Treatment outcomes of fixed or removable implant-supported prostheses in the edentulous maxilla. Part II: Clinical findings

Statement of problem. There is a widespread belief that maxillary overdentu re prostheses are associated with a higher frequency of complications and r equire more maintenance than fixed implant prostheses. Purpose. This prospective clinical study compared the treatment outcomes of fixed and removable implant-supported restorations in the edentulous maxil la with the main emphasis on the clinician's point of view. Material and methods. Ten patients were treated with fixed screw-retained i mplant prostheses (group 1), and 10 patients were treated with removable im plant-supported overdentures (group 2) in the edentulous maxilla. Recall wa s scheduled at 6-month intervals to investigation the prosthodontic treatme nt outcomes, including implant survival, prosthesis time until retreatment, and maintenance issues. Clinical parameters gingival index (GI), plaque in dex (PI), the clinical attachment level, and radiographic marginal bone lev els measured, along with any biologic and mechanical complications were rec orded. Results. Patients were followed over a mean period of 39 months (SD=7; grou p 1) and 27 months (SD=10; group 2) after implant placement. Cumulative imp lant survival was 97.6% for group 1 and 94.4% for group 2 after an 18-month observation period. The mean time until retreatment after prostheses inser tion was 23.4 months fur group 1 and 19.8 months for group 2 (n.s.). In bot h groups, the increase over time in the radiographically investigated bone level was found to be significant. The indices given for the mucosal health and oral hygiene status (GI and PI) were highly correlated in both groups at each recall appointment, but no significant differences were found betwe en groups 1 and 2. Conclusion. In groups 1 and 2, comparable prosthodontic treatment outcomes were achieved ed. The majority of mechanical complications could be managed chairside during recall visits and did not require additional appointments , so that the time and costs involved in providing maintenance were kept do wn.