Temperature rise in cavities prepared by high and low torque handpieces and Er:YAG laser.
OBJECTIVE
The aim of this study was to compare intrapulpal temperature increases produced by a high-speed high-torque (speed-increasing) handpiece, a high-speed low-torque handpiece (air-turbine) and an Er:YAG (Erbium: Yttrium-Aluminum-Garnet) laser.


METHODS
Thirty bovine incisors were reduced to a dentine thickness of 2.0 mm. Class V preparations were prepared to a depth of 1.5 mm, measured with a caliper or by a mark on the burs. A thermocouple was placed inside the pulp chamber to determine temperature increases ( degrees C). Analysis was performed on the following groups (n = 10) treated with: G1, low-torque handpiece; G2, high-torque handpiece; and G3, Er:YAG laser (2.94 microm at 250 mJ/4 Hz), all with water cooling. The temperature increases were recorded with a computer linked to the thermocouples.


RESULTS
The data were submitted to ANOVA and Tukey statistical test. The average temperature rises were: 1.92+/-0.80 degrees C for G1, 1.34+/-0.86 degrees C for G2, and 0.75+/-0.39 degrees C for G3. There were significant statistical differences among the groups (p = 0.095). All the groups tested did not have a change of temperature that exceeds the threshold of 5.5 degrees C.


CONCLUSIONS
Temperature response to the low and high torque handpieces seemed to be similar, however the Er:YAG laser generated a lower temperature rise.
Faculty of Dentistry UNESP, Restorative Dentistry, Av. Eng. Francisco José Longo, 777 - Jd São Dimas, São José dos Campos 12245-000 SP, Brazil. leilyfiroozmand@hotmail.com
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Firoozmand
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Faria
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Araujo
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di Nicoló
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Huthala
D000704:Analysis of Variance; D000818:Animals; D001831:Body Temperature / Q000528:radiation effects; D002417:Cattle; D003731:Dental Caries / Q000601:surgery*; D003737:Dental Cavity Preparation / Q000145:classification / Q000295:instrumentation*; D003754:Dental High-Speed Equipment; D003782:Dental Pulp / Q000528:radiation effects; D003786:Dental Pulp Cavity / Q000528:radiation effects / Q000601:surgery*; D006358:Hot Temperature; D007180:Incisor; D053685:Laser Therapy / Q000295:instrumentation*; D053844:Lasers, Solid-State; D018709:Statistics, Nonparametric; D019415:Torque