Long‐term clinical effectiveness of oral implants in the treatment of partial edentulism

Abstract

One hundred and eight‐seven ITI^® implants were prospectively followed from November 1992 to July 2000, in order to evaluate the clinical efficiency and the long‐term prognosis in 109 partially edentulous patients (69 women and 40 men; average age 41.3 years). Of these 187 implants, 69.5% were placed in the mandible and 30.5% in the maxilla. After a healing period that ranged from three to six months, the osseointegrated implants (n = 184) were restored with single crowns. Three implants were extracted prior to loading the fixture and were considered early failures. Each implant was reassessed on a yearly basis, both clinically and radiographically. The results of the investigation, which were evaluated according to predefined success criteria, were reviewed in accordance with a life table method. During the follow‐up, six cases were deemed to be late failures. In each of these cases, a suppurative infection of the peri‐implant tissue was diagnosed: in one implant, the infection could not be eradicated and the implant was removed. When 11 drop‐outs were included in the analysis, the cumulative survival and success rates for the whole sample group were 96.77% and 93.6%, respectively. When only prosthetically loaded implants were considered, the results increased to 99.35% for the cumulative survival rate and 96.18% for the cumulative success rate. The analysis on disaggregated data showed better results for maxillary restorations (survival rate 100%) in comparison to mandible restorations (survival rate 95.11%). It was concluded that, under standard anatomic conditions (bone site height > 8 mm, thickness > 6 mm), prosthetic restoration of partially edentulous patients with the ITI system can be described as a reliable and efficient therapy in the long term.