Dentistry – Prosthodontics – Tooth construction
Reexamination Certificate
1999-10-08
2002-09-17
Lewis, Ralph A. (Department: 3732)
Dentistry
Prosthodontics
Tooth construction
C106S035000, C501S059000
Reexamination Certificate
active
06450813
ABSTRACT:
The invention relates to porcelain material. The invention provides a repair porcelain composition and method. The repair porcelain composition of the invention is a dental material for use with ceramic restorations in a metal free system, which can be used for fabrication of single unit dental restorations, such as crowns, veneers, inlays and onlays. Preferably the metal free system contains a pressed ceramic core (analogous to the metal copings in traditional porcelain-fused-to-metal dental crowns) and a low-fusing porcelain. The dental restoration is formed by building the porcelain over a pressed ceramic core and fusing the outer porcelain to the core material.
One of the major steps in preparation of metal free dental crowns is molding of a ceramic core. This step is fairly labor-intensive and time-consuming. Although it is unlikely to happen in the metal free system, sometimes the all-ceramic core copings or full-contours may contain internal imperfections, such as blisters, bubbles, chipped edges, etc. Copings with such imperfections normally need to be discarded, and a new coping needs to be made. Remaking a ceramic core is a costly and ineffective way to fix the problem.
Defective and/or damaged core copings of the prior art are not repaired, but are discarded. The invention effectively restores damaged core copings, by applying the repair porcelain. Use of repair porcelain of the invention allows laboratory technicians to repair the damaged core copings or full-contour crowns with no demarcation being detectable. Thus, an imperfect core coping can be restored to a perfectly esthetic crown, resulting in cost savings. The only known materials that have a similar function to the repair porcelain are the overglaze (D-OG) and the add-on (D-AO) porcelains in the Dicor glass-ceramic system.
The invention provides a dental porcelain product, comprising a core layer of core material and a repair layer of repair material. The core material has a core material melting temperature and the repair material has a repair material melting temperature. The core material melting temperature is higher than the repair material melting temperature. The core material comprising 58 to 64 percent by weight silicon dioxide, from 10 to 16 percent by weight aluminum oxide, from 4.5 to 8 percent by weight sodium oxide, from 9.5 to 12.0 percent by weight potassium oxide, and from 1 to 4 percent by weight boron trioxide. The repair material comprising 59 to 63 percent by weight SiO
2
, 6 to 11 percent by weight Al
2
O
3
, 8 to 10 percent by weight Na
2
O, from 7 to 10 percent by weight K
2
O. The core material comprises a portion of crystalline core material and a portion of glass core material. The repair material comprises a portion of crystalline repair material and a portion of glass repair material. The portion of crystalline core material is greater than the portion of the crystalline repair material.
It is an object of the invention to provide a dental porcelain product, comprising a core layer of core material and a repair layer of repair material, the core layer being formed on a mold, the repair layer being formed on and integrally connected to a minor portion of the core layer, the core material comprising silicon dioxide and aluminum oxide and having a core material melting temperature and the repair material comprising silicon dioxide and aluminum oxide and having a repair material melting temperature, and the core material melting temperature effectively being higher than the repair material melting temperature.
It is an object of the invention to provide a method of making a dental porcelain product, comprising providing core material and a repair material, the core material effectively having a higher melting temperature than the repair material, the core material comprising a crystalline portion of core material and a glass portion of core material, the repair material comprising a crystalline portion of repair material and a glass portion of repair material, wherein the crystalline portion of core material is greater than the crystalline portion of the repair material, forming a core layer of the core material, the core layer having an outer surface, coating the repair material on a minor portion of the core layer outer surface.
It is an object of the invention to provide a dental porcelain product, comprising a core layer of core material and a repair layer of repair material, the core material having a core material melting temperature and the repair material having a repair material melting temperature, and the co re material melting temperature is higher than the repair material melting temperature, wherein the core material comprises from 58 to 64 percent by weight silicon dioxide, from 10 to 16 percent by weight aluminum oxide, from 4.5 to 8 percent by weight sodium oxide, from 9.5 to 12.0 percent by weight potassium oxide, and from 1 to 4 percent by weight boron trioxide, and repair material comprises 59 to 63 percent by weight SiO
2
, 6 to 11 percent by weight Al
2
O
3
, 8 to 10 percent by weight Na
2
O, from 7 to 10 percent by weight K
2
O, and core material comprises a portion of crystalline core material and a portion of glass core material, and the repair material comprises a portion of crystalline repair material and a portion of glass repair material, and the portion of crystalline core material is greater than the portion of the crystalline repair material.
Crystalline portion of core material as used herein refers to the crystalline portion by weight (for example in percent by weight) of dental ceramic crown core material.
Glass portion of core material as used herein refers to the glass portion by weight (for example in percent by weight) of dental ceramic crown core material.
Crystalline portion of repair material as used herein refers to the crystalline portion by weight (for example in percent by weight) of dental ceramic crown repair material.
Glass portion of repair material as used herein refers to the glass portion by weight (for example in percent by weight) of dental ceramic crown repair material.
Minor portion of a material as used herein refers to a portion by weight amounting to less than 50 percent by weight of the material.
Major portion of a material as used herein refers to a portion by weight amounting to more than 50 percent by weight of the material.
BRIEF SUMMARY OF THE INVENTION
The invention provides a dental porcelain product, comprising a core layer of core material and a repair layer of repair material, the core layer being formed on a mold, the repair layer being formed on and integrally connected to a minor portion of the core layer, the core material comprising silicon dioxide and aluminum oxide and having a core material melting temperature and the repair material comprising silicon dioxide and aluminum oxide and having a repair material melting temperature, and the core material melting temperature effectively being higher than the repair material melting temperature.
The invention provides a method of making a dental porcelain product, comprising providing core material and a repair material, the core material effectively having a higher melting temperature than the repair material, the core material comprising a crystalline portion of core material and a glass portion of core material, the repair material comprising a crystalline portion of repair material and a glass portion of repair material, wherein the crystalline portion of core material is greater than the crystalline portion of the repair material, forming a core layer of the core material, the core layer having an outer surface, coating the repair material on a minor portion of the core layer outer surface.
The invention provides a dental porcelain product, comprising a core layer of core material and a repair layer of repair material, the core material having a core material melting temperature and the repair material having a repair material melting temperature, and the core material melting temperature is higher than the repair material melting temperature, wherein the
Chu Cha-Yang
McDonald Albert F.
Bieber James B.
Dentsply Research & Development Corp.
Lewis Ralph A.
Lovercheck Dale R.
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