PECULIARITIES OF MINERALIZING FUNCTION OF ORAL LIQUID IN CHILDREN WITH DIFFERENT LEVELS OF ENAMEL RESISTANCE

Abstract

Oral fluid, as a natural biological environment, plays an important role in the vital activity of tooth tissues, in particular enamel, by maintaining the homeostasis of the oral cavity. The mineralizing function of the oral fluid is the main one for ensuring the secondary mineralization of the enamel after the eruption of the teeth. The regulation of metabolic processes in the tooth enamel under normal conditions is based on mechanisms that ensure a state of constant dynamic equilibrium of the composition of the enamel and oral fluid, which is maintained at the required level thanks to the balance of two processes – the dissolution of enamel hydroxyapatite crystals and their formation. Oral fluid can crystallize with the formation of patterns that differ depending on the degree of activity of the carious process. This method is non-invasive, easy to perform, affordable, provides an opportunity to perform research independently. and determine the cariesogenic situation in the oral cavity. It has been established that microcrystallization of oral fluid has individual characteristics and can change under the influence of various factors and age. Studies of microcrystallization of oral fluid depending on the level of enamel resistance deserve special attention. The purpose of our research is to study the features of microcrystallization and mineralization potential of oral fluid depending on the level of enamel resistance. Research methods. The study of crystal formation of oral fluid and the study of mineralization potential was conducted in 581 children of 5-16-year-old from Lviv (279 boys and 302 girls). Morphological properties of oral fluid were assessed by crystal types. The assessment of the mineralizing potential of the oral fluid was expressed as an average score depending on the types of crystals detected. Children were divided into groups with cariesresistant, conditionally resistant and caries-susceptible enamel, depending on the level of enamel resistance. The results were processed statistically using the Student's test. Scientific novelty. In this study, it was found that among children with type I crystal formation, 72.41±8.30 % of individuals had caries-resistant enamel, while 6.91±4.71 % of children had enamel susceptible to caries. This indicates that with this type of crystal formation there are the most favorable conditions for the formation of caries-resistant enamel. On the other hand, among children with type III crystals, only 10.71±5.84 % had caries-resistant enamel, 14.28±6.61 % had conditionally resistant enamel, and most of them had caries-susceptible enamel. It was established that the mineralizing potential of oral fluid in children with caries-resistant enamel is, on average, 4.30±0.28 points (very high), and in children with conditionally resistant enamel it is high (3.59±0.37 points), which indicates a high mineralizing capacity of oral fluid in children of these age groups. On the other hand, in children whose enamel is susceptible to caries, the average value of the mineralizing potential of oral fluid is 1.91±0.52 points, which corresponds to a low level. On the other hand, in children whose enamel is susceptible to caries, the average value of the mineralizing potential of oral fluid is 1.91±0.52 points, which corresponds to a low level. The value of mineralization potential in children with caries-resistant enamel is 2.25 times higher compared to children with caries-susceptible enamel. In children with caries-resistant and conditionally resistant enamel, the average value of the mineralizing potential of oral fluid in all age groups corresponds to a high level. Conclusions. The microcrystallizing function of oral fluid has individual characteristics and depends on age and the level of enamel resistance. The most favorable crystal formation was established in children aged 9-16 years, which is manifested by a significant increase in type II and type I crystals. In the active period of eruption of permanent teeth, i.e. at 5-8 years, the predominance of crystals of III and II types and the lowest values of mineralization potential were found, which indicates a reduced mineralization function of oral fluid in children in this age period. It was found that among children with type I crystal formation, 72.41±8.30 % had cariesresistant enamel, while 6.91±4.71 % of children had enamel susceptible to caries, which determines the formation of caries-resistant enamel with this type of crystal formation. It was established that the value of the mineralizing potential in children with caries-resistant enamel is 2.25 times higher than the MPS value in individuals with caries-susceptible enamel. The obtained results of the study substantiate the need for preventive measures aimed at the formation of enamel resistance to cariogenic factors.