Ichijo T, Yamashita Y, Terashima T
Department of Oral Anatomy, Faculty of Dentistry, Tokyo Medical and Dental University.
Bull Tokyo Med Dent Univ. 1993 Jun;40(2):93-112.
In a series of studies to investigate the structural features of the biological crystals such as the tooth and bone, following the previous observations of the tooth crystal using an electron microscope, we examined the ultrastructure of the human bone crystals at near atomic resolution through the cross and longitudinal sections of the crystals. The materials used for this study were the normal bone tissue obtained from the buccal alveolar compact bone of the human mandible in the portion of the lower first molar. The small cubes of the bone tissue were fixed in glutaraldehyde and osmium tetroxide and embedded in epoxy resin using the routine methods. The ultrathin sections were cut with a diamond knife without decalcification. The sections were examined with the HITACHI H-800 type transmission electron microscope operated at 200 kV. Each crystal was observed at the initial magnification of 300,000 times and at the final magnification of 10,000,000 times and over. Using this approach, we showed the configuration of the hydroxyapatite structure in the cross and longitudinal sections of the bone crystals deposited within and between the collagen fibrils (intrafibrillar and interfibrillar crystals) in the bone tissue. Furthermore, using the same approach, we observed the crystal lattices of the hydroxyapatite structure appearing in the cross and longitudinal sections. We sincerely believe that the electron micrographs shown in this report are the first atomic images from the section obtained from the hydroxyapatite crystal from the human alveolar bone.
在一系列旨在研究牙齿和骨骼等生物晶体结构特征的研究中，继先前使用电子显微镜对牙齿晶体的观察之后，我们通过晶体的横断面和纵断面，以近原子分辨率研究了人体骨晶体的超微结构。本研究使用的材料是取自人类下颌第一磨牙部位颊侧牙槽骨密质骨的正常骨组织。将骨组织小块用戊二醛和四氧化锇固定，并采用常规方法包埋于环氧树脂中。用金刚石刀在不脱钙的情况下切取超薄切片。切片用工作电压为200 kV的日立H - 800型透射电子显微镜进行观察。对每颗晶体先以300,000倍的初始放大倍数观察，然后以10,000,000倍及以上的最终放大倍数观察。通过这种方法，我们展示了沉积在骨组织中胶原纤维内部和之间（纤维内和纤维间晶体）的骨晶体横断面和纵断面中羟基磷灰石结构的形态。此外，使用相同方法，我们观察到了在横断面和纵断面中出现的羟基磷灰石结构的晶格。我们坚信本报告中所示的电子显微照片是来自人类牙槽骨羟基磷灰石晶体切片的首批原子图像。
