A new model system for measuring intracanal temperatures.

A new model system was developed which allows intracanal temperature measurements to be recorded during repeated obturations of a human tooth root canal. A human central incisor was embedded in clear orthodontic resin and sectioned longitudinally. Sixteen thermocouples were secured at 2-mm intervals along two surfaces of the root canal. The thermocouples were connected to a computerized temperature recording system to measure intracanal temperatures produced by high-temperature thermoplasticized injectable gutta-percha. The system was capable of recording 16 simultaneous temperatures every second with an accuracy of a hundredth degree centigrade. There was a linear increase in the recorded temperatures in the root canal. However, the actual temperatures were lower than expected.