The Effects of Sodium Fluoride and Chlorhexidine Use on Salivary IL-6 and Matrix Metalloproteinase Levels in Children With Active Caries

This study aims to compare salivary IL-6, MMP-8, MMP-9, and TIMP-1 levels between healthy children and caries-active children, and to evaluate the effects of 5% sodium fluoride (NaF) varnish and 2% chlorhexidine (CHX) used in caries prevention on these biomarkers. The study will be conducted at Alanya Alaaddin Keykubat University, Faculty of Dentistry, Department of Pediatric Dentistry. Informed consent will be obtained from children and their parents/guardians. Investigator calibration will be performed using Cohen's kappa method prior to data collection. Sample size was calculated assuming 80% power (1-β = 0.80), α = 0.05, and Cohen's d ≈ 0.8, resulting in 20 participants per group using G\*Power 3.1 software. Study groups: Group A: 5% NaF varnish. Group B: 2% CHX + 5% NaF varnish. Group C: Standard oral hygiene education (negative control). Group D: Caries-free children (biological reference; baseline saliva sampling only). Saliva samples will be collected at T0 (baseline), T1 (30 minutes post-application), and T2 (1 month). Unstimulated whole saliva will be collected, centrifuged at 5,000 g for 10 minutes at 4°C, and stored at -80°C. IL-6, MMP-8, MMP-9, and TIMP-1 levels will be measured using CE-marked/FDA-approved human saliva ELISA kits.