IN-VITRO STUDY OF A ND-YAP LASER IN ENDODONTIC RETREATMENT

Nd:YAP laser is a dental laser with a 1340 nm wavelength. The laser be am is carried by a 200 to 300 mu m fiberoptic and is suitable for endo dontic therapy. We used the Nd:YAP laser in an in vitro experiment to study its effectiveness in endodontic reteatment. Temperature measurem ents and irradiation parameters were first defined. Then Nd:YAP laser irradiation was used, alone or in combination with hand instruments, t o remove various canal sealers and broken instruments. Clinical parame ters were monitored and scanning electron microscopic observations wer e conducted. When used at 200 mJ-with a pulse duration of 150 ms, an e xposure time of 1 s and a frequency of 10 Hz-Nd:YAP laser preserved th e dentinal walls of the root canal and enabled root canal retreatment without thermic elevation harming periodontal tissue. It is concluded that, in combination with hand instruments, the Nd:YAP laser is an eff ective device for root canal preparation in endodontic retreatment.