TEMPERATURE-CHANGES INDUCED BY LOW-ENERGY CO2-LASER IRRADIATION IN ENAMEL

Studies by Stern [1964, J. Dent. Res., 43 (Suppl.), p. 873 (Abs. 307)] demonstrated that a laser could be used to heat the surface of human enamel, increasing enamel resistance to surface demineralisation. Rece nt studies have shown the CO2 laser to be suitable in preventive denti stry. Because the mechanism of inhibition is not still exactly known w e have focused on finding the relation between energy density, wavelen gth and induced surface temperature. We worked with a tunable TEA CO2 laser using 9.3, 9.6, 10.3, 10.6 mu m wavelength and energy density be tween 0.1 and 2 J/cm(2). This corresponded to the temperature range of 100 to 4000 degrees C. We prepared a 200 mu m thick enamel slide whic h we irradiated from the front side. The temperature was measured at t he opposite side with a microthermometer and the front side temperatur e was obtained by heat-transfer equation calculation.