An important role in maintaining homeostasis of hard tooth tissues belongs to oral fluid, which pro vides the physical and chemical processes of exchange between the tooth enamel and oral cavity. The study of mineralizing properties of oral fluid by taking into account the nature of its microcrystallization in terms of the vari ous effects of external and internal environment remains an important research method in terms of diagnosis and prediction of pathological conditions of the oral cavity and the assessment of preventive measures. In the course of the dental examination 188 children aged 12, who suffer from dental caries without somatic pathology, and live in different climatic and geographical areas of the IvanoFrankivsk region, were examined. The analysis of the morphological features of mixed saliva of children of the plain area indicates the predomi nance of the crystals of type II in its structure, their share is 44,93 ± 6,03 %. The picture of microcrystallization of the oral fluid of type I by Leus children of the area was observed in 20,29 ± 4,87 % of cases. The crystals of type III in children of the area were recorded in 34,78 ± 5,78 % of cases. In the saliva of the children of the foothill zone similar to the plain zone the crystals of type II dominated, but their share in comparison to the data of the pupils of the plain zone was bigger – 51,52 ± 6,2 % (p>0. 05). The share of crystals of type I and type III was 18,18 ± 4,78 % and 30,3 ± 5,7 % respectively. The oral fluid of children of the mountainous zone is characterized by low mineralizing function, and lower in comparison to the flat and foothill zones share of crystals of type I 13,21 ± 4,7, whereas the formation of crystals of type III, the most unfavourable as to prognosis for the occurrence of dental caries, was detected in 35,85 ± 6,65 % of cases. The results of the research of oral fluid crystallization among children depending on the activity of the caries process indicate that the share of crystals of type I was the biggest in the group of healthy children – 34,78 ± 7,1 %, which is in 2,78 times bigger than that of in the group children with decompensated course of dental caries, where this type of crystals was recorded only in 12,5 ± 4,46 % (p < 0,01). These data show that the share of crystals of type II was significantly bigger (p > 0,05) than the share of the crystals of I and III types among the examined children and at the average was 49,15 ± 3,28 %. With the increasing intensity of dental caries among children the level of crystals of type II decreases and reaches the minimum level of 46,43 ± 6,73 among the children with decompensated course of dental caries. The analysis of the changes in the content of crystals of type III in oral fluid of children indicates the statistically significant (p > 0,05) increase in their percentage alongside with the growth of the caries process from 19,57 ± 5,9 % of healthy children up to 41,07 ± 6,63 % of children with high degree of caries. According to the obtained data, the mineralizing potential of mixed saliva in children of plain and foothill zones, at the average was assessed as satisfactory – 2,06 ± 0,16 and 2,09 ± 0,14 points, respectively. The children of moun tainous zones mineralizing potential of saliva turned out to be in 1,6 times lower (p>0,05) than that of the children of plain and foothill zones (1,86 ± 0,13), which corresponded to its low level. The analysis of the research results shows that oral fluid of the children with intact oral cavity have the high est, interpreted as satisfactory, mineralizing potential which value in the flat zone is 2,69 ± 0,33, in foothill zone – 2,79 ± 0,33, and mountainous zone – 2,56 ± 0,31 points. With the increasing intensity of dental caries mineralizing potential of saliva among children significantly decreases and reaches its lowest level among the children with de compensated form of tooth caries and is 1,69 ± 0,23 in flat zone, 1,72 ± 0,23 – in foothill zone, and 1,44 ± 0,31 points in mountainous zone (p>0,05). The results show a significant increase in the proportion of crystals of type III, and reduce in the proportion of crystals of type I in the mixed saliva of children with decompensated course of dental caries in comparison to the control group (p < 0,05). The low mineralizing potential of oral fluid among the children, who live in the mountainous zone, which was at the average 1,86 ± 0,13 and a big share of crystals of type III in it (35,85 ± 6,65 %) indicate insufficient mineralizing properties of mixed saliva and is unfavourable as to prognosis for the occurrence of dental caries.
