Inflammatory cytokine profiles in the crevicular fluid around clinically healthy dental implants compared to the healthy contralateral side during the early stages of implant function

Objective: To describe and compare cytokines levels in clinically healthy sites of dental implants and natural teeth. Materials and methods: A total of 90 dental implants in 71 periodontal healthy patients with function time of less than 6 months after the completion of the implant prosthesis were included in this study. PICF (peri-implant crevicular fluid) and GCF (gingival crevicular fluid) samples were collected from implants and the contralateral natural teeth. In addition, we performed a dynamic collection of crevicular fluid from 18 dental implants and their contralateral natural teeth at four time nodes (first day, first week, first month, third month). The profiles of 45 common cytokines in PICF and GCF were analyzed by Luminex multiplex assays. Results: The total volume of PICF was significantly higher when compared to the volume of GCF (p < 0.01). In contrast, the concentrations of IL-18, IL-2, IL-23, IL-21, IL-1 alpha, IL-12p70, VEGF-A, HGF, FGF-2, BDNF, PlGF-1, MIP-1 beta, TNF-alpha, and IFN-gamma in PICF were significantly lower than those in GCF (p < 0.05). In the longitudinal component of the study, the cytokines found in PICF underwent a brief wave of expression in the 3-month period, with the smallest gap difference of cytokine expression between the PICF and the GCF being at first month. Conclusions: This study observed that the levels of 14 cytokine profiles were lower in PICF than in GCF. Within the implants load for one month, the levels of above differential cytokines in PICF increased and gradually approached the cytokine profiles in GCF.