Assessment of an Impact of a Diode Laser Mode with Wavelength of 980 nm on a Temperature Rise Measured by Means of k-02 Thermocouple: Preliminary Results

Abstract

© by Wroclaw Medical University and Polish Dental Society. Background. Diode lasers are utilized successfully in a soft tissue surgery. Modern diode lasers allow to set power in the range of 0–10 W with modification of a pulse and interval duration (Ton and Toff). Objectives. The aim of this study was to establish if there is a difference in temperature rise during operation of pomoa diode laser in continuous and pulsed wave mode (CW and PW) with different Ton/Toff settings and laser power. The temperature gradient was assessed in CW and PW mode for the same energy dose sent by the laser. Material and Methods. Thermocouple and a diode laser handle were clamped stationary in a vise. Thermocouple was irradiated using a 980 nm diode laser, in CW and PW mode with a different Ton/Toff. Laser parameters were as follows: fiber – 200 μm, distance of the thermocouple to the fiber – 1 mm, CW mode (power in W) – 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, PW mode (W) – 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, Ton/Toff – 100/100, 200/200, 300/300, 400/400, 500/500. The temperature was measured continuously after 10, 20, 30 and 60 s of exposure using a calibrated digital thermometer. Results. The results indicated a significant increase in temperature with the increase of power in CW and PW mode. The temperature increase for CW was higher compared to PW mode in a power range 0.5–4 W. There was no difference in results of temperature rise depending on Ton/Toff ratio. The results showed no significant difference in temperature increase for a diode laser operating in CW and PW mode, after 60 s, for the same energy values (30, 60, 90, 120, 160, 180 J). Conclusions. The temperature increase for the same laser power is bigger in CW mode. However, sending the same energy dose at the same time by a diode laser results in a higher increase in temperature when operating in PW mode.