TNF and Peri-Implantitis: These results suggest that the presence of elevated levels of IL-1 β and TNF-α in saliva may serve as a potential biomarker for the diagnosis and follow-up of peri-implantitis (51); however, Sanchez-Fernandez et al. (18) found that only those cases with a PD ≥5 mm showed a significantly greater reduction (p = 0.04) in IL-1β concentrations at 45 days, along with a greater reduction in BOP in the experimental group.