RESUMO
BACKGROUND: A broader understanding of the immune inflammatory profile of peri-implant diseases could be helpful in the development of host-targeted preventive and therapeutic strategies. The aim of this study is to answer two clinical questions: 1) whether patients with peri-implantitis (PP) present higher prevalence of any specific inflammatory cytokine in peri-implant crevicular fluid (PICF) compared with healthy patients; and 2) whether local inflammation measured in PICF can be used as a predictor for incipient PP. METHODS: A systematic review of the literature on the most common cytokines released in PICF in healthy and PP-affected sites was conducted from 1996 up to and including October 2013 using predefined search strategies. Cross-sectional and prospective longitudinal studies were considered. Meta-analyses were done separately for healthy, mucositis (MU), and PP outcomes. RESULTS: Interleukin (IL)-1ß was the most studied cytokine (n = 12), followed by tumor necrosis factor (TNF)-α (n = 10). Other cytokines were also linked to PP, such as IL-4, IL-6, IL-8, IL-10, IL-12, and IL-17. Statistical differences were revealed when IL-1ß release was compared between healthy implant sites and PP (P = 0.001) or MU sites (P = 0.002), respectively; when PP and MU were compared, no statistical differences could be detected (P = 0.80). For TNF-α release, significant differences were found between healthy and PP implants (P = 0.02). CONCLUSIONS: PICF containing inflammatory mediators, such as IL-1ß and TNF-α, can be used as additional criteria for a more robust diagnosis of peri-implant infection. Additionally, once the inflammatory process is installed, no differences were found between peri-implant MU and PP.