@phdthesis{oai:osaka-dent.repo.nii.ac.jp:00000162,
 author = {北尾, 徳嗣 and Kitao, Noritsugu},
 month = {2017-04-20, 2017-04-19},
 note = {We investigated the processing of ceramic blocks using a femtosecond Ti:sapphire laser. The materials used were completely-sintered zirconia, semi-sintered zirconia, alumina, and hydroxyapatite. The conditions varied were the wavelength, intensity, and defocus distance of the laser beam, the movement speed of the automatic stage, the use of an air flow for removing debris, and whether the samples had been soaked in water prior to laser processing. The effect of these settings on the depth and sectional area of the cut trace produced by laser irradiation was examined.
The results indicated that the cutting force increased with increasing penetration of water to the interior of the material. Blackening of the zirconia was observed, but this disappeared upon reheating. The cutting force was found to depend on the laser intensity irradiating the sample. The depth and sectional area of the cut increased sharply with irradiation power up to about 20 mW, and then more gradually. For the same irradiation power, the cutting amount was larger for a shorter wavelength and pulse width. Cutting proceeded more effectively when the debris were removed during the process. The surface roughness at the floor of the formed cavity was at a clinically applicable level.
These results suggest that a femtosecond Ti:sapphire laser can be used for high-precision processing of dental ceramics.},
 school = {大阪歯科大学},
 title = {Processing of Ceramic Blocks Using Femtosecond Lasers},
 year = {},
 yomi = {キタオ, ノリツグ}
}