低能量激光调控大鼠正畸保持期骨改建因子的表达

Low-level laser regulates the expression of bone remodeling factors during orthodontic retention in rats

目的?探究低能量激光对大鼠牙齿移动后保持期骨改建因子的影响。方法80只Wistar大鼠随机分为空白对照组和4个模型组(复发组、保持组、保持+激光组、复发+激光组),每组16只。空白对照组不进行主动加力,不施加任何措施。其余4组制作第一磨牙近中移动模型,在21 d主动加力结束后拆除口内装置;然后,复发组不安装保持装置,保持组安装保持装置,保持+激光组安装保持装置并隔日照射低能量激光,复发+激光组不施加保持装置但隔日照射低能量激光。在主动加力21 d后进入保持期的第2、5、10、15天处死大鼠,提取大鼠第一磨牙周围2 mm组织的总RNA,采用qPCR法检测Runt相关转录因子2(Runx2)、碱性磷酸酶(ALP)、Ⅰ型胶原蛋白(COLⅠ)、活化T细胞核因子(NFATc)、组织蛋白酶K(CTSK)、基质金属蛋白酶9(MMP9)等6个骨改建因子的mRNA表达。结果4个模型组大鼠的6个骨改建因子的mRNA表达均较空白对照组呈升高趋势,在大部分时间点差异有统计学意义(P均<0.05)。复发组的6个骨改建因子的mRNA表达较保持组呈升高趋势,在各时间点差异均有统计学意义(P均<0.01)。随着时间延长,保持+激光组6个骨改建因子的mRNA表达较保持组升高,从第5天开始差异均有统计学意义(P均<0.05),第10天差异最为明显。复发+激光组除MMP9外的5个骨改建因子的mRNA表达在大部分时间点均较复发组升高(P均<0.05)。结论在大鼠第一磨牙的固定保持过程中,低能量激光的干预增加了骨组织改建因子的表达,加速了牙槽骨的改建。

Objective To investigate the effect of low-level laser on periodontal bone remodeling factors during orthodontic retention after tooth movement in rats.Methods A total of 80 Wistar rats were randomly divided into blank control group and 4 model groups(relapse group,retention group,retention+laser group,and relapse+laser group),with16 rats in each group.In the blank control group,no active force was applied and no measures were taken.The first molar mesial movement model was constructed in the other 4 groups,and the intraoral device was removed after 21 d of active force application.The relapse group was equipped without retention device,the retention group was equipped with retention device,the retention+laser group was equipped with retention device and irradiated with low-level laser every other day,and the relapse+laser group was equipped without retention device but irradiated with low-level laser every other day.The rats were sacrificed on the 2,5,10and 15day of the retention period after 21 d of active force application,and the total RNA of 2-mm tissues around the first molar was extracted.The mRNA expression of bone remodeling factors(Runtrelated transcription factor 2[Runx2],alkaline phosphatase[ALP],typeⅠcollagen[COLⅠ],nuclear factor of activated T cell[NFATc],cathepsin K[CTSK],and matrix metalloproteinase 9[MMP9])were detected by quantitative polymerase chain reaction(qPCR).Results The mRNA expression of the 6 bone remodeling factors in the 4 model groups was higher than that in the blank control group,and the differences were statistically significant at most time points(all P<0.05);the mRNA expression of the 6 bone remodeling factors in the relapse group was significantly higher than that in the retention group at each time point(all P<0.01).As time went on,the mRNA expression of 6 bone remodeling factors in the retention+laser group was higher than that in the retention group,and the difference was significant from the 5day(all P<0.05)and peaked on the 10day.Except for the MMP9,the mRNA expression of the other 5 bone remodeling factors in the relapse+laser group was higher than that in the relapse group at most time points(all P<0.05).Conclusion In the retention process of the first molar in rats,the low-level laser can increase the expression of bone remodeling factors and accelerate the remodeling of alveolar bone.