Intrapulpal Temperature during Cavity Preparation

¹ Department of Oral Pathology, United States Army Institute of Dental Research, Walter Reed Army Medical Center, Washington, D.C.

This study was undertaken to determine the intrapulpal temperature during cavity preparation. An instrument consisting of a thermister probe for insertion into the pulp, a telethermometer, and a recorder, was specially designed for this study. Forty class V cavities were prepared in teeth of four dogs. Cavities were cut at low speed, at low speed with a coolant, at high speed, and at high speed with a coolant: (1) With low speeds without a coolant, the mean intrapulpal temperature increase was 5.4° C. (2) With low speeds with a coolant the mean intrapulpal temperature dropped by 5.3° C. (3) With high speed and high speed with a coolant, the mean intrapulpal temperature drop was 2.5° C. and 8.1° C., respectively.

On the basis of these findings, it can be assumed that under the usual operative procedures there is a drop in the intrapulpal temperature. Consequently, the well-known pulpal changes associated with cavity preparation cannot be due to heat production. It is most likely that these occur as a consequence of severance of the odontoblastic processes, dehydration, and perhaps the "cooling effect" of cavity preparations.