A PHYSIOLOGICAL STUDY ON THE CHEMICAL STIMULATION OF DENTAL PULP NERVE AND AN ETIOLOGICAL STUDY ON THE PAIN WITH PULPAL DISEASES.

我们进行了外周和中枢神经系统反应性改变与牙髓疼痛刺激的基础动物实验相结合的研究，以及口面部、头颈部疼痛与牙髓疾病关系的临床研究。结果如下：(1)小纤维兴奋剂和炎症剂芥子油作用于大鼠磨牙牙髓，可引起大鼠下颌肌静息肌电活动增加，尤其是同侧咬肌有明显变化。(2)化学条件刺激同侧犬牙髓可增强猫颈髓(C3区C2)神经元对电刺激下牙槽神经(IANDN)的反应性，即在施加芥子油后，IANDN的兴奋性增加，皮肤感受野扩大。这些结果表明，芥子油刺激牙髓可以激活中枢敏化机制。(3)芥子油对牙髓的化学刺激增加了单个牙周机械感受性初级纤维对尖端压力刺激的兴奋性，并产生了敏化，这可能是由轴突反射引起的神经源性炎症所介导的。(4)临床检查显示，这些疼痛与所谓的感染根管系统密切相关。这些结果表明，芥子油化学刺激牙髓神经为研究牙髓炎症变化与其相关疼痛的关系提供了有用的实验方法。

We performed a combined study of basic animal experments on the alteration of peripheral and central nervous system responsiveness with painful pulpal stimulation and clinical research on the relationship between the oro-facial, head and neck pain and the pulpal diseases. The results obtained are as follows ;(1) A small fiber exciant and inflammatory agent, mustard oil, applied to the rat molar tooth pulp, produced an increase activities in resting EMG of the rat jaw muscles, and a significant change especially in the ipsilateral masseter muscle.(2) Chemical conditionong stimulation of mustard oil to the ipsilateral canine tooth pulp enhenced the responsiveness of the cat cervical spinal cord (C2 of C3) neurons responding to the electrical stimulation to the inferior alveolar nerve (IANDN) ; that is, a temporal increase of the excitability as well as an expansion of cutaneous receptive field was observed in the IANDNs during the post-application periods of mustard oil. These results suggested that the mustard oil pulpal stimulation could activate the central sensitization mechanisms.(3) Chemical stimulation of the tooth pulp with mustard oil increased the excitability of the single periodontal mechanoreceptive primary fiber responding to the pressure stimulation to the canine tip, and produced the sensitization, which might be mediated by the neurogenic inflammation due to the axon reflex.(4) A clinical examination of the patients suffering from the severe pain in the oro-facial, head and neck region with respect to the pulpal diseases revealed that these kinds of pain were closely related with so-called infected root canal system, and that some of them were thought to be classified into the ideopathic pain groups.These results indicated that the chemical stimulation of the tooth pulp nerve with mustard oil provided useful methods in the experimental study on the relationship between the pulpal inflammatory changes and their related pain.