[Study on the pressure on ceramic veneers during cementation]. / Izuchenie velichiny davleniya na keramicheskie viniry vo vremya ikh tsementirovaniya.

OBJECTIVE: The aim of the study is measuring the magnitude and determining the method of finger pressure exerted by doctors on ceramic veneers during their fixation. MATERIAL AND METHODS: A simulation model was designed in order to measure the volume of finger pressure. Veneers were produced for 2 central incisors. Doctors alternately placed veneers on the model and applied pressure on them for 20 seconds simulating the clinical stage of cementing. The operator recorded the maximum readings of the scales and entered the result on the research protocol. In addition, it was recorded which finger the doctor exerts on the veneer during its cementing to ensure a tight fit: thumb or index finger. RESULTS: The values obtained during cementation of 54% doctors ranged up to 1 kg, 27% of doctors from 1 to 2 kg and only 19% more than 2 kg. 80% of doctors applied the main pressure on the veneer using their thumb, while the pressure force was 1.4 kg. For those doctors who pressed the veneer to the tooth with their index finger, the impact value was 0.8 kg. CONCLUSION: The finger pressure on the veneer during cementation applied by dentists varies, the average pressure on the veneers was about 1.5 kg. The amount of pressure on cement during laboratory tests of cements for fixing veneers differs from clinical values many times. The development of a veneers fixation protocol, taking into account the conducted research, will ensure a reliable and accurate fit of the veneer at the stage of its cementing.

[Comparison of the film thickness of composites of different degrees of viscosity]. / Tolshchina plenki kompozitov raznoi stepeni vyazkosti.

The measurement of the film thickness of the composite cement Variolink Esthetic («Ivoclar-Vivadent¼, Liechtenstein) and the microhybrid composite Enamel («Micerium¼, Italy) was carried out according to ISO 4049: 2009 standards with a load force of 5 kg. While reducing the load force to 5 kg, all materials showed an increase in the film thickness; the film thickness of the Variolink Esthetic composite cement was changed from 23 microns (at 15 kg) to 32 microns (at 5 kg), and the film thickness of the microhybrid composite film Enamel was changed from 39 microns (at 15 kg) to 102 microns (at 5 kg). After preheating, the film thickness was changed from 23 microns (at 15 kg) to 44 microns (at 5 kg).

[Study of the film thickness of dental composite resins after preheating]. / Izuchenie tolshchiny plenki kompozitov posle ikh nagrevaniia.

PURPOSE: To compare film thickness of adhesive resin cement and dental composite resins after they are preheated with hot air. MATERIAL AND METHODS: The film thickness was measured using adhesive resin cement Variolink esthetic (Ivoclar-Vivadent, Liechtenstein), micro-hybrid composite Enamel (Micerium, Germany) and nanofilled composite Estelite sigma quick (Tokuyama Dental, Japan) at different temperatures. RESULTS: The film thickness of the Variolink esthetic at room temperature was 23 µm, and the dental composites after preheating them with hot air and applying adhesive on both surfaces to be joined produced the following results: Estelite 62 µm and Enamel 25 µm. CONCLUSION: As a result of the study, it was found that the proposed method allows one to achieve a film thickness for high-viscosity composites comparable to the film thickness of composite cements.