Salivary IL-8 and TNF-α as potential diagnostic biomarkers for dental caries

Abstract

Dental caries constitutes the major burden on oral health worldwide, with untreated dental caries being among the most prevalent health conditions. Cytokines play a critical role in the immunopathogenesis of dental caries. It is worth mentioning that the salivary levels of interleukin (IL)-8) and tumor necrosis factor-α (TNF-α) have been reported to differ between patients with caries and those without caries. The aim of the present study was to determine the diagnostic accuracy of salivary levels of cytokines (IL-8 and TNF-α) for differentiating between subjects with caries and those without caries. For the present case-control study, whole unstimulated salivary samples were collected from 44 adult individuals who were divided into two groups as follows: 22 subjects with dental caries and 22 without caries. Clinical parameters were recorded, including caries experience (decayed, missing, filled surfaces), plaque index and gingival index. Enzyme-linked immunosorbent assay was used to determine the salivary levels of cytokines. The results revealed that the mean levels of salivary cytokines (IL-8 and TNF-α) were elevated in the group with caries as compared to those without caries (the control group; P<0.05). IL-8 was able to discriminate between patients with dental caries from healthy controls (area under the curve value, 0.735). Moreover, the levels of salivary cytokines exhibited positive correlations (P<0.05). On the whole, the present study found higher amounts of cytokines in the saliva of patients with caries; thus, these cytokines perhaps contribute to the development of caries. IL-8 demonstrated moderate clinical accuracy in discriminating patients with caries from the controls.