Background
dentine caries, caries-risk, caries
EARLY CHILDHOOD CARIES, DEMINERALIZATION, CARIES
Early childhood caries (ECC) remains highly prevalent in many countries [Sodium fluoride (NaF) 5% varnish is a professional topical fluoride recommended for application in moderate and high caries-risk children every 3–6 months to prevent caries development. The mechanism of action of fluoride is the inhibition demineralization and enhancement of remineralization [Silver diamine fluoride (SDF) is another popular high concentration topical fluoride that has remarkable effectiveness in treating dentine caries [Both topical fluoride agents are child friendly interventions; however, a limited number of randomized clinical trials have evaluated the caries-preventive effects on approximal surfaces of primary teeth. Therefore, this study aimed to evaluate the effectiveness of two professional fluoride agents on preventing approximal carious development in primary teeth in high caries-risk preschool children: 5% NaF varnish and 38% SDF. The null hypothesis was that the approximal caries development rates of the group either treated with 5% NaF varnish or 38% SDF were comparable to that of the group treated with placebo.