Precision attachment-retained removable partial dentures: Part 2. Long-term study of ball attachments.

Patients provided with 24 ball attachment-retained removable partial dentures were followed up to 23.5 years. The prosthetic treatment included fixed partial dentures in 8 arches, and combinations of crowns and splint bars in 16 arches. All ball attachment matrices were supplied with vertical occlusal stops in contact with the patrices. A nonresilient hinged coupling was established between fixed partial dentures and removable partial dentures. Seventeen arches had only two or three remaining teeth. A total of 66 abutments for fixed partial dentures were included, 30 of which were root canal treated and supplied with posts. No technical failures (loss of retention/cement failure, root or tooth fracture, metal framework fracture) with the fixed partial dentures were recorded. With the removable partial dentures, additional retention with clasps was introduced in 2 of the dentures (in addition to 8 originally), 2 had to be remade after fractures, and 4 dentures were relined.