| Object:The aim of the study was to observe the expression of matrix metalloprotein-ases-13(MMP-13) and dentin phosphoprotein (DPP) in gingival crevicular fluid (GCF) before and after different orthodontic forces in clinical experiment. To discuss the effect of MMP-13and DPP in respect of orthodontic root movement, reconstruction of alveolar bone and root resorption and compare the sensitiveness of MMP-13with DPP during orthodontic root movement and root resorption. Sequentially, to enable the clinician to find a new prompt treatment of early diagnosis about root resorption.Method:21cases aged from12to18years old of fixed orthodontic treatment whose maxillary first premolars had been removed were divided into three groups on different orthodontic forces as follows:Og force (control group),100g force (slight group) and300g force (heavy group).7cases of deciduous teeth of which the panoramic radiograph have shown obvious root absorption. The maxillary canines were drawn to distal direction by using a orthodontic tension spring. The GCFs were collected at the1st,7th,10th,14th and28th day before and after the giving of orthodontic strength. The quantities of the two biomarkers in GCF from all canines and deciduous teeth of which the panoramic radiograph have shown obvious root absorption were evaluated by the biochemistry techniques of SDS-PAGE and Western blot;The densities of the two biomarkers in GCF from all canines were assayed by ELISA technique. The statistical software SPSS13.0was chosen to analyse the experimental data.Result:1. MMP-13determination by ELISA: MMP-13in GCF from slight group performed a stable changes which had a cycle about14days in different viewpoints:the level rose significantly in the1st,7th and10th day after giving forces, and mounted to the peak in the10th day while fell back to the level unforced in the14th day. The heavy group showed a greater range but also given a cyclic changing, yet the level of MMP-13from the control group had hardly changed. The levels of MMP-13from slight and control group were both lower than those from the heavy group, statistically significant differences were seen between them(P<0.05).2. DPP determination by ELISA:The levels of DPP from the control group and slight group were very low and there was no significant difference (P>0.05) in the relative DPP levels when comparing the two group in the1st,7th,10th,14th and28th day after giving forces to the maxillary incisors. The level of DPP from the heavy group were higher than those from the slight and control group in the14th and28th day after giving orthodontic forces, but there was no significant difference (P>0.05) in longitudinal comparison among the three groups.3. MMP-13determination by Western blot:There was significant difference (P>0.05) about the MMP-13levels in the heavy group when comparing the control group and light group in the7th,10th,14th and after giving forces. To be an action, the expression of MMP-13in the GCF of deciduous teeth which had been absorbed was higher;The expression of MMP-13levels of the control group and light group in the1st,7th,10th,14th and28th day after giving forces were very low, and there was not obvious changing. The expression of MMP-13in the heavy group became higher in the10th day after giving forces, and getting to the peak level in the14th day which was higher than the action; in the28th day the expression of MMP-13began to wane.4. DPP determination by Western blotThe Vertical Comparison of the expression of MMP-13in the GCF of orthodontic teeth in different time (1st,7th,10th,28th day) in the control group, light group and heavy group didn’t show significant difference(P>0.05). The expression of DPP in the GCF of orthodontic teeth in the three groups in different time(lst,7th,10th,14th and28th day) were very low, and the levels which changed by time were not obvious in the control group and light group; The expression of MMP-13was getting higher slightly in the heavy group when compared the level in the14th day with which in the10th day after giving forces.Conclusion:1. The expression of MMP-13in the GCF of orthodontic teeth were relate to the alveolar bone reconstruction and obsorbtion of the moving teeth. It shows that the obsorbtion of tooth root start very early. The MMP-13can be used as an bio marker in ambulatory monitoring of tooth movement and root obsorbtion, and gives instruction in choosing the appropriate orthodontic force value and early detection of the occurrence of orthodontics root absorb in clinical orthodontic treatment have important significance.2. The expression of DPP in the GCF of the orthodontic teeth showed that the level had no relationship with alveolar bone reconstruction and obsorbtion. But as the force value duration, DPP expression increased significantly, It can prompt the root obsorbtion but the sensibility was lower than MMP-13. |
