The influence of occlusal overload on the threshold of tooth pain.

咬合过度负荷引起的活髓牙过敏在牙科实践中已被发现，但其机制尚不清楚。本研究旨在探讨咬合负荷对牙髓及牙周组织的影响。将高嵌体放置在志愿者的牙齿中，并使用IP-TOX测量额外的高度。测量电刺激引起的牙齿疼痛阈值、牙齿垂直移动值和牙周脉动幅度。在高嵌体植入前后，用咬合纸记录牙弓咬合接触情况。研究结果如下：1. 21颗牙齿中，16颗牙齿疼痛阈值降低，3颗牙齿疼痛阈值升高，2颗牙齿疼痛阈值无特征性变化。2.牙痛阈值的降低可能是由于牙髓组织的可逆性炎症，而增加可能是由于牙髓血流的反复轻微减少或牙周组织顶端的牙髓神经上的压力。3.牙齿疼痛阈值的变化与牙齿垂直移动的状态和牙周膜搏动的幅度有明显的关系。4.高嵌体有时会引起整个牙弓咬合接触的变化，即使在进行了适当的咬合调整之后也是如此。

The hypersensitivity of a vital tooth caused by occlusal overload is found in dental practice, but this mechanism is an open question. In this research the influence of occlusal overload on tooth pulp as well as periodontal tissue was studied. A high inlay was placed in a tooth of a volunteer and the additional height was measured with IP-Checker. The threshold of tooth pain induced by electrical stimulation, the value of vertical tooth migration and the amplitude of periodontal pulsation were measured. The condition of occlusal contacts in a dental arch was recorded with an articulating paper before and agter the placement of a high inlay. The results are as follows:1. 21 teeth studied, 16 decreased in the threshold of tooth pain, three increased and two did not show the characteristic change. 2. The decrease in the threshold of tooth pain might be due to reversible inflammation of the pulpal tissue, while the increase might be due to repetitive slight decrease of the pulpal blood stream or to pressure on the pulpal nerve at the apex of periodontal tissue. 3. The threshold changes of tooth pain had a significant relationship to the state of the vertical tooth migration and the amplitude of periodontal pulsation. 4. a high inlay sometimes induced the change in occlusal contacts throughout the dental arch even after the proper occlusal adjustment was done.