Introduction: Tooth decay is a multifactorial and chronic infectious disease, it causes the destruction of dental tissues. This destruction leads to the composition of a roughly important cavity. All the particularities (oral, interactive, psychological) exist in school children, classifying dental caries as one the most common diseases among them. Materials and Methods: This is a cross-sectional descriptive epidemiological study for the clinical evaluation of the state of oral health, conducted by the Conservative Odontology/Endodontics department of the University Hospital Center of Oran, from May,02nd to May,30th,2022 using a questionnaire. The survey took place at a public primary school, named Bouras Belkacem, located in the western region of Oran. Results: The sample is made up of 124 school children, of whom 49.2% are boys and 50.8% are girls. 54% of them are between 6 and 8 years old, while 46% are between 9 and 11 years old. 78.20% of these little ones have mothers who do not work outside their homes. 58.1% of them have already consulted a dentist based on the idea of school health. Most of these students only brush their teeth once a day. The average CAD of deciduous teeth is 1.22, and the average CAD of permanent teeth is 0.70. Conclusion: We consider that the results obtained by our survey are worrying, therefore, the need to rethink the methods of raising awareness among children and to strengthen and multiply screenings. All these measures are aimed at preventing the installation and development of the carious process and keeping the tooth in the arch.