Introduction: Utilizing 38% silver diamine fluoride (SDF) has been demonstrated in clinical trials to prevent and halt early childhood caries (ECC). Based on a research evaluation, it has been found that 38% SDF can effectively prevent new tooth decay and stop existing tooth decay in children's primary teeth. Objective: This study aimed to assess the survival of teeth treated with repeated applications of 38% SDF in children with ECC and to compare the outcomes between single and multiple applications. Materials and methods: A split-mouth, double-blind, active-control, parallel-arm randomized controlled trial was conducted following Consolidated Standards of Reporting Trials (CONSORT) guidelines. Children aged 4–5 years with bilateral ECC were recruited from a primary government school in Maharashtra, India. Treatment involved applying 38% SDF to carious lesions, with lesions randomized into two groups: single application and double application. Follow-ups were conducted at 6 and 12 months to assess lesion progression, depth, and survival. Results: Eighty-four primary carious teeth from 42 female participants were included. Lesions were predominantly occlusal or proximal, with varying sizes and depths. After 12 months, 12 lesions failed in group I (single application) and 3 in group II (double application). The intergroup comparison of mean levels at 12 months showed a statistically significant difference (p = 0.01). Intragroup comparisons showed an increase in lesion depth and level from baseline to 6 months, with a subsequent rise from 6 to 12 months in group I. The mean survival rate of teeth after SDF application at the end of 12 months was around 94% for group II, while for group I it further decreased from 70 to 58%. Conclusion: Repeated applications of 38% SDF showed improved survival rates of teeth in children with ECC compared to single applications. Double application of SDF demonstrated superior efficacy in maintaining tooth survival over 12 months.