THE EFFECTS OF SODIUM FLUORIDE AND CHLORHEXIDINE USE ON SALIVARY IL-6 AND MATRIX METALLOPROTEINASE LEVELS IN CHILDREN WITH ACTIVE CARIES

Summary

Methods:The study will be conducted at Alanya Alaaddin Keykubat University, Faculty of Dentistry, Department of Pediatric Dentistry. The study will be initiated after obtaining ethics committee approval. The nature of the study will be explained to the children and their parents/guardians; informed consent will be obtained through patient information forms and informed consent forms. Investigator calibration will be conducted to minimize measurement error and eliminate inter-observer variability. In this context, the investigator will perform active caries assessment on a group of children excluded from the study at two different time points, and the consistency between the two measurements will be evaluated using Cohen's kappa method. If the agreement coefficient reaches a sufficient level, the investigator will be permitted to begin clinical data collection. Similarly, trial samplings will be conducted for the saliva collection protocol, and study procedures will commence once consistency in sample collection time, volume, and processing steps is ensured. Sample size calculations were performed assuming 80% power (1-β = 0.80), a significance level of α = 0.05, and Cohen's d ≈ 0.8 effect size for a two-independent-group comparison. Analyses were conducted using G\*Power 3.1 software (Heinrich-Heine-Universität Düsseldorf, Germany), and the sample size was determined as 20 participants per group:Group A: 5% Sodium Fluoride (NaF) varnish - topical applicationGroup B: 2% Chlorhexidine (CHX) +5% NaF varnish - topical application. Group C: Standard care / oral hygiene education (negative control). Group D: Caries-free children (biological control; matched by age and sex; no intervention, baseline saliva sampling only). Measurement Time Points: T0 (Baseline): Pre-intervention (preferably between 09:00-11:00 AM; at least 1 hour after eating/tooth brushing/sugar consumption), dmft/ICDAS assessment and saliva collection. T1: Post-intervention , T2: 1 month (30 days). Saliva Collection, Processing, and Storage:Participants and their parents will be asked not to eat or drink for at least 1 hour prior to saliva collection. Morning hours will be preferred for sample collection, and the time of application will be recorded. First, the patient will be asked to accumulate unstimulated saliva, which will then be aspirated from the floor of the mouth using disposable syringes to prevent potential contamination. The sample will then be transferred to an Eppendorf tube and labeled. All procedures will be performed under isolation using sterile dental instruments, cotton rolls, and aspirators. Samples will be identified by code numbers assigned during collection and processing, and the same codes will be used for subsequent sample collections.Saliva samples will be re-collected after preventive applications. Patients will be recalled at 1 month for saliva sampling. Each sample will be transported immediately after collection, then centrifuged at 5,000 g for 10 minutes at 4 °C to remove insoluble particles. Eppendorf tubes will be stored at -80 °C in a freezer.Subsequently, IL-6, MMP-8, MMP-9, and TIMP-1 levels in saliva samples will be evaluated using a human saliva enzyme-linked immunosorbent assay (ELISA) kit. ELISA (Enzyme-Linked Immunosorbent Assay) will be used for the quantitative measurement of target biomarkers. All analyses will be conducted in accordance with the manufacturer's protocol, and the kits are CE-marked and/or FDA-approved.Aim:To compare the biomarkers IL-6, MMP-8, MMP-9, and TIMP-1-representing the key components of the inflammation-matrix degradation axis-between healthy children and caries-active children, and to evaluate the effects of materials such as NaF and CHX used in caries prevention on these parameters.Inclusion Criteria:Age: 6-8 years, (Groups A, B, C): Participants must meet at least one of the following criteria:dmft ≥ 6, or, Presence of at least one active caries lesion with an ICDAS code ≥ 3, or, Clinical evidence of active caries on ≥ 10 surfaces.(Group D):All surfaces caries-free and non-high-risk individuals (ICDAS II = 0). (Only baseline (T0) saliva sampling will be performed.)Exclusion Criteria:Professional topical fluoride application or continuous CHX use within the past 3 months., Systemic chronic disease, immunodeficiency, or severe neuromotor disorder., Presence of gingival redness, swelling, or bleeding., All first permanent molars not yet erupted., Known allergy to fluoride compounds., Behavioral problems that would prevent safe cooperation during application., Regular antibiotic use within the past 1 month., According to Ethics Committee regulations: individuals with infectious diseases, those at high risk of endocarditis, those with allergy to varnish components, individuals with a history of substance dependence, those with epilepsy, and those with renal failure or immunosuppression.

Conditions

• Dental Caries
• Dental Caries in Children

Interventions

OTHER

5% Sodium Fluoride Varnish

Teeth are gently air-dried for 30 seconds under isolation with cotton rolls and aspirator. Approximately 0.5 mL of 5% NaF varnish is applied to all tooth surfaces sequentially by quadrant starting from the upper jaw using an applicator tip and left in place for 1 minute. Parents are instructed to restrict water and hard food intake for 1 hour post-application. This is a routine preventive application; no off-label use is involved.

OTHER

2% Chlorhexidine Pre-Treatment + 5% NaF Varnish

Following isolation and air-drying, 2% chlorhexidine solution is applied to the lesion/tooth surfaces using an applicator tip and left in place for 30 seconds. Excess CHX is then absorbed. Precautions are taken to prevent ingestion. This pre-treatment is performed immediately prior to 5% NaF varnish application. This is a routine preventive application; no off-label use is involved.

BEHAVIORAL

Standard Oral Hygiene Education

Children and parents receive standardized oral hygiene education including instruction on twice-daily brushing with fluoride toothpaste, reduction of sugar intake frequency, and a brief parent information brochure. No professional topical agent is applied. Necessary treatment will be offered at the end of the study upon request (wait-list design).

Sponsors & Collaborators

• Alanya Alaaddin Keykubat University

  collaborator OTHER

• Gül Keskin

  lead OTHER

Principal Investigators

• GÜL KESKİN, DDS, PhD · Alanya Alaaddin Keykubat University

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

6 Years

Max Age

8 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2026-05-15

Primary Completion

2027-01-01

Completion

2027-06-30

Countries

• Turkey (Türkiye)

Study Locations