Temperature rise during root canal preparation--a possible cause of damage to tooth and periodontal tissue

Temperature rise on the surface of extracted human premolar roots was recorded during root canal preparation using a thermo-couple. It was found that time, pressure exerted on the reamer, type of reamer and rotational speed influenced the temperature rise. Starting from about 30 degrees C temperatures up to 87 degrees C were recorded, generally in less than 50 seconds' working time, using routine instrument and technique. Possible effects of this temperature rise on tooth substance, periodontal membrane and supporting bone are discussed.