Introduction. Acid resistance is one of the most important properties of tooth enamel, which determines the caries resistance and consists of two components: structural and functional. The determination of structural and functional acid resistance of teeth enamel with vital pulp is carried out according to the enamel resistance test. Remineralization potential of oral fluid pertaining enamel protection was determined by the clinical estimation test of enamel remineralization rate. The problem pertaining the influence of oral fluid and pulp as well as their certain role in restoring processes of enamel demineralized areas is still unsolved. The aim of the study is to represent clinical objectivation for the influence of tooth vital pulp and remineralizing properties of oral fluid in providing enamel restoration after acid-dosed action. Object and methods of research. Examination included 40 patients aged 18-20 years, distributed into four groups of 10 people. Patients of the first group carried out the enamel resistance test on the vestibular surface of intact upper central incisor in equator area (point A and B). Identical test in two points was performed to the second group of patients, when pulp hemostimulation with sodium chloride solution between two points was carried out; patients of the third group carried out enamel resistance test twice, followed by further insulation of demineralized areas by matrix cap; patients of the fourth group performed enamel resistance test with hemostimulation and area insulation twice. Clinical evaluation of the enamel remineralization rate was accomplished on the second and third days. Also the enamel resistance test on free area (point C) was performed on the third day to all patients. The results of the study and their discussion. Initial findings of structural and functional acid resistance of tooth enamel of all groups patients did not differ significantly: 5,5 ± 0,17; 5,7 ± 0,15; 5,4 ± 0,16 and 5,6 ± 0,16 points according to group numeration (p > 0,05). After hemostimulation the findings of the second and fourth groups patients were reliably (p < 0,05) improved to 4,4 ± 0,22 and 4,2 ± 0,20 points, correspondingly, which can be explained by the dynamics of functional component. On the third day, the results of the second and fourth groups patients, with pulp hemostimulation (without and with enamel insulation) displayed the most rapid restoration of demineralized areas, that was proved by the coloration intensity at points A and B: 1,5 ± 0,17 and 1,3 ± 0,15 points and 1,6 ± 0,16 and 1,5 ± 0,17 points, correspondingly, but the difference unreliability (p > 0,05) balances the influence of oral fluid. The final findings of structural and functional acid resistance of enamel with hemostimulation in patients of these groups (2,9 ± 0,23 and 2,7 ± 0,26 points) were significantly (p < 0,05) better, than similar in the patients of the first and third groups (5,3 ± 0,15 and 5,4 ± 0,16 points). The color intensity of the acid microdefects of enamel at the points A and B in patients of other two groups was reliably (p < 0,05) significant: 3,4 ± 0,16 and 3,2 ± 0,25 points and 4,2 ± 0,20 and 4,1 ± 0,23 points, correspondingly. Conclusions. The achieved results define the leading role of pulp in providing restoration of enamel demineralized areas in vital teeth of patients aged 18-20 years. Remineralized properties of oral fluid recede into the background. This should be considered when planning individualized caries preventive measures.
