Non-invasive management of early caries lesions has become a cornerstone of contemporary minimally invasive dentistry. The ICON resin infiltration technique allows for the arrest of non-cavitated carious lesions and significant esthetic improvement, particularly in cases of white spot lesions. This review aims to present current scientific evidence on the effectiveness, indications, limitations, and clinical perspectives of ICON for the treatment of initial enamel caries. Recent systematic reviews, meta-analyses, and clinical studies from 2021–2024 were analyzed. The findings confirm that ICON is highly effective in arresting the progression of early carious lesions, especially on proximal surfaces, and in masking esthetic defects following orthodontic treatment and mild fluorosis. Proper case selection, strict adherence to the clinical protocol, and operator experience are crucial for therapeutic success. Limitations include reduced effectiveness in deep or inactive lesions, high technique sensitivity, and the cost of the procedure. Recent research focuses on combination therapies, novel infiltrant materials, and the application of digital diagnostics and artificial intelligence. ICON has the potential to become the standard for microinvasive treatment of early caries in the future, contributing to patient comfort, esthetic outcomes, and tooth preservation within the framework of preventive dentistry.