Assessment of Debris Apical Extrusion, Unprepared Surface Areas, and Dentinal Crack Formation after Root Canal Preparation Using ProTaper Next, ProTaper Ultimate, and R-Motion File Systems.

INTRODUCTION

This study evaluated and compared the amount of apically extruded debris, unprepared wall surface areas, and dentinal crack formation resulting from root canal preparation using ProTaper Next (PTN), ProTaper Ultimate (PTU), and R-Motion (RM) file systems.

METHODS

Forty-five palatal roots of maxillary first molars were shortened to a uniform length of 12 mm. The samples were divided randomly into 3 groups (n = 15/group) to be prepared using either PTN, PTU, and RM file systems. The investigator adopted modified Myers and Montgomery's approach to replicate the temperature of the human body. Debris was collected in vials and weighed before and after instrumentation with a sensitive balance. Every specimen was irrigated using distilled water during preparation, utilizing a side-vented needle. Weight before instrumentation was subtracted from weight after instrumentation to identify the weight of the collected debris. Cone-beam computed tomography (CBCT) scans were taken before and after canal preparation using a Planmeca ProMax CBCT machine. The unprepared canal surface area was calculated by superimposing preoperative and postoperative CBCT images using the Mimics Medical program. After preparation, a low-speed diamond disc horizontally sectioned the roots at 3, 6, and 9 millimeters from the apex. The specimens were examined under a digital microscope to detect crack formation. Statistical analysis was carried out using one-way (ANOVA) and Tukey (HSD) tests, with a significance level of P < .05.

RESULTS

There was no statistically significant difference in the quantity of debris extruded apically and dentinal crack numbers among the 3 shaping files (P > .05). Only the apical third of root canals prepared by PTU displayed a significantly lower unprepared surface area compared to PTN and RM.

CONCLUSIONS

Instrumentation with PTN, PTU, and RM yielded similar amounts of apically extruded debris and dentinal cracks. The PTU files demonstrated higher effectiveness in preparing the apical third by reducing the unprepared surface area in the prepared root canal.