The purpose of this study was to determine the change of organic matters in enamel which was irradiated by AOQ-Sw,Nd:YAG laser.

Research Project

Project/Area Number	60480444
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	小児・社会系歯学
Research Institution	TOHOKU UNIVERSITY
Principal Investigator	KAMIYAMA Kikuo Tohoku University Professor, 歯学部, 教授 (20013881)
Co-Investigator(Kenkyū-buntansha)	NISHIMAKI Hiroko Tohoku University,Instructor, 歯学部附属病院, 助手 (20180630) YAMADA Keiko Tohoku University,Instructor, 歯学部, 助手 (60125680)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥6,600,000 (Direct Cost: ¥6,600,000) Fiscal Year 1986: ¥1,100,000 (Direct Cost: ¥1,100,000) Fiscal Year 1985: ¥5,500,000 (Direct Cost: ¥5,500,000)
Keywords	AOO-Sw / Nd:YAG Laser / Young premolar / Enamel / Organic matter / Amino acid / Enamel section / H-E染色
Research Abstract	The purpose of this study was to compare the difference of organic matters between lased enamel and unlased enamel. Materials and methods Young premolars which had been extracted for the orthodontic treatment and had stored in 70% alcohol solution were used and treated by following two methods. Experiment 1: The materials were irradiated by AOO-Sw,Nd:YAG laser.Thereafter, the longitudinal sections were prepared from them and the surfaces were dicalcified by 0.5M lactic acid for 5 minites prior to be stained with H-E solution. Another sections were not dicalcified prior to be stained. Both sections were observed by microscope and SEM. Experiment 2: Enamel sections(1 mm of thickness) of young premolars were prepared. The surfaces of them were polished by brush corn and were irradiated by AOO-Sw, YAG laser. Then the amino acids which were contained in the enamel sections were analized (quantity and quality) by amino acid analizer with routine technique. Resuts 1) In dicalcified sections, lased enamel sections were less stained than unlased enamel sections, and the area where the enamel was less stained was 100-300 um of depth from the enamel surface. 2) Noched lines were observed in area of just under lased enamel surface and it was thought that these lines were craks which had been produced by AOO-Nd:YAG laser irradiation. 3) Enamel prisms were seen more obviously in unlased enamel sections than in lased enamel sections by SEM observation. 4) The qualities of amino acids which were contained in lased enamel were especially reduced fro unlased enamel.