AN ASSESSMENT OF MICROBIAL CORONAL LEAKAGE IN TEETH ROOT FILLED WITH GUTTA-PERCHA AND 3 DIFFERENT SEALERS

The aim of this in vitro study was to determine the effect of three di fferent root canal sealers on the bacterial penetration of obturated r oot canals. Eighty extracted human teeth with straight, single root ca nals were prepared using the modified double-dared technique with bala nced force under copious irrigation until the master apical file was s ize 40. The teeth were divided randomly into experimental groups (60 t eeth) and control groups (20 teeth). Twenty experimental teeth each we re obturated by lateral condensation of cold gutta-percha with AH26, A pexit or Tubliseal EWT sealer. In the control groups, 10 teeth were ob turated using the same technique with AH26, Apexit or Tubliseal EWT se aler. These teeth were completely sealed to serve as negative controls . The remaining 10 teeth were not obturated and served as positive con trols. The root surface of each tooth, except the apical 2 mm, was sea led with nail varnish. The coronal part of each root canal was sealed with the cut end of a polypropylene tube and placed in a glass bottle containing sterile Todd-Hewitt Broth (THB). Aliquots of 0.5 ml of THB were injected into the polypropylene tube and the model system was cen trifuged at 168 g. An innoculum of Streytococcus sanguis in THB was ad ded to the tube at 5-day intervals and daily observations were made fo r bacterial growth in the apical reservoir for 90 days. Ah positive co ntrol teeth showed bacterial penetration within 24 h and negative cont rol teeth remained uncontaminated throughout the test period. Leakage through the experimental teeth varied from 7 to 86 days. There was no statistically significant difference (P > 0.05) in leakage of the obtu rated canals between AH26, Apexit and Tubliseal EWT sealers.