ObjectiveDental implants show impressive survival and like rates, but peri-implantitis is a frequent inflammatory disease which affects the implant-surrounding tissues. While biofilms on the implant surface is considered its etiologic reason, several risk factors determine the pace of progression of peri-implant bone loss. Some risk factors are generally accepted while others are still unconfirmed and a matter of ongoing discussion. Among the latter, tissue macrophage sensitization on TiO2 has gained scientific interest in recent years. The aim of the present case-control study was to test for potential associations between clinically manifest peri-implantitis and MS related parameters.Materials and methodsIn patients with implants affected by peri-implantitis in the test group and healthy implants in the control group clinical parameters (peri-implant pocket depths (PPD) and bleeding on probing (BOP) were measured. Samples of aMMP-8 were taken from the entrance of the peri-implant sulcus and bacterial samples were collected from the sulcus. Blood samples were obtained from the basilic vein to assess MA-related laboratory parameters. Potential correlations between clinical and laboratory parameters were tested by multiple regression (p < 0.05).ResultsNo statistically significant correlations were found between clinical or bacteriological findings and laboratory parameters were found.ConclusionsBased on the findings of this study elevated MA-related laboratory parameters do not appear to be linked to peri-implantitis.Clinical relevanceSensitization on TiO2 is not associated with clinical symptoms of peri-implantitis.