title: Histopathological Verification of Osteoimmunological Mediators in Peri-Implantitis and Correlation to Bone Loss and Implant Functional Period.
abstract: Peri-implantitis (PI) is characterized by inflammation and bone resorption eventually leading to implant failure, but the characteristic pathologic determinants are undefined to date. This study aims to elucidate the parameters involved in PI pathogenesis, including intraoral implant retention time, extent of bone loss, smoking history, and identification of osteoimmunological markers for inflammation and bone loss. Peri-implant tissues (n = 21) displaying clinically diagnosed PI from patients with vertical bone loss ranging from 0-12 mm and implant function period between 1 and 60 months were evaluated by histochemistry and immunohistochemistry for TRAP, CD3, RANK, RANKL, OPG, and TNF-α. Statistical analyses were performed with the Welch test and correlation coefficients were calculated. Most bone resorption occurred during the first 12 months of implant function and correlated with the extent of inflammation, although histological signs of inflammation strongly varied between samples from minimal appearance of inflammatory cells to extended infiltrates. Implant function period and smoking history did not significantly affect the degree of inflammation. Higher RANK levels emerged in the first 12 months of implant function compared to longer retention times and were negatively correlated to the occurrence of RANKL. Additionally, histological signs of inflammation were about two-fold higher in specimens with bone resorption up from 5 mm compared to under 5 mm. CD3(+) cells were more prevalent in extensive inflammatory infiltrates and samples derived from smokers. Our analyses proved that PI-induced bone loss is differentially influenced by the parameters evaluated in this study, but a distinct interconnection between disease severity and implant retention time can be established.
authors.affiliation: 1  Department of Orthodontics, University of Bonn, Bonn, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Konermann
authors.affiliation: 1  Department of Orthodontics, University of Bonn, Bonn, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Götz
authors.affiliation: 1  Department of Orthodontics, University of Bonn, Bonn, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Le
authors.affiliation: 2  Department of Oral Technology, University of Bonn, Bonn, Germany.
authors.forename: Cornelius
authors.initials: C
authors.lastname: Dirk
authors.affiliation: 1  Department of Orthodontics, University of Bonn, Bonn, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Lossdörfer
authors.affiliation: 3  Department of Dental Prosthodontics, Gerontostomatology and Medical Materials Science, University of Greifswald, Greifswald, Germany.
authors.forename: Friedhelm
authors.initials: F
authors.lastname: Heinemann
mesh_terms: D016301:Alveolar Bone Loss; D015415:Biomarkers; D001862:Bone Resorption; D015921:Dental Implants; D006801:Humans; D057873:Peri-Implantitis; D012907:Smoking; D014409:Tumor Necrosis Factor-alpha
chemical_list: D015415:Biomarkers; D015921:Dental Implants; D014409:Tumor Necrosis Factor-alpha
keywords: bone loss; inflammation; peri-implantitis