インプラント治療に用いた磁性アタッチメントの腐食症例

抄録

This report presents a case of a magnetic attachment being used to enhance the adhesiveness of the upper structure of an implant(Conus). The result was removal of the attachment caused by deteriorating expansion of the magnet. A scanning electron microscope (SEM) was used to verify the cause of deterioration.
Four POI 2-part implants were implanted, two on each side, in a patient lacking mandibular molars on both sides. A Conus-type bridge made of platinum alloy was attached to the implants by using two pieces of High Colex Super J® 4515 on one side and two of 3515 on the other. Two and a half months after adding the upper structure the 4515 magnet corroded. The 3515 magnet corroded into a dome shape after three months. The upper structure was recreated but three weeks later slight but similar corrosion was detected. Using a scanning electron microscope(SEM), scratches and cracks on the laser fused ring section of the magnet were found suggesting contamination to the neodymium center of the magnet which caused demagnetization and ineffectiveness of the magnetic attachment.