Evaluation of Temperature Elevation During Root Canal Treatment with Dual Wavelength Laser: 2780 nm Er, Cr:YSGG and 940 nm Diode

Objective: The purpose of this study was to evaluate the effects of dual wavelength (2780nm Er,Cr:YSGG and 940nm diode) laser with radial firing tip (RFT) on the external root surface and sub-surfaces, in terms of temperature changes during laser-assisted root canal treatment. Background data: A significant factor that may limit the use of lasers in endodontics is the possible thermal injury to tooth supporting structures. Materials and methods: A total of 50 sound single-rooted extracted teeth were divided randomly into two groups (n=25). Group A, irradiated with Er,Cr:YSGG laser at 1.06W, 50Hz, and 50s was a control group, and group B was irradiated with dual wavelength of Er,Cr:YSGG laser with the same settings as group A and a diode laser of 0.51W at 4ms and 10ms pulse duration. K-type thermocouples were used to record temperature changes at the cervical, middle, and apical root thirds, on root surfaces and sub-surfaces, arising from delivery of laser energy through RFT. Results: Temperature elevation in group B was significantly higher in the middle and apical thirds of the prepared samples than in group A (p<0.0001). Group B presented a mean temperature elevation of 5.07 degrees C on the apical surface region corresponding to a 1.48mm dentin thickness, whereas a mean temperature increase of 7.72 degrees C was recorded corresponding to dentin thickness of 0.95mm. Conclusions: Within the studied parameters, the dual wavelength laser did not result in adverse thermal changes on the external root surface in vitro.