Evaluation of the effectiveness of dental implant therapy in a practice-based network (FOCUS).

Evaluations of multicenter clinical trials are needed to determine the effectiveness of care in routine implant therapy in clinical practice.Ninety-two clinicians in 75 clinics in 13 countries recruited five subjects per clinic who were in need of a minimum of two dental implants to restore a partially edentulous quadrant and were followed for a minimum of 1 year after loading. A centralized Internet-based case report form was developed to coordinate data recording. Data entry was done by each clinic, with follow-up source verification.The study recruited 549 subjects in 101 clinics with 1,893 implants placed. Three hundred forty subjects completed the 1-year recall (gender distribution of 56\% female, 44\% male; mean age of 57 years with a range of 18 to 84 years). In all, 1,246 dental implants were followed; a majority of subjects had two to four implants. Twenty-eight percent of subjects received osseous grafting prior to or coincident with implant placement. In the maxilla, 779 (63\%) implants were placed, 256 in the anterior and 523 in the posterior; in the mandible, 467 implants were placed, 85 in the anterior and 382 in the posterior arch. The median edentulous period prior to implant placement was 24 months (range, 0 to 480 months); 46\% of all patients received implants within 12 months of tooth loss. At 1 year after prosthesis insertion, 15 subjects had lost a total of 17 implants, for a cumulative implant survival rate of 98.6\%. Chi-square and Fisher exact tests indicated a higher risk of implant loss at sites with advanced resorption and for wider-diameter implants (5-mm tapered body). There was no statistical relationship with implant loss relative to implant length or anatomic location within the oral cavity.The outcomes support the need for ongoing involvement of clinicians in routine practice assessments of patient-based outcomes of implant therapy.