RETROSPECTIVE MULTICENTER ANALYSIS OF 3I ENDOSSEOUS DENTAL IMPLANTS PLACED OVER A 5-YEAR PERIOD

Osseointegrated dental implants have now become an accepted form of tr eatment for patients with a fully or partially missing dentition. The purpose of this study was to evaluate the performance of 3i threaded a nd cylindrical implants. During a 5-year period, a total of 1969 3i en dosseous implants were placed at 6 centers in the United States and 2 elsewhere in the edentulous and partially edentulous jaws of 653 conse cutive patients ranging in age from 18 to 82 years. Of the total numbe r of implants placed, 1341 were commercially pure titanium threaded im plants and 628 were titanium plasma-sprayed implants with a cylindrica l configuration. A total of 28 patients with 110 implants were lost to follow-up. Implants in these patients were considered neither a succe ss nor a failure. Success was predicated on the osseointegration of ea ch and every implant followed in this analysis rather than the persist ence of prosthetic function. Confirmed bone anchorage was considered e ssential for success. A total of 625 patients with 1871 implants remai n in the study with a follow-up period ranging from 6 to 60 months. A total of 93 implants (5.0% of the total implants followed) were consid ered as failures. A mean implant survival rate was 95.0% for both the threaded and the cylindrical implant was calculated. The success rate of threaded implants was 97.0% in the mandible and 93.8% in the maxill a. The success rate for the 3.3-mm cylindrical implants was 96.0% in t he mandible and 95.5% in the maxilla, and the success rate of 4.0-mm-d iameter cylindrical implants was 95% in the mandible and 92.0% in the maxilla. Causes of failure consisted of loss of osseointegration (2.3% ), crestal bone loss requiring periodontal therapy after the first yea r of function (1.7%) and mechanical problems associated with the prost hesis (0.9%). This retrospective analysis of the 3i endosseous implant system is comparable to previous reports on other implant systems in terms of implant survival and prosthesis stability. It is demonstrated that 3i implants are predictable and can provide lasting osseointegra tion leading to improvement of oral function if the recommended surgic al and restorative protocol is followed.