The implant-supported milled bar overdenture: a literature review.

PURPOSE This bibliographical review aims to determine the present situation of the implant-supported milled bar overdenture as a therapeutic option in implantology, as well as to set and compare the techniques and materials currently used for making them. MATERIALS AND METHODS By searching the main electronic bibliographical data in indexed Medline articles, we obtained a total number of 20 articles that fulfilled the requirements of this bibliographical review. RESULTS The implant-supported milled bar overdenture offers excellent long-term successful results, although complication rates are higher in emergency cases of patients initially planned for a fixed prosthesis. Krenmair and collaborators found cumulative survival rates of implants on milled bars after 5 years, of 99% in mandible cases, and of 97.8% in maxilla cases. No detailed protocols specifying the necessary number of implants or their characteristics have been found, though they are never made with less than 4 implants in mandible or 4-6 in the maxilla. Milled bars are screwed, generally cast in a precious metal alloy, with a metal or acrylic suprastructure and include attachments that regulate the tightness. The suprastructure adjusts precisely and rigidly to the milled bar, and presents similar biomechanical movements to those of fixed prostheses. The overdenture is removable and its prophylaxis is simple. CONCLUSIONS The implant supported milled bar overdenture is a very interesting option in the treatment of patients with moderate to severe reabsorbed maxilla problems. It offers both the advantages of removable prostheses as well as the stability and retention of a fixed prosthesis.