インプラントにおける磁性アタッチメントの応用

―第4報　磁性アタッチメントの使用目的による分類―

抄録

Magnetic attachments have various properties not found in other retainers because of their specific retentive force by magnetic energy, and they have received attention as excellent retainers with different functions. However, no sufficient guidelines have been established for designing magnetic attachments used in clinical treatment. In this study, we focused on the ability usefulness of magnetic attachments, and classified them according to their purpose of application, to obtain guidelines for their design:
[Classification of magnetic attachments by purpose of application](Tanaka ＆ Hoshino)
Type R:for retention mainly. Support and bracing are not expected.
Type SR:for support and retention. Bracing is not expected.
Type BSR:for bracing, support, and retention.
Type R should be applied to cases in which the amount of available remaining bone for implantation is insufficient, and the permanent abutment teeth condition is poor. That is, support should be obtained from the mucosa, and mainly retention alone should be obtained from the magnetic attachment abutments;therefore, magnetic attachment abutments should be placed in the area as far as possible from the area to which strong occlusal force is applied. We considered that this approach useful for protecting the abutments.
In cases in which the amount of available remaining bone for implantation is sufficient, and the permanent abutment teeth condition is good, the application of Type SR is possible, and we considered that, by placing magnetic attachment abutments in the area, such as molar areas, where strong support was expected, the magnetic attachments could be used for improving occlusal support.
Furthermore, in cases in which a sufficient number of magnetic attachment abutments are available, the application of Type BSR is possible, and we considered that, by placing magnetic attachment abutments in the anterior and molar areas, not only retention but also support and bracing could be expected.
It is known that the prognosis of dental implant becomes poor not only by excessive lateral force but also by vertical force, and understanding this aspect is important in designing implants. It was suggested that, in applying magnetic attachments to implants, and also in order to bring out many advantages in magnetic attachments, using the above classification, in which not only retention but also support and bracing were considered, was very useful.