Comparative evaluation of sealing properties of different obturation systems placed over apically fractured rotary NiTi files

AIM: To evaluate sealing properties of different obturation systems placed over apically fractured rotary NiTi files. MATERIALS AND METHODS: Forty freshly extracted human mandibular premolars were prepared by using Protaper (Dentsply-Maillefer, Ballaigues, Switzerland) or the RaCe (FKG Dentaire, La Chaux-de-Fonds, Switzerland) systems (n=20 for each), after which half of the specimens were subjected to instrument separation at the apical level. Roots with and without apically separated instruments (n=5) were filled with the two obturation systems i.e. Thermafil and lateral compaction technique. The modified glucose penetration setup was used to assess the microleakage. The leakage data was statistically analyzed. RESULTS: The amount of leakage was significantly lower in specimens containing fractured instruments, regardless of the obturation method used. Roots obturated with Thermafil displayed significantly less leakage than cold lateral compaction technique, both, in the presence and absence of separated instruments. There was no significant difference among specimens prepared with ProTaper and RaCe when Thermafil obturation was done. But with cold lateral compaction technique, RaCe system showed less leakage as compared to ProTaper system. CONCLUSION: The type of obturation may play more important role than the type of instrument or retained/non-retained instrument factor.