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目的探讨低强度脉冲超声(low-intensity pulsed ultrasound,LIPUS)对大鼠正畸牙移动速度及牙槽骨改建过程中环氧化酶-2(cyclooxygenase-2,COX-2)和前列腺素E_2(prostaglandin E_2,PGE_2)表达的影响。方法健康6~8周雄性Sprague-Dawley(SD)大鼠25只,采用左右对照实验,分为单纯加力组(左上颌,对照组)以及LIPUS+加力组(右上颌,实验组),2组各又下设LIPUS刺激后1、3、5、7、14 d5个时相点。建立正畸牙移动动物模型,每只实验鼠右上颌加力后第2天行LIPUS刺激(频率1.5 MHz、强度30 m W/cm~2、脉冲宽度200μs、重复频率1 k Hz),每天1次,每次20 min,左上颌行不开功率的假刺激,于相应时间点处死实验鼠,取上颌第一磨牙至第三磨牙及周围牙槽骨用于牙齿移动距离测量,脱钙后取第一磨牙及周围牙槽骨行免疫组织化学染色。结果实验组牙齿移动速度快于对照组,第5、7、14天2组比较差异有统计学意义(P<0.01);免疫组织化学染色结果显示:实验组COX-2、PGE_2的表达均高于对照组,均在第7天达到高峰,实验组第5、7天表达明显高于对照组(P<0.05)。结论 LIPUS能有效促进牙槽骨改建过程中COX-2、PGE_2的表达,从而促进牙槽骨改建,对加快正畸牙移动有一定的促进作用。
Objective To investigate the effect of low-intensity pulsed ultrasound (LIPUS) on the movement of orthodontic tooth and the expression of cyclooxygenase-2 (COX-2) and prostaglandin E2 , PGE_2) expression. Methods Twenty-five male Sprague-Dawley (SD) rats, healthy for 6-8 weeks, were divided into two groups according to left and right control: left ventricular maxillary and left maxillary, control group, LIPUS + Each group also under the LIPUS stimulation 1,3,5,7,14 d5 time points. An animal model of orthodontic tooth movement was established. LIPUS stimulation (frequency 1.5 MHz, intensity 30 mW / cm ~ 2, pulse width 200μs, repetition frequency 1 k Hz) Times, each time 20 min, left maxillary line does not open the power of false stimulation, at the corresponding time point mice were sacrificed, take the maxillary first molar to the third molar and surrounding alveolar bone for tooth movement distance measurement, after decalcification The first molar and surrounding alveolar bone immunohistochemical staining. Results The tooth movement speed in the experimental group was faster than that in the control group, and there was significant difference between the two groups on the 5th, 7th and 14th days (P <0.01). The immunohistochemical staining showed that the expression of COX-2 and PGE_2 in the experimental group were all higher In the control group, all of them reached the peak on the 7th day, and the expression in the experimental group on the 5th and 7th day was significantly higher than that in the control group (P <0.05). Conclusions LIPUS can effectively promote the expression of COX-2 and PGE_2 during alveolar remodeling, promote alveolar bone remodeling and accelerate the orthodontic tooth movement.