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, 271 (3), 453-60

Bone-like Nodules Formed in Vitro by Rat Periodontal Ligament Cells


Bone-like Nodules Formed in Vitro by Rat Periodontal Ligament Cells

M Mukai et al. Cell Tissue Res.


The periodontal ligament has been shown to possess the ability to regenerate both new cementum and alveolar bone as well as a self-regenerative capacity; however, the source of cementoblasts and osteoblasts is not still clear. We investigated the development of bone-like tissue in vitro by periodontal ligament cells, in order to determine whether the periodontal ligament contains osteoprogenitor cells. Periodontal ligament cells were obtained from periodontal ligament tissue attached to the maxillary incisors of 6-week-old WKA rats by means of the explant technique. Cells at passage #3 were cultured for long term in alpha-minimum essential medium containing 10% fetal bovine serum, antibiotics, and 50 micrograms/ml ascorbic acid, and were then examined using phase-contrast microscopy, histochemistry, transmission electron microscopy, X-ray microanalysis, and electron diffraction. Nodules were formed in the cultures, and when 10 mM Na-beta-glycerophosphate was added, these nodules became mineralized. The mineralized nodules were identified as bone-like elements in view of the presence of osteoblast-like and osteocyte-like cells, collagenous matrix, a mineral composed of hydroxyapatite, and intense alkaline phosphatase activity. The results show that the periodontal ligament contains osteoprogenitor cells, which differentiate into osteoblasts and produce bone-like tissue.

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Cited by 4 PubMed Central articles


    1. J Clin Periodontol. 1982 May;9(3):257-65 - PubMed
    1. J Periodontol. 1976 May;47(5):256-60 - PubMed
    1. Calcif Tissue Int. 1982 Jan;34(1):76-9 - PubMed
    1. J Clin Periodontol. 1984 Sep;11(8):494-503 - PubMed
    1. J Periodontal Res. 1983 Jul;18(4):339-52 - PubMed

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