2014 Volume 25 Issue 1 Pages 2-7
Less-invasive treatment of caries has been investigated based on the characteristic absorption of dentin at wavelengths of approximately 6μm. In our previous study, a nanosecond pulsed laser with the wavelength of 5.85μm was found to be effective for selective removal of carious dentin. However, variability of the ablation property under the same irradiation conditions was observed. In this study, the ablation property of human carious dentin at the wavelength of 5.85μm was investigated based on dentin hardness. Extracted human teeth were irradiated at the average power density of 30W/cm2. Vickers hardness around the irradiation spot was measured with a dynamic microhardness tester. Selective removal and increase of ablation depth due to a decrease of Vickers hardness were observed.