Mayer I, Schneider S, Sydney-Zax M, Deutsch D
Department of Inorganic and Analytical Chemistry, Hadassah Faculty of Dental Medicine, Hebrew University, Jerusalem, Israel.
Calcif Tissue Int. 1990 Apr;46(4):254-7. doi: 10.1007/BF02555004.
The decomposition of forming, maturing, and mature enamel was studied between room temperature and 1,000 degrees C by powder X-ray diffraction and infrared absorption methods. In mature dental enamel, carbonate decomposition proceeds relatively fast until 500 degrees C and at a slower rate beyond it. In forming and maturing enamel, decomposition is faster and is completed around 800 degrees C. The formation of beta-Ca3(PO4)2 is observed in dental enamel at 500 degrees C. At 1,000 degrees C, the apatite phase in forming and maturing enamel transforms almost completely to beta-Ca3(PO4)2, whereas in mature enamel, even at 1,000 degrees C, only partial decomposition occurs. Infrared results show the appearance in dental enamel of (1) A-type carbonate at room temperature and in the 500-900 degrees C range, in addition to the commonly observed B-type carbonate, and (2) intermediate CO2 molecules during carbonate decomposition (200-500 degrees C).
通过粉末X射线衍射和红外吸收法，研究了在室温至1000摄氏度之间正在形成、成熟和成熟的牙釉质的分解情况。在成熟的牙釉质中，碳酸盐分解在500摄氏度之前进行得相对较快，之后速率较慢。在正在形成和成熟的牙釉质中，分解速度更快，在800摄氏度左右完成。在500摄氏度时，在牙釉质中观察到β-Ca3(PO4)2的形成。在1000摄氏度时，正在形成和成熟的牙釉质中的磷灰石相几乎完全转变为β-Ca3(PO4)2，而在成熟牙釉质中，即使在1000摄氏度时，也只发生部分分解。红外结果表明，在牙釉质中，（1）除了常见的B型碳酸盐外，在室温以及500-900摄氏度范围内还出现了A型碳酸盐，（2）在碳酸盐分解过程中（200-500摄氏度）出现了中间态的CO2分子。
