IN-VITRO STUDY OF THE EFFECTS OF ND-YAG LASER PROBE PARAMETERS ON BOVINE ORAL SOFT-TISSUE EXCISION

Background and Objectives: Lasers are now used for intraoral, soft tis sue procedures. The effects of Nd:YAG probes on cutting efficiency and temperature rise were evaluated in vitro. Study Design/Materials and Methods: Three hundred twenty-micron 400-mu m, 500-mu m, and 600-mu m probes were used to ablate bovine gingiva, mucosa, and tongue at vario us power and frequency settings. Thermocouples positioned under the su bjacent cortical bone measured temperature rise. Tissue samples were e valuated histologically. Results: Mean pooled temperature rise was 1 d egrees C at 3 W and 1.4 degrees C at 5 W. Excision width ranged from 0 .63 mm to 0.79 mm at tested settings, cutting depths from 0.19 mm to 0 .49 mm, lateral and deep coagulation from 0.27 mm to 0.62 mm. Conclusi on: Temperature rise in bone was related to increased power. Cutting e fficiency of laser probes was not significantly improved by increased power. Probes of 320 to 500 mu m provided efficient cutting at 3 W and 5 W, thus reducing the potential for unacceptable temperature rise in bone. (C) 1997 Wiley-Liss, Inc.