Dentistry in Japan最新文献_第5页

Accuracy of complete dental arch impressions and stone casts using a three-dimensional measurement system. Effects on accuracy of rubber impression materials and trays. 使用三维测量系统测量完整牙弓印模和石模的准确性。对橡胶压模材料及托盘精度的影响。

Dentistry in Japan Pub Date : 1990-01-01

K Ishida

{"title":"Accuracy of complete dental arch impressions and stone casts using a three-dimensional measurement system. Effects on accuracy of rubber impression materials and trays.","authors":"K Ishida","doi":"","DOIUrl":"","url":null,"abstract":"The purpose of this study was to investigate and compare the accuracy of complete dental arch impressions and stone casts made with two kinds of impression materials (addition-type silicone and polysulfide rubber) and trays (custom tray and modified custom tray). In addition, the effect of the quantity of stone was examined. Impressions were made from a metallic model of a simplified maxillary dentition. Impressions and stone casts were measured respectively with a three-dimensional measuring microscope. The results were as follows: 1. Distortions of impressions were so small that the reproducibilities of impressions were superior three-dimensionally. These kinds of impressions and trays did not influence the accuracy of impressions. 2. The setting expansion of the stone in the impression occurred in the outward direction and was affected by the kinds of impressions and trays. 3. The arch widths and lengths of the stone casts tended to increase in number. 4. Stone casts made with addition-type silicone impression material and a custom tray were the most accurate because the combination of the impression material and tray effectively suppressed the setting expansion of stone. 5. The accuracy of stone casts could be improved by controlling the quantity of stone.","PeriodicalId":75798,"journal":{"name":"Dentistry in Japan","volume":"27 1","pages":"73-9"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13253918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Observations on the structural features and characteristics of biological apatite crystals. 1. Observation on the shape and arrangement of the cross sectioned enamel crystals. 生物磷灰石晶体结构特征及特性观察。1. 釉质横截面晶体形态及排列的观察。

Dentistry in Japan Pub Date : 1990-01-01

T Ichijo, Y Yamashita, T Terashima

{"title":"Observations on the structural features and characteristics of biological apatite crystals. 1. Observation on the shape and arrangement of the cross sectioned enamel crystals.","authors":"T Ichijo, Y Yamashita, T Terashima","doi":"","DOIUrl":"","url":null,"abstract":"In a series of studies to investigate the structural features of biological crystals, using transmission electron microscope, the observations have been made on the shape and arrangement of the cross-sectioned crystal obtained from cross sections through the body of adult human enamel rod, in the surface layer, and in the middle and deep layers. The shapes of the cross sectioned crystals in the surface layer of the enamel are generally different from those in the middle and deep layers. In the surface layer of the enamel, the cross sectioned crystals show a considerable variation in shape and size, and have an irregular shape. The crystals are densely packed. Each crystal is adjacent to the neighboring one, and usually, the arrangement of crystals have an appearance rather like a \"stone wall\". In contrast, the cross sectioned enamel crystals in the middle and deep layer, are somewhat small than those in the surface layer, and have greater gaps between the crystals. In the middle and deep layers of the enamel, it is rare for the shapes of the crystals to be irregular, therefore, they retain their original shape, most of which are long and hexagonal.","PeriodicalId":75798,"journal":{"name":"Dentistry in Japan","volume":"27 1","pages":"11-6"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13254095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Historical studies on the striae of Hunter-Schreger. 亨特-施雷格氏纹的历史研究。

Dentistry in Japan Pub Date : 1990-01-01

K Homma

{"title":"Historical studies on the striae of Hunter-Schreger.","authors":"K Homma","doi":"","DOIUrl":"","url":null,"abstract":"When the ground section of a human tooth is observed through a microscope, the oblique section, or the cross section, the enamel rod is dark and the vertical section it is light. These striae have been called the bands of Schreger. In his book published in 1961, Professor Fujita quoted a paper presented by Preiswerk (1894) as follows: \"Schreger found the striae in 1800 (Rosenmüller's und Isenflamm's Beiträge für die Zergliederungskunst, Bd. I, H. 1, Leipzig), but John Hunter from England reported the same findings earlier. For this reason, such striae were called the bands of Hunter-Schreger in Europe and America. In his paper of 1894, Preiswerk reported that Hunter found the striae in 1780; however, in the second edition of his book, The Natural History of the Human Teeth, published in 1778, Hunter showed an illustration that seemed to be the striae and annotated the illustration. The striae may have been reported even in his first edition (1771), but neither edition of the book is available in Japan.\" Quoting the first edition of Hunter's book, Hoffmann-Axthelm included the illustration of the striae in his book. Through this book, I found that Professor Fujita's conjecture was correct. Moreover, I recently had an opportunity to read the first and the second editions of John Hunter's book. Accordingly, I am reporting this report.","PeriodicalId":75798,"journal":{"name":"Dentistry in Japan","volume":"27 1","pages":"141-5"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13254719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Age changes of mandibular condyles and glenoid fossae in mice fed a liquid diet. 液体喂养小鼠下颌髁突和盂窝的年龄变化。

Dentistry in Japan Pub Date : 1990-01-01

K Kuroe, G Ito

引用次数: 0

Discovery and uses of super-elasticity in clinical orthodontics. 超弹性材料在临床正畸中的发现与应用。

Dentistry in Japan Pub Date : 1990-01-01

F Miura

引用次数: 0

Desensitization of mucin secretion from rat submandibular tissues in response to isoproterenol. 异丙肾上腺素对大鼠下颌下组织黏蛋白分泌的脱敏作用。

Dentistry in Japan Pub Date : 1990-01-01

Y Ishikawa, I Amano, H Ishida