The development of the dental status can be favorably influenced by both components of dental care – curative and preventive care. Part of prevention is also searching for, evaluation and in particular elimination of etiological factors of caries and periodontopathies. One of the frequently mentioned influences on the cariosity of permanenet teeth is also increased cariosity of the deciduous dentition. The investigated group comprises 303 children who had dispensary care at the paediatric department of the First Stomatological Clinic in Olomouc. According to the documentation on the dental status of the children a retrospective transverse study (after the age of 6 years) and a longitudinal follow up (age group 6 and 12 years) was implemented. A statistically significant relationship was proved between the cariosity of the second deciduous molar and the first permanent molar. In children with a carious lesion of the second deciduous molar at the age of 6 years, there is as more frequent affection of the first permanent molar. An association of greater cariosity of the first permanent molar and second deciduous molar is found, though less marked in 12-year-old children. This is why it is important to emphasize the need of care of deciduous teeth which is underrated at present by some parents and dentists. Our assumption of a direct relationship between the cariosity of deciduous teeth on the permanent dentition was confirmed. The assembled results are consistent with epidemiological values in our republic. Based on the revealed relationship the authors recommend not only early and regular repair but also prevention of dental caries in the deciduous dentition,

        Key words: mixed dentition – second deciduous molar – first permanent molar – increased cariosity – age groups 6 and 12 years