The effect of the CO₂, nd:yag and er:yag lasers on dentin and pulp tissues in dogs

Although there has been interest in lasers in dentistry since lasers were first developed in the early 1960's, this interest was limited until recently. Over the past five, years there has been a flurry of interest to find the most effective wavelength and parameters of treatment. With this interest has come clinical and experimental reports. This project is a pilot study to investigate laser effects on dogs teeth. Multiple teeth from 2 dogs(n=40) were treated using either a CO₂, Nd:YAG, or an Er:YAG laser,or slow-speed rotary instrumentation. One dog died after treatment and was not used in this study. The second dog was sacrificed four days after treatment with the lasers and the teeth were decalcified and processed for light microscopy. The dentin and pulpal tissues were then evaluated for changes from their normal histologic patterns. The purpose of this study was to first determine if the dog would be a good model for in-vivo histologic testing of lasers and second to evaluate the histologic effects of different lasers on dog's teeth. Our findings suggest that each laser causes a different degree of effect to the treated teeth. The specifics of these effects are discussed herein.