[Action of a CO2 laser on dental tissues]

In order to investigate the effect of a CO2 laser on dental tissues, 51 healthy human teeth were lased and prepared for macroscopic, histological and SEM examination using standardized methods. The alterations induced by the thermic shock varied according to the tissue's composition and the lasing's intensity. The effects generally appeared as cracks with fragmentation of the superficial enamel, and a carbonization of the cavity. The underlying pulp showed a disintegration of the odontoblastic layer and an oedema, the severity of which depended on the residual dentinal thickness and the lasing's intensity. The study's results, divergent from those often found promising in the abundant literature, bring to light the biological incompatibility of this type of hard laser regarding the dental organ and suggest caution concerning eventual therapeutic indications.