CORONAL LEAKAGE OF MIXED ANAEROBIC-BACTERIA AFTER OBTURATION AND POSTSPACE PREPARATION

Objectives. The purpose of this study was to assess bacterial leakage of a mixed anaerobic community of organisms in obturated canals after post space preparation. Study design, A mixed microbial community of s trict anaerobic organisms (F. nucleatum, P. micros and C. rectus) was developed. With the use of an in vitro model system, coronal leakage w as assessed in 40 anterior teeth after obturation and post space prepa ration. The specific leakage time in days for each organism to penetra te through the obturating material was determined. In addition, coloni zation of the apical canal space was assessed by scanning electron mic roscope after longitudinal splitting of randomly selected specimens. R esults. Eighty percent of the teeth demonstrated coronal leakage of F: nucleatum and C, rectus by the 90 day interval. Bacterial penetration occurred from 48 days to 84 days, Scanning electron microscope examin ation showed a heterogeneous biofilm of coccal and bacillary species c olonizing the apical portion of the canal wall. Conclusions, This stud y demonstrated that coronal leakage phenomena do occur after loss of c oronal seals. The model system developed using mixed, anaerobic bacter ial cultures is more clinically relevant and may be used to assess bac terial penetration through gutta percha obturation.