According to the data of the survey of 120 edentulous patients, it was established that between the quality of complete removable dentures and the level of life according OHIP-14, there is a direct, average power, correlation (r = 0.62, p ˂ 0.05). The most frequent mistakes of prosthetics (70.0 ± 4.2%) were due to insufficient use of the area of the prosthetic bed, the absence of the closing valve, the loose adherence of the bases to the tissues of the prosthetic bed, all which is the result of poor-quality final impression.
Proceeding from the basic laws of biomechanics, during chewing the biggest pressure occurs on the areas located perpendicular to the direction of the force, that is, at the apex of the alveolar ridge. So, to ensure the increase of the precision of final impressions under complete denture prosthetics is possible due to the optimal distribution of chewing pressure under the basis by creating perforations on custom trays, the number and location of which is determined not only by the anatomical and topographical features of the mucous membrane, but also by the configuration of the alveolar ridge.
The bigger flow of polyester materials, which is stored for a longer period, allows increasing the time of active forming of impression without pressure on the mucosa, which provides the advantage of these materials for final unloading impressions in edentulous patients. The highest fluidity is recorded for polyester material Impregum Garant L DuoSoft, the smallest - for C-silicone manual mixing Speedex Light Body (р < 0.001). After measuring the "fin" in 25 seconds after mixing the Impregum Garant L DuoSoft fluidity exceeded the values obtained for Speedex Light Body in 2.2 times (23.7 ± 0.7 mm vs. 11.0 ± 0.3 mm). For A-silicone Panasil Contact Plus the resulting values of fluidity (12.4 ± 0.4 mm) were smaller than for the Impregum Garant L DuoSoft, polyester material, in 2.0 times (р < 0.001).
According to the results of clinical approbation, conducted among 60 edentulous patients, it was established that using developed method of final impression in combination with the rational choice of impression material allows to raise the level of life to good one in 96.7 ± 2.3% of patients vs. 83.3 ± 4.8% of the comparison group. It provided the equal distribution of the masticatory pressure between the left and right sides, as well as the absence of supracontacts, in 93.3 ± 4.6% vs. 20,0 ± 7,3% of the comparison group (p ˂ 0.05). In applying the developed technique, the intensity of inflammation and the size of the overload areas of the mucous membrane of the prosthetic bed decreased (1.08 ± 0.12 cm2 vs. 1.18 ± 0.13 cm2 of the comparison, р ˃ 0.05), which facilitates adaptation to the manufactured dentures, as well as the best indicators of chewing efficacy in the nearest term (55.2 ± 1.6% vs. 50.0 ± 1.5% of the comparison, p ˂ 0.05) and in the remote observation period (60.6 ± 1.7% vs. 56.0 ± 1.6% of the comparison, p ˂ 0.05). Enough fixation of complete removable dentures in long-term use in patients of the main group was observed in 100% vs. 80.0 ± 5.2% in the comparison group (p ˂ 0.05).
