Electrical stimulation enhances tissue reorganization during orthodontic tooth movement in rats

This study evaluated the effects of a low-intensity electric current on tissue reorganization during experimental orthodontic tooth movement. Thirty-two animals were divided into two groups evaluated on days 3 and 7: OTM-orthodontic tooth movement and OTM + MC-orthodontic tooth movement and microcurrent application (10 mu A/5 min). The samples were processed for histological, morphometric, and Western blotting analysis. Analysis of the periodontal ligament (PL) showed a significantly smaller number of granulocytes in the OTM + MC group on day 7.The number of fibroblasts was significantly higher in the OTM + MC group on days 3 and 7. The area of birefringent collagen fibers was more organized in the OTM + MC group on days 3 and 7. The number of blood vessels was significantly higher in the OTM + MC group on day 7. Microcurrent application significantly increased the number of osteoclasts in the compression region of the PL. In the OTM + MC group on day 7 of tooth movement, the expression of TGF-beta 1 and VEGF was significantly reduced whereas the expression of bFGF was increased in PL. Electrical stimulation enhances tissue responses, reducing the number of granulocytes and increasing the number of fibroblasts, blood vessels, and osteoclasts and modulates the expression of TGF-beta 1, VEFG, and bFGF. This technique is used in many areas of medicine, but poorly explored in dentistry and orthodontics. This treatment is cheap and non-invasive and can be applied by own orthodontist, and it can improve the treatment with a faster and safe tooth movement, without pain.