INTEGRATED PORCELAIN SYSTEM FOR A DENTAL PROSTHESIS

Abstract

An integrated dental porcelain system for making dental prostheses and restorations is provided. The system includes three universal major components: a) opaque porcelain composition; b) pressable dentin ingot; and c) veneering porcelain composition that can be used interchangeably for making restorations. Techniques for making the prostheses and restorations include porcelain fused-to-metal (PFM), press-to-metal (PTM), and either pressed and/or machined all-ceramic methods. The system uses both a hand-layering of veneering porcelain (PFM technique) and a hot-pressing process (PTM and all-ceramic technique) to fabricate the prostheses and restorations.

Claims

1. A method for forming a dental prosthesis comprising the steps of: providing a metal substructure; applying a first layer over the metal substructure, the first layer having a composition including the following components: TABLE-US-00006 Components Concentration Range (Wt. %) SiO.sub.2 42-46% Al.sub.2O.sub.3 8-12% Na.sub.2O 2-5% K.sub.2O 6-9% Li.sub.2O 0-2% CaO 0-2% MgO 0-2% ZrO.sub.2 20-30% SnO.sub.2 1-4% Tb.sub.4O.sub.7 0-2% CeO.sub.2 0-3% TiO.sub.2 0-2% Sb.sub.2O.sub.3 0-0.1% Fluorescing agent 0-5% heat treating the first layer to a temperature in the range of 860 to 900 C. to form an opaque coating over the metal substructure to form the dental prosthesis.

2. The method of claim 1 further comprising the step of applying a second layer over the opaque coating, the second layer having a composition including the following components: TABLE-US-00007 Oxide Concentration Range (Wt. %) SiO.sub.2 63-66% Al.sub.2O.sub.3 10-14% Na.sub.2O 3-7% K.sub.2O 9-12% Li.sub.2O 0-2% CaO 1-4% BaO 0-3% Tb.sub.4O.sub.7 0-2% CeO.sub.2 0-2% pressing the second layer at a temperature in the range of 870 C. to 910 C. to form a dentin body coating over the opaque coating.

3. The method of claim 2, further comprising the step of applying a third layer and/or a forth layer over the dentin body coating, the third layer and/or the forth layer having a composition including the following components: TABLE-US-00008 Oxide Concentration Range (Wt.%) SiO.sub.2 56-64% Al.sub.2O.sub.3 6-13% Na.sub.2O 7-15% K.sub.2O 7-15% Li.sub.2O 0-5% CaO 0-3% MgO 2-5% SnO.sub.2 0-4% Tb.sub.4O.sub.7 0-3% CeO.sub.2 0-2% B.sub.2O.sub.3 0-5% Sb.sub.2O.sub.3 0-0.5% F 0-2.5% TiO.sub.2 0-1% heat treating the third layer or the forth layer to a temperature in the range of 780 to 840 C. to form a shade stain coating and/or glaze overlayer coating over the dentin body coating.

4. The dental prosthesis of claim 1 further comprising the step of applying a fifth layer over the opaque coating, the fifth layer having a composition including the following components: TABLE-US-00009 Oxide Concentration Range (Wt.%) SiO.sub.2 62-65% Al.sub.2O.sub.3 8-11% Na.sub.2O 8-11% K.sub.2O 4-7% Li.sub.2O 0-2% CaO 2-5% BaO 0-3% MgO 1-4% SnO.sub.2 0-2% Tb.sub.4O.sub.7 0-2% CeO.sub.2 0-2% Sb.sub.2O.sub.3 0-2% P.sub.2O.sub.5 0-0.1% TiO.sub.2 0-0.1% F 0-1% heat treating the fifth layer at a temperature in the range of 810 C. to 860 C. to form a dentin-enamel coating over the opaque coating.

5. The dental prosthesis of claim 4, further comprising the step of applying a sixth layer over the dentin-enamel coating, the sixth layer having a composition including the following components: TABLE-US-00010 Oxide Concentration Range (Wt.%) SiO.sub.2 56-64% Al.sub.2O.sub.3 6-13% Na.sub.2O 7-15% K.sub.2O 7-15% Li.sub.2O 0-5% CaO 0-3% MgO 2-5% SnO.sub.2 0-4% Tb.sub.4O.sub.7 0-3% CeO.sub.2 0-2% B.sub.2O.sub.3 0-4% heating treating the sixth layer to a temperature in the range of 780 to 840 C. to form a glaze overlayer coating over the dentin-enamel coating.

6. The dental prosthesis of claim 2, further comprising the step of applying a seventh layer over the dentin body coating, the seventh layer having a composition including the following components: TABLE-US-00011 Oxide Concentration Range (Wt.%) SiO.sub.2 62-65% Al.sub.2O.sub.3 8-11% Na.sub.2O 8-11% K.sub.2O 4-7% Li.sub.2O 0-2% CaO 2-5% BaO 0-3% MgO 1-4% SnO.sub.2 0-2% Tb.sub.4O.sub.7 0-2% CeO.sub.2 0-2% Sb.sub.2O.sub.3 0-2% P.sub.2O.sub.5 0-0.1% TiO.sub.2 0-0.1% F 0-1% heat treating the seventh layer to a temperature in the range of 810 C. to 860 C. to form an enamel layer coating over the dentin body layer coating.

7. The dental prosthesis of claim 6, further comprising a sixth layer over the enamel layer coating, the sixth layer having a composition including the following components: TABLE-US-00012 Oxide Concentration Range (Wt.%) SiO.sub.2 56-64% Al.sub.2O.sub.3 6-13% Na.sub.2O 7-15% K.sub.2O 7-15% Li.sub.2O 0-5% CaO 0-3% MgO 2-5% SnO.sub.2 0-4% Tb.sub.4O.sub.7 0-3% CeO.sub.2 0-2% B.sub.2O.sub.3 0-4% heat treating the sixth layer to a temperature in the range of 780 to 840 C. to form a glaze overlayer coating over the pressed enameled dentin body layer coating.

8. A method for forming a dental prosthesis comprising the steps of: providing an all-ceramic core, and applying a first layer over the all-ceramic core, the first layer having a composition including the following components; TABLE-US-00013 Oxide Concentration Range (Wt.%) SiO.sub.2 63-66% Al.sub.2O.sub.3 10-14% Na.sub.2O 3-7% K.sub.2O 9-12% Li.sub.2O 0-2% CaO 1-4% BaO 0-3% Tb.sub.4O.sub.7 0-2% CeO.sub.2 0-2% pressing the first layer at a temperature in the range of 870 C. to 910 C. to form a dentin body layer coating over the all-ceramic core to form the dental prosthesis.

9. The method of claim 8, further comprising the steps of applying a second layer over the dentin body layer coating, the second layer having a composition including the following components TABLE-US-00014 Oxide Concentration Range (Wt.%) SiO.sub.2 62-65% Al.sub.2O.sub.3 8-11% Na.sub.2O 8-11% K.sub.2O 4-7% Li.sub.2O 0-2% CaO 2-5% BaO 0-3% MgO 1-4% SnO.sub.2 0-2% Tb.sub.4O.sub.7 0-2% CeO.sub.2 0-2% Sb.sub.2O.sub.3 0-2% P.sub.2O.sub.5 0-0.1% TiO.sub.2 0-0.1% heat treating the second layer to a temperature in the range of 810 C. to 860 C. to form an enamel layer coating over the dentin body layer coating.

10. The method of claim 9, further comprising the steps of applying a third layer over the fired enamel layer, the third layer having a composition including the following components: TABLE-US-00015 Oxide Concentration Range (Wt. %) SiO.sub.2 56-64% Al.sub.2O.sub.3 6-13% Na.sub.2O 7-15% K.sub.2O 7-15% Li.sub.2O 0-5% CaO 0-3% MgO 2-5% SnO.sub.2 0-4% Tb.sub.4O.sub.7 0-3% CeO.sub.2 0-2% B.sub.2O.sub.3 0-4% heat treating the third layer to a temperature in the range of about 780 to 840 C. to form a glaze overlayer coating over the dentin body layer coating.

11. The method of claim 1, wherein the first layer composition is in powder or paste form prior to being fired.

12. The method of claim 1, wherein the first layer composition is applied to the metal substructure by spraying, slurry dipping, or electro-depositing.

13. The method of claim 4, wherein the later applied dentin-enamel layer is applied by a hot pressing technique or hand build-up technique.

14. The porcelain composition of claim 6, wherein the later applied dentin-enamel layer is applied by a hand build-up technique.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The novel features that are characteristic of the present invention are set forth in the appended claims. However, the preferred embodiments of the invention, together with further objects and attendant advantages, are best understood by reference to the following detailed description in connection with the accompanying drawings in which:

[0016] FIG. 1 is a cross-sectional schematic view of a PFM crown on a die model fabricated with components in accordance with the invention;

[0017] FIG. 2 is a cross-sectional schematic view of a full-contour PTM crown on a die model fabricated with components in accordance with the invention;

[0018] FIG. 3 is a cross-sectional schematic view of an incisal cutback PTM crown on a die model fabricated with components in accordance with the invention;

[0019] FIG. 4 is a cross-sectional schematic view of a full-contour, pressed all-ceramic crown on a die model fabricated with components in accordance with the invention;

[0020] FIG. 5 is a cross-sectional schematic view of an incisal cutback, pressed all-ceramic crown on a die model fabricated with components in accordance with the invention;

[0021] FIG. 6 is a cross-sectional schematic view of a full-contour, CAM-machined all-ceramic crown on a die model fabricated with components in accordance with the invention; and

[0022] FIG. 7 is a cross-sectional schematic view of an incisal build-up, CAM-machined all-ceramic crown on a die model fabricated with components in accordance with the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention relates to materials, methods, and kits for making dental prostheses. The materials of this invention which may be supplied as components of a kit, can be used to provide porcelain/metal restorations, using either hand layering of veneering porcelain (PFM) or a pressing process (PTM) to apply a finished surface, along with all-ceramic restorations.

[0024] The materials for making the dental prostheses in accordance with this invention include principally: (1) universal opaquing porcelains, in either powder or paste form, for masking the surface of metal framework that would otherwise be visible through the porcelain veneer. This is used for making both PFM and PTM restorations; (2) universal pressable ingots for pressing dentin body over opaqued metal framework to make PTM restorations or for pressing a stand-alone all-ceramic core; and (3) universal dentin/enamel porcelain for building incisal layer in making either PFM, PTM, and/or all-ceramic (either pressed or machined) restorations. These materials can be supplied in a kit to a dental laboratory for making the dental prostheses.

[0025] In addition, the kit may include a shade stain porcelain paired with a glaze porcelain for shading and finishing either full-contour PTM and/or all-ceramic restorations. The applied shade stain and glaze porcelain compositions are fired in a single step. Also, the same glaze porcelain can be used for finishing PFM, incisal cutback PTM, and all-ceramic restorations in accordance with this invention. Further, the kit may include other porcelain materials such as opaceous dentin, dentin modifier, correction, margin, and final margin porcelain for finishing the prosthesis, as necessary. The different components of the kit are discussed in further detail below.

Universal Opaque Porcelain

[0026] The universal opaque porcelain composition is used for coating the metal substructure of the prosthesis. The opaque coating masks the metal substructure and prevents the dark-colored surface and edges of the substructure from being visible. This coating step results in an opaqued metal substructure. The opaque porcelain can be applied over the metal substructure in powder or paste form. The opaque porcelain can be applied by spraying, slurry dip, electro-depositing, or other methods known to those skilled in the art. Then, the composition is fired to form a hard and durable coating. The firing temperature of the opaque porcelain is preferably between 800 C. and 1000 C., more preferably between 830 C. and 930 C., and most preferably between 860 C. and 900 C.

[0027] The opaque coating, which forms as a result of this firing step, has thermal compatibility and thermal stability with a later applied porcelain veneer layer. By the term, thermal compatibility or thermally compatible with respect to the opaque coating, it is meant that no substantial cracks are visible in the coating after firing at a temperature between 800 C. and 1000 C. upon examining the coating under an optical microscope (10 magnification); and no substantial cracks, are visible in the porcelain veneer layer after firing at a temperature between 700 C. and 1000 C. upon examining the layer under an optical microscope (10 magnification). The thermal compatibility between the opaque coating and porcelain veneer layer of this invention is due to several reasons including the chemical composition of materials and similar coefficient of thermal expansion (CTE) values. In general, the CTE of the opaque coating is approximately equal to or slightly lower than that of the metal substructure and is approximately equal to or slightly greater than that of the veneering porcelain.

[0028] By the term, thermal stability or thermally stable with respect to the opaque coating, it is meant that the opaque coating retains its shape and form and remains adhered to the metal substructure after multiple firings (that is, at least two and up to five firings) of the subsequently applied porcelain veneer layer at a temperature between 700 C. and 1000 C. The thermal stability of the opaque coating can be determined by examining the restoration coated with the opaque coating and porcelain veneer layer under optical microscope (10 magnification). If the opaque coating has drifted or migrated away from the metal substructure, the opaque coating is not considered to be thermally stable with the porcelain veneer layer. The porcelain veneer layer can be applied to the opaque coating by hot-pressing or manual hand-layering as described further below.

[0029] A preferred opaque porcelain composition is described in the following Table 1.

TABLE-US-00001 TABLE 1 CHEMICAL COMPOSITION OF OPAQUE WHITE PORCELAIN PASTE Oxide Concentration Range (Wt. %) SiO.sub.2 42-46% Al.sub.2O.sub.3 8-12% Na.sub.2O 2-5% K.sub.2O 6-9% Li.sub.2O 0-2% CaO 0-2% MgO 0-2% ZrO.sub.2 20-30% SnO.sub.2 1-4% Tb.sub.4O.sub.7 0-2% CeO.sub.2 0-3% TiO.sub.2 0-2% Sb.sub.2O.sub.3 0-0.1% Fluorescing Agent 0-5% Total 100%

[0030] The materials of this invention, including the opaque porcelain composition, can be used with various metal copings and substructures. In general, metals and alloys and their mixtures, such as nobel alloys, palladium-based alloys, cobalt-based alloys, nickel-based alloys, pure titanium and alloys, gold-based metal-ceramic alloys, nickel chromium alloys, and the like can be used as copings and substructures. More particularly, two commercially-available alloys suitable for use are non-precious DeguDent U and high-noble UltraCrown SF, both marketed by Dentsply International. These alloys can be used to make a framework by conventional casting techniques known to those skilled in the dental arts. The materials of this invention are particularly suitable for used with conventional PFM alloys, for example, having coefficients of thermal expansion (CTE) of about 14.0 ppm/C at 500 C.

Universal Pressable Ingots

[0031] The universal pressable ingots are used to form a dentin body layer over the opaqued metal framework in Press-to-Metal (PTM) protheses or stand-alone, all-ceramic cores using a hot-pressing technique. An appropriate amount of dentin body ingots, in either 2 gram or 5 gram size, is pressed into the prostheses mold. The shade of the dentin body ingots is selected so that the resulting layer will matches the natural color of the dentin in the patient's teeth. The pressing temperature is preferably between 700 C. and 1000 C., and more preferably between 840 C. and 940 C., and most preferably between 870 C. and 910 C. The typical pressing conditions are as follows: 700 C. (low temperature); 890 C. (high temperature); 60 C. per minute (heat rate); 20 minutes (time at high temperature); 10 to 30 minutes (pressing time) and 2.5 to 4.25 bars (pressing time). The prosthesis is then divested of the molding material for subsequent veneering porcelain application as discussed further below.

[0032] After the ingot has been pressed at a temperature in the range of 870 C. to 910 C., the pressed ingot material forms a dentin body layer that is thermally compatible with the other porcelain layers, that is, the opaque coating, and the subsequently applied veneering, and stain layers. The dentin body layer is also thermally stable when the veneering and stain layers are subsequently applied and fired.

[0033] By the term, thermal compatibility or thermally compatible with respect to the dentin body layer, it is meant that no substantial cracks are visible in the dentin body layer after the layer has been pressed at a temperature between 870 C. and 910 C. upon examining the pressed layer under an optical microscope (10 magnification); and no substantial cracks, are visible in the porcelain veneer layer after firing at a temperature between 810 C. and 860 C. upon examining the layer under an optical microscope (10 magnification).

[0034] By the term, thermal stability or thermally stable with respect to the dentin body layer, it is meant that the dentin body layer retains its shape and form and remains adhered to the opaqued metal substructure after multiple firings (that is, at least two and up to five firings) of the subsequently applied porcelain veneering layer at a temperature between 810 C. and 860 C.

[0035] A preferred ingot porcelain composition that can be used in accordance with this invention is described in the following Table 2

TABLE-US-00002 TABLE 2 CHEMICAL COMPOSITION OF INGOT PORCELAIN COMPOSITION FOR MAKING DENTIN BODY LAYER Oxide Concentration Range (Wt. %) SiO.sub.2 63-66% Al.sub.2O.sub.3 10-14% Na.sub.2O 3-7% K.sub.2O 9-12% Li.sub.2O 0-2% CaO 1-4% BaO 0-3% Tb.sub.4O.sub.7 0-2% CeO.sub.2 0-2% Total 100%

Universal Veneering Porcelain

[0036] The universal veneering porcelain composition is used to form a veneer layer over the opaqued metal substructure or all ceramic core. The veneering porcelain composition is applied to the dental prosthesis to form a dentin-enamel layer (PFM applications where a dentin body layer has not been formed previously) or enamel layer (PTM and all-ceramic applications where a dentin body layer has been formed previously.) After the composition has been fired to a temperature in the range of 800 to 850 C., the coating forms a hard and durable layer having a shade that matches the shade and translucency of the patient's natural teeth. The resulting layer is thermally compatible and thermally stable with the opaqued metal substructure and all-ceramic core.

[0037] By the term, thermal compatibility or thermally compatible with respect to the veneering porcelain dentin-enamel or enamel layer, it is meant that no substantial cracks are visible in the dentin-enamel or enamel layer after the layer has been fired at a temperature between 810 C. and 860 C. upon examining the fired layer under an optical microscope at 10 magnification; and no substantial cracks, are visible in the dentin body layer after pressing at a temperature between 870 C. and 910 C. upon examining the layer under an optical microscope at 10 magnification.

[0038] By the term, thermal stability or thermally stable with respect to the veneering porcelain dentin-enamel or enamel layer, it is meant that the dentin-enamel or enamel layer retains its shape and form and remains adhered to either the opaqued metal substructure or dentin body layer after firing the subsequently applied shade stain and glaze overlayer at a temperature between 780 C. and 840 C.

[0039] A preferred veneering porcelain composition is described in the following Table 3.

TABLE-US-00003 TABLE 3 CHEMICAL COMPOSITION OF INGOT VENEERING PORCELAIN FOR MAKING DENTIN-ENAMEL OR ENAMEL LAYERS Oxide Concentration Range (Wt.%) SiO.sub.2 62-65% Al.sub.2O.sub.3 8-11% Na.sub.2O 8-11% K.sub.2O 4-7% Li.sub.2O 0-2% CaO 2-5% BaO 0-3% MgO 1-4% SnO.sub.2 0-2% Tb.sub.4O.sub.7 0-2% CeO.sub.2 0-2% TiO.sub.2 0-2% P.sub.2O.sub.5 0-0.1% TiO.sub.2 0-0.1% F 0-1% Total 100%

[0040] In addition, a one-step fired shade stain material paired with a glaze porcelain material can be applied over PTM and/or all-ceramic full-contour crowns and bridges made with full-contour technique to complete the restoration. The shade stain porcelain composition provides the restoration with the proper color shade so that the restoration matches the color shade of neighboring teeth. Meanwhile, the glaze porcelain provides the restoration with a hard and smooth film coating. The finished restoration has a shiny and glossy appearance after the shade stain and glaze materials have been applied. The shade stain and glaze are separate and distinct materials, but they are normally applied together and are collectively and singularly referred to herein as forming an overlayer. Once the shade stain and porcelain materials are applied, they are fired in a single step. The firing temperature of the shade stain and glaze overlayer is preferably between 750 C. and 950 C., more preferably between 800 C. and 900 C., and most preferably between 780 C. and 840 C. It is also recognized that, the same glaze porcelain can be applied over PFM, incisal cutback PTM and/or all-ceramic cores to complete these restorations. In the case of PFM, incisal cutback PTM and/or all-ceramic cores, it is not necessary to apply the shade stain porcelain material, because these products are already shaded. Additional shade stain does not need to be applied to these restorations. The components used to make the shade stain and glaze porcelain materials are listed generally in the following Table 4. It should be understood that the shade stain composition will differ from the glaze porcelain composition in view of the different oxides and/or weight percentage of ingredients used in the respective compositions.

TABLE-US-00004 TABLE 4 COMPONENTS USED IN SHADE STAIN AND GLAZE PORCELAIN MATERIALS Oxide Concentration Range (Wt.%) SiO.sub.2 56-64% Al.sub.2O.sub.3 6-13% Na.sub.2O 7-15% K.sub.2O 7-15% Li.sub.2O 0-5% CaO 0-3% MgO 2-5% SnO.sub.2 0-4% Tb.sub.4O.sub.7 0-3% CeO.sub.2 0-2% B.sub.2O.sub.3 0-5% Sb.sub.2O.sub.3 0-0.5% F 0-2.5% TiO.sub.2 0-1% Total 100%

[0041] Referring now to the Figures, the dental prostheses made in accordance with this invention are shown in detail. FIG. 1 shows a crown (8) made by a porcelain fused-to-metal (PFM) process is shown positioned on a die model (10). The crown includes a metal coping or substructure (12) which is coated with a universal opaquing porcelain layer (14), universal dentin veneering porcelain layer (16), universal enamel veneering porcelain layer (18), and overglaze porcelain layer (20).

[0042] FIG. 2 shows a PTM crown (8) made using a full-contour technique on a die model (10). The crown (8) has a metal coping (12) with a universal opaquing porcelain (14), universal pressable ingot that forms a dentin body layer (22), and a shade stain/glaze porcelain (24).

[0043] FIG. 3 shows a PTM crown (8) made using an incisal cutback technique on a die model 10. The crown (8) has a metal coping (12) with a universal opaquing porcelain (14), universal pressable ingot that forms a dentin body layer (22), universal enamel veneering porcelain (18), and overglaze porcelain (20).

[0044] FIG. 4 shows an all-ceramic crown (8) made using a full-contour technique on a die model (10). The crown (8) has an all-ceramic coping pressed using a universal pressable ingot that forms a dentin body layer (22), and shade stain/glaze porcelain (24).

[0045] FIG. 5 shows an all-ceramic crown (8) made using an incisal cutback technique on a die model (10). The crown (8) has an all-ceramic coping pressed using a universal pressable ingot that forms a dentin body layer (22); a universal enamel veneering porcelain that forms an enamel layer (18); and overglaze porcelain (20).

[0046] FIG. 6 shows an all-ceramic crown (8) made using a machinable block on a die model (10). The crown (8) has an all-ceramic full-contour coping machined using machinable block (26) with a shade stain/glaze porcelain 24.

[0047] FIG. 7 shows an all-ceramic crown (8) made using machinable block on a die model (10). The crown (8) has an all-ceramic coping machined using machinable block (26); a universal enamel veneering porcelain that forms an enamel layer (18); and overglaze porcelain (20).

[0048] The finished restoration made in accordance with this invention can be subjected to a thermal shock test to further evaluate its thermal properties. In this test, the finished restoration is heated to a given temperature in a furnace. After the restoration has been removed, it is quenched into iced water (normally having a temperature between 0 C. and 5 C.). Then, the restoration is examined under an optical microscope (10 magnification) to determine if any cracks have formed in the restoration. For example, the restoration can heated to 80 C. in the furnace, removed, and quenched in cool water. If no cracks are visible upon microscopic examination, the restoration is placed back in the furnace and heated to a higher temperature. Normally, the temperature is incrementally increased by ten degrees (10 C.). Thus, the restoration is heated to 90 C. in the furnace, removed, and quenched in cool water. The restoration is microscopically examined for cracks. This sequence of heating and quenching is repeated until the critical quenching temperature (temperature at which cracks first appear) is determined. Preferably, both single unit crowns and three-unit bridges made in accordance with this invention have a critical quenching temperature of about 110 C.

Physical/Mechanical Properties

[0049] The physical/mechanical properties of the integrated dental porcelain system of this invention are described in the following Table 5. The components were tested for different properties according to the methods described in ISO 6872 (1995 Sep. 2001) for dental porcelains and ISO 9693 (1999) for metal-ceramic dental restorative systems. The components meet all ISO requirements as shown in Table 5.

TABLE-US-00005 TABLE 5 PHYSICAL/MECHANICAL PROPERTIES OF INTEGRATED DENTAL PORCELAIN SYSTEM Universal Machinable ISO Universal dentin/ Universal block all- Property Requirement Opaque enamel Ingot ceramic Flexural strength 50 (PFM/PTM) 162 80 135 115 (MPa) 100 (all-ceramic core) Thermal 0.5 (2x & 4x- 12.9 0.4 12.1 0.4 12.0 0.4 12.5 0.4 expansion applies to (as-sintered) (@ 25- (as- coefficient opaque & 13.1 0.4 480 C.) sintered) @ 25-500 C. dentin) (simulated 13.0 0.4 (ppm/ C.) pressing) (simulated pressing) Glass transition 20 540 20 500 20 600 20 575 20 temperature ( C.) Chemical 100 (dentin & 17.7 22.6 33.1 40.4 solubility opaque) (g/cm.sup.2) 2,000 (ingot & machinable block)

[0050] The integrated dental porcelain system of the present invention is designed for making PFM, PTM, and all-ceramic restorations in a simplified manner. As described above, the system includes three major universal components: opaque coating, dentin/enamel porcelain, and pressable ingots that can be used interchangeably. For example, the same pressing temperature and same ingot can be used to press either the dentin body when making a PTM restoration and/or all-ceramic core. Furthermore, the same firing temperature and the same opaque coating can be used to overlay metal substructures for making PFM and/or PTM restorations. And, the same firing temperature and same dentin/enamel porcelain can be used to veneer over an opaqued metal substructure for making PFM restorations and/or it can be used to veneer over either pressed and/or machined all-ceramic cores for making all-ceramic restorations.

[0051] It should be understood that while the present invention has been described in considerable detail with respect to certain specific embodiments thereof, it should not be considered limited to such embodiments but may be used in other ways without departing from the spirit of the invention and scope of the appended claims.