Clinical and genetic aspects in dental implant loss

Osseointegration failure is a complex, multifactorial trait shown to concentrate in some treated populations. There has been shown evidence for genetic contribution to dental implant failure. Genetic polymorphisms have been classically considered genetic risk factors for several diseases and, more recently, for dental implant loss. Objectives: The purpose of this study was to access clinical factors related to failure process, and to investigate the relationship between a vitamin D receptor (VDR) polymorphism (rs731236, TaqI) and dental implant loss. Methods: Two hundred and seventeen unrelated patients, mean age 51.7 ± 11.3 years, were divided into two groups: i) Control group (C), 137 individuals presenting at least one osseointegrated implant in function for six months or more and without any implant failure, and ii) Study group (S), 80 individuals presenting at least one implant loss. After DNA collection and purification, VDR TaqI polymorphism analysis was performed by PCR-RFLP. Differences between control and study groups and between healthy (H; n=1232) and lost (L; n=135) implants were accessed. Results: Positive evidence of association has been detected between implant failure and the following variables: edentulism, implant position, primary stability, and implant length. Cox Regression model showed that primary stability, surgical technique and bone quantity were related to implant survival over time. No association between genotypes or alleles of VDR TaqI polymorphism and implant loss was found between the groups. Conclusion: It was observed that clinical variables, but not the study polymorphism, were associated with implant dental failure.