Dental magnetic attachments are currently used in clinical dentistry and are also very useful whenever denture retention is needed. The keeper may disturb MRI diagnosis, which is the most seious clinical problem of magnetic attachments. The purpose of this study was to examine the interference and differences in volume and form of the keeper in MRI. The results were as follows: 1. MRI artifacts were reduced ally to reductions volume of the keeper. MRI artifact size of keepers 1.00 and 0.60mm thick were less than half and less than 1/10 as compared to that with the 0.10mm thick keeper, respectively. 2. A 1.00mm sample keeper was placed into a subjects, maxillary 2 nd molar and the MRI artifact was quite large but did not reach the cranium. A 0.05mm thick sample keeper was also placed in the same area and the artifact was localized to the alveolar region.
