HYBRID RESIN WORKPIECE FOR DENTAL MILLING AND METHOD OF MAKING CROWN Russian patent published in 2025 - IPC A61C5/77 A61C13/87 A61C13/09 A61K6/16 A61K6/60 A61K6/65 A61K6/887 C08L33/12 

FIELD: medicine; chemistry.

SUBSTANCE: group of inventions relates to chemistry and dentistry, specifically to a hybrid resin workpiece for dental milling, including a processed part with a single-layer and multi-layer structure, as well as to a method of making a crown by milling a machined part of the workpiece by computer-aided design/computer-aided manufacturing (CAD/CAM). In the disclosed workpiece, the processed part includes a layer of a dye-containing hybrid resin of a structural colour comprising a polymer matrix that is a cured product of at least one type of (meth)acrylic monomer, and in which inorganic particles are dispersed, which are particles of a composite oxide based on silicon dioxide and oxide of a titanium group element with diameter of 100-1000 nm, and one or more pigments of dye contained in amount of 800-8000 wt.pts. per million, wherein said dye includes 70 wt.% or more of a chromatically similar pigment defined as follows: on the spectral reflection curve (horizontal axis is the wavelength of the reflected light, and the vertical axis is the reflection coefficient) of the hybrid resin of the structural colour without dye, obtained by measuring a sample with thickness of 3 mm on a black background using a colorimeter, wavelength at which the maximum reflection coefficient obtained from the structural colour occurs is defined as the wavelength of the structural colour, and wavelength region in which 85% or more of the maximum reflection coefficient is located is defined as wavelength region A; on the pigment substance spectral reflection curve obtained by measuring 3 mm thick hybrid resin workpiece spectral reflection coefficient, containing 2-10 wt.% dye, on a black background using a colorimeter, wavelength at which the maximum reflection coefficient occurs is defined as the pigment wavelength; pigment, which wavelength is in the region A of wavelengths, is defined as a chromatically similar pigment, where the hybrid resin workpiece has a structural colour wavelength in range of 590-690 nm, and in which, with thickness of 1 mm, the dye-containing hybrid resin of the structural colour has a spectral reflection curve with a first maximum reflection coefficient ML and a second maximum reflection coefficient MH, satisfying the condition: MH/ML > 1.00, when measured on a black background using a colorimeter, where ML is the maximum reflection coefficient in the wavelength range of 400-500 nm, and MH is the maximum reflection coefficient in the wavelength range of 600-750 nm.

EFFECT: group of inventions provides reduction of changes in the shade of the workpiece before and after milling (high compatibility of the colour tone).

4 cl, 7 tbl, 19 ex