Histological results following in-vivo cavity preparation with an Er:YAG laser

This study was performed in order to evaluate the safety of pulpal and dentinal tissue when exposed to the 2.94 micron pulsed Er:YAG laser radiation for the clinical procedures of caries removal, cavity preparation and laser etching prior to acid etching and restoration. This paper discusses the histological changes observed in dentin and pulpal tissue induced by the Erbium laser and the dental drill as performed in the clinical setting at five test sites. Carious teeth were treated in-vivo and then extracted at various periods ranging from immediately to 1 year post treatment. Following extraction, the specimens were evaluated by a double-blind histological examination of dentin and pulp tissue for comparison of results. Specimens were ranked and scored according to the absence or severity of the histopathologic changes observed and the results subjected to statistical analysis (ANOVA) to determine if significant differences existed between treatment groups (laser vs. drill) and/or procedure. Conclusions: Analysis of the results indicate that there were no significant differences attributable to method of treatment. Etching by either method resulted in no discernible change. Cavity preparation and caries removal resulted in mild to moderate changes in the tissues.