Lanthanum oxide-doped glass-ceramics
View Patent ↗Glass-ceramic compositions exhibiting high reliability and tensile strength are described. The compositions can include crystal phases including roedderite and/or potassium fluorrichterite. The glass-ceramic compositions are bioactive, and can be used as components of a wide variety of biomedical devices such as dental restorations.
1. A bioactive glass-ceramic composition consisting essentially of:
SiO 2 : 50-70;
MgO: 8-25;
Na 2 O: 1.5-9;
K 2 O: 2-12;
CaO: 4-15;
BaO: 0-2;
Li 2 O: 0-3;
F: 3-8; and
La 2 O 3 : 0.1-8
by weight percentage.
2. The glass-ceramic according to claim 1 , wherein the range of weight percentage of La 2 O 3 is from about 0.1 to about 1.
3. The glass-ceramic according to claim 2 , wherein the composition comprises potassium fluorrichterite.
4. The glass-ceramic according to claim 2 , wherein the composition has a biaxial flexural strength from about 450 to about 500 MPa.
5. The glass-ceramic according to claim 4 , wherein the composition has a Weibull modulus of 17 or more.
6. The glass-ceramic according to claim 2 , wherein the composition includes large prismatic crystals having a length of about 2 micrometers and small crystals with a hexagonal section and a diameter of about 60 to 80 nanometers.
7. The glass-ceramic according to claim 1 , wherein the range of weight percentage of La 2 O 3 is from about 5 to about 8.
8. The glass-ceramic according to claim 7 , wherein the composition comprises roedderite.
9. The glass-ceramic according to claim 7 , wherein the composition has a biaxial flexural strength from about 350 to about 400 MPa.
10. The glass-ceramic according to claim 9 , wherein the composition has a Weibull modulus of 17 or more.
11. The glass-ceramic according to claim 7 , wherein the composition comprises well dispersed, interlocking prismatic crystals with a size of about 2×0.3 micrometers.
12. The glass-ceramic according to claim 1 , wherein the composition further comprises 0.5 to 3.5 wt. % coloring and fluorescent metal oxides.
13. A biomedical device comprising a bioactive glass-ceramic composition consisting essentially of:
SiO 2 : 50-70;
MgO: 8-25;
Na 2 O: 1.5-9;
K 2 O: 2-12;
CaO: 4-15;
BaO: 0-2;
Li 2 O: 0-3;
F: 3-8; and
La 2 O 3 : 0.1-8
by weight percentage.
14. The biomedical device of claim 13 , wherein the device is selected from the group consisting of bone plates, middle ear implants, intervertebral spacers, scaffolds, blanks, and dental restorations.
15. The biomedical device of claim 14 comprising a dental restoration selected from the group consisting of inlays, onlays, bridges, abutments, facings, veneers, facets, crowns, partial crowns, frameworks, copings, and dental implants.
16. The biomedical device of claim 14 , wherein the bioactive glass-ceramic composition has a biaxial flexural strength from about 350 to about 500 MPa.
17. The biomedical device of claim 15 , wherein the bioactive glass-ceramic composition has a Weibull modulus of 17 or more.