Histopathological changes in dental pulp after preparation of cavities with a high-speed drill.

Histopathological changes occur very rapidly in the pulp when the highspeed drill, which cuts into the dentin, is used. In this investigation, we wanted to confirm possible changes occurring in the histology of healthy, vital pulp within the first thirty post-operative minutes. Six premolars extracted for orthodontic reasons in adolescents between 12 and 17 years of age were evaluated. The teeth were removed and serial sections of the specimen, using classical histological procedures, were made. The histological evalua­ tion under the light microscope revealed changes in the pulp, characteristic for acute inflammatory reaction, that is, hyperemia, extravasation of blood cells and aspiration of the odontoblast in dentin tubulus. We concluded that the turbine drill should be used only on the enamel of the tooth. We recommend using the low speed drill with maximal cold water for work on the dentin. Exposed odontoblastic processus and tubulus should be protected immediately after the preparation of the cavity.