Strong Glass-Ceramic
The present invention relates generally dental ceramics. In particular, invention relates to a high strength, high reliability, dental glass-ceramic that contains uniform, ellipsoidal reinforcing leucite crystals.
1 . A glass-ceramic containing ellipsoidal leucite crystals of uniform size.
2 . The glass-ceramic of claim 1 , wherein the leucite crystals are less than one micron in size.
3 . The glass-ceramic of claim 1 , wherein the leucite crystals are less than one half of one micron in size.
4 . The glass-ceramic of claim 1 , wherein the glass ceramic has a high flexural strength.
5 . The glass-ceramic of claim 4 , wherein the flexural strength is greater than 166 MPa.
6 . The glass-ceramic of claim 5 , wherein the flexural strength is at least about 245 MPa.
7 . The glass-ceramic of claim 1 , wherein the glass-ceramic has a Weibull Modulus of greater than 6.5.
8 . The glass-ceramic of claim 7 , wherein the Weibull Modulus is at least about 11.9.
9 . A glass-ceramic comprising small, uniform, ellipsoidal reinforcing leucite crystals, wherein said glass-ceramic has low abrasivity toward the natural enamel of opposing teeth.
10 . The glass-ceramic of claim 9 , wherein the leucite crystals are less than one micron in size.
11 . The glass-ceramic of claim 9 , wherein the leucite crystals are less than one half of one micron in size.
12 . The glass-ceramic of claim 9 , wherein the glass ceramic has a high flexural strength.
13 . The glass-ceramic of claim 12 , wherein the flexural strength is greater than 166 MPa.
14 . The glass-ceramic of claim 13 , wherein the flexural strength is at least about 245 MPa.
15 . The glass-ceramic of claim 9 , wherein the glass-ceramic has a Weibull Modulus of greater than 6.5.
16 . The glass-ceramic of claim 15 , wherein the Weibull Modulus is at least about 11.9.
17 . A glass-ceramic comprising small, uniform, ellipsoidal reinforcing leucite crystals, wherein said glass-ceramic has low abrasivity toward the natural enamel of opposing teeth and wherein said leucite crystals are less than one micron in size.
18 . The glass-ceramic of claim 17 , wherein the leucite crystals are less than one half of once micron in size.
19 . The glass ceramic of claim 17 , wherein the glass-ceramic has a flexural strength that is at least about 245 MPa and a Weibull Modulus that is at least about 11.9.
20 . The glass ceramic of claim 19 , wherein the glass-ceramic comprises about 20-30% leucite crystals by volume.
21 . The glass ceramic of claim 1 , wherein the glass-ceramic is prepared by a method comprising:
preparing a leucite-free glass;
grinding the glass to the desired particle size in order to control the size of the leucite crystal in the finished ceramic; and
refiring to produce the glass-ceramic.