Self-Adjusting File Cleaning-Shaping-Irrigation System Optimizes the Filling of Oval-shaped Canals with Thermoplasticized Gutta-percha

IntroductionThis study aimed to compare the filling ability of carrier-based thermoplasticized gutta-percha in flat-oval canals prepared using either rotary ProTaper files (Dentsply Maillefer, Ballaigues, Switzerland) or the Self-Adjusting File system (SAF) (ReDent-Nova, Ra'anana, Israel).MethodsThirteen pairs of mandibular incisors were selected from a random collection. The teeth in each pair had single root canals with a flat-oval cross-section and similar sizes and dimensions. Teeth from each pair were randomly assigned to 1 of 2 experimental groups. One group was instrumented using the ProTaper NiTi system, whereas the SAF system was used in the other. Root filling was performed with Thermafil obturators (Dentsply Tulsa Dental Products, Tulsa, OK), and teeth were sectioned at 6, 5, 4, and 3 mm from the apex; the cut surface was subjected to morphometric measurement to establish the percent gutta-percha–filled area (PGFA) for each section. The Wilcoxon matched-pairs signed rank test was used to assess the effect of the 2 preparation methods on the PGFA.ResultsThe median PGFA in the ProTaper group was 77.5%, whereas the median PGFA was 90.5% in the SAF group (P < .05). In the SAF-instrumented group, 17.8% of the specimens had a PGFA ≥95% compared with only 5.8% of the ProTaper-instrumented specimens (P < .05).ConclusionsInstrumentation of the flat-oval canals with the SAF system led to a significantly higher PGFA compared with ProTaper instrumentation with syringe and needle irrigation.