Association Between IL-6 And Oral Tissue Responses in Patients Wearing Dental Prostheses

Abstract

The oral mucosa of the dental prosthesis bearing areas are subjected to permanent stresses and it is a chronic infection which may lead to inflammatory conditions produced by pro-inflammatory cytokines. Interleukin-6 (IL-6) is an important mediator of inflammation that participates in regulation and damage of mucosal immune, but little is known about its relevance to prosthesis-induced oral tissue changes. The objective of the current case–control study was to measure salivary levels of IL-6 in patients who wore dental prostheses and healthy controls and seek possible associations between IL-6 concentrations and clinical responses in oral tissues as mucosal erythema, mucosal edema, ulceration, or gingival inflammation. This cross-sectional study was performed in the Dental Clinics of Al-Najaf Center for Dentistry, Al-Najaf, Iraq from April 2024 to February 2025. A total of 120 subjects were included, which consisted of 66 denture wearers and 54 healthy systemically control individuals that were age and sex matched. Full-mouth clinical examinations were conducted to evaluate tissue alterations that were graded by the degree of severity. Whole unstimulated saliva samples were collected in the morning under standardized conditions and analyzed with a commercial enzyme-linked immunosorbent (ELISA) for IL-6 concentrations. Results Statistical analysis was conducted with SPSS version 25, which included chi-square tests for categorical variables, independent-samples t-tests to compare the groups, one-way ANOVA (F-test) for subgroup comparisons and Pearson’s correlation in order to test the association between IL-6 levels and tissue response indices. It was also found that mean salivary IL-6 level of the prosthesis-wearing group was significantly higher than that of the controls (p = 0.013). Statistically, a significant difference in mucosal erythema, ulcers, mucosa edema and the degree of gingival inflammation between patients and controls was found (p < 0.05). IL-6 levels were progressively higher with the severity of tissue alterations, and differed significantly between subgroups for mucosal erythema, edema, ulceration and gingival index (p < 0.05). The correlation analysis showed a significant positive relationship between IL-6 levels and mucosal erythema (p = 0.002), mucosal edema (p = 0.003) and gingival inflammation (p = 0.04), but not with ulceration. In summary, salivary IL-6 levels are significantly connected with local inflammatory responses in oral tissue of patients using dental prostheses. These results reveal the important role of IL-6 as a mediator of prosthesis-induced mucosal inflammation and its potential use as a non-invasive biomarker for monitoring oral tissue response in prosthodontic patients.

Keywords:

Interleukin-6, Dental Prosthesis, PPD, CAL, BOP, PI, GI

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