Sealing Properties of Different Obturation Systems Applied over Apically Fractured Rotary Nickel–Titanium Files

Abstract This study investigated the sealing properties of cold laterally compacted gutta percha and Thermafil applied over different apically fractured rotary nickel-titanium files. Extracted human premolars were prepared by using ProTaper (Dentsply-Maillefer, Ballaigues, Switzerland) or ProFile (Dentsply-Maillefer) systems ( n = 40 for each), after which half of the specimens in each subgroup were subjected to instrument separation at the apical level. For each rotary system, roots with and without apically separated instruments ( n = 10 for each) were filled with the two obturation systems and the levels of fluid conductance were recorded. In the absence of instrument separation, the leakage of Thermafil (Dentsply Maillefer) was significantly less than that achieved with cold lateral compaction (p 0.05). These results reveal the variability of leakage associated with apically fractured ProFile and ProTaper files and different obturation methods used.