Dental caries is a multifactorial disease caused by an alteration in the composition of the bacterial biofilm, leading to an imbalance between demineralization and remineralization processes. It is the most common childhood disease, affecting 60-90% of school-age children, and is responsible for millions of lost school days every year. It is strongly linked to the patient's dietary habits, sugar intake, salivary flow, salivary fluoride levels and dental preventive behaviours. In developed countries, the prevalence of dental caries is declining due to the installation of community dental facilities and the introduction of preventive programs, whereas an unprecedented increase in prevalence is reported in developing countries due to the growing consumption of sugary foods, insufficient exposure to fluorides, poor tooth-brushing habits and lack of adequate dental services.