CLINICAL AND HISTOLOGICAL-EVALUATION OF THERMAL-INJURY THRESHOLDS IN HUMAN TEETH - A PRELIMINARY-STUDY

The effect on healthy dental pulp of thermal increases ranging from 8. 9 to 14.7 degrees C was evaluated. These temperature increases corresp ond approximately to those caused by certain restorative procedures, s uch as tooth preparation with highspeed instruments and the fabricatio n of direct provisional crowns. Two criteria of evaluation have been u sed in conjunction, a clinical (symptomatic) and a histological one, t o assert with greater precision potential damage to the pulp. The resu lts suggest a low susceptibility of cells to heat, which does not appe ar to be a major factor of injury, at least in the short term. The mai n cause of postoperative inflammation or necrosis of the pulp is proba bly the injury of the dentine, a tissue in direct functional and physi ological connection with the pulp.