Analysis and clinical application of bone formation mechanism in immediate loading implant using materials driven by magnetic field

本研究的目的是阐明磁场驱动材料即刻加载种植体的成骨机制，并将其应用于临床。为了控制负载，我们利用振动使用环氧树脂和磁性物质金属（钴铁氧体粉末）的混合材料在这项研究中。通过交变电场和磁场（磁场：0.5特斯拉，磁极之间的距离）（TEM-5000-G1，Toei，Sendai）提供振动材料和植入物的磁场。本机可通过输出电流控制磁场强度（最大：0.649特斯拉）。将直径1.0- 1.2mm、长10-15 mm的钛合金植入雄性大鼠股骨和胫骨。实验组将种植体一端暴露于皮肤上，将磁场驱动材料固定于种植体暴露端。在交变电场和磁场作用下，植入物通过磁场驱动材料的介入而振动。组织切片观察。初期植入物周围可见纤维或肉芽组织伴轻度炎性细胞浸润。但在长期观察中，种植体周围未见新骨形成，无炎症反应。实验组和对照组种植体表面均有新骨形成。最佳的振动能促进种植体周围骨形成和骨小梁的快速排列。在临床上，振动装置的发展可能有助于长期稳定种植体。利用磁场驱动材料的新医疗方法由于其微创性，将应用于各个医疗领域。

The aim of this study was to clarify the mechanism of bone formation in immediate loading implants using material driven by magnetic field and apply this material as clinical instrument. To control the loading, we utilized vibration using mixture materials of epoxy resin and magnetic substance metals (cobalt ferrite powder) in this study. The magnetic field to vibrate the materials and implant was provided by alternating electric and magnetic field (magnetic field: 0.5 tesla, the distance between magnetic poles) (TEM-5000-G1, Toei, Sendai). This machine can control the magnetic field intensity (Max: 0.649 tesla) by output current. We implanted the titanium alloy (diameter: 1.0-1.2 mm, length 10-15 mm) in femur and tibia of male rats. In experimental group, an end of implant was exposed on skin, and the material driven by magnetic field was fixed on the exposed end of implant. By alternating electric and magnetic field, implant vibrated through the intervention of material driven by magnetic field. Histological sections were observed. In initial stage, fibrous or granulation tissue with slight inflammatory cells infiltration was observed around implant. However, in long term observation, new bone formation without inflammatory reaction was seen around the implant. Newly formed bone was observed on the surface of implant in experimental and control groups. The optimal vibration will induce the bone formation and the prompt arrangement of bone trabecular around the implant. Clinically, the development of vibratory device may contribute to stabilize the implant for long time. The new medical treatment using materials driven by magnetic field will apply in various medical fields due to less invasive therapies.