SDF With or Without Fluoride Varnish for Caries Arrest in Primary Teeth of Young Children

Dental caries is a biofilm-mediated disease driven by dietary sugars and bacterial acid production. The prevalence in primary dentition is high worldwide, especially in low- and middle-income countries. Conventional restorative treatments are difficult to perform in very young or behaviorally uncooperative children, and may require sedation or general anesthesia. Therefore, minimally invasive methods such as silver diamine fluoride (SDF) have gained importance as a practical option for arresting active caries lesions.

Rationale and Objectives SDF (38%) is a topical solution with antimicrobial and remineralizing properties that has been shown to arrest dentin caries in children. A limitation is that it stains carious surfaces black. Fluoride varnish (5% NaF) is widely used as a preventive agent to reduce new caries formation. Combining the two may offer dual benefits: SDF for arresting existing lesions and varnish for preventing new ones. The objective of this randomized clinical trial was to compare the effectiveness of two protocols-SDF alone versus alternating SDF and fluoride varnish-for arresting dentin caries in uncooperative young children with primary teeth.

Study Design This was a two-arm, parallel-group, randomized controlled clinical trial conducted in a pediatric dental setting. A total of 104 children aged 1.5-8 years with at least one active dentin caries lesion in primary teeth were enrolled and randomized in a 1:1 ratio. Children with systemic conditions contraindicating participation were excluded. Informed consent was obtained from parents or guardians, and the protocol was approved by the national ethics committee.

Interventions

Group 1 (SDF only): Lesions received 38% SDF application every 6 months.

Group 2 (SDF + FV): Lesions received 38% SDF application every 6 months, with 5% NaF varnish applied to all teeth every 3 months.

All treatments were delivered by calibrated operators according to standardized protocols. Oral hygiene and dietary advice were given to caregivers.

Outcome Measures

Primary outcome: Caries arrest at 24 months, defined as hardening of the lesion surface with no further progression, assessed visually and tactually by blinded examiners.

Secondary outcomes:

Comparative efficacy between the two protocols

Incidence of new caries in non-treated teeth

Influence of baseline factors (oral hygiene, sugar intake, socioeconomic status) on treatment outcomes

Adverse effects, including pulp symptoms and parental acceptance of staining

Follow-up and Data Collection Clinical examinations were performed at baseline, 6, 12, 18, and 24 months. Standardized diagnostic criteria were used. Lesion depth and activity were recorded, and intra-examiner reliability was periodically tested. Caregivers were interviewed about oral health behaviors. Data were entered into an electronic database with quality control checks.

Statistical Analysis Descriptive statistics were used to summarize baseline characteristics. Caries arrest rates were compared between groups using mixed-effects logistic regression to account for clustering of multiple surfaces within each child. Effect modification by baseline covariates (oral hygiene, sugar intake, socioeconomic status, lesion depth) was tested through interaction terms. Statistical significance was set at p < 0.05. Analyses were performed using Stata software.

Safety and Monitoring SDF and fluoride varnish are approved topical agents for dental use and have well-established safety profiles. Adverse events were monitored and reported. No independent Data Monitoring Committee was appointed given the minimal risk nature of the interventions.

Expected Impact This trial provides comparative evidence on two practical, non-invasive caries management protocols in uncooperative pediatric patients. The findings may inform public health strategies and clinical guidelines for the management of early childhood caries in similar populations.