Graded glass/zirconia/glass structures for damage resistant ceramic dental and orthopedic prostheses
The present invention provides a functionally graded glass/ceramic/glass sandwich system for use in damage resistant, ceramic and orthopedic prosthesis. The functionally graded glass/substrate/glass composite structure comprises an outer residual glass layer, a graded glass-ceramic layer, and a dense interior ceramic. The functionally graded glass/substrate/glass composite structure may further comprise a veneer on an exterior surface. The present invention also provides a method for preparing a functionally graded glass/ceramic/glass sandwich system. A powdered glass-ceramic composition is applied to the accessible surfaces of a presintered zirconia substrate to thereby substantially cover the substrate surfaces. The glass of the composition has a CTE similar to that of the substrate material. The glass-ceramic composition is infiltrated into and densifies the substrate by heating the assembly to at least the sintering temperature of the substrate.
1. A functionally graded glass/ceramic/glass composite structure comprising an outer residual glass layer, an underlying graded glass-ceramic layer, and a dense interior ceramic wherein a top and a bottom surface of the ceramic are infiltrated with glass.
2. A functionally graded glass/ceramic/glass composite structure in accordance with claim 1 , substantially non-susceptible to warppage or bending.
3. A functionally graded glass/ceramic/glass composite structure in accordance with claim 1 , wherein the underlying ceramic comprises yttria-tetragonal zirconia polycrystal (Y-TZP).
4. A functionally graded glass/ceramic/glass in accordance with claim 1 wherein the CTE of the glass is substantially the same as the CTE of the yttria-tetragonal zirconia polycrystal (Y-TZP).
5. A functionally graded glass/ceramic/glass in accordance with claim 1 further comprising a veneer on an outer surface.
6. A medical or dental prosthesis comprising a functionally graded glass-ceramic/ceramic/glass-ceramic composite structure or a graded glass-ceramic/ceramic structure wherein a top and a bottom surface of the ceramic are infiltrated with glass.
7. A medical or dental prosthesis according to claim 6 selected from the group consisting of an aesthetic and damage-resistant ceramic orthopedic prosthesis, an orthopedic stem, an orthopedic or dental anchor, an orthopedic or dental implant, a dental prosthesis, and an endodontic post.
8. A medical or dental prosthesis according to claim 6 wherein the ceramic comprises zirconia.