REMOVABLE MAGNETIC KEEPER FREE FROM MRI ARTIFACT

可拆卸的磁性保持器，免受 MRI 伪影的影响

• 批准号: 06671946
• 负责人: NAKAMURA Kazuo
• 金额: $ 1.22万
• 依托单位: TOKYO MEDICAL AND DENTAL UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06671946/
• 关键词: REMOVABLE MAGNETIC KEEPER; DENTAL MAGNETIC ATTACHMENT; MRI; ARTIFACT; ア-ティファクト; 可撤式キ-パ-; 磁性アタッチメント

Dental magnetic attachments are one of the intraoral atattiments and consist of two parts, the magnetic assembly and the magnetic keeper. Both parts are made by magnetic substances and these materials can cause MRI artifact, when they are used in the imaging field. The magnetic assembly are usually mounted in the prosthesis, so the magnetic assembly are easily kept away from the imaging field by removing the prosthesis. But the keeper is casted within the root cap cemented in the root, and it can be a artifact of the MRI.The aims of this investigation were to develope the removable magnetic keeper, and to make sure the efficiency of the removable magnetic keeper clinically.1.Removable magnetic keeper assemblyThe removable magnetic keeper assembly consists of a magnetic keeper and a nonmagnetic housing. The magnetic keeper is a disk with a screw-shaped lateral wall or a bolt-shaped disk. The housing is a nut-shaped ring. The magnetic keeper is screwed into the housing and fixed tightly. In the clinical evaluation, the patients was comprised of 28 partially edentulous subjects, 17 women and 11men, provided with dental magnetic attachments with the removable keeper. They were followed up for 0.5-3 years. During this period, none of these removable keepers were dropped out and all of them were kept clean and they coould be easily removed.2.Influence on MRIA volunteer test subject with combinations of keepers in lower premolar region was examined by MRI.The images of the magnetic removable keeper and the housing were defective and showed same size of distortion as the ordinary keeper, but the images of the housing only , where the keeper was removed , showed no distortion.

牙科磁性附着体是口腔内附着体的一种，由磁性组件和磁性保持器两部分组成。这两个部分都是由磁性物质制成的，这些材料在成像领域使用时会产生磁共振伪影。磁性组件通常安装在假体中，因此通过移除假体可以容易地使磁性组件远离成像场。本研究的目的是研制可拆卸的磁性保持器，并在临床上确保可拆卸磁性保持器的效率。1.可拆卸的磁性保持器组件可拆卸的磁性保持器组件由磁性保持器和非磁性外壳组成。磁性保持器是具有螺纹状侧壁的圆盘或螺栓形圆盘。外壳是一个螺母形状的环。磁性保持器拧入壳体内并紧紧固定。在临床评价中，患者包括28名部分无牙列受试者，17名女性和11名男性，他们配备了带有可拆卸保持架的牙科磁性附着体。术后随访0.5~3年。在此期间，所有这些可拆卸保持器都没有脱落，而且都保持清洁，易于拆卸。2.对志愿者受试者使用下前磨牙区的保持器组合进行磁共振成像检查，发现磁性可拆卸保持器和外壳的图像存在缺陷，显示出与普通保持器相同大小的变形，但只有被移除保持器的外壳图像没有失真。

项目成果

中村 和夫,水谷 紘,ほか: "磁性合金の補綴領域における応用 第8報 ネオジム磁石を応用した磁性アッタチメント" 日本補綴歯科学会雑誌. 34 94特別号. 139 (1995)

Kazuo Nakamura、Hiro Mizutani 等人：“磁性合金在修复领域的应用第 8 部分：使用钕磁铁的磁性附件”日本修复医学会杂志 34 94 特刊（1995 年）。

H.Mizutani,K.Nakamura,et al.: "Influence of Thermal Cycle on Attractive Force of Magnetic Attachment." J Dent Res. 74. 471 (1995)

H.Mizutani,K.Nakamura,et al.：“热循环对磁性附着吸引力的影响”。