The Level Of IL-17 In Gingival Crevicular Fluid In Response To Orthodontic Force

Periodontal tissue remodeling which will occur under mechanical force is the biological foundation of tooth movement. Fibroblast, osteoblasts (OB) and osteoclasts (OC) play the key roles in the process. Recently, the bone and immune system is found to share the same regulatory factors among which IL-17 is a novel pro-inflammatory cytokine.IL-17 mainly is produce by Th17 which is a new type of T cell subsets.IL-17 is involved in the process of OC differentiation, maturation and activation..This experiment study the interaction between immune system and skeletal system in tooth movement by IL-17 which is detected in gingival cervieal fluid.Objective:To investigate the expression of IL-17 in GCF in tension and compression sites after application of mechanical force by enzyme-linked immunosorbent assay (ELISA). Analysis quantitatively was performed to discuss whether IL-17 is involved in alveolar bone remodeling during tooth movement. To illustrate the molecular biological mechanisms of orthodontic tooth movement and periodontal tissue remodeling from theoretical and practical basisMethods:20 patients aged from 12 to 15 years with maxillary protrusion and no significantly malposition canine who required first premolar extraction were enrolled. The right upper canines were selected. GCF was sampled twice from compression (distal) and tension (mesial) sites at baseline and four weeks after application of force respectively. The average of GCF weigh was record from the orthodontic patient using straight wire appliance. Converting specific gravity of 1 into volume and record the periodontal clinical parameters. ELISA was used to detect the total amount and concentration of IL-17 in GCF. The OD was examined at 450 nm wavelength. After drawing standard curves,Calculated the concentration of IL-17 in samples according to the standard curves. Combined with periodontal clinical parameters, to analysis and compare the variation before and after application of force, as well as the compression site and tension site.The total amount and concentration of IL-17 were represented by symbols X±S, Before and after application of force, the concentrations and the total amount of IL-17 in GCF from tension and compression sites was analyzed by ANOVA and SNK-q test.P<0.05 was considered significant difference.Results The periodontal clinical parameters were shown no significance before and after application of force (P>0.05).The concentration and total amount of IL-17 in GCF at compression site was significant different before and after application of force (P<0.001).The concentration of IL-17 at compression site after application of force was significantly higher than that before. After application of force, the total amount of interleukin-17 in GCF at tension site was higher than that before (P<0.05), No significant defference was found for the concentration, (P>0.05). After application of force, the concentration and total amount of IL-17 in GCF was significantly different between compression and tension sites (P<0.001), the concentration and total amount of IL-17 in GCF at compression site were significantly higher than that at tension site.Conclusion1. IL-17 is detectable in GCF under healthy state. IL-17 has a closely relation with periodontal tissue metabolism.2. Under orthodontic force, the level of interleukin-17 in gingival crevicular fluid (GCF) was higher in compression site than that in tension site.3. The expression of IL-17 in GCF was increased under orthodontic force, which indicated that IL-17 was involved in periodontal remodeling during tooth movement induced by mechanical force.