[Studies on the structure of the matrix in cementum regenerated in healing process of periodontal tissues].
The purpose of this study was to investigate the structure of the matrix in regenerated cementum on surgically denuded root dentin and on acid-demineralized root dentin in dogs. Non-decalcified specimens were examined two to 16 weeks after surgery. The arrangement of the matrix fiber, the fiber component and the crystal deposition of the cementum were studied by light microscopy and electron microscopy. The results were as follows: 1. There were many differences in the structures of regenerated cementum. The differences were dependent on the presence of resorption of the root dentin, existence of lamellar structure, and density of Sharpey's fibers. 2. Regions without surface resorption of dentin exhibited a dense deposition of crystallites and a rare arrangement of collagen fibrils at the cementodentinal junction. 3. Regions of surface resorption of dentin exhibited a layer where dentinal and cemental crystallites were amalgamated, and/or dentinal and cemental matrix fibers were interdigitated at the cementodentinal junction. 4. Regions subjected to artificial demineralization by citric acid exhibited similar structure to that where surface resorption of dentin was observed. 5. It is suggested that the resorption of dentinal surface during the healing process of a surgically created wound in periodontal tissue occurred as an intermediate stage followed by the establishment of a stronger bind by the increase of superficial contact area at the cementodentinal junction.
Kinoshita
A
A
Department of Periodontology, Faculty of Dentistry, Tokyo Medical and Dental University.
D000818:Animals; D001857:Bone Matrix / Q000502:physiology / Q000648:ultrastructure*; D001861:Bone Regeneration; D003739:Dental Cementum / Q000502:physiology / Q000648:ultrastructure*; D004285:Dogs; D008854:Microscopy, Electron; D010519:Periodontium / Q000502:physiology*; D013997:Time Factors; D014945:Wound Healing