Survival of Dental Implants Placed in Sites of Previous Failures

OBJECTIVE: The purpose of this study was to characterize and determine the success of dental implants placed in sites of previously failed implants. METHODS: IRB approval was obtained to review the records of all patients identified with failed implants placed in the post-graduate periodontics clinic at the University of Maryland from 2000 to 2006. A retrospective review of the identified patient records was performed to characterize the population and to determine the location, time to failure, and the outcome of re-implantation at the sites of previous failure. Data were submitted to Chi-square analysis. RESULTS: Of the 55 patients identified with implant failures, 27 proceeded with re-implantation in 35 sites during the 6-year study period. All but 4 patients were diagnosed with periodontitis. Initial failure rates were not associated with sex, race, or smoking (p>0.05). Initial implant failures occurred more frequently in the posterior than anterior sextants (3:1 ratio, respectively). The mean time to initial implant failure was significantly shorter for the posterior mandible than the posterior maxilla (8.1 ± 12.4 vesus 2.9 ± 2.2 months, respectively). Re-implantation occurred at a mean of 7.2 ± 4.8 months post initial failure. Clinical integration was not achieved for 6 of the 35 implants, reflecting a re-treatment success rate of 83.8%. The majority of re-treatment failures occurred in patients with more than one initial implant failure. No re-treatment failures occurred in the anterior mandibular area. CONCLUSIONS: At one year post-treatment, an overall clinical success rate of nearly 85% was achieved following second implant placement, suggesting that re-treatment provides a viable option for patients undergoing management of failed implants. Persons with multiple initial implant failures may be at higher risk for re-treatment failure.