Aoba T, Moreno E C
Physical Chemistry Department, Forsyth Dental Center, Boston, MA 02115.
Calcif Tissue Int. 1990 Dec;47(6):356-64. doi: 10.1007/BF02555887.
The present study was undertaken to investigate changes in the crystalline structure and composition of procine enamel mineral during amelogenesis. Special attention was given to the carbonate location in the forming apatite crystal. Enamel samples were obtained from the outer (young) secretory, inner (old) secretory, maturation, and mature (hard) enamel of the permanent incisors of slaughtered piglets. The crystalline structure and composition of these enamel samples were studied using Fourier transform infrared spectroscopy, X-ray diffraction, and chemical analyses. The initial enamel mineral in the outer secretory enamel was rich in acid phosphate and carbonate. The carbonate was mainly substituted for phosphate groups in the apatite crystals of the early (outer) secretory enamel. Developmental advancement from the outer secretory to the inner secretory (as well as early maturation) stages brought about significant changes in crystal parameters, namely, shrinkage and expansion of the c and a unit cell dimensions, respectively, and the shift of a v3 PO4 band to higher wavenumbers in the FTIR spectrum. X-ray diffraction patterns indicated that mineralization during the tissue maturation was characterized by a gradual growth of enamel crystals parallel to the a-axis direction. A most prominent finding was that, with developmental advancement, a decrease in CO3 per unit mass of P (or Ca) in the tissue, and a concomitant increase in the CO3 occupying OH sites in the crystalline lattice became apparent.
本研究旨在调查猪牙釉质矿化过程中晶体结构和组成的变化。特别关注了形成中的磷灰石晶体中碳酸盐的位置。从屠宰仔猪的恒切牙的外层（年轻）分泌性、内层（年老）分泌性、成熟和成熟（坚硬）牙釉质中获取牙釉质样本。使用傅里叶变换红外光谱、X射线衍射和化学分析研究了这些牙釉质样本的晶体结构和组成。外层分泌性牙釉质中的初始牙釉质矿物质富含酸性磷酸盐和碳酸盐。碳酸盐主要取代早期（外层）分泌性牙釉质磷灰石晶体中的磷酸基团。从外层分泌性到内层分泌性（以及早期成熟）阶段的发育进展导致晶体参数发生显著变化，即c轴和a轴晶胞尺寸分别收缩和扩大，并且在傅里叶变换红外光谱中v3 PO4带向更高波数移动。X射线衍射图谱表明，组织成熟过程中的矿化特征是牙釉质晶体沿a轴方向逐渐生长。一个最显著的发现是，随着发育进展，组织中每单位质量的P（或Ca）中的CO3含量降低，并且晶格中占据OH位点的CO3含量随之增加。
