Analysis of association of clinical aspects and vitamin D receptor gene polymorphism with 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 loss. Genetic polymorphisms have been classically considered as 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. Material and 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 6 months or more and without any implant loss, 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 polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP). Differences between C and S, and between healthy (H; n=1232) and lost (L; n=135) implants were accessed. Results: Positive evidence of association has been detected between implant loss and the following variables: edentulism, implant position, primary stability, and implant length. Cox's 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 dental implant loss.