Abstract: Abstract：Objective To study the influence of the acute stimulation on the dental pulp of injured teeth in rat. Methods The first molar occlusal surface of 24 SD rats injured by grounding with turbines were randomly divided into acute stimulation group （12 rats given daily cold bath，fasting，water deprivation） and control group （n = 12，no stimulation）. They were killed in batches at 5，13，20，28 days，and the gross examination，pathology section and P2X3 receptor-positive in rat dental pulp were done to explore the acute stimulation in the pathogenesis of dental caries. Results There were congestion and edema，neutrophils，lymphocytes and other inflammatory cell infiltration，and dental pulp cells degeneration and necrosis in the rat dental pulps of the acute stimulation group by HE staining pathological sections. P2X3 receptor expression increased a little at 5 and 13 days，greatly at 20 days but decreased gradually at 28 days，in acute stimulation group which showed statistical significance compared with the control group. Conclusion The acute stimulation could induce the inflammation in the pulp of the injured rat teeth，resulting in pulp pain.

Key words: acute stimulation, dental pulp, P2X3 receptor

摘要： 目的 探讨急性刺激对预先制备的大鼠受损牙齿牙髓的影响。方法 本研究于2011年10—12月在大连大学附属新华医院实验中心进行。将24只SD大鼠的两侧上颌第一磨牙用涡轮机钻洞至牙本质深层，用氧化锌暂封，随机分为2组。应激组（12只）给予冷刺激，断食，断水；对照组（12只）正常饲养。在应激刺激第5、13、20、28 天各组分别随机抽取3只大鼠，处死后取上颌双侧第一磨牙，检测牙髓炎症的变化及P2X3受体表达情况。结果 HE染色显示应激组大鼠牙髓充血水肿，有淋巴细胞、中性粒细胞等炎细胞浸润，后期出现牙髓细胞变性坏死。应激组牙髓中P2X3受体阳性表达在刺激第5、13天轻微增高，第20天明显增高，第28天逐渐下降；与对照组比较，差异有统计学意义（P < 0.05）。结论 急性刺激可造成大鼠受损牙齿的牙髓炎症反应，从而导致大鼠出现牙髓来源的疼痛。

关键词: 急性刺激, 动物模型, P2X3受体