THERMAL EFFECTS AND ANTIBACTERIAL PROPERTIES OF ENERGY-LEVELS REQUIRED TO STERILIZE STAINED ROOT CANALS WITH AN ND-YAG LASER

Thermal effects and antibacterial properties of an Nd:YAG laser were s tudied to establish clinically safe levels of energy to deliver into t he root canal and to determine the energy level needed to sterilize in fected root canals. The results indicate that lasing cycles of 3 J(-s) for 15 s followed by a 15-s recovery interval can be continued for pr olonged periods without risk of thermal damage to surrounding tissues, In vitro lasing of root canals inoculated with dark stained bacteria showed that two such lasing cycles sterilized only two out of eight ca nals, whereas when four cycles were used seven out of eight canals wer e sterilized, Guidelines for energy levels in endodontic Nd:YAG laser work are discussed, and base data for calculating appropriate energy l evels are given.