Influence of calcium hydroxide intracanal medication on apical leakage

OBJECTIVE: To compare the apical sealing ability of Thermafil with that of the single-cone technique after filling root canals dressed with CalcipexII, a calcium hydroxide intracanal medicament. METHODS: Ninety simulated curved canals and 90 simulated straight canals were prepared in clear resin blocks (Nissin, Kyoto,Japan) using EndoWave rotary instruments (J Morita, Osaka, Japan) to size 30 (0.06 taper) on apical dimensions. Each type of specimen were divided into 3 groups (n=30), respectively; CalcipexII(Nippon Shika-Yakuhin, Shimonoseki,Japan) remaining, CalcipexII removed, and without CalcipexII (control) groups. Specimen were filled with gutta-percha and sealer, Thermafil (Dentsply Maillefer, Tulsa, OK, USA) + Canals (Showa Yakuhin,Tokyo,Japan), Thermafil+ Canals-N (Showa Yakuhin,Tokyo,Japan), Thermafil+ Sealapex (Kerr, Romulus, MI, USA), single-cone + Canals, single-cone + Canals-N, and single-cone + Sealapex. All specimen were immersed in India ink for 72 hours. Dye penetration data were analyzed and compared using Steel-Dwass's multiple comparison test (P < 0.05). RESULTS: Significant differences were found between the CalcipexII remaining, CalcipexII removed and without CalcipexII (control) groups (P < 0.05). No significant difference was found between simulated curved and simulated straight canals in the clear resin blocks (P < 0.05). No significant difference was found among Canals, Canals-N, and Sealapex (P < 0.05). No significant difference was found between the Thermafil and single-cone techniques (P < 0.05). CONCLUSIONS: After filling root canals dressed with CalcipexII, Thermafil was unable to create a better apical seal than that achieved by the single-cone technique.