JOE august 2013 - The Incidence of Root Microcracks Caused by 3 Different Single-file Systems versus the ProTaper System

The Incidence of Root Microcracks Caused by 3 Different Single-file Systems versus the ProTaper System

Rui Liu, DDS,* Ben Xiang Hou, DDS, PhD,* Paul R. Wesselink, DDS, PhD,† Min-Kai Wu, MSD, PhD,† and Hagay Shemesh, DDS, PhD†

Abstract

Introduction: The aim of this study was to compare the incidence of root cracks observed at the apical root surface and/or in the canal wall after canal instrumenta- tion with 3 single-file systems and the ProTaper system (Dentsply Maillefer, Ballaigues, Switzerland). Methods: One hundred mandibular incisors were selected. Twenty control teeth were coronally flared with Gates-Glidden drills (Dentsply Maillefer). No further preparation was made. The other 80 teeth were mounted in resin blocks with simulated periodontal ligaments, and the apex was exposed. They were divided into 4 experimental groups (n = 20); the root canals were first coronally flared with Gates-Glidden drills and then instrumented to the full working length with the ProTaper, OneShape (Micro- Mega, Besancon, France), Reciproc (VDW, Munich, Germany), or the Self-Adjusting File (ReDent-Nova, Ra’a- nana, Israel). The apical root surface and horizontal sections 2, 4, and 6 mm from the apex were observed under a microscope. The presence of cracks was noted. The chi-square test was performed to compare the appear- ance of cracked roots between the experimental groups. Results: No cracks were found in the control teeth and teeth instrumented with the Self-Adjusting File. Cracks were found in 10 of 20 (50%), 7 of 20 (35%), and 1 of 20 (5%) teeth after canal instrumentation with the Pro- Taper, OneShape, and Reciproc files, respectively. The difference between the experimental groups was statisti- cally significant (P < .001). Conclusions: Nickel-titanium instruments may cause cracks on the apical root surface or in the canal wall; the Self-Adjusting File and Reciproc files caused less cracks than the ProTaper and OneShape files. (J Endod 2013;39:1054–1056)

Key Words

Root crack, single-file system 


download paper in pdf