Comparative evaluation of bacterial microleakage of three root canal filling materials; Resilon, GuttaFlow and Gutta-Percha with AH26 sealer

Apical leakage of tissue fluids around root canal space was cited as the most common cause of root canal treatment failures, for which, fillings of root canal with root filling materials was suggested to achieve adequate apical seal and to prevent leakage. Due to the importance of adequate apical seal, different root canal filling materials were developed and used for this purpose. The purpose of this study was to compare bacterial apical leakage through root canal filling materials of Resilon, GuttaFlow and Gutta-Percha with AH26 sealer. In this in vitro experimental study, 55 single-rooted teeth with healthy roots meeting the study inclusion criteria were selected and randomly divided in 3 experimental groups each containing 15 specimens and 2 positive and negative control groups each with 5 samples. The teeth crown were sectioned near the CEJ, the teeth canals were instrumented with step- back technique while group 1 was obturated with Gutta-Percha, and group 2 with Resilon using a cold condensation technique. Group 3 was obturated with GuttaFlow as recommended by manufacturer. Two-chamber bacterial methods were used to assess bacterial apical leakage by means of Enterococcus Faecalis bacterium during a 60 days time interval. The data were analyzed by Kaplan-Meier test. In root canals filled with Resilon, the median of the day in which leakage was occurred was 17, in Gutta-Percha specimens it was 18 and in canals filled with GuttaFlow the median was 19. 93.3% of the roots filled with each Resilon or Gutta-Percha showed apical bacterial leakage during 60 days while in canals filled with GuttaFlow, the leakage was observed in 80%. Kaplan-Meier test showed no significant differences comparing the day in which the leakage was occurred or the overall incidence of leakage in three materials. Under the conditions of the present study, three root canal filling materials showed similar rates of apical bacterial leakage as no significant statistical differences were noted among them.