EVALUATION OF THE ANTIBACTERIAL EFFECTS OF INTRACANAL ND-YAG LASER IRRADIATION

Fifty canals of extracted single-rooted teeth were prepared to a size 50 master apical file, sterilized in ethylene oxide, and inoculated wi th a known quantity of Bacillus stearothermophilus spores. Five groups of 10 canals each were used. The control group received no treatment. The four treatment groups were exposed to pulsed Nd:YAG laser radiati on or 0.5% NaOCl alone and in combination. The root canals were flushe d with sterile distilled water to recover spores, and serial dilutions were incubated on blood agar and the number of colony-forming units r ecovered was determined. Analysis of the data indicated a 2-log reduct ion in colony-forming units among the four treatment groups as compare d with the controls; however, no significant differences were observed among the treatment groups. In none of the treatment groups were the root canals sterilized.