Characteristics of Early Versus Late Implant Failure: A Retrospective Study

Purpose: Implant failures can be divided into early and late according to the timing of failure. The purpose of this study was to characterize and compare both types. Patients and Methods: A retrospective cohort study was conducted in 194 patients (98 men and 96 women) who presented after dental implant failures during a 6-year period (2000 to 2006). The patient served as the unit of analysis. A history of at least 1 failed and removed dental implant served as the inclusion criterion. Patients were excluded from this study whenever their files had missing data. The collected data included a patient's characteristics, failure characteristics, and the anatomic status of the alveolar ridge after failure. Results: Late failures were associated with moderate to severe bone loss, a larger number of failed implants per patient, a higher incidence in men, and mostly in posterior areas. Early failures were associated with minimal bone loss, occurred more in women, at a younger age, and in most cases the implants were intended to support single crowns. Conclusions: Meticulous follow-up is needed to reveal and treat failing or ailing implants. Once established as hopeless, they should be removed as soon as possible to prevent further bone loss.