A new retainer using magnetic attachment.

PATIENT: A 58-year-old man with a complaint of masticatory disturbance presented. His mandibular left premolars and molars were missing, and the mandibular left canine, which was neighboring to the missing part, showed marked labial tipping. A cobalt-chromium removable partial denture was fabricated using a new magnetic attachment retainer because it seemed difficult to apply a conventional clasp for this case. This retainer is constructed from the buccal hook arm sliding bucco-lingually and the magnetic attachment which works to lock the movable part when it was closed. Six years after the delivery of this denture, both the abutment tooth and the periodontal tissue are healthy, and the denture is functioning well.

DISCUSSION: As this retainer does not use the elasticity of clasp arms, block out area can be minimized, and the maximum area of the contacting surface of the hook arm brings about very positive retention and bracing. The function of attractive force is to resist the splitting force and not to become directly involved in the retention of the denture. Therefore, the attractive force for this system does not need to be very strong. This system also provides the advantages of a sectional denture, allowing protection of the abutment tooth and the use of the abutment tooth in its original form.

CONCLUSION: The retainer described in this report has many advantages including, no hazardous lateral force, adequate retentive force, and application to natural teeth or tipped teeth.