| 摘要 |
A method for producing a dental prosthesis based on lithium silicate glass or lithium silicate glass-ceramic, including the steps of: melting a powder mixture containing at least SiO2, Li2O, Al2O3; producing spherical, lens-shaped or rod-shaped glass particles solidified from the melt; portioning the glass particles and filling them into a crucible; melting the glass particles in the crucible and setting a viscosity v, wherein 4 dPa·s≦v≦80 dPa·s; casting the thus produced melt into a negative mold which is enclosed by an embedding compound and corresponds to the dental prosthesis and; solidifying the melt in the negative mold, and crystallizing lithium metasilicate and/or lithium disilicate from the solidified melt. |
| 主权项 |
1. A method for producing a dental prosthesis based on lithium silicate glass or lithium silicate glass-ceramic, comprising the steps of:
(a) melting a powder with the composition in wt-%SiO2 50-70%;Li2O 5-25%;Al2O30.1-20%;K2O0.1-15%;CeO20.1-15%;B2O3 0-5%;P2O5 0-15%;Tb2O3 0-2%;ZrO2 0-15%;ZnO 0-4%; andat least one additive between 0.1 and 5 wt-%, the additive being selected from the group consisting of BaO, CaO, MgO, MnO, Er2O3, Gd2O3, Na2O, Pr2O3, Pr6O11, Sm2O3, TiO2, V2O5, and Y2O3, (b) producing spherical or lens-shaped glass particles solidified from the melt; (c) portioning the glass particles and filling them into a crucible; (d) melting the glass particles in the crucible and setting a viscosity v, wherein 4 dPa·s≦v≦80 dPa·s; (e) casting the thus produced melt into a negative mold which is enclosed by an embedding compound and corresponds to the dental prosthesis to be produced; (f) solidifying the melt in the negative mold; and (g) crystallizing lithium metasilicate as main crystalline phase from the solidified melt by employing a first heat treatment at a temperature between 600° C. and 760° C. over a time between 20 min and 120 min, wherein the heat treatment of the solidified melt takes place either in the negative mold or after removal from the negative mold. |
