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Salivary cotinine and S100A8/A9 levels in children exposed to environmental tobacco smoke: a case-control study

Arzu Koçkanat, Sukran Acipinar

Journal of Applied Oral Science, 2026

150 participants

Abstract

Abstract Exposure to environmental tobacco smoke (ETS) poses significant risks to children’s oral health by inducing oxidative stress and triggering inflammatory responses. Even in the absence of clinically evident oral inflammation, early biological changes can be detected in children exposed to ETS. Objectives This study aimed to evaluate salivary cotinine and S100A8/A9 levels in children exposed to ETS and to examine the relationship between exposure intensity and inflammatory biomarker expression. Methodology This observational case-control study included 150 systemically healthy children aged 6–12 years. ETS exposure was determined using parent-reported questionnaires. Clinical parameters, including plaque index, gingival index, and probing pocket depth, were recorded. Unstimulated saliva samples were analyzed for cotinine, S100A8, and S100A9 using ELISA kits. Group comparisons were conducted using the Mann–Whitney U test, and correlations were assessed using Spearman’s rank correlation coefficient. Statistical significance was set at p0.05). However, salivary cotinine, S100A8, and S100A9 levels were significantly higher in ETS-exposed children (p<0.05). Cotinine demonstrated a moderate positive correlation with S100A8, while its correlation with S100A9 was weak and non-significant. Exposure intensity was positively associated with cotinine and S100A8 levels, but not with S100A9. Conclusion ETS exposure in children is associated with early biochemical signs of…

How strong is the evidence?

Evidence Hub reads this as a case-control, done in people. Its evidence level is 4 of 5 (Low · observational). Observational designs can show an association but not prove cause. Reported size: 150 participants or records.

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