低强度激光对大鼠实验性牙齿移动牙髓与牙周组织中P物质表达的影响

背景目前国外的研究认为骨改建的过程可能部分地受神经肽调控.目的观察低强度激光照射对大鼠实验性牙齿移动牙髓与牙周组织中P物质表达的影响.设计随机对照的研究.地点和材料于吉林大学第二临床学院动物室对45只Wistar大鼠进行动物实验.干预利用免疫组化ABC染色,结合计算机图像分析,测定45只Wistar大鼠正畸牙齿移动在0,,6,2,4和72h的实验侧和对照侧牙髓P物质免疫组化(SP-like immumoreactivity,P-IR);以及在0(0h),(24 h),(72 h),,14和21 d时实验侧和对照侧牙周组织中SP-IR的灰度值.实验动物被分为9组,每组5只.于上颌第一磨牙和切牙之间拴结镍钛闭合螺旋弹簧,力值为40g.左侧为实验侧,右侧为对照侧.实验侧为低强度激光照射侧,采用He-Ne激光与C02激光同时照射的方法.主要观察指标①牙髓中SP-IR灰度值变化.②牙周膜压力区SP-IR灰度值变化.③牙周膜张力区SP-IR灰度值变化.④实验侧和对照侧的牙周膜压力区与张力区SP-IR灰度值变化的比较.结果实验侧牙髓中SP-IR免疫组化灰度值低于对照侧,以第12,4h明显(P＜0.01);实验侧牙周膜压力区SP-IR免疫组化灰度值在7 d时明显高于对照侧(P＜0.01);在14d时较高于对照侧(P＜0.05).实验侧牙周膜张力区SP-IR免疫组化灰度值在14d时较高于对照侧(P＜0.05).结论低强度激光照射对正畸初始牙髓中P物质的表达及牙周组织中P物质的表达均有影响.

Effect of low energylaser irradiation on the expression of substance P in dental pulp and periodontium duringexperimental orthodontic tooth movement in rats

BACKGROUND: As believed by recent domestic and international researches,the bone reconstruction process might be partly modulated by neuropeptides.OBJECTIVE: To investigate the effect of low power laser irradiation on the expression of substance P (SP) in dental pulp and periodontium during experimental orthodontic tooth movement in rats.DESIGN: A randomized controlled trial SETTING and MATERIALS: Forty-five Wistar rats were selected in the study in the animal laboratory of the Second Clinic Medicine College of Jilin University.INTERVENTIONS: The immunohistochemical reactivity of SP(SP-IR) in dental pulp on both study side and control side of 45 Wistar rats with orthodontic tooth movement was assayed at 0,3,6,12,24,and 72 hours,as well as the gray scale of SP-IR in periodontium on both study side and control side at 0 (0 hour),1(24 hours),3(72 hours),7,14,and 21 days by immunohistochemical ABC staining combined with computerized image analysis system. Forty-five Wistar rats were allocated into 9 groups according to experimental time of 0,3,6,12,24 hours,3 days,7 days,14 days,and 21 days with 5 rats each. A NiTi coil spring with 40g connected the maxillary upper first molar to the upper incisor and fixed bilaterally by a ligature wire. The left side was set as study side and the right side was set as control side. Study side received low energy laser irradiation irradiated by He-Ne laser and CO2laser simultaneously.gray scale alterations at periodontal pressure and tension side between study side and control side.RESULTS: The dental pulp SP-IR gray scale was lower in study side than that of control side,with most significant alteration at 12 hours,and 24hours ( P ＜ 0. 01 ). Periodontal pressure side SP-IR gray scale in study side was significantly higher than that of control side at the 7th day ( P ＜ 0.01 )and higher than control side at the 14th day ( P ＜ 0.05). At tension sides of study sides,the periodontal SP-IR gray scale was higher than that of control sides at the 14th day ( P ＜ 0.05).CONCLUSION: Low energy laser affects SP expressions in both dental pulp and periodontium during the initial orthodontic tooth movement.