各種修復材料が犬の象牙質および歯髄に与える影響についての電子顕微鏡的研究
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概要
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The study was performed on 192 contra-lateral canine and molar teeth of dogs. Uniform cavities, Class V, were prepared in the buccal surface. The floor of each cavity was covered by a thick layer of the following four restorative materials : (1) calcium hydroxide paste, "Dycal" ; (2) non-zinc amalgam, "Hi-Atomic M" ; (3) polycarboxylate cement, "Unident" ; or (4) composite resin, "Adaptic". After varying times following the application of the restoratives, the cavity dentinal tubules were observed by scanning electron microscopy, and the odontoblastic layer beneath the cavity was examined by transmission electron microscopy. Energy dispersive x-ray microanalysis of the intratubular granules was performed with a spectrometer (Kevex 7000Q EDS) fitted to an electron microscope (H-700H) with a scanning transmission attachment. Results were as follows : A. Transmission electron microscopic findings : 1. Five and ten days after restoration, the odontoblastic changes beneath cavities filled with any one of the four restorative materials were much the same. Enlargement of the intercellular space and margination of the chromatin were observed in the odontoblastic layer, and the organelles were well developed. 2. Thirty days after restoration, the odontoblasts below the dentin which was covered with Dycal, Hi-Atomic M and Unident were nearly normal, but in the case of Adaptic, the shape of the nucleus was markedly irregular and well-developed organelles, lysosomes and an increased number of lipofuscin granules were seen. 3. One hundred fifty days after restoration, ultrastructural changes were similar to those of thirty days after restoration. B. Scanning electron microscopic findings : 1. Five days after restoration, fine granules attached to minute reticulate fibers were seen scattered on the dentinal tubules of cavities containing any of the four experimental restorative materials, although there were fewer granules on the Adaptic-covered dentinal tubules. 2. Twenty days after restoration, although the tubules of cavities coated with either Dycal or Unident were filled with the fine granules, the tubules of Hi-Atomic M and Adaptic treated cavities contained only a scattering of the granules. Similar findings were seen at thirty and sixty days after restoration, too. 3. One hundred fifty days after restoration, the dentinal tubules were tightly sealed with the granular deposits in the Dycal and Unident groups, being moderately so in the Hi-Atomic M, and loosely in the Adaptic. 4. On the pulpal side of dentinal tubules covered with Hi-Atomic M and Adaptic, globular-shaped substances from 0.1 to 0.3μm in diameter were often observed. C. Energy dispersive x-ray microanalysis findings : 1. Analysis of the spots representing the fine granules in the cavity dentinal tubules disclosed high peaks for calcium and phosphorus. 2. The quantity of calcium in the fine granules was higher than that in intertubular dentin.
- 九州歯科学会の論文
- 1984-06-25