Baad-Hansen Lene, Jensen Troels Staehelin, Svensson Peter
Department of Clinical Oral Physiology, Dental School, University of Aarhus, Vennelyst Boulevard 9, DK-8000 Aarhus C, Denmark.
J Orofac Pain. 2003 Fall;17(4):333-40.
To examine, in a double-blind and placebo-controlled crossover manner, the effect of topical application of capsaicin on the alveolar mucosa with a battery of intraoral quantitative sensory testings (QST) in 16 healthy volunteers.
Thirty microL of 5 mg/mL capsaicin or vehicle (control) was applied to a 3 x 3-mm paper disk and applied to the alveolar mucosa under an oral bandage. The subjects rated the perceived pain intensity on a 0 to 10 electronic visual analog scale (VAS) for 15 minutes. Quantitative sensory testings were performed before and immediately after the 15-minute application and consisted of assessments of cold detection threshold, warmth detection threshold (WDT), cold pain threshold, beat pain threshold (HPT), mechanical sensitivity to single and repeated punctate mechanical stimulation with von Frey filaments and to single and repeated brush stimulation with a cotton swab, and detection and pain thresholds to electrical stimulation of the alveolar mucosa and maxillary first premolar tooth. Analysis of variance was used to test the data.
Application of capsaicin caused moderate levels of pain (VASpeak scores 5.0 +/- 1.9) whereas the vehicle was practically painless (VASpeak 0.9 +/- 2.4). No significant effects of vehicle on QST could be detected (P > .143). In contrast, capsaicin application was associated with significant decreases in WDT and HPT (P < .001). No other significant changes in QST were observed for capsaicin application.
The intraoral capsaicin pain model is associated with signs of heat hyperalgesia, but not mechanical hyperalgesia. Since the somatosensory sensitivity is not well characterized in most orofacial pain conditions, mainly due to lack of tradition and techniques, intraoral QST may provide a better description of the somatosensory sensitivity and underlying mechanisms in orofacial pain conditions.
采用双盲、安慰剂对照交叉试验的方式，通过一系列口腔内定量感觉测试（QST），研究16名健康志愿者局部应用辣椒素对牙槽黏膜的影响。
将30微升5毫克/毫升的辣椒素或赋形剂（对照）滴于一张3×3毫米的纸片上，在口腔绷带覆盖下贴于牙槽黏膜。受试者在0至10的电子视觉模拟量表（VAS）上对15分钟内感觉到的疼痛强度进行评分。在15分钟应用前和应用后立即进行定量感觉测试，包括冷觉检测阈值、热觉检测阈值（WDT）、冷痛阈值、热痛阈值（HPT）、用von Frey细丝对单次和重复点状机械刺激以及用棉棒对单次和重复刷擦刺激的机械敏感性，以及对牙槽黏膜和上颌第一前磨牙进行电刺激的检测阈值和疼痛阈值。采用方差分析对数据进行检验。
应用辣椒素引起中度疼痛（VAS峰值评分5.0±1.9），而赋形剂几乎无痛（VAS峰值0.9±2.4）。未检测到赋形剂对QST有显著影响（P>.143）。相比之下，应用辣椒素与WDT和HPT显著降低有关（P<.001）。应用辣椒素后，未观察到QST的其他显著变化。
口腔内辣椒素疼痛模型与热痛觉过敏迹象有关，但与机械性痛觉过敏无关。由于在大多数口面部疼痛情况下，体感敏感性尚未得到很好的表征，主要是由于缺乏传统方法和技术，口腔内QST可能会更好地描述口面部疼痛情况下的体感敏感性及其潜在机制。
