Linder-Aronson A, Forsberg C M, Rygh P, Lindskog S
Department of Oral Histology and Cell Biology, School of Dentistry, Karolinska Institutet, Huddinge, Sweden.
Eur J Orthod. 1996 Dec;18(6):581-8. doi: 10.1093/ejo/18.6.581.
Interest in using magnets for generating orthodontic forces started with the widespread availability of rare earth magnetic alloys. In vivo studies have indicated that a static magnetic field and/or corrosion products from the magnetic materials may induce biological effects when in close contact with cells or tissues. In the clinical situation, orthodontic magnets are often situated some distance away from the gingiva and bone. Consequently, the previously observed biological effects may not be found in an experimental situation mimicking the clinical setting. Thus, the present experimental study was undertaken to test this hypothesis using commercially available cobalt-samarium magnets for orthodontic treatment in comparison to treatment with Sentalloy closed coil springs with respect to possible side effects on alveolar bone growth, gingival epithelial thickness as well as rate of space closure. Corrosion of the uncovered areas of the magnets was already evident after 6 weeks. No statistical differences were found between the magnet and coil spring specimens with respect to rate of space closure, bone formation or epithelial thickness. The only two variables that differed significantly between magnet and coil spring specimens was that there were more resorption and more tetracycline labelled osteocyte lacunae under the magnets. In conclusion, although some marginal statistical differences were found between the magnet and coil spring specimens with respect to cell and tissue reactions, the near lack of cell and tissue effects of the magnets in the present clinical experimental situation compared to previous studies in which the magnets were positioned in close contact with the tissue under study, indicate limited adverse clinical effects.
利用磁铁产生正畸力的研究始于稀土磁性合金的广泛应用。体内研究表明，静磁场和/或磁性材料的腐蚀产物在与细胞或组织紧密接触时可能会诱导生物学效应。在临床情况下，正畸磁铁通常与牙龈和骨骼保持一定距离。因此，在模拟临床环境的实验中可能无法发现先前观察到的生物学效应。因此，本实验研究旨在使用市售的钴钐磁铁进行正畸治疗，与使用Sentalloy闭合线圈弹簧治疗相比，测试其对牙槽骨生长、牙龈上皮厚度以及间隙关闭速率的可能副作用。6周后，磁铁未覆盖区域的腐蚀已经很明显。在间隙关闭速率、骨形成或上皮厚度方面，磁铁和线圈弹簧样本之间未发现统计学差异。磁铁和线圈弹簧样本之间仅有的两个显著不同的变量是，磁铁下方有更多的吸收和更多的四环素标记骨细胞陷窝。总之，尽管在细胞和组织反应方面，磁铁和线圈弹簧样本之间发现了一些边缘统计学差异，但与之前磁铁与所研究组织紧密接触的研究相比，在目前的临床实验情况下，磁铁对细胞和组织的影响几乎不存在，表明临床不良反应有限。
