Kvinnsland I, Heyeraas K J
Department of Cariology and Endodontics, School of Dentistry, University of Bergen, Norway.
Histochemistry. 1992;97(2):111-20. doi: 10.1007/BF00267300.
Traumatic occlusion provides a trauma that affects the whole tooth and its supporting tissues. To study the effect of this trauma on CGRP and SP immunoreactive nerve morphology in pulp and periodontium, traumatic occlusion was induced in 2-months-old rats. The occlusal surface of the first maxillary molar in 30 rats were unilaterally raised 1 mm with a composite material. At different observation periods up to 30 days, the rats were transcardiacally perfused, the jaws demineralized, sectioned and processed for immunohistochemistry with the avidin-biotin-peroxidase method. Changes in nerve morphology, distribution and density in first and second molars and their supporting tissues were analyzed and compared in experimental (n = 30) and control rats (n = 14). Already after 5 days with traumatic occlusion, 22% of the experimental teeth had increased density of CGRP and SP immunoreactive nerves locally in gingiva, the periodontal ligament and the pulp, while in 15%, axonal proliferation and changed nerve morphology were found in the whole pulp (severe reaction). During a 20-day period, the pulpal nerve reactions progressed and included the whole pulp in 46% of the experimental teeth. The periodontal nerve responses were still localized only to the cervical and apical regions, and they remained local in these areas throughout the experimental periods. After 20 days the number of teeth with severe nerve changes seemed to decrease. The study shows that an unilateral change in occlusion of the first molar initiate nerve responses in the total molar dentition. In this experimental model the pulpal axons containing CGRP and SP reacted more serious to occlusal trauma than the nerves in the periodontium. The results indicate that the nerve changes in some cases might be transient.
创伤性咬合会造成影响整个牙齿及其支持组织的损伤。为研究这种损伤对牙髓和牙周组织中降钙素基因相关肽（CGRP）和P物质（SP）免疫反应性神经形态的影响，对2月龄大鼠诱导产生创伤性咬合。用复合材料将30只大鼠上颌第一磨牙的咬合面单侧抬高1毫米。在长达30天的不同观察期，对大鼠进行经心灌注，将颌骨脱钙、切片，并用抗生物素蛋白-生物素-过氧化物酶法进行免疫组织化学处理。对实验组（n = 30）和对照组大鼠（n = 14）的第一和第二磨牙及其支持组织中神经形态、分布和密度的变化进行分析和比较。创伤性咬合5天后，22%的实验牙齿在牙龈、牙周膜和牙髓局部的CGRP和SP免疫反应性神经密度增加，而15%的实验牙齿在整个牙髓中发现轴突增生和神经形态改变（重度反应）。在20天的时间里，牙髓神经反应进展，46%的实验牙齿整个牙髓都出现反应。牙周神经反应仍仅局限于颈部和根尖区域，并且在整个实验期间在这些区域保持局部反应。20天后，出现严重神经变化的牙齿数量似乎减少。该研究表明，第一磨牙咬合的单侧改变会引发整个磨牙牙列的神经反应。在这个实验模型中，含有CGRP和SP的牙髓轴突对咬合创伤的反应比牙周组织中的神经更严重。结果表明，在某些情况下神经变化可能是短暂的。
