The Effect of Canal Preparation on Fill Length in Straight Root Canals Obturated with GuttaCore

摘要

Introduction: A common critique of using thermoplasticized carrier-based obturators is the incidence of overextension. It would be of benefit to clinicians to have a technique for canal preparation that would allow for predictable length control. This study compared straight canals instrumented to a size 40 file using a 0.04 standardized taper preparation (SIP) and a varied taper preparation (VTP) by evaluating the extension of GuttaCore (GC) obturators (Dentsply Tulsa Dental, Tulsa, OK). Methods: Eighty extracted mature human premolars with single straight canals were randomly divided into 2 experimental groups (n = 40). The STP group was instrumented to size 40/.04 'at the working length (WL). The VTP group was instrumented to size 40/.02 at the WL. Both groups were obturated with a size 40 GC obturator. Extension of the material, in relation to the WL, was evaluated and assessed Ordinally. Statistically significant differences were determined by a 2-group chisquare test with a 2-sided P value set at P = .05 and a Fisher exact test of equal proportions. Results: Significant differences in extrusion existed between the STP and VIP groups when controlling for the type of apical preparation (P = .0005). The SIP group resulted in a 47.2% incidence of overextension, whereas the VTP group resulted in 10.5% overextension of obturating material. Conclusions: The results indicate that when filling straight canals with GC obturators the canal can be instrumented using a varied tapered canal preparation with a low likelihood of overexterision.