INTRODUCTION
Medical microbiology entered a new era towards the end of the nineteenth century. It was during these golden years that path-breaking work of Pasteur, Koch and others in the development of broth and agar media led to the ability to grow a majority of pathogenic micro-organisms which were deemed uncultivable till then. In 1894, WD Miller published his findings on the bacteriological investigation of pulps. The results of past studies have generally agreed that the microorganisms that are most commonly isolated from infected root canals were the alpha (α), …show more content…
faecalis is known to have a high resistance to antibacterial substances and is therefore often detected in non resolving apical lesions or retreatment cases6. Eliminating the residual micro-organisms within the biofilm in the complex root canal system is a challenging task. The antibacterial activity of different intracanal dressings were tested in the present study and E. faecalis was selected as the prime endodontic microorganism.
The results of the study indicates that intracanal medicaments alone have little quantitative effect on the viability of E. faecalis. Culture density values obtained in the present study found a complete inability of any of these medicaments to remove biofilm completely. This is consistent with findings by Norrington et al. 7. A major reason for the lack of effectiveness is the intrinsic resistance of E. faecalis to several commonly used intracanal medicaments, and perhaps more importantly, its ability to acquire resistance to all currently available medications and antibiotics, either by mutation or by horizontal gene transfer8. The close proximity of bacterial cells within the biofilm readily allows the exchange of genetic information, including the transfer of antibiotic resistance. In addition to the intrinsic or acquired antibiotic resistance of E. faecalis, the organisation of cells in a biofilm structure could be a further factor contributing to the lack of antimicrobial