Effects of lowered temperatures on rat pulp and gingivae

The histologic appearance of pulp and interdental papilla was observed for 2 months after cryosurgery of dental tissues in the molar region of twelve Colworth-Wistar rats. The reduction in temperature achieved was also calculated from thermocouples in the pulp chamber of freshly killed animals. Reduction to -13 degrees C. in 1 1/2 minutes was followed by destruction of the odontoblast layer and fibrosis of the pulp. Destruction of the epithelium was followed by regeneration and was characterized by a sterile inflammatory reaction. Cryotherapy is suggested to be a useful alternative to standard gingivectomy, especially in patients with blood dyscrasias, and may also be used to treat internal resorption or "pink spot."