High-speed cavity preparation techniques with different water flows.
BACKGROUND
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.


OBJECTIVE
This study evaluated the efficiency of 3 different water flows for 2 different tooth preparation techniques to determine which are safe for use.


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.


CONCLUSIONS
The results of this study confirm the necessity of using a low-load technique and water coolants during cavity and tooth preparation procedures.
Cavalcanti
Bruno Neves
BN
Department of Dental Materials and Prosthetics, School of Dentistry, Sâo Paulo State University-UNESP, Brazil. brunocavalcanti@aol.com
Otani
Choyu
C
Rode
Sigmar Mello
SM
D000818:Animals; D001831:Body Temperature; D002417:Cattle; D003080:Cold Temperature; D003737:Dental Cavity Preparation / Q000379:methods*; D003754:Dental High-Speed Equipment / Q000009:adverse effects; D003782:Dental Pulp / Q000293:injuries; D006358:Hot Temperature / Q000009:adverse effects; D014867:Water
D014867:Water