Experimental studies of the applications of the holmium laser in dentistry.

The purpose of this study is to evaluate the possibility of using a pulsed Ho:YLF laser for endodontic surgery access, preparation of cavities, etching of dental enamel, and treatment of dental caries. Specimens were irradiated with a prototype of pulsed Ho:YLF laser (2,065 microns). Laser energies in the range of 120-750 mJ per pulse were used. The study of morphological changes on enamel and dentine was conducted on light and scanning electron microscopes. Perforation of approximately 4 mm depth with homogeneous and smooth aspect of its wall surfaces was obtained. There was no carbonization. Irradiation with low energy results in melted and recrystalized surface with small and shallow pits. In accordance with our results the Ho:YLF laser produces surfaces that are white in appearance in contrast to the Nd:YAG modified enamel and dentine surfaces, that were darkened. These are indications that the holmium laser may be useful for dentistry in the future.