著者

Tetsuro Kono Takao Kuwada-Kusunose Tomohiko Hirayama Kunihiro Suzuki

出版者

Research Institute of Oral Science, Nihon University School of Dentistry at Matsudo

雑誌

International Journal of Oral-Medical Sciences (ISSN:13479733)

巻号頁・発行日

vol.17, no.3-4, pp.81-85, 2019-03-20 (Released:2019-03-30)

参考文献数

21

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Most mammals possess microstructural decussation in the tooth enamel. The HunterSchreger bands(HSB)are the important microstructure created by differently directed enamel prisms, as observed under a reflective light microscope. The prism decussation of some rhinocerotoids reveals that HSB run vertically along the axis of the tooth. The boundary between the bands is definite in the tangential section. Teleoceras is an extinct rhinocerotoid that was commonly found in the Miocene area of North America. Our observations revealed vertical prism decussation in the inner two-thirds to four-fifths of the Teleoceras molar enamel. The prisms strongly twisted on each axis, and the path of each prism undulated at the border of the bands. Their relative relations revealed inclinational changes and displacement to the adjacent zone of the HSB. Reconstructed threedimensional images were used for complementation of microscopic observations.

著者

Hiroya Gotouda Ikuo Nasu Tetsuro Kono Yukari Ootani Takeshi Kanno Ryo Tamamura Takao Kuwada-Kusunose Kunihiro Suzuki Tomohiko Hirayama Tatsuya Hirayama Toshiro Sakae Hiroyuki Okada

出版者

硬組織再生生物学会

雑誌

Journal of Hard Tissue Biology (ISSN:13417649)

巻号頁・発行日

vol.26, no.1, pp.81-86, 2017 (Released:2017-01-06)

参考文献数

20

被引用文献数

5

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The aim of this study was to show the reaction varieties of human tooth enamel and dentin with a carbonated soft drink, Sprite. After one week exposing into the soft drink, the sliced tooth specimens were examined by macroscopic and microscopic and then carried out the micro X-ray diffraction analysis using a 100 μm diameter X-ray beam. The macroscopic and microscopic results showed the wide varieties from the one showing a very slight increase white-spot areas in the enamel to the another showing almost complete decay of the enamel. The crystallites in the examined enamel and dentin changed drastically as follows; the one enamel sample showed the decrease of crystal amount and some ionic substitutions, and the another dentin sample showed the increase in crystallinity and ionic substitutions. These results clearly showed that the original tooth enamel and dentin had their own crystallographic properties differing from each others. This study provided a crystallographic basic data which will be applied to a tayler-made individual preventive dentistry in near future.

著者

Tetsuro Kono Arata Watanabe Takeshi Kanno Yukari Ootani Ryo Tamamura Toshiro Sakae Hiroyuki Okada

出版者

THE SOCIETY FOR HARD TISSUE REGENERATIVE BIOLOGY

雑誌

Journal of Hard Tissue Biology (ISSN:13417649)

巻号頁・発行日

vol.28, no.2, pp.129-138, 2019 (Released:2019-04-24)

参考文献数

44

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To elucidate the crystallo-chemical reaction between the enamel and carbonated soft drink, a micro-X-ray diffraction analysis (micro-XRD) was conducted using the human tooth sections soaked in the drink (Sprite®) for 1 and 7 days. In this study, 4 typically and heavily dissolved teeth were selected from 20 teeth, and the divergence of the crystallographic properties of the enamel was analyzed.All of the untreated human tooth enamels exhibited only the apatitic XRD patterns. We confirmed that the carbonated soft drink changed the macro- and microscopic morphological features of individual tooth enamel. The following 4 results were obtained from our study: i) the unit cell dimensions and crystallinity of the untreated enamel apatite varied between the layers and the individual teeth; ii) after the soaking experiment, the crystallographic properties of the enamels changed remarkably and displayed non-uniformity; iii) no relationship was discerned between the enamel’s crystallographic properties and the sensitivity of the carious attack; and iv) the intermediate reaction product of soaking was uncovered; however, it was not identified at this time. The presence or absence of occurrence and variations in the amount of intermediate product reflected the complex chemical and crystallo-chemical reactions between the decalcification solution and the human tooth enamel crystallites.We clearly established that the untreated human tooth enamels differed in their crystallographic properties and did not react in the same manner, which resulted in varied apatitic structures after soaking. These results necessitate reconsideration of the generally accepted caries protection methods that are applied as common standards for all individuals and tooth enamels.