Does bruxism affect periodontal sensation?

重度磨牙患者临床上有时可出现低牙周感。虽然有一些研究试图定量评价牙周感觉，但还没有完全澄清，特别是关于牙周内机械感受器和牙周韧带机械感受器之间的反应方式的差异。本研究旨在1)建立一种评估牙周膜机械感受器牙周感觉阈值的可靠方法；2)研究非bruxer患者牙周感觉的特性（一天内力阈值的波动、日常波动和瞬态机械负荷的影响）；3)比较bruxer患者和非bruxer患者的牙周感觉阈值。低速机械刺激器是由弹性泡沫聚合物制成的无声力发生器，能够对目标齿施加缓慢稳定增长的无声机械载荷。因此，该刺激器可以测量牙周韧带机械感受器产生的力阈值。18名牙列完整的非磨牙者参与了牙周感觉的检查。每个志愿者的左上侧门牙都受到了影响。对于力阈值在一天内的波动和逐日的波动，没有观察到显著差异。然而，在短暂的机械负荷后，牙周感觉明显增加。对20名自然牙列完整的志愿者（10名无磨牙者和10名磨牙者）进行牙周感觉的比较。肌电图证实夜间磨牙。主观牙均为左上侧门牙。所有受试牙均未观察到咬合小面。磨牙组牙周韧带机械感受器的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.