METHOD OF ASSESSING ADHESION STRENGTH IN CONNECTION OF DENTAL MATERIALS WITH TOOTH TISSUES Russian patent published in 2020 - IPC A61C5/00 

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to orthopedic dentistry, and aims at determining the adhesion force of dental materials to hard tooth tissues. Method includes preparation of a tooth sample removed by orthodontic readings by drilling a through hole in the tooth root, through which an orthodontic wire is drawn and with its help a tooth is fixed in a dental flask. After that, Protakryl-M plastic is introduced into the tray and the fixed molar is treated with torpedo-shaped borer to form a ledge at the level of the enamel-cement boundary of the shoulder, which serves as a fixator of the crown fixation. All-metal crown is made, in the center of which on the chewing surface side there is a fixing ring as to the impression taken from the tooth specimen. Test dental material is introduced into the crown, the crown is fixed on the prepared tooth, the sample is held in water at temperature of 37±1 °C for 24 hours. Specimen is reinforced with a crown fixed in a dental flask in a testing machine, and the adhesion strength of the dental material is measured in conjunction with the solid dental tissues by applying uniaxial tension to the ring on the masticatory surface of the bit, and the obtained data are recorded, in which the following new features are introduced: molar treatment is performed by known torpedo-shaped borer with bringing the stump diameter to 7.0–7.5 mm; thereafter chewing surface of the tooth stump is prepared to produce a flat surface; shaping of shoulder is performed by additional treatment of tooth stump with diamond crown, made in form of hollow cylinder of regular shape with inner diameter equal to 6 mm, and height of inner wall of crown equal to 6 mm, on lower edge of working part of which there is a chamfer inside at angle of 45°, and coating with diamond crumbs to a height of not more than 20 % of the height of the inner wall of the bit, which enables to form a shoulder on the lower part of the dental stump of a uniform shape and size. As a result of molar treatment with similar diamond crown, identical stump teeth of regular cylindrical shape of preset diameter equal to 6 mm are formed with height from shoulder equal to height of crown inner part h equal to 6 mm, with shoulder at angle of 45°.

EFFECT: method enables assessing the adhesion strength of dental materials in connection with hard tooth tissues and providing the accuracy of measurements by standardizing formation of the molar stump.

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