Byers M R, Taylor P E, Khayat B G, Kimberly C L
Department of Anesthesiology, University of Washington, Seattle.
J Endod. 1990 Feb;16(2):78-84. doi: 10.1016/S0099-2399(06)81568-2.
Several studies dealing with the reactions of dental nerve fibers to injury and inflammation are reviewed in this article. The subgroup of dental nerve fibers that contains calcitonin gene-related peptide (CGRP) was examined by immunocytochemistry at various times (1 to 35 days) after one of three degrees of injury: (a) Mild: Four days after making shallow cavities into cervical dentin of first molars of anesthetized adult rats, we found that CGRP fibers had sprouted into the subjacent odontoblast layer and dentin, and then returned to normal by 3 wk. (b) Intermediate: If the cervical cavities were acid etched, we found damage to the odontoblast layer, microabscess formation, and sprouting of CGRP fibers near the abscess, with subsequent formation of reparative dentin and healing. (c) Severe: If the pulp was exposed, a variety of reactions could occur, the most prevalent of which was a severe necrosis leading to development of periapical lesions. Analysis of the progressive stages of pulpal abscess and necrosis showed sprouting CGRP nerve fibers (a) at the retreating interface between abscess and vital pulp; (b) in periapical areas during onset of lesions; and (c) around chronic abscesses in granulomatous periodontal tissues. These studies are discussed in relation to various dental clinical problems such as hypersensitive teeth, episodic toothache, early onset of periapical lesions, dental anesthesia, and possible roles for sensory fibers and neuropeptides in tissue defense and healing.
本文综述了几项关于牙神经纤维对损伤和炎症反应的研究。通过免疫细胞化学方法，在三种不同程度损伤后的不同时间（1至35天），对含有降钙素基因相关肽（CGRP）的牙神经纤维亚组进行了检测：（a）轻度：在麻醉的成年大鼠第一磨牙颈部牙本质制备浅洞4天后，我们发现CGRP纤维已长入下方的成牙本质细胞层和牙本质，然后在3周时恢复正常。（b）中度：如果对颈部洞进行酸蚀，我们发现成牙本质细胞层受损、微脓肿形成以及脓肿附近CGRP纤维的芽生，随后形成修复性牙本质并愈合。（c）重度：如果牙髓暴露，可能会发生多种反应，其中最常见的是严重坏死，导致根尖周病变的发展。对牙髓脓肿和坏死的进展阶段分析表明，CGRP神经纤维芽生出现于：（a）脓肿与活髓之间的退缩界面；（b）病变开始时的根尖周区域；（c）肉芽肿性牙周组织中的慢性脓肿周围。结合各种牙科临床问题，如牙齿敏感、发作性牙痛、根尖周病变的早期发生、牙科麻醉以及感觉纤维和神经肽在组织防御和愈合中的可能作用，对这些研究进行了讨论。
