| Co-Investigator(Kenkyū-buntansha) |
TAKAMIZU Masaaki TSURUMI UNIVERSITY, SCHOOL OF DENTAL MEDICINE, ASSOCIATE PROFESSOR, 歯学部, 助教授 (30089411)
SHINTANI Hideaki HIROSHIMA UNIVERSITY, SCHOOL OF DENTISTRY, PROFESSOR, 歯学部, 教授 (80034239)
KATO Yoshito THE NIPPON DINTAL UNIVERCITY, SCHOOL OF DEMTISTRY, AT NIIGATA, PROFESSOR, 新潟歯学部, 教授 (20060452)
NIKAIDO Toru TOKYO MEDICAL AND DENTAL UNIVERSITY, FACULITY OF DENTISTRY, ASSISATNT PROFESSOR, 歯学部, 講師 (00251538)
HUKUSHIMA Masayoshi NIIGATA UNIVERSICY, FACULITY OF DENTISTRY, ASSISTANT PROFESSOR, 歯学部・付属病院, 講師 (30156773)
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| Research Abstract |
We obtained the following results from the study. The distribution of discolored and colored teeth in Japan was investigated. We also investigated the relationship to age or to the shift in the amount of tetracycline antibiotics produced. No regional differences in the distribution range were found in 258 patients who were consulted. Many patients were born in the later period of 1960 when the production of tetracycline was large, and it was thus found that the production amount and patients' age distribution corresponded to each other. Although the use of tetracycline is said to cause discolored teeth, it became clear that the action of tetracycline solution on hydroxyapatite adheres to apatite, Moreover, it was found that ultraviolet irradation on tetracycline adhesion reagents significantly reduced the brightness of apatite. Moreover, permanently discolored teeth were analyzed by a Zeeman atomic absorption photometer, and it was found that iron (Fe) and magnesium(Mg) decreased and z
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inc increased significantly. The results of the analysis of aminoacids, in which the dental enamel outer layers were divided into colored part and transparent part, showed that amino-acid components such as Glu, Ala, and Tyr were different, and the proportion of D body derived from bacteria was large, as well as difference of bacterial flora involved in the coloration. Color classification of discolored teeth was conducted from the results obtained in surveys of acual situations of discolored teeth and the color was reproduced in model materials. Then, we evaluated color-shielding effects by beneer made by a CAD/CAM system with a color model material as a background color. This method is very useful in expressing natural color in which the color of discolored teeth is integrated. To reproduce a partial coloration and subtle lightness and darkness of color which discolored teeth have, a fine corolation becomes possible and color expression becomes easier when an ornament method by a heat-resisting color pencil is combined in a coloring fire-resisting model. Less
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