Analysis of Genetic Variations in Patients With Peri-implantitis

The primary objective of this study is to evaluate interleukin-1(IL-1) gene group polymorphisms in patients with peri-implantitis and to compare them with patients with peri-implant health (control group), taking into account smoking status, gender, age and history of periodontitis.The aim of this investigation is also to look at the levels of the inflammatory response markers IL-1 beta, prostaglandin E2 (PGE2) and tumor necrosis factor alpha (TNF alpha) in the peri-implant crevicular fluid of patients with healthy oral implants in comparison with individuals with peri-implantitis, under consideration of the patients´ individual IL-1 genotype. The main hypothesis is that individuals carrying the polymorphism in the IL-1 gene cluster are susceptible to develop peri-implantitis through altered IL-1 and IL-1 receptor antagonist (IL-1Ra) production. A second hypothesis is that both in healthy individuals and especially pronounced in patients having peri-implantitis, an IL-1-positive genotype will result in higher levels of inflammatory cytokines (IL-1 beta, PGE2 and TNF alpha) than an IL-1- negative genotype. Patients included in the study will be recruited from the Dental Clinic Egas Moniz implant maintenance program and will only be used for this study. All possible candidates will receive a questionnaire and if the patient's medical history is in accordance with study inclusion criteria, and if they agree to participate, informed consent will be signed. All clinical data will be collected by the same examiner. Genes IL-1A and IL-1B control the production of the proinflammatory proteins, IL-1 alpha and IL-1 beta, respectively. IL-1RN gene controls the synthesis of the IL-1Ra, which impedes the function of IL-1alpha and IL-1beta by competing for receptor binding. Polymorphisms of the following genes will be analyzed: IL-1A-889, IL-1B + 3954, IL-1B-511 and IL-1 RN from patients with peri-implantitis and peri-implant health. For the investigation of genetic polymorphi