AN IN-VITRO STUDY OF THE CORONAL LEAKAGE OF 2 ROOT-CANAL SEALERS USING AN OBLIGATE ANAEROBE MICROBIAL MARKER

The aim of this in vitro study was to investigate the coronal leakage of obligate anaerobes into root canals obturated with lateral condensa tion of cold gutta-percha with two root canal sealers. Sixty extracted human teeth with straight, single root canals were prepared using the modified double-flared technique with balanced force under copious ir rigation until the master apical file was size 40. The teeth were divi ded randomly into experimental groups (40 teeth) and control groups (2 0 teeth). In the experimental groups, 20 teeth were obturated with lat eral condensation of cold gutta-percha and AH26 sealer and 20 teeth we re obturated with the same technique using TubliSeal EWT sealer. In th e control groups, 10 teeth were obturated with the same technique eith er with AH26 or TubliSeal EWT sealer. These teeth were completely seal ed to serve as negative controls. The remaining 10 teeth were not obtu rated and served as positive controls. The root surface of each tooth was sealed with nail varnish except the apical 2 mm. The coronal part of each root canal was sealed with the cut end of polypropylene tube a nd placed in a glass bottle containing sterile Fastidious Anaerobe Bro th (FAB), Aliquots of 0.5 mL of FAB were injected into the polypropyle ne tube and the model system was centrifuged at 168 g. An inoculum of Fusobacterium nucleatum in FAB was placed in each coronal chamber at 7 -day intervals and daily observations were made for bacterial growth i n the apical reservoir for 12 weeks, All positive control teeth showed bacterial leakage within a week, while the negative control teeth rem ained uncontaminated throughout the test period, All the experimental teeth exhibited leakage of bacterial metabolites within 12 weeks, rang ing from 1 to 12 weeks. The mean time for complete leakage in the AH26 and the TubliSeal EWT groups was 8.4 and 8.2 weeks respectively, Ther e was no statistically significant difference (P > 0.05) in leakage be tween the AH26 and the TubliSeal EWT groups.