Effect of Diode Lasers(675nm & 810nm) in Hardness of Dental Ceramic

Abstract

This research was study the effect of diode laser in hardness of the material used in the combinations of teeth (ceramics) by using the hardness tester (TH 160) to test the hardness . 2 Hardness was measured for samples divided into six groups, each group containing ten test sample, before and after it irradiated with the diode laser with wavelength 675 nm and power 30 mW, for a period of time two minutes for the first group, and ten minutes for the second. Also used a diode laser with wavelength 810 nm and various power 30, 200, 500 mW, with irradiation power of 200 mW for duration two minutes and ten minutes to the third and fourth groups, and irradiation power of 30 and 500 mW for duration one minute for the last two groups. The results showed that a significant increase in the hardness of ceramic material for irradiated samples compared to non-irradiated samples, where found that the highest percentage of hardness was (41.6%) obtained upon irradiation with a laser wavelength 675 nm, and power of 30 mW for duration two minutes. The results also showed that the increase in the irradiated time of the samples from two minutes to ten minutes, as well as increased power from 30 to 500 mW does not have a significant effect in increasing the hardness of the ceramic material. Also we found that irradiation of samples at power 30 mW of visible laser with wavelength of 675 nm, hardness ratio was higher (41.6%) compared with the hardness ratio ‫‪(18.28%) at the same irradiation power but invisible laser‬‬ ‫.‪at wavelength 810 nm‬‬