Relationships Between Speed Of Tooth Movement And Enzymes And Cytokines In Gingival Crevicular Fluid Under Different Orthodontic Forces

Objectives: The objectives of this research are:1.To measure the velocity of the canine of maxillary under different orthodontic forces and different time and analyze the changing rule of alkaline phosphatase (ALP), aspartate aminotransferase(AST)and interleukin-1β(IL-1β)in gingival crevicular fluid;2.To investigate the relationships between velocity of tooth movement and biochemical event in periodontium which was force received;3.To explore a suitable index as a kind of reference standard for clinics.Methods: Select thirty-two cases which fit experiment condition.The cases divided randomly into 4 groups, 8 cases for every group. The distal forces of 50g, 100g, 150g and 250g were exerted to the canine on the one side of different groups separately, and the canines of the other side were treated as controls.1.The movement of canines(both test groups and control groups) were measured at 24h, 48h, 72h, 7d,14d, 21d and 28d after the orthodontic forces were exerted. The stable reference points were the position where micro-implant anchorages are.2.The gingival crevicular fluids(GCF) from the medial and distal position of canines(both test groups and control groups) were collected at baseline, 24h, 48h, 72h, 7d,14d, 21d and 28d after the orthodontic forces were exerted. After eluting, the levels of ALP and AST in GCF were analyzed using biochemical analysator.3. The GCF samples of 100g group and 250g group were picked out and the levels of IL-1βin GCF was analyzed using ELISA method. All the data were statistical analyzed using SPSS 13.0. GLM repeated measurement were used to explore the relationships of movement and enzymes, cytokines in GCF under different orthodontic forces and different times.Results:1.Interaction was present between groups and times for velocity study. The velocity of canines from different groups has statistical significant difference among different times(P<0.001). And the velocity of canines from different groups also has statistical significant difference among different orthodontic forces(P<0.01).2.Interaction were found among the three factors except between groups and positions when measuring the levels of AST in GCF(P<0.001). There were statistical significant differences for levels of AST among times, orthodontic forces and positions(P<0.001). Interaction were found among the three factors when measuring the levels of ALP in GCF(P<0.001). There were statistical significant differences for levels of ALP among times, orthodontic forces and positions(P<0.001).3. Interaction were found among the three factors except between groups and positions when measuring the levels of IL-1βin GCF. There were statistical significant differences for levels of IL-1βamong different times and different orthodontic forces(P<0.01)but no statistical difference was found between different position.Conclusion: The velocity of movement increased along with the increment of orthodontic force when the force is smaller than 100g. It did not increase obviously when the force is larger than 100g. As a kind of special protein, enzymes has the intimate association with the orthodontic forces , continuing times and different positions. The levels of AST and ALP were stable when the orthodontic force is 100g. At that time, the reaction of periodontium is light and the reparation is fast. The change of levels of enzymes could be a kind of reference index for judging optimized orthodontic force in clinic.