Matthews B, Baxter J, Watts S
Brain Res. 1976 Aug 20;113(1):83-94. doi: 10.1016/0006-8993(76)90008-1.
Experiments have been carried out to investigate whether all tooth pulp afferent nerves are capable of producing pain. Monopolar and bipolar stimuli were applied to teeth in human subjects and sensory thresholds determined. EMGs were recorded from the masseter and the anterior digastric muscles. With stimuli up to three times the sensory threshold, no response could be detected in the digastric but at, or just above, the sensory threshold, inhibitory effects were produced in masseter muscle. The latency of the muscle response with bipolar stimulation was 18-22 msec. There was no evidence of stimulus spread to nerves outside the teeth. Bipolar and monopolar stimulation both produced the same sensation but this was not described as painful. It is concluded that some pulpal afferent nerves may not be capable of producing pain, and that the sensory and reflex responses at threshold were probably produced by the same fibres.
已开展实验以研究是否所有牙髓传入神经都能引发疼痛。对人类受试者的牙齿施加单极和双极刺激，并测定感觉阈值。记录了咬肌和二腹肌前腹的肌电图。当刺激强度高达感觉阈值的三倍时，未在二腹肌中检测到反应，但在感觉阈值或略高于感觉阈值时，咬肌产生了抑制作用。双极刺激时肌肉反应的潜伏期为18 - 22毫秒。没有证据表明刺激扩散到了牙齿以外的神经。双极和单极刺激产生的感觉相同，但这种感觉并未被描述为疼痛。结论是一些牙髓传入神经可能无法引发疼痛，并且阈值时的感觉和反射反应可能由相同的纤维产生。
