ASPECTS OF SURFACE ENAMEL MINERALIZATION IN PERMANENT TEETH OF CHILDREN FROM DIFFERENT AGE GROUPS
Authors: Oliinyk R. P. , Khabchuk V. S. , Rozhko M. M. , Kostiuk I. R. , Atamanchuk O. V. 
Published: October 2024

The purpose of our study was the examination of external surface enamel mineralization in permanent teeth of children from different age groups. We examined sections of 50 extracted for orthodontic indications premolars in patients from different age groups.
A study of 16 teeth was conducted in 11-13 years old children, 8 teeth were investigated in each group of 13-15 years old, as well as 9 teeth in 15-16-year-old patients. All patients were appointed with remineralization therapy during the first six months after tooth eruption fallowed by application of “Tooth Mousse” ones a day for 2 weeks every six months with appropriate monitoring.
The comparison group, on the other hand, consisted from extracted teeth taken from children who were not subjected to any preventive remineralization measures. The distribution by age and the studied material was identical to the main group.
Segmentation of the teeth was carried out after the tooth extraction with separation of the crown structure and further polishing of the crown using polishing brushes without pastes. Sections 0.3-0.5 mm thick were formed with a diamond disc.
The enamel samples were cleaned and degreased and then examined in a polarizing microscope (Optika B-150POL-B 40x-640x Bino) at a magnification in 500 times. The description of the enamel microscopic surface was carried out according to the following parameters: surface heterogeneity, surface opaqueness/shininess, surface roughness/smoothness. The surface homogeneity was assessed by calculating the ratio of identified surface areas that visually differed from the overall enamel texture, which was characteristic of the predominant investigated surface enamel.
There were  criteria for evaluating the enamel surface heterogeneity according to the research data in a polarizing microscope : the presence of numerous well-defined cracks, the visualization and number of areas from which the enamel prisms extend, the presence and number of enamel surface irregularities confirmed by a change in the direction of the light beam, the percentage of surface homogeneity, which was calculated as the ratio of the area of ​​the visually homogeneous enamel surface to the area with ​​any microscopically detected changes.
To assess the opacity of the enamel surface by the microscopic polarization study, the criteria of visual assessment of shiny and dark areas of interest were used.
The study suggested that microscopic changes are characterized by a decrease of total number in enamel surface irregularities and an increase of its glossiness and smoothness at the approach of structural compositional stabilization at 15-16 years.
The analysis also revealed that there were marked microscopic differences observed in enamel of 15-16 years old after remineralization with the "Tooth Mousse" gel and a comparison group (without remineralization therapy).The difference between them is reliable (p<0.01) according to the indicators of the relative average level of surface heterogeneity, and also statistically different from similar indicators that were registered in the age groups 11-13 and 13-15 years old (p<0.01).
The gained results can be considered as the expediency grounds for implementation of dental caries prevention at the early stages of secondary mineralization (immediately after eruption) and throughout the entire period of its intensive phase, which will further contribute to the stabilization of the caries-resistant enamel.