Raab W H
Department for Restorative Dentistry and Periodontology, University of Ulm, Germany.
Proc Finn Dent Soc. 1992;88 Suppl 1:469-79.
During dental treatment temperatures can be reached which might possibly damage the tooth pulp. To determine the effect of both thermal stimulation on pulpal microcirculation and local anesthesia on thermoregulation we measured the pulpal blood flow by using laser Doppler flowmetry. Experiments were carried out on lower incisors of Wistar rats anaesthetized with thiopental. The rats were divided into three groups, with one remaining untreated, and the others being either desensitized with capsaicin or sympathectomized with guanethidine. In a range between 33 degrees C and 42 degrees C there was no substantial change in blood flow, which, however, was the case below 33 degrees C. Up to 49 degrees C an increase could be recorded in both untreated and guanethidine pretreated animals, whereas the capsaicin groups showed almost no reaction. This increase in blood flow can be blocked reversibly by local anaesthesia. For this purpose we tested articain 5% and mepivacain 3%, both without constrictor. Intravital microscopic studies show that the temperature related increase in blood flow is also associated with plasma extravasation. From these results we draw the conclusion that pulpal thermoregulation is linked to nociceptive sensory neurons and can be described as "neurogenic inflammation".
在牙科治疗过程中，可能会达到一些温度，这些温度有可能损害牙髓。为了确定热刺激对牙髓微循环的影响以及局部麻醉对温度调节的作用，我们使用激光多普勒血流仪测量了牙髓血流量。实验在硫喷妥钠麻醉的Wistar大鼠的下切牙上进行。大鼠被分为三组，一组不做处理，其他两组分别用辣椒素脱敏或用胍乙啶进行交感神经切除术。在33摄氏度至42摄氏度的范围内，血流量没有实质性变化，然而，在33摄氏度以下则不然。在未处理和胍乙啶预处理的动物中，高达49摄氏度时血流量会增加，而辣椒素组几乎没有反应。这种血流量的增加可被局部麻醉可逆地阻断。为此，我们测试了5%的阿替卡因和3%的甲哌卡因，两者均不含血管收缩剂。活体显微镜研究表明，与温度相关的血流量增加也与血浆外渗有关。从这些结果中我们得出结论，牙髓温度调节与伤害性感觉神经元有关，可被描述为“神经源性炎症”。
