Survey on use of titanium dentures in Tsurumi University Dental Hospital for 11 years.

PURPOSE: The purpose of this study was to survey the production of titanium dentures in Tsurumi University Dental Hospital and to study the actual use of titanium dentures in our university. METHODS: The survey was based on the metal base dentures produced at Tsurumi University Dental Hospital during an 11-year period between April 1995 and March 2006, with relation to the types of metals used in the dentures, types of dentures, dental condition, and the number of artificial teeth. RESULTS: 1871 metal base dentures were produced in the study period. The dentures consisted of 1290 cobalt-chromium alloy dentures (68.9%), 350 titanium dentures (18.7%) and 231 platinum-added gold alloy dentures (12.3%). Within the titanium denture groups, 132 were complete dentures (37.7%), 55 were complete overdentures (15.7%) and 163 were removable partial dentures (46.6%). JIS type 3 pure titanium was used in the titanium base of 252 dentures (72.0%). The average number of artificial teeth was 10.9, which was the highest among the three types of metal bases, exhibiting significant differences (P<0.01). CONCLUSION: Approximately 32 titanium dentures per year on average were delivered at our university and they were applied to almost edentulous arch compared with the other metal base dentures.

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.