[Pulp-dentin reactions after CO2 laser treatment of the dentin]

The use of a CO2 laser in the treatment of dentinal caries in vital teeth seemed to be an important therapeutical progress compared to traditional means of carious tissue removal with rotary mechanical instruments. Forty sound premolars from patients with a mean age of twelve years were prepared according to a standard method for biological controls and submitted to the action of a CO2 laser of 3 Watts, equipped with a convergent lens of a 38 mm focal distance. The pulpal reactions were observed on day 15, 30, 50 and 80. No clinical post-operative symptomatology was observed in all treated teeth. The pulpal reactions related to the thickness of residual dentine consisted in the presence of reversible inflammatory changes, in the absence of degenerative processes and in an important production of tertiary dentine. The structural modifications occurring on the dentinal walls in these experimental conditions seemed not to induce a barrier totally tight to bacterial penetration.