High-speed cavity preparation techniques with different water flows.

Abstract

STATEMENT OF PROBLEM: Cavity and tooth preparations generate heat because the use of rotary cutting instruments on dental tissues creates friction. Dental pulps cannot survive temperature increases greater than 5.5 degrees C. PURPOSE: This study evaluated the efficiency of 3 different water flows for 2 different tooth preparation techniques to determine which are safe for use. MATERIAL AND METHODS: Thermocouples were placed in the pulpal chambers of 30 bovine teeth, and 1 of 2 tooth preparation techniques was used: a low-load intermittent tooth preparation technique or a high-load tooth preparation technique without intervals. Water flows of 0, 30, and 45 mL/min were associated with each technique, for a total of 6 different groups. The results were analyzed with a 2-factor analysis of variance (P<.05). RESULTS: Temperature increases with the high-load technique were 16.40 degrees C without cooling (group I), 11.68 degrees C with 30 mL/min air-water spray cooling (group III), and 9.96 degrees C with 45 mL/min cooling (group V). With the low-load tooth preparation technique, a 9.54 degrees C increase resulted with no cooling (group II), a 1.56 degrees C increase with 30 mL/min air-water spray cooling (group IV), and a 0.04 degrees C decrease with 45 mL/min cooling (group VI). The low-load technique was associated with more ideal temperature changes. CONCLUSION: The results of this study confirm the necessity of using a low-load technique and water coolants during cavity and tooth preparation procedures.