Biological response to peri-implantitis treatment

Objective: To investigate biological markers of peri-implantitis (PIP) in crevicular fluid before and after surgical and antimicrobial therapy. Material and Methods: Forty-eight participants (24 healthy implants and 24 PIP) were clinically evaluated, and peri-implant crevicular fluid (PICF) samples were collected at baseline for both groups, and at 3-months after surgical and antimicrobial treatment (ie, n = 21 PIP completers). Samples were analyzed for interleukin-1β (IL-1β), matrix metalloproteinase-8 (MMP-8), and macrophage inflammatory protein-1α (MIP-1α) using immunoassay and the results compared between groups. Results: Peri-implantitis sites at baseline demonstrated significantly higher mean periodontal probing depths, percentage bleeding on probing (P ≤ 0.001), and mean IL-1β concentration in PICF compared to healthy implant sites (17.9 vs 1.7 pg/μL; P = 0.02). Three months after treatment, periodontal probing depths, bleeding on probing, suppuration (P < 0.05), and the mean concentration of MMP-8 decreased significantly compared with baseline (12.1 vs 6.7 ng/μL, P = 0.04). MIP-1α concentrations showed no differences between the groups. Conclusion: Elevated concentrations of IL-1β in PICF were consistent with PIP. A decrease in MMP-8 concentration in PICF at three months after treatment is consistent with a healing biological response.