Bosshardt D D
Department of Periodontology and Fixed Prosthodontics, School of Dental Medicine, University of Berne, Freiburgstrasse 7, CH-3010 Berne, Switzerland.
J Dent Res. 2005 May;84(5):390-406. doi: 10.1177/154405910508400501.
Experimental studies have shown a great potential for periodontal regeneration. The limitations of periodontal regeneration largely depend on the regenerative potential at the root surface. Cellular intrinsic fiber cementum (CIFC), so-called bone-like tissue, may form instead of the desired acellular extrinsic fiber cementum (AEFC), and the interfacial tissue bonding may be weak. The periodontal ligament harbors progenitor cells that can differentiate into periodontal ligament fibroblasts, osteoblasts, and cementoblasts, but their precise location is unknown. It is also not known whether osteoblasts and cementoblasts arise from a common precursor cell line, or whether distinct precursor cell lines exist. Thus, there is limited knowledge about how cell diversity evolves in the space between the developing root and the alveolar bone. This review supports the hypothesis that AEFC is a unique tissue, while CIFC and bone share some similarities. Morphologically, functionally, and biochemically, however, CIFC is distinctly different from any bone type. There are several lines of evidence to propose that cementoblasts that produce both AEFC and CIFC are unique phenotypes that are unrelated to osteoblasts. Cementum attachment protein appears to be cementum-specific, and the expression of two proteoglycans, fibromodulin and lumican, appears to be stronger in CIFC than in bone. A theory is presented that may help explain how cell diversity evolves in the periodontal ligament. It proposes that Hertwig's epithelial root sheath and cells derived from it play an essential role in the development and maintenance of the periodontium. The role of enamel matrix proteins in cementoblast and osteoblast differentiation and their potential use for tissue engineering are discussed.
实验研究表明牙周再生具有巨大潜力。牙周再生的局限性很大程度上取决于牙根表面的再生潜力。细胞内源性纤维牙骨质（CIFC），即所谓的骨样组织，可能会形成，而不是理想的无细胞外源性纤维牙骨质（AEFC），并且界面组织结合可能较弱。牙周膜含有能够分化为牙周膜成纤维细胞、成骨细胞和牙骨质细胞的祖细胞，但其确切位置尚不清楚。也不清楚成骨细胞和牙骨质细胞是否起源于共同的前体细胞系，或者是否存在不同的前体细胞系。因此，关于在发育中的牙根与牙槽骨之间的空间中细胞多样性如何演变的知识有限。这篇综述支持这样一种假说，即AEFC是一种独特的组织，而CIFC与骨有一些相似之处。然而，在形态、功能和生化方面，CIFC与任何骨类型都有明显不同。有几条证据表明，产生AEFC和CIFC的牙骨质细胞是与成骨细胞无关的独特表型。牙骨质附着蛋白似乎是牙骨质特异性的，并且两种蛋白聚糖，即纤维调节素和核纤层蛋白，在CIFC中的表达似乎比在骨中更强。本文提出了一种理论，可能有助于解释牙周膜中细胞多样性是如何演变的。该理论认为，赫特维希上皮根鞘及其衍生细胞在牙周组织的发育和维持中起着至关重要的作用。还讨论了釉基质蛋白在成牙骨质细胞和成骨细胞分化中的作用及其在组织工程中的潜在用途。
