Assessment of the Association Between Peri-implant Bone Tissue Status and Systemic and Local Inflammatory Factors

BACKGROUND: Detection of proinflammatory cytokines during dental treatment planning may serve as a prognostic indicator for the potential inflammatory response to integrated implants, particularly in the form of uncontrolled local bone resorption.

AIM: The work aimed to evaluate the relationship between the concentration of proinflammatory cytokines—interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), and C-reactive protein (CRP) — and the condition of jawbone tissue in the area of installed dental implants, taking into account inflammatory processes in the peri-implant region.

METHODS: A total of 75 patients aged 27 to 72 years were examined. Based on cone-beam computed tomography findings, participants were divided into three groups according to the extent of vertical bone resorption around dental implants: group 1 (n = 29), resorption < 1/3 of implant length; group 2 (n = 32), resorption up to 1/2 of implant length; and group 3 (n = 14), resorption > 2/3 of implant length. The serum concentrations of IL-6, TNF-α, and CRP were evaluated, the implant hygiene index was analyzed, and a macrohistochemical assessment of inflammation in the transgingival portion of the abutments was performed.

RESULTS: Jawbone resorption and proinflammatory cytokine concentrations in group 1 were as follows: resorption 0.6 ± 0.1 mm, IL-6 concentration 0.34 ± 0.31 pg/mL, TNF-α concentration 0.5 ± 0.1 pg/mL, CRP concentration 2.6 ± 6.0 pg/mL; in group 2, resorption was 2.4 ± 0.8 mm, IL-6 concentration 1.3 ± 0.5 pg/mL, TNF-α concentration 1.7 ± 0.5 pg/mL, CRP concentration 3.45 ± 3.40 pg/mL; in group 3, resorption was 4.6 ± 1.6 mm, IL-6 concentration 2.3 ± 0.4 pg/mL, TNF-α concentration 2.3 ± 0.2 pg/mL, CRP concentration 3.0 ± 2.2 pg/mL. Comparative analysis of cone-beam computed tomography data and concentrations of IL-6 and TNF-α revealed significant intergroup differences (p < 0.001). Correlation analysis of IL-6 and TNF-α concentrations demonstrated a notable association with bone resorption across the entire sample (p < 0.001). Assessment of the relationship between hygiene levels in the transgingival portion of the abutment and the degree of inflammation established a moderate correlation across the entire sample (p < 0.001). The relationship between IL-6 and TNF-α cytokine concentrations and the severity of inflammation was also statistically significant.

CONCLUSION: The degree of bone resorption in the implant area has a direct correlational relationship with the concentrations of proinflammatory cytokines IL-6 and TNF-α. These findings may indicate the importance of assessing the concentrations of these proinflammatory cytokines to identify a risk group among patients with implants under load for five or more years, considering localized inflammation in the transgingival portion of abutments. Additionally, cytokine status can be monitored during implant planning, potentially serving as a predictive factor for forecasting the long-term stability of implants.