Ceramic articles with increased surface roughness and methods for manufacturing the same

Abstract

Disclosed herein is a ceramic article with an increased surface roughness. The ceramic article includes a ceramic body having an engagement surface and a composite porous layer disposed on the engagement surface of the ceramic body. The composite porous layer is formed from a material including multiple first ceramic particles and multiple second ceramic particles. The sintering temperature of the first ceramic particle is lower than the melting temperature of the second ceramic particle, and at least some of the second ceramic particles are disperse within the composite porous layer whereby increasing the surface roughness of the ceramic article. Methods for manufacturing such ceramic article are also disclosed.

What is claimed is: 
     
         1 . A ceramic article with an increased surface roughness, comprising,
 a ceramic body, wherein the ceramic body has an engagement surface configured to engage with an underlying structure for retention thereto; and   a composite porous layer disposed on the engagement surface, wherein
 the composite porous layer is formed from a material comprising a plurality of first ceramic particles and a plurality of second ceramic particles, wherein the sintering temperature of the first ceramic particle is lower than the melting temperature of the second ceramic particle, and 
 at least some of the plurality of the second ceramic particles are dispersed within the composite porous layer whereby increasing the surface roughness of the engagement surface of the ceramic article. 
   
     
     
         2 . The ceramic article of  claim 1 , wherein the composite porous layer of the ceramic article has an average surface roughness (Ra) of at least about 0.5 μm. 
     
     
         3 . The ceramic article of  claim 2 , wherein the average surface roughness is about 0.85-1.7 μm. 
     
     
         4 . The ceramic article of  claim 1 , wherein the ceramic body is made of a material comprising a metal oxide ceramic. 
     
     
         5 . The ceramic article of  claim 4 , wherein the metal oxide ceramic is zirconium oxide or aluminum oxide. 
     
     
         6 . The ceramic article of  claim 1 , wherein the first ceramic particle is a glass ceramic. 
     
     
         7 . The ceramic articles of  claim 6 , wherein the glass ceramic is an opaque dental ceramic. 
     
     
         8 . The ceramic articles of  1 , wherein the second ceramic particle has a Mohs hardness of at least 8.5. 
     
     
         9 . The ceramic articles of  claim 8 , wherein the second ceramic particle is yttria-stabilized zirconia (YSZ) in which the yttria is present in an amount of about 0.5-35 mole percent. 
     
     
         10 . The ceramic articles of  claim 9 , wherein the second ceramic particle is 8 mol % yttria-stabilized zirconia (8YSZ). 
     
     
         11 . The ceramic articles of  claim 1 , wherein the composite porous layer has a thickness of about 5-20 μm, and the second ceramic particle has an average diameter of about 0.1-0.8 μm. 
     
     
         12 . The ceramic articles of  claim 1 , wherein the ceramic articles is a dental restoration. 
     
     
         13 . A method for manufacturing a ceramic article with an increased surface roughness of  claim 1 , comprising the steps of:
 (a) coating a first ceramic slurry on the engagement surface of the ceramic body, wherein the first ceramic slurry comprises a plurality of first ceramic particles;   (b) sintering the ceramic body from the step (a) to fuse the first ceramic particles whereby forming a ceramic basal layer on the engagement surface of the ceramic body;   (c) coating a second ceramic slurry on the ceramic basal layer, wherein the second ceramic slurry comprises a plurality of first ceramic particles and a plurality of second ceramic particles in a weight ratio of about 9:1 to 1:1, wherein the sintering temperature of the first ceramic particles is lower than the melting temperature of the second ceramic particles; and   (d) sintering the ceramic body from the step (c) to fuse ceramic basal layer and the first ceramic particles without fusing the second ceramic particles whereby forming the composite porous layer on the engagement surface of the ceramic body, wherein at least some of the plurality of the second ceramic particles are dispersed within the composite porous layer whereby increasing the surface roughness of the engagement surface of the ceramic article.   
     
     
         14 . The method of  claim 13 , wherein the composite porous layer of the ceramic article has an average surface roughness (Ra) of about 0.85-1.7 μm. 
     
     
         15 . The method of  claim 13 , wherein the ceramic body is made of zirconium oxide or aluminum oxide. 
     
     
         16 . The method of  claim 13 , wherein the first ceramic particle is an opaque dental ceramic. 
     
     
         17 . The method of  claim 13 , wherein the second ceramic particle has a Mohs hardness of at least 8.5. 
     
     
         18 . The method of  claim 13 , wherein the second ceramic particle is 8 mol % yttria-stabilized zirconia (8YSZ). 
     
     
         19 . The method of  claim 13 , wherein the composite porous layer has a thickness of about 5-20 μm, and the second ceramic particle has an average diameter of about 0.1-0.8 μm. 
     
     
         20 . The method of  claim 13 , wherein the ceramic articles is a dental restoration.