Teeth are an important part of the human body in research, both in human remains and in living people. The mineral composition is the basis of tooth tissue and any change that can affect the crystal structure changes the physico-chemical properties of the tooth. The notion of tooth quality can be related to teeth in which the chemical structure of the crystal has not changed. The paper analyzes tooth samples of human remains of early medieval respondents from Naklice-Grebčine and Ostrovica-Greblje (G1), human remains from the first half of the 20th century from the island of Daksa (G2) and recent respondents who are patients of active dental practice in Žrnovnica G3). The frequency of carious lesions in all groups was determined using DMFT and ICDAS methods and the frequency of abrasion using Brabant index. Atomic absorption spectrometry (AAS) for the determination of calcium, magnesium and zinc and molybdenum blue UV VIS spectrometry for the determination of phosphorus were used for the chemical analysis of the determination of elements in dental tissue. The determined frequency of caries by ICDAS method in group G1 is 64.34%, G2 59.47%, and in G3 81.57%, while the results of caries frequency by DMFT method in group G1 were 16.52%, in G2 28.75% , and at G3 67.10%. Analyzing the mineral composition of teeth, calcium and phosphorus concentrations were higher in subjects from the early Middle Ages (G1) than in recent subjects (groups G2 and G3), while concentrations of zinc and magnesium were higher in subjects from groups G2 and G3 and up to 2.5 times than in G1 subjects. The decrease in the concentration of calcium in the tooth samples in relation to the increase in the degree of the carious lesion is shown through the statistical significance of the negative impact in groups G1 and G3. In conclusion, subjects from the early Middle Ages have a lower frequency of caries lesions than subjects from the recent population. Only the concentration of calcium is negatively related to the degree of carious lesions, and it is most pronounced in the modern population and in men. Fast food rich in phosphates may be associated with a higher frequency of caries.