DENTAL BLANK FOR MILLING AND METHOD OF ITS PRODUCTION Russian patent published in 2023 - IPC A61K6/16 A61K6/17 A61K6/831 A61K6/84 A61K6/884 A61C13/87 A61C5/77 

FIELD: dental materials.

SUBSTANCE: group of inventions concerns a dental workpiece for milling and a method of its manufacture. The following is proposed: a dental workpiece having a part to be milled, made of a polymer material, which includes a composite material containing inorganic particles dispersed in a polymer matrix. The polymer matrix is a cured product of at least one type of (meth)acrylic compound, which has a refractive index from 1.40 to 1.57. Inorganic particles include the following: at least one group of spherical particles of the same diameter (G-PID), including inorganic particles with a defined average primary particle diameter from 100 nm to 1,000 nm, having a narrow particle size distribution, and a group of ultra-fine particles (G-SFP), including inorganic particles with an average primary particle diameter of less than 100 nm. The particles forming the G-PID group or groups are particles of a complex oxide based on silicon dioxide and titanium group element oxide, which have a refractive index from 1.45 to 1.58; wherein the average diameters of the primary particles of different groups of G-PID particles differ from each other by 25 nm or more. The average diameter of G-SFP primary particles is 25 nm or more smaller than that of G-PID group particles with the smallest particle size. The total number of particles dispersed in the polymer matrix is as follows: for G-PID particles — from 100 to 800 parts wt., for G-SFP particles — from 0.1 to 5 parts wt., per 100 parts wt. including polymer matrix. The arrangement of all particles from G-PID groups in the polymer matrix has a short-range order structure that satisfies certain conditions. A method of producing the said preform involves mixing of an appropriate polymerizable monomer component (A), the above inorganic particles (B) and a polymerization initiator (C) to form a polymerizable curable composition; carrying out the casting and polymerization of the polymerizable curable composition to form a three-dimensional body of composite material, which forms all or a part of the target milling part in compliance with the above conditions.

EFFECT: group of inventions provides the following useful effects: the workpiece can have the desired color in a wide color range without the need to regulate the color using a pigment or dye; moreover, the blank provides restoration with an appearance that is in harmony with the color of the restored teeth, even when it is used to form a thick denture.

7 cl, 5 tbl, 9 dwg, 6 ex