PORCELAIN in hundred m and t about l about and h e-skoy to practice is applied at production of dentures.
For removable prostheses the industry releases ready front (kramponny) and side (dnato-richesky) teeth from porcelain of various styles and shades; for production of porcelain crowns and facing of fixed metal prostheses — sets of porcelain mass of various shades, to-rye contain 60 — 75% of potassium feldspar (K20 • A1203 • 6 Si02), 15 — 35%
of quartz or mountain crystal (Si02) and 3 — 10% of a kaolin or aluminosilicate (A120 of g • 2 Si02 • 2noo). At production of porcelain weight in a certain ratio connect feldspar and quartz, to-rye melt and cement, receiving so-called frit. Frit is ground, cleared of impurity. Grind and clear a kaolin of impurity. Then the ground frit is mixed with powder of a kaolin, water or a suspension of corn starch with addition of dyes.
The simulated teeth burn in vacuum furnaces.
Because F. during the roasting about 15 — 20% shrink, porcelain crowns model and burn on a cap from platinum.
Dentures with porcelain teeth meet the esthetic and functional requirements.
See also Dentures. Bibliography: Doynikov A. I. and With and - N and tsyn V. D. Dental materials science. M, 1981; The Guide to
orthopedic stomatology, under the editorship of A. I. Evdokimov, M., 1974; Matte g and r M.'s t 3. and B and t about in with to and y V. N. Guide to dental materials science, D., 1981; Breustedt A. Zalmarztliche Keramik, V., 1968.
A. I. Doynikov.