Abstract
Background: This study investigated the relationship of the interleukin-1 (IL-1) genotype, smoking status, and the patient's age to the survival of osseointegrated dental implants. Methods: Twenty-seven patients with 33 implants that had been lost or who had at least 50% bone loss on radiographs were compared to a group of 38 patients who had experienced no bone or implant loss. All lost implants in a private practice were included in the data, except those that had fractured with no previous bone loss. Results: Smoking was demonstrated to increase the risk of implant failure by a factor of almost 2.5. Conclusions: Statistical testing failed to provide evidence of an increased risk for implant failure for patients who are positive for the IL-1 genotype. There was no apparent relationship between the patient's age at the time of placement and implant loss. This study raises several questions concerning the etiology of implant loss and the comparative biology of tissues surrounding implants when compared to those surrounding natural teeth.