New scientific dental developments, in the last decades of the twentieth century and at the beginning of the XXI century provided high quality in dental treatment and higher percentage of restored teeth. Now as well, is very obvious that the dental problems cannot be solved only through application of therapeutic procedures. Considering the importance of the dental health, our purpose was dealing and collection of data around the role of the practice of the oral hygiene and the food quality in the maintenance of the oral health, the effect of KEP and the pH value of saliva, in comparison of published data from us on 2016. The purpose was realized by analyzing four research groups of the primary teeth, permanent teeth and mixed teeth with the control group, which consisted of student who followed schools where educative lessons for the oral health took place. All participants filled a questionnaire and were subject of additional clinical and lab analyses. The data of this study will help us to gain a real reflection on the frequency of the appearance of the caries in the territory of the Republic of North Macedonia; these data also can be of large help as a starting point on the creation of a new strategy for the systematic and preventive restoration.