象牙質に対する炭酸ガスレーザーの照射効果 The Effect of CO<SUB>2</SUB> Laser Irradiation on Dentin
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The purpose of this study was to examine the morphlogical changes and the thermal effects of the CO2 laser irradiation on dentin. For this study, eighteen extracted hu man molars were used. In the experiment examining morphological changes, the irradiation power was 1 to 10 watts, the pulse times were 10 to 500ms and the irradiation frequency was 1 to 20 times. On the dentin surface irradiated by CO2 laser under various conditions, the carbonized area became wider, if the irradiation energy increased.<BR>But the depth and width of the cavity was the same, when the irradiation power was con stant. the irradiation energy densities were less than 153J/cm2, the dentin surface changed without making any cracking.<BR>In the experiment examining thermal effects, dentin blocks, 1.0 and 2.0mm in thickness, of extracted molars were prepared. These were lased by the CO2 laser using 1 to 5 watts at 10ms pulse mode for 30 seconds.<BR>The thermal increase transmitted from the lased surface was measured with the thermoco uple. The results indicate that the thermal increase depends on the dentin thickness and is in inversely proportional to the square of the dentin thickness. For example the thermal in crease should not rise more than 5 degrees for 10 seconds, when the dentin thickness is more than 2mm and the irradiated power is less then 2 watts. This result suggests that this laser irradiation may be successfully used in clinical situation as one of dentin treatment tech niques after further clarification of thermal effects on dental pulp.
- Journal of Japanese Society for Laser Dentistry
Journal of Japanese Society for Laser Dentistry 5(1), 73-80, 1994
Japanese Society for Laser Dentistry