0.04 (P = 0.017). Wider canals, when instrumented with a #30/0.04, had more extrusion of debris than #30/0.06. However, the difference between 0.04 and 0.06 taper was not significant. Conclusion: The apical diameter and instrument taper are essential factors to be considered to minimize debris extrusion. Narrower diameter, when instrumented with greater taper, exhibited more apical debris extrusion.