Bondemark L, Kurol J, Larsson A
Orthodontic Clinic, Hässleholm, Sweden.
Eur J Orthod. 1995 Apr;17(2):85-91. doi: 10.1093/ejo/17.2.85.
The aim of this intra-individual study was to examine human dental pulp and gingival tissue after exposure to static magnetic fields generated by orthodontic samarium-cobalt magnets. In seven individuals, aged between 11.5 and 17.5 years, the maxillary first premolars and immediately adjacent gingival tissues were exposed to a static magnetic field from a bonded magnet on one side (test) and a demagnetized magnet was used as a control on the contralateral side. After a period of 8 weeks the test and control teeth were clinically examined regarding gingival conditions, then biopsies of the buccal gingival tissues were taken and the maxillary first premolars were extracted. The teeth and the tissue biopsies were examined histologically. The static magnetic field exposure (flux density) of the coronal pulp sections on the test sides ranged between 100 and 150 Gauss, and the exposure of the buccal gingival tissues ranged between 200 and 900 Gauss. The contralateral control tissues were exposed to flux density values at the level of the natural magnetic field on earth (0.3-0.6 Gauss). Static magnetic fields produced by orally placed orthodontic rare earth magnets did not result in any change in human dental pulp or gingival tissue adjacent to the magnets. There was no difference in clinical gingival conditions between test and control sites.
这项个体内研究的目的是，在正畸用钐钴磁体产生的静磁场作用下，对人类牙髓和牙龈组织进行检测。在7名年龄介于11.5岁至17.5岁之间的个体中，上颌第一前磨牙及其紧邻的牙龈组织一侧暴露于粘结磁体产生的静磁场（测试侧），对侧使用退磁磁体作为对照。8周后，对测试牙和对照牙的牙龈状况进行临床检查，随后采集颊侧牙龈组织活检样本，并拔除上颌第一前磨牙。对牙齿和组织活检样本进行组织学检查。测试侧冠部牙髓切片的静磁场暴露（通量密度）范围为100至150高斯，颊侧牙龈组织的暴露范围为200至900高斯。对侧对照组织暴露于地球天然磁场水平的通量密度值（0.3 - 0.6高斯）。口腔内放置的正畸稀土磁体产生的静磁场，并未导致磁体附近的人类牙髓或牙龈组织出现任何变化。测试部位和对照部位的临床牙龈状况没有差异。
