Study Of The Expression Of Cyclooxygenase-2 And The Effect Of Lower Power Laser Irradiation During Experimental Tooth Movement

ObjectThe purpose of the present study was to investigate the expression patterns of COX-2 during experimental tooth movement and the effect of lower power laser irradiation on COX-2 expression, which would provide detailed information on the mechanism of the tooth movement and the promotion effect of lower power laser.MethodsThirty-five Wistar rats were used in this study. The animals were divided into 7 groups on average: untreated,1d,3d,5d,7d, 14d,21d. An orthodontic appliance, consisting of a coil spring ligated to the first molar connecting it to an orthodontic wire ligated onto the incisors, and exerting a force of approximately 30 g.The right was designed as experimental group, left as control group, in the self-control. Experimental group received irradiation of lower power laser. The animals from each group were killed at the time discontinued. The histological sections were stained with goat anti-rat COX-2 monoclonal antibody to express COX-2 immunoreactivity , using a SP KIT , and counterstained with hematoxylin.Omitting the primary antibody,and substituting it with PBS tested the specificity of the immune reaction.ResultsIn this study COX-2 was demonstrated in PDL of rat molar,in both experimental group and control group. In the control group,COX-2 expression was significantly higher in the pressure side on 1,3,5,7days after initiating the experiment,while was significantly higher in the tension side on5,7,14days. Compared to controlgroup,treatment with lower power laser irradiation significantly decreased COX-2 staining at 1 day and significantly increased COX-2 staining at 3,5,7days in the pressure side,but in the tension side,there was statistically significantly increased COX-2 staining at1, 3,5,7days. Conclusion 1. During tooth movement,the COX-2 expression in PDL was promoted by mechanical stimuli to the periodontium. 2. The patterns of COX-2 expression were different in the pressure side from that in the tension side,but they were consistent with the period of PDL reconstruction. 3. Lower power laser irradiation can upregulate the expression of COX-2 and can effectively accelerate the vascularized reaction in PDL of rat during experimental tooth movement.