A cross-sectional assessment of biomarker levels around implants versus natural teeth in periodontal maintenance patients.

Background: Recent studies point to the clinical utility of using peri-implant sulcular fluid (PISF) as a valuable diagnostic aid for monitoring peri-implant tissue health. The objectives of this study are to determine the levels of key biomarkers in PISF in periodontal maintenance participants and compare them with their corresponding levels in gingival crevicular fluid (GCF) obtained from the same participants.

Methods: PISF and GCF were collected from an implant and a contralateral natural tooth after the clinical examination of 73 participants. The levels of interleukin (IL)-1α, IL-1β, IL-6, IL-8, IL-10, IL-12, IL-17A, tumor necrosis factor (TNF)-α, C-reactive protein, osteoprotegerin, leptin, and adiponectin were determined using multiplex proteomic immunoassays. The correlation of biomarker concentrations between GCF versus PISF, within GCF or PISF, and with several covariates (age, brushing frequency, days since professional cleaning, probing depth [PD], and plaque index) were also determined.

Results: Significantly higher levels of IL-17A (P = 0.02) and TNF-α (P = 0.03) were noted in PISF when compared with their levels in GCF. Significant positive correlations were noted between the concentrations of cytokines in PISF versus their levels in GCF. Among the covariates, a significant positive correlation was noted between mean PDs around implants and levels of IL-1β (P <0.05) and IL-8 (P <0.05) in PISF.

Conclusion: The results of this study point to the differential expression of specific biomarkers in GCF versus their levels in PISF in periodontal maintenance patients, which is critical information before establishing PISF as a diagnostic fluid to monitor peri-implant health.