First Experience of Rotary Nickel Titanium Root Canal Instrumentation Performed by Undergraduate Students and General Dentists

Abstract

Introduction: The purpose of the present study was to evaluate comparatively the efficiency of two rotary Nickel Titanium (NiTi) file systems in instrumentation of simulated curved canals performed by undergraduate dental students and general dentists.

Methodology: Twenty undergraduate dental students and 20 dentists participated in this study. After an introductory lecture, two simulated curved root canals in resin blocks with the same size and geometry were prepared by each participant, using the ProTaper Next or iRace file systems. The preparation time was recorded, and each participant received a questionnaire for self-assessment and evaluation of the difficulty of the systems. Blocks were collected, coded, photographed digitally, and evaluated microscopically. The status of the apical foramen of the simulated root canals was classified as intact, blocked or instrumented. The shape of root canal was evaluated further for the presence of zipping or transportation. T-test and Fisher’s exact test were used for statistical analysis of the collected data (p < 0.05).

Results: The mean time for instrumentation with the ProTaper Next system by the group of students was significantly greater than that prepared by the group of dentists. The time for instrumentation was significantly greater for the ProTaper Next system than that for the iRace system prepared by the group of students, while no significant difference was seen in the group of dentists between instrumentation with the two rotary systems. In general, no significant differences were observed between the two systems in terms of technical quality of instrumentation. In the group of students, significantly greater number of canals with blocked apical foramen were produced with ProTaper Next than the iRace system, while the number of over-instrumented canals was significantly greater with the iRace system. In the group of dentists, significantly greater number of canals with blocked apical foramen with the iRace than the ProTaper Next system was seen, while the number of over-instrumented canals was significantly greater with the ProTaper Next system.

Conclusion: No significant difference in the technical quality of simulated curved canal preparation was detected between the ProTaper Next and iRace rotary Ni-Ti files systems. Although no difference in the occurrence of procedural errors produced by the in experienced students or experienced dentists groups was noticed, the types of procedural er-rors in relation to the used rotary files system were different between the two groups of participants.