Long-Term Stability of Bee-Fill, Microseal and Thermafil after 12 months

 Method: The coronal part of 30 single-rooted teeth was removed at the CEJ at 12 ± 1mm and then roots were instrumented up to #30 apical size with Mtwo rotary NiTi instruments (Sweden & Martina, Padova, Italy).  Specimens were divided into three groups (n=10) according to the obturation system: A) warm vertical compaction of gutta-percha using the BeeFill 2in1 Obturation Delivery System (VDW Silver, Munich, Germany); B) Microseal (Tycom, Irvine, CA, USA); C) Thermafil (Dentsply, Maillefer, Switzerland). In each group was used AH Plus endodontic sealer (Dentsply, Konstanz, Germany). Specimens were then immersed in a simulated body fluid (Hanks Balanced Salt Solution, HBSS). A digital fluid flow-meter working at 70 cm H₂O was used to detect the fluid filtration and evaluate the apical microleakage at 1 week, 1 month and 1 year after  immersion in HBSS at 37°C. Data were analyzed by one-way analyses of variance and Dunn’s post-hoc tests.

Result:   After 1 week, teeth filled with Bee Fill and Thermafil showed lower values of permeability when compared with other groups, but the differences were not significant (P>0.05). After 1 month, all the tested systems showed a decrease of their sealing ability but the discrepancy was not statistically different (P>0.05). After 12 months, in every group the sealing ability diminished significantly (P<0.01). Thermafil technique showed slighter degree of degradation after 12 months than other tested obturation systems (P>0.05). 

Conclusion: All the examined gutta-percha systems revealed a progressive reduction of their sealing ability that was significant at 12 months. Nevertheless, Thermafil showed lower values of apical microleakage.