Abstract
The purpose of this study was to investigate the sensory response of dental pulp in vivo and the threshold of the occurrence of any subjective symptoms when living human teeth were irradiated with a Q-switched Nd-YAG laser. These experiments were carried out with the cooperation of two volunteers from our dental school. The subject teeth were sound premolars which were expected to be extracted for orthodontic purposes.
In preliminary experiments with extracted teeth an increment of temperature at the tooth surface and at a side wall of the pulp chamber was measured during exposure to radiation under various conditions. An estimated optimal energy for the in vivo experiment was obtained from the preliminary experiments.
The results from the experiments in vivo were the following. 1) Unpleasant subjective symptoms did not occur with a laser energy of less than 10.83J/cm2/pulse at a repetition rate of 28 pps. 2) A clinical pulp examination such as the electric pulp test, the thermal test and/or the response to percussion revealed that no sensory abnomality occurred in any of the irradiated teeth under the experimental conditions.
