Electrical stimulation enhances tissue reorganization during orthodontic tooth movement in rats

Objective: This study evaluated the effects of a low-intensity electric current on tissue reorganization during experimental orthodontic tooth movement. Materials and methods: 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 μA/5 min). The samples were processed for histological, morphometric, and Western blotting analysis. Results: 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-β1 and VEGF was significantly reduced whereas the expression of bFGF was increased in PL. Conclusions: 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-β1, VEFG, and bFGF. Clinical relevance: 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.