Measurement of pulp temperature increase to externally applied heat (argon laser, hot water, drilling).

In order to weld cracks in tooth enamel, it is necessary to bring the surface of the tooth to the fusion temperature of the enamel (greater than 1,000 degrees C). The study investigated whether this increase in surface temperature can cause damage to the vitality of the tooth by recording, using a thermocouple, the temperature in the pulp chamber of teeth exposed to argon laser irradiation (power density after focusing: 4000 W/cm2; duration of continuous irradiation: 1-5 seconds). These pulp temperature increases were compared with those considered safe for the tooth, i.e., contact with a hot drink, drilling of cavities with air + water cooling. It was shown that punctual irradiations with an argon laser for periods of 2 or 4 seconds generated temperature increases in the pulp chamber which were less than inferior to those caused by contact with water at 54-55 degrees C for 1 or 2 seconds, and were of the same order as those caused by the drilling of class III or V cavities of 1 mm in depth and 1 mm in diameter. These results suggest that it is worth continuing research into applying the technique in the mouth.