An In vitro Comparison of Anti Bacterial Effect of AH26 and AHplus Sealers on Infected Root Canals with Enterococcus Faecalis Bacteria

Statement of Problem: Bacteria and their destructive byproducts are the main causes of pulpal and periapical diseases. The main goal of the root canal therapy is to eliminate these bacteria from the root canal systems to prepare a suitable environment for the healing of periradicular tissues. Total elimination of these bacteria from root canal system is impossible, even by cleaning, shaping and irrigating with antibacterial solutions; therefore, utilization of antibacterial filling materials can help to achieve a better result. The purpose of this study was an in vitro comparison of antibacterial effect of AH26 and AHplus sealers on infected root canals with enterococcus faecalis bacteria. For this experimental study, 90 single rooted human teeth including upper incisors and canine were chosen. The crowns were removed and the root canals were cleaned and shaped. Smear layer was removed from canals and the roots were contaminated with entrococcuous faecalis bacteria following their sterilization. The roots were randomly divided into four experimental groups. The root canals of two groups were obturated using gutta percha and AH26 sealer with the lateral condensation technique. Root canals of the remaining groups were obturated by the same method but by using AHplus sealer. After incubation periods of 2 and 7 days, 4 mm segments were prepared from the middle third of roots and following removal of gutta percha from the segments, dentinal shavings were collected from the inside walls of the segments. The dentinal shavings were cultured and the presence of bacteria and the number of colonies were evaluated. The data were compared with each other by Mann-Withney and Chi-Square tests. The findings of this study demonstrated that AH26 sealer can kill all the bacteria in 2 and 7 days but AHplus sealer can not eliminate the bacteria from the infected root canals and a significant rise in the number of colonies was seen when comparing the incubation period of 2 days with 7 days. The findings of this survey illustrated a strong antibacterial effect of AH26 in comparing with AHplus which may be due to the greater amount of formaldehyde releases from this sealer.