乳歯抜歯創の骨性治癒過程に関する実験的研究
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概要
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The third deciduous molars of young dogs about 3 months old were extracted, and daily changes in the extraction wounds and the surrounding tissue were investigated radiologically, optically, and pathohistologically from the 3rd to the 30th day after extraction. The results were as follows : 1. On the 3rd postoperative day, radiograms showed about the same radiolucency for the extarction wounds of the medial and distal roots. In microphotograms, however, the lower portion of the extraction wound of the distal root showed low density curves. Pathohistologically, new bone formation was seen in the distal side of the bottom of the extraction wound of the distal root. 2. In the radiograms on the 7th day, healing of the distal side in the middle portion of the extraction wound of the distal root was remarkable. Healing of the medial side in the middle and lower portions of the extraction wound of the distal root was active. Pathohistologically, epithelium extended to half of the surface of the extraction wound of the medial root. In the extraction wound of the distal root, epithelium covered nearly all of the surface. Where bone healing was markedly seen, many osteoblasts were observed. 3. On the 14th day, epithelium tissue completely covered the surface of the extraction wound of the medial root. Healing of the medial and distal sides was faster than that of other sites and tissue fusion of new trabeculae and the surrounding alveolar bone was observed. Osteoblasts were found up to the upper portion of the extraction wound of the distal root. New trabeculae were seen in all parts of the extraction wound. 4. On the 21st day, gingival epithelium of stratified rquamous epithelium widened its stratum corneum and corvered the surface layer of the extraction wound. Although the extraction wounds of the medial and distal roots were markedly radioopaque, healing of the middle portion of the extraction wound of the medial root continued and that of the central and distal sides especially was remarkable. In the extraction wound of the distal root, healing of the distal side in the upper portion was remarkable. 5. On the 30th day, the gingival epithelium covering the extraction wound widened its stratum corneum and formation of secondary papillae was remarkable. The proper layer of the connective tissue immediately below was continuous with the surrounding healthy tissue. Although healing of the central and distal sides was still in progress, new formation of trabeculae was seen in the medial and distal sides in the upper portion of the extraction wound. Appearance of osteoclasts in the distal side of the alveolar bone was remarkable because of growth of the succeeding permanent tooth in the extraction wound of the distal root. 6. Observation of changes in density in radiograms showed that the postoperative duration from the 7th to 14th days was the period when new bone formation was very active in healing process of the extraction wounds of deciduous teeth. The process mainly consisted of bone healing in the medial side of the middle portion of the extraction wound of the medial root and in the distal side of the middle portion of the extraction wound of the distal root. 7. In the subjects on the 3rd and the 7th day after extraction of deciduous teeth, slight inflammatory round cell infiltration and sparseness were observed in connective tissue of the dental sac surrounding the succeeding permanent tooth. However, extraction of deciduous teeth had almost no effect on formation and eruption of germs of permanent teeth.
- 九州歯科学会の論文
- 1985-12-25