Does bruxism affect periodontal sensation?

重度磨牙者临床上有时可观察到低牙周感。虽然已有一些研究试图定量地评价牙周感觉，但尚未完全阐明，特别是关于牙内力感受器和牙周膜机械感受器之间的反应方式的差异。本研究旨在1)建立一种可靠的方法来评估牙周膜机械感受器的牙周感觉阈值，2)检验非磨牙者的牙周感觉特性(力阈值在一天内的波动，3)比较磨牙和非磨牙的阈值。低速机械刺激器由弹性泡沫聚合物制成的无声发力器，能够对靶牙齿施加缓慢而稳定增加的无声机械载荷。因此，该刺激器可以测量来自牙周膜机械感受器的力阈值。18名具有完整自然牙列的非磨牙者参与了牙周感觉特性的检测。对每个志愿者的左上侧切牙进行检查。关于武力阈值在一天内的波动和逐日波动，没有观察到显著差异。20名完全自然牙列的志愿者(10名非磨牙者，10名磨牙者)进行了牙周感觉的比较。夜间磨牙症通过肌电检查得到证实。主观牙为每位志愿者的左上切牙。所有受试牙均未观察到咬合面。磨牙组的牙周膜机械感受器阈值明显高于非磨牙组。

Low periodontal sensation could sometimes be observed clinically in heavy bruxist. Although several studies have tried to quantitatively evaluate periodontal sensation, it had not yet been fully clarified especially in regard to the difference of response modality between intradental mechanoreceptors and periodontal ligament mechanoreceptors.This study aimed to 1) establish a reliable method for evaluating the threshold of periodontal sensation from periodontal ligament mechanoreceptors, 2) examine the properties of periodontal sensation in non-bruxers (fluctuation of the force threshold within a day, day-to-day fluctuation and the effect of transient mechanical loading and 3) compare the threshold in bruxer and non-bruxer.Low speed mechanical stimulator had silent force generator made of elastic foamed polymer and was capable of exerting the silent mechanical load with slow and steady increase to the target tooth. This stimulator, hence, could measure the force threshold derived from periodontal ligament mechanoreceptor.Eighteen non-bruxers with full natural dentition participated in examining the properties of periodontal sensation. Upper left lateral incisor of each volunteer was subjected. As regards fluctuation of the force threshold within a day and day-to-day fluctuation, no significant difference was observed. However significant increase of periodontal sensation was observed after a transient mechanical loading.Twenty volunteers with full natural dentition (10 non-bruxers, 10 bruxers) was subjected in comparing the periodontal sensation. Nocturnal bruxism was confirmed by electromyography. Subjective tooth was upper left lateral incisor of each volunteer. Occlusal facet was not observed in all subjected tooth. The threshold for periodontal ligament mechanoreceptors in bruxers was significantly higher than that in non-bruxers.