THERMAL RESPONSE TO MULTIPLE USE OF A TWIST DRILL

The objective of the present investigation was to determine whether in jurious thermal changes occur in the pulp chamber if a twist drill is used 10 times, and to find whether there is a correlation between temp erature rise and distance between a drilled channel and the pulp chamb er. Twenty caries-free, human, premolar teeth were randomly distribute d to two dentists. With a new 2 mm twist drill, each dentist prepared 10 pinholes (one hole per tooth). Intrapulpal temperature change durin g the drilling procedure was recorded. The data were statistically ana lyzed by the Spearman rank order correlation coefficient. The results showed that twist drills should not be used for more than five pinhole s (p < 0.001). The distance between the pin channel and the pulp chamb er does not influence heat generation in the pulp chamber.