A four-year retrospective study of 3i threaded implants.

The use of osseointegrated implants can be considered as one of the most productive developments in dentistry during this century. Although initially introduced for use in fully edentulous patients, their present widespread use in nearly all forms of tooth loss, as well as for the rehabilitation of maxillofacial prosthetics and in orthodontics, has significantly expanded the realm of restorative dentistry. The present multicentre retrospective study evaluates the results of 327 patients rehabilitated with 1047, 3i (Implant Innovations Inc.) threaded implants over a four-year period. Eight patients with 22 implants dropped out and were excluded from the study as they could not be evaluated. A total of 319 patients with 1025 implants remained. Nine implants failed in the mandible and 14 in the maxilla. There was a success rate of 98.2 percent in the mandible and 97.3 percent in the maxilla. The mean overall success rate was 97.75 percent, with little variation between the four study centres. These results are similar to previously published studies on titanium threaded implants and indicate that, with careful adherence to accepted principles of surgery and restorative dentistry, the 3i threaded implant system can be used confidently to provide the necessary support for an osseointegrated implant-supported prosthesis.