ECC affects teeth that erupt early and are least protected by which factor?

• A. Saliva
• B. Fluoride
• C. Enamel
• D. Pulp

Answer: (B)

Early-erupting teeth are at higher risk for ECC because they have less time in the mouth to acquire protective fluoride on their enamel surface. Fluoride strengthens enamel by promoting remineralization and forming fluorapatite, making it harder for acids to demineralize the tooth. When teeth just erupt, the outer enamel is immature and may not yet have absorbed sufficient fluoride from saliva or fluoride-containing products, so these teeth are least protected by fluoride. Saliva helps with cleansing and buffering, enamel is the mineral tissue that caries attack targets, and pulp isn’t a protective factor in this context. So, the factor providing the least protection for early-erupting teeth is fluoride.