IMPLANT-SUPPORTED OVERDENTURES - THE COPENHAGEN EXPERIENCE

Objectives: To evaluate the functional and biological effect of implan t-supported overdenture treatment in the lower jaw. Methods and Materi als: Thirty two patients were consecutively treated with Astra Tech im plants in the lower jaw for retaining overdentures. All implants had a diameter of 3.5 mm and all but two of the implants were longer than 1 0 mm. For the implant supported overdentures two methods of attachment were used, a bar or a ball. Results. One of 69 fixtures was lost duri ng the 4-5 year observation period. The mean bone loss for all fixture s was less than 0.2 mm per year. Complications included 15 fractures o f the ball attachment and 26 episodes of looseness of the matrices hol ding the screw in place. Patient satisfaction with the treatment of th e lower jaw was high although 7 patients found that control of the upp er denture was poor following treatment. Conclusions: When the bone qu ality and quantity is sufficient, two implants can support an overdent ure in the lower jaw, providing prosthesis which functions well. (C) 1 997 Elsevier Science Ltd.