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°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°C without cooling (group I), 11.68°C with 30 mL/min air-water spray cooling (group III), and 9.96°C with 45 mL/min cooling (group V). With the low-load tooth preparation technique, a 9.54°C increase resulted with no cooling (group II), a 1.56°C increase with 30 mL/min air-water spray cooling (group IV), and a 0.04°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. (J Prosthet Dent 2002;87:158-61.)