Further electron microscope studies of dentine

Scanning and Transmission Electron Microscopic Studies of the Etched Dentin Surface

“…In the present study, the membranous tubular structure studied under scanning electron microscope were shown to be identical with the structure consisting of fine crystals accumulating in membranous fashion under transmitted electron microscope in view of the shape, location and diameter. This probably represents the inner organic sheath mainly consisting of collagen fibrils according to SHROFF et al [7] or fine crystals constituting peritubular dentin persisting without being dissolved are equivalent to the inner hypocalcified layer according to AJISAKA et al [3] and ISOKAWA et al [4]. No reprecipitation of large needle-like crystal described by SELvIG [11] was found, probably due to the difference in the method of preparation of specimens.…”

“…The acid-resistant layer at the border between peritubular dentin and intertubular dentin probably corresponds to the outer organic sheath according to SHROFF et al [7] or outer hypocalcified layer according to ISOKAWA et al [4].…”

“…[6,7]; TAKumA [8]; JOHANSEN [9] ; BOYDE and LEsTER [10]; SELvic[ 1 1]; AJISAKA et al . [3] and ISOKASA et al [4]) in our department demonstrated scanning electron microscopically a rapid dissolution of peritubular dentin in acid and membranous structures within the dentinal tubules.…”

Organic Structures of the Hypercalcified Peritubular Matrix in Horse Dentine

“…5, 8], Takuma [4] found by using TEM on the replicas that the inner organic sheath contained collagen fibrils with regular 64-nm striations, and Isokawa et al [9] showed tubular membranous structures of a fibrous feltwork in it by scanning electron microscopy (SEM). Reliable evidence on the fibrillar outer organic sheath, however, has not been reported [1.5], although the outer organic sheath which did not show fibrils was faintly observed in the half-decalcified ultrathin sections [ 10] as well as in the replicas previously reported [2,7], For morphological studies of the PM in human dentine, various acids have been used, for example formic acid, for mic acid-sodium citrate, hydrochloric acid, nitric acid and phosphotungstic acid, and as a result the organic structures within the PM showed fine fibrils [2,7], a feltwork of deli cate fibrils [5], a low density of amorphous substance [8] and matrix fibres [9] by TEM or SEM.…”

Electron Microscope Studies of the Submicroscopic Structure of the Dentinal Matrix

“…It has been described as a homogeneous calcified cementing substance7 or a cement composed of inorganic salts and an organic material sensitive to the action of papain.8 For this paper, the dentin matrix is defined as that region in dentin occupied by the mineral salts hydroxyapatite, and will include not only the intertubular region but also the outer calcified sheaths of the dentinal tubules. 3 Since prevailing histologic concepts of the fine structure of dentinal matrix are not clear, the present investigation was necessary to determine the microstructure of sheep's teeth as part of a programme being carried out to find the cause of the excessive wear when the sheep feed on certain improved pastures.9 A comparison with human dentin was of interest and a sperm whale tooth was chosen to see if the largest mammal had identical dentin microstructure.…”