Retrospective multicenter study of an anodized, tapered, diminishing thread implant: success rate at exposure

Performance of a new tapered, threaded implant at exposure was evaluated retrospectively using conservative assessment criteria. The criteria used were intended to ensure that an implant in the early stages of failing as well as those implants that have clearly failed would be identified as such. These results reflect an evaluation preliminary to comparing the performance of the implant at exposure and its performance (i.e., success rate) observed after longer periods (i.e., > or = 1 year) of loaded service. Data from 663 patients treated in the setting of the authors' private practice offices were evaluated to assess the performance of the implant under representative "clinical practice" usage conditions. The implant success/failure criteria were prospectively defined and applied to data obtained in a masked fashion from patients' records. Neither the dentist nor personnel involved in the analysis of the data were aware of which patients were qualified for and included into the study. Of 1100 implants available for evaluation, 15 implants failed at or before exposure. The success rate at exposure was 98.6%. There was no correlation between the anatomical region in which an implant was placed and the incidence of implant failure. Implants placed in fresh extraction sites and/or grafted sites appeared to be more likely to fail at exposure. Conversely, the failure rate of implants placed using a single-stage surgical procedure was comparable to that of implants placed using a conventional two-stage surgical methodology. Immediately loaded implants experienced a success rate comparable to that of implants placed using conventional two-stage surgical procedures. Factors under the clinician's control may play a substantial role in determining implant performance at exposure.