Introduction: Caries is a widespread polyetiological disease. Oral fluid properties and composition play an important role in its development and progression. Objectives: The aim of this study was to present the ability of different voxel sizes in identifying osseous defects of mandibular condyle using CBCT images. Material and methods: We determined Сa 2+ , РО 4 3-, and SO 4 2using spectrophotometric method, Na + , K + , Al by atomic emission spectrometry, Mg 2+ , Zn by atomic absorption spectrometry, Clusing chloride-selective electrode of pH-meter in oral fluid of 22 patients divided into two groups: case DMFT = 1.45 ± 0.48 and control DMFT = 0. Correlation of oral fluid and cervical enamel chemical composition of 19 extracted teeth was made.Results: The values of molar coefficients were high in intact teeth enamel: P/Ca by 10%, Mg/Ca by 82%, and K/Na by 50%. The following values were lower: Ca/P by 10%, Ca/Cl by 16%, and Mg/P by 43% (p ≤ 0.05). The distinctive feature of correlation of oral fluid and enamel chemical composition in the control group patients was the presence of average Mg 2+ bond strength: direct with Cl -, K + , and Na + , and inverse with Сa 2+ and РО 4 3-(p < 0.0001). The correlation between molar coefficients of oral fluid and enamel of patients with intact hard tissues was distinguished by the presence of high direct correlation of Mg 2+ /Са 2+ with РО 4 3-/Сa 2+ , moderate inverse correlation of Са 2+ /Clwith РО 4 3-/Сa 2+ , and the absence of moderate correlation of Mg 2+ /Са 2+ with Са 2+ /РО 4 3-(p < 0.0001). Conclusions: Revealed correlations may be used to diagnose cervical caries and control the effectiveness of its prevention in terms of mixed saliva over time.

Introduction:The increase in the intensity of caries and non-carious lesions of the teeth leads to significant disorders in the dentoalveolar apparatus manifested themselves not only as aesthetic but also as functional disorders in the absence of timely adequate treatment. Objectives: The increase in the prevalence and intensity of cervical lesions of hard dental tissues is the cause of aesthetic and functional disorders in the dentoalveolar apparatus. To study the morphological structure of enamel, its features depending on the presence and type of cervical pathology; to determine correlations of the chemical composition of enamel and dentin in intact teeth and with cervical pathology. Material and methods: There were examined 29 clinically extracted teeth of both jaws and their longitudinal sections using a JSM-6490 LV focused beam electron microscope with system of energy-dispersive X-ray microanalysis. The chemical composition of 290 enamel areas and 235 dentine areas in the incisal region (tubercle), equator, cervical area. Results: The correlation between enamel and dentin has been determined: inverse -based on the content of P and C, Ca and O (in all anatomical areas), Mg and Ca, Mg and P (in the incisal region (tubercle), equator); direct -based on the content of Mg and Ca, Mg and P (cervical area). The exception was the correlation between Mg and Ca in the incisal region (tubercle) in the group of the teeth with cervical pathology (r = 0.363), Ca and O in the cervical area in the group of the teeth with cervical caries and clinically intact hard tissues (r = 0.620). Conclusions:The revealed features in the morphological structure and chemical composition of enamel, the presence of the correlations with dentin will allow to understand the mechanism of the development of cervical pathology deeper and substantiate the principles of its treatment and prevention.

Introduction:The microstructure and chemical composition of tooth dentin reflect the complex processes associated with pathological conditions. Therefore, the study of their features is relevant in understanding the tactics of diagnosis and prevention of cervical lesions. Aim of the research: A comparative analysis of the morphological structure and chemical composition of the dentin of intact teeth, teeth with cervical caries, and a wedge-shaped defect. Material and methods:The study included 29 clinically extracted teeth of both jaws and their longitudinal sections, from patients aged 25-54 years, using a JSM-6490 LV focused-beam electron microscope (scanning) with system of energy-dispersive X-ray microanalysis. The chemical composition of 235 dentine areas in the incisal region (tubercle), equator, and cervical area was determined as a percentage of the weights of carbon, oxygen, calcium, phosphorus, sodium, magnesium, sulphur, chlorine, zinc, potassium, and aluminium. Results: The differences in the content of oxygen, sodium, and zinc in the dentin of all studied anatomical regions were determined, depending on the state of hard dental tissues (p ≤ 0.05). The teeth with cervical caries had less oxygen and more zinc while the teeth with a wedge-shaped defect had less sodium (p ≤ 0.05). An inverse correlation was revealed between carbon and phosphorus, and carbon and calcium in the area of the incisal region (tubercle); direct correlation between phosphorus and calcium (p ≤ 0.05) at the equator and in the cervical region was also revealed. Conclusions:The heterogeneity of mineral dentin content in the studied zones is probably because of the load on various areas and their morphological characteristics. StreszczenieWprowadzenie: Mikrostruktura i skład chemiczny zębiny odzwierciedlają złożone procesy zachodzące w przebiegu stanów chorobowych. Z tego względu ich analiza ma istotne znaczenie dla prawidłowej strategii diagnostyki i zapobiegania uszkodzeniom szyjek zębowych. Cel pracy: Analiza porównawcza budowy morfologicznej i składu chemicznego zębiny w zębach zdrowych oraz zębach z próchnicą w obrębie szyjek i ubytkami klinowymi. Materiał i metody: Badaniem objęto 29 zębów po ekstrakcji klinicznej z obu szczęk, a także ich przekroje podłużne. Zęby pochodziły od pacjentów w wieku 25-54 lat. Analizę przeprowadzono przy użyciu skaningowego mikroskopu elektronowego JSM-6490 LV z wiązką skupioną, z systemem mikroanalizy rentgenowskiej z dyspersją energii. Skład chemiczny 235 obszarów zębiny w okolicy brzegu siecznego (guzka) i równika oraz szyjki określono jako procent masy węgla, tlenu, wapnia, fosforu, sodu, magnezu, siarki, chloru, cynku, potasu i aluminium. Wyniki: Określono różnice w zawartości tlenu, sodu i cynku w zębinie wszystkich badanych okolic anatomicznych w zależności od stanu tkanek twardych zęba (p ≤ 0,05). W zębach z próchnicą szyjek stwierdzono niższą zawartość tlenu i wyższą zawartość cynku, natomiast w zębach z ubytkiem klinowym mniej sodu (p ≤ 0,05). Zaobserwowano odwrotną zależność między zawar...

Annotation. Significant prevalence of cervical lesions of hard dental tissues is the reason for the search for the ways to predict their development that is possible only with an individual approach to solving this problem. The aim of the study is to determine the chemical composition of the patients’ oral fluid with clinically intact hard tissues, cervical caries and wedge-shaped defect, identify its critical values and the subsequent development of the method for individual prediction of the onset of pathology in young people. To accomplish it we used JSM-6490 LV focused beam electron microscope (scanning) to determine the chemical composition of the enamel and dentin of 29 teeth and their longitudinal sections, the chemical composition of the oral fluid of 33 patients who were divided into three groups depending on the state of their hard dental tissues. The approbation of the proposed method was carried out in 45 young people, the results were compared with the data of the clinical examination of 42 patients a year later. To verify the relationship between the variables, the Pearson parametric correlation method was used based on the determination of the Brave-Pearson parametric coefficient (r) with a 95% confidence level. The reliability of the obtained results was evaluated by Student's t-test, the correlation between indicators – by Student’s test using the Z-test (Fisher’s z-test). The level of significance of differences at p≤0.05 was considered statistically significant. It was determined that the values of the Ca+Na+Mg/P coefficient in enamel, dentin and oral fluid significantly differed depending on the state of hard dental tissues (p≤0.05). Moderate and high inverse correlation was revealed between Ca/P and Ca+Na+Mg/P coefficients in cervical enamel and oral fluid (p≤0.05). Obtained results became the basis for the development of the method for individual prediction of the onset of cervical pathology in young people: with the values of the Ca+Na+Mg/P coefficient higher than 22 – a low level, from 11 to 22 – an average level, lower than 11 – a high risk level. Thus, we have proved that the proposed method is informative (the predictive accuracy reaches 85%), its non-invasiveness is the basis for its widespread use. We consider the search for the ways of individual prediction of the development of cervical caries and wedge-shaped defect in young people based on the parameters of the oral fluid to be promising.

Annotation. Significant prevalence of cervical caries and teeth with wedge-shaped defect is the reason for the search for ways to predict their development that is possible only with an individual approach. The purpose of the study is to design and test the method for predicting the development of cervical caries and teeth with wedge-shaped defect in young people based on the results of determining the chemical composition of enamel, dentin and oral fluid. The chemical composition of the enamel and dentin of 29 teeth was examined using JSM-6490 LV focused beam electron microscope (scanning). We determined the content of the chemical elements in the oral fluid of 33 patients: Сa2+, РО43-, SO42 - by spectrophotometric method, Na+, К+, Al3+ by atomic emission spectrometry, Mg2+, Zn2+ by atomic absorption spectrometry, Cl- using chloride selective electrode of pH meter. Statistical analysis was performed using the computer program Statistica 8.0 (STA862D175437Q). Analysis of variance (Welch test), Pearson's parametric correlation method (Brave-Pearson coefficient (r)) was used. The reliability of the obtained results was evaluated by Student's t-test, the correlation between the indicators – by Student's test using the Z-test (Fisher's z-test) at p≤0.05. It was determined that the values of the К/Na+Са/Сl coefficient in enamel (equator, cervical region), dentin (cervical region), oral fluid significantly differed depending on the state of hard dental tissues (p≤0.05). Direct correlation of moderate and high strength was revealed between Са/Р and К/Na+Са/Сl – coefficients in cervical enamel and saliva (p≤0.0001). Obtained results became the basis for the development of the method for individual prediction of the development of cervical pathology in young people. Its approbation was carried out in 43 patients, its effectiveness was assessed a year later. With the values of the К/Na+Са/Сl 2 coefficient and lower we diagnosed the absence of the risk of developing cervical caries and wedge-shaped defect, from 2.1 to 5.3 the risk of developing cervical caries was diagnosed, from 5.4 and more the risk of developing wedge-shaped defect was found out. It was confirmed that the proposed method is informative (the prediction accuracy reaches 83,7%), its non-invasiveness is the basis for widespread use. We consider the search for the ways to predict particularly the development of teeth cervical pathology based on the parameters of the oral fluid and dental biofilm to be promising.