Pulsed laser beam effects on gingiva.

The effects of CO2 lasers on human gingiva have been evaluated. Pulsed Nd:YAG lasers have only been available for clinical use in dentistry since 1990. This study evaluated the efficacy of a low-power pulsed laser in removing pocket lining epithelium in humans with moderate periodontitis. 24 specimens of gingival tissue, from 6 patients, were studied microscopically following the application of a pulsed Nd:YAG laser (1064 nm) contact probe with a spotsize of 320 mu. Power settings of 1.25 and 1.75 Watts and a frequency of 20 Hz were used. Treatment time varied from 2 to 3 min. The specimens were fixed and processed in the usual manner. Four representative sections for each tooth were examined with the light microscope at 25 and 100 x magnification. Most sections (83%) exhibited complete removal of epithelium except for traces of viable basal cell remnants at the coronal sulcular margin (17%). The underlying connective tissue demonstrated no evidence of necrosis or carbonization. Morphologic features showed minimal change other than removal of pocket lining epithelium, compared to control sites. The pulsed Nd-YAG laser can remove pocket lining epithelium in moderately deep pockets at 1.25-1.75 W of power.