Temperature rise in cavities prepared by high and low torque handpieces and Er:YAG laser

Abstract

• In this study low and high torque handpieces and Er:YAG laser did not promote an increase in intrapulpal temperature higher than 5ºC.• Even the high torque handpiece did not promote a statistically signifi cant high temperature increase.• The Er:YAG laser generated a lower temperature rise. This fact denotes the possible advantage of Er:YAG laser compared to the conventional handpieces. I N B R I E F RESEARCHObjective 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. Subject and 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 (°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 µm 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±0.80ºC for G1, 1.34±0.86ºC for G2, and 0.75±0.39ºC 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 o C. Conclusion Temperature response to the low and high torque handpieces seemed to be similar, however the Er:YAG laser generated a lower temperature rise.

Thermal irritation of teeth during dental treatment procedures

“…An in vitro study measuring intrapulpal temperature increase with a 0.5 mm residual dentin thickness, found temperature increases of 1.8℃, 1.4℃, and 0.7℃, with the low-speed handpiece, high-speed handpiece, and laser, respectively 3. There were no statistically significant differences between low-speed handpiece and high-speed handpiece groups, but with the laser group, there was a significant observation with a low temperature rise.…”

“…When tooth preparation was conducted using high- and low-torque handpieces, the tooth surface or intrapulpal temperature increases were approximately 0.8 - 3.0℃ 3,4. The maximum intrapulpal temperature increase was 7.8℃ when the composite resin was photopolymerized,5-7 and was 3.4 - 12.3℃ during fabrication of direct provisional crowns with acrylic resins 8,9.…”

Interferon regulatory factor-3 activation, hepatic interferon-stimulated gene expression, and immune cell infiltration in hepatitis C virus patients

“…Several studies (Armengol et al, 2000; Brandão et al, 2012; Corrêa‐Afonso et al, 2008; Firoozmand et al, 2008; Geraldo‐Martins et al, 2005; Hibst, 2002; Park et al, 2007; Raucci‐Neto et al, 2007; Staninec et al, 2006) evaluating the thermal and morphological changes induced by Er:YAG laser irradiation have been accomplished during cavity preparation using sound dentin. However, these results may not be extrapolated when the situation involves caries removal, as the carious dentin is structurally different from sound dentin (Kuboki et al, 1977).…”

Cytotoxicity evaluation of dentin contacting materials with dentin barrier test device using erbium-doped yttrium, aluminum, and garnet laser-treated dentin

“…With this duration, heat damage to the pulp is unlikely to occur with the energy settings used. 27,28 There are several different theories for explaining the effect of laser irradiation on dentin, but the most approved one suggests the sealing of dentinal tubules by the melting and recrystallization of dentin. 17 So far, no published data are available concerning the effectiveness of an Er:YAG laser in decreasing the cytotoxicity of dental materials, whereas the use of lasers has often been propagated for dentine hypersensitivity.…”