EFFECT OF SURFACE TREATMENT PROTOCOLS OF ZIRCONIUM DIOXIDE MULTILAYER RESTORATIONS ON FUNCTIONAL PROPERTIES OF THE HUMAN ORAL MUCOSA STROMAL CELLS.

Aim - to study the effect of protocols of surface treatment of zirconium dioxide multilayer restorations on the functional properties of stromal cells of the human oral mucosa using molecular biological methods. For all experiments, identical standardized specimens of different types of zirconia with a diameter of 10 mm and a height of 1 mm were used. These types included Katana (Kuraray Noritake Dental, Tokyo, Japan) HTML (control) UTML, STML and ZirCAD Prime (Ivoclar Vivadent). DMEM/F12 growth medium (Paneco, Russian Federation) with addition of fetal calf serum (Gibco, USA) up to 10% and penicillin-streptomycin (Paneco, Russian Federation) up to 1% was used in the experiment. Cells were detached from the culture substrate with trypsin-EDTA solution (Paneco, RF) and their number and viability were assessed using an automatic counter TC-20 (Bio-Rad, USA). For repopulation, samples were transferred into wells of a 96-well culture plate (1 sample in 1 well) and cell suspension was layered at the rate of 12.5 thousand or 25 thousand live cells per well. After 48 hours, the cytotoxic properties of the tested samples were evaluated in vitro. According to the results of MTT test we can conclude that samples of ZirCad Prime and Katana UTML groups do not show cytotoxic properties (score "0" on the cytotoxicity scale according to GOST R ISO 10993-5-2009 "National Standard of the Russian Federation. Medical devices. Evaluation of biological effect of medical devices. Part 5. Studies on cytotoxicity: in vitro methods"). The samples of Katana STML group samples were slightly reduced compared to the control (about 12%), nevertheless, these samples can also be considered non-cytotoxic. Analyzing the direct contact with the material in all samples, a good occupancy of the material by cells was observed, in particular, the polished surface prevailed over the glazed one, however, this difference is not statistically significant. Analysis of human oral stromal cells to zirconium dioxide showed no statistically significant effect of different surface treatment protocols. However, the number of fibroblasts prevailed on the polished surface.