Macrophage Sensitization to TiO2: Insights from Failed and Survived Implant Cases

Background/Objectives: To evaluate whether patients with prior implant loss without clinical symptoms of peri-implantitis exhibit elevated cytokine levels (TNF-α and IL-1β) compared to age- and gender-matched controls with healthy peri-implant conditions after 10 years, hypothesizing an association between implant loss and increased cytokine expression. Methods: Patients were selected from a long-term randomized controlled trial, including individuals with implant loss and controls with healthy peri-implant tissues. Blood samples were exposed to titanium dioxide (TiO2) particles and analyzed for cytokine release using a macrophage stimulation test. Results: No significant association was observed between implant loss and TNF-α levels. IL-1β levels were elevated in the implant loss group when tested with correction for non-normally distributed data. Within the limitations of this study, the results align with recent studies questioning systemic cytokine-peri-implant health relationships while contrasting with findings of heightened cytokine levels in typical peri-implantitis cases. Conclusions: This preliminary study highlights variability in host immune responses and suggests that systemic biomarkers alone may not explain implant loss, particularly in non-inflammatory scenarios such as potential mechanical overload. Larger studies with diverse populations and integrated systemic and local inflammatory analyses are needed to better understand the underlying mechanisms of implant complications and refine diagnostic approaches.