Mass production of shells and models for dental restorations produced by solid free-form fabrication methods

Abstract

Solid free form fabrication techniques such as fused deposition modeling and three-dimensional printing are used to create a shell used in the manufacture of a dental restoration. Three-dimensional printing includes ink-jet printing a binder into selected areas of sequentially deposited layers of powder. Each layer is created by spreading a thin layer of powder over the surface of a powder bed. Instructions for each layer may be derived directly from a CAD representation of the restoration. The area to be printed is obtained by computing the area of intersection between the desired plane and the CAD representation of the object. All the layers required for an aesthetically sound shell can be deposited concurrently slice after slice and sintered/cured simultaneously. While the layers become hardened or at least partially hardened as each of the layers is laid down, once the desired final shaped configuration is achieved and the layering process is complete, in some applications it may be desirable that the form and its contents be heated, cooled or cured at a suitably selected temperature to further promote the integrity of solid free-form structures.

1 . A process for manufacturing a shell used in the manufacture of a dental restoration comprising: 
 (a) using digitized data to provide a shape for the shell;    (b) depositing a layer of a polymeric material; and    (c) repeating step (b) a number of times to produce a number of layers of the polymeric material which are bonded to one another to form the a shape of the shell based on the digitized data.    
     
     
         2 . The process of  claim 1  wherein the polymeric material comprises a thermoplastic material.  
     
     
         3 . The process of  claim 1  wherein the polymeric material comprises wax, plastic, rubber, composite material or mixture thereof.  
     
     
         4 . The process of  claim 3  wherein the wax material comprises a wax having a modulus of elasticity below about 10 GPa.  
     
     
         5 . The process of  claim 1  further comprising (d) applying a bonding material onto the polymeric layer.  
     
     
         6 . The process of  claim 1  wherein the polymeric layer is hardened before the deposition of another layer.  
     
     
         7 . The process of  claim 1  wherein the polymeric layer is deposited in a dry state.  
     
     
         8 . The process of  claim 1  wherein the polymeric layer material is deposited in a wet state.  
     
     
         9 . The process of  claim 1  wherein the digitized data comprises a selected pattern.  
     
     
         10 . The process of  claim 9  wherein the selected pattern is based on a computer assisted design.  
     
     
         11 . A shell used for the manufacture of a dental restoration formed by the method of  claim 1 .  
     
     
         12 . A process for manufacturing a dental restoration comprising: 
 manufacturing a shell by rapid prototyping:    filling the shell with refractory material to form a model;    removing the model from the shell; and    applying ceramic, metal or composite material on the model to form a dental restoration.    
     
     
         13 . A process for manufacturing a dental restoration comprising: 
 manufacturing a shell by rapid prototyping;    filling the shell with dental model material to form a master model;    removing the master model from the shell;    duplicating the master model to form a working model; and    applying ceramic, metal or composite material on the working model to form a dental restoration.    
     
     
         14 . The process of  claim 13  wherein the model material comprises gypsum or epoxy material.  
     
     
         15 . A dental restoration formed by the process of  claim 12 .  
     
     
         16 . (cancelled)  
     
     
         17 . (cancelled)  
     
     
         18 . A process for manufacturing a shell used in the manufacture of a dental restoration comprising: 
 (a) using digitized data to provide a shape for the shell;    (b) depositing a preselected quantity of powder material;    (c) spreading the powder material in a layer of preselected thickness over a predetermined region;    (d) applying a binder material to selected regions of the powder material to cause the powder material to become bonded at the selected regions; and    (e) repeating steps (b), (c) and (d) a number of times to produce a number of successive layers whereby the successive layers become bonded to one another at the selected regions to form the shell based on the digitized data.    
     
     
         19 . The process of  claim 18  wherein the powder material comprises a polymeric material.  
     
     
         20 . The process of  claim 19  wherein the polymeric material comprises a thermoplastic material.  
     
     
         21 . The process of  claim 19  wherein the polymeric material comprises wax, plastic, rubber, composite material or mixture thereof.  
     
     
         22 . A shell used in the manufacture of a dental restoration manufactured by the process of  claim 18 .  
     
     
         23 . A process for producing a shell used in the manufacture of a dental restoration comprising: 
 (a) using digitized data to provide a shape for the shell;    (b) providing a mixture of powder material dispersed in a binder; and    (c) dispensing the mixture from a dispensing apparatus onto a platform based on the digitized data to build a three dimensional shell.    
     
     
         24 . The process of  claim 23  wherein the mixture is dispensed in the form of a bead.  
     
     
         25 . The process of  claim 24  wherein the bead comprises a slurry or a liquidfied filament.  
     
     
         26 . The process of  claim 25  wherein the slurry comprises a wax, plaster, plastic, rubber, or composite material or mixture thereof.  
     
     
         27 . The process of  claim 25  wherein the liquefied filament comprises wax, plaster, plastic, rubber, or composite material or mixture thereof.  
     
     
         28 . A shell used in the manufacture of a dental restoration manufactured by the process of  claim 23 .  
     
     
         29 . A process for forming a shell used in the manufacture of a dental restoration comprising: 
 (a) using digitized data to provide a shape for the shell;    (b) supplying polymeric material to a dispensing apparatus; and    (c) dispensing the polymeric material from a dispensing apparatus onto a platform to build a three dimensional shell based on the digitized data.    
     
     
         30 . The process of  claim 29  wherein the polymeric material comprises a wax, plaster, plastic, rubber, or composite material or mixture thereof.  
     
     
         31 . A shell used in the manufacture of a dental restoration manufactured by the process of  claim 29 .  
     
     
         32 . A process for manufacturing a model used in the manufacture of a dental restoration comprising: 
 (a) depositing a layer of a investment material;    (b) repeating step (a) a number of times to produce a number of layers of the investment material which are bonded to one another to form a shape of the model; and    (c) curing the shaped material to form the model.    
     
     
         33 . The process of  claim 32  wherein the investment material comprises gypsum.  
     
     
         34 . The process of  claim 32  wherein the investment material comprises a refractory material and a binder.  
     
     
         35 . The process of  claim 34  wherein the refractory material comprises quartz, cristobalite, silica, leucite, zirconia, hafnia, zircon, alumina, magnesia, zircon, aluminosilicate, cordierite, mica, silicon nitride, silicon carbide, silica-alumina-nitrides, mullite, garnet, or mixtures thereof.  
     
     
         36 . The process of  claim 34  wherein the binder comprises an inorganic material, an organic material, or mixtures thereof.  
     
     
         37 . The process of  claim 36  wherein the organic material comprises polyvinyl pyrrolidine, polyvinyl alcohol, polyvinyl acetate, polyvinyl chloride, polyvinyl butryal and polystyrene, or mixtures thereof.  
     
     
         38 . The process of  claim 36  wherein the inorganic material comprises magnesium oxide, ammonium phosphate, colloidal silica, calcium sulfate, magnesium phosphate, alkaline silicates, silica hydrosol, colloidal clays, or mixtures thereof.  
     
     
         39 . The process of  claim 32  wherein the investment material layer is cured before the deposition of another layer.  
     
     
         40 . The process of  claim 32  wherein the investment material layer is deposited in a dry state.  
     
     
         41 . The process of  claim 32  wherein the investment material layer is deposited in a wet state.  
     
     
         42 . The process of  claim 32  wherein the investment material layer forms a selected pattern.  
     
     
         43 . The process of  claim 32  wherein the selected pattern is based on a computer assisted design.  
     
     
         44 . A model used for the manufacture of a dental restoration formed by the method of  claim 32 .  
     
     
         45 . A process for manufacturing a model used in the manufacture of a dental restoration comprising: 
 (a) depositing a preselected quantity of powder material;    (b) spreading the powder material in a layer of preselected thickness over a predetermined region;    (c) applying a binder material to selected regions of the powder material to cause the powder material to become bonded at the selected regions; and    (d) repeating steps (a), (b) and (c) a number of times to produce a number of successive layers whereby the successive layers become bonded to one another at the selected regions.    
     
     
         46 . The process of  claim 45  wherein the powder material comprises an investment material.  
     
     
         47 . The process of  claim 46  wherein the investment material comprises a refractory material and a binder.  
     
     
         48 . The process of  claim 47  wherein the refractory material comprises quartz, cristobalite, silica, leucite, zirconia, hafnia, zircon, alumina, magnesia, zircon, aluminosilicate, cordierite, mica, silicon nitride, silicon carbide, silica-alumina-nitrides, mullite, garnet, or mixtures thereof.  
     
     
         49 . The process of  claim 47  wherein the binder comprises an inorganic material, an organic material, or mixtures thereof.  
     
     
         50 . The process of  claim 49  wherein the organic material comprises pyrrolidine, polyvinyl alcohol, polyvinyl acetate, polyvinyl chloride, polyvinyl butryal and polystyrene, or mixtures thereof.  
     
     
         51 . The process of  claim 49  wherein the inorganic material comprises magnesium oxide, ammonium phosphate, colloidal silica, calcium sulfate, magnesium phosphate, alkaline silicates, silica hydrosol, colloidal clays, or mixtures thereof.  
     
     
         52 . A model used in the manufacture of a dental restoration manufactured by the process of  claim 45 .  
     
     
         53 . A process for producing a model used in the manufacture of a dental restoration comprising: 
 providing a mixture of powder material dispersed in a binder;    dispensing the mixture from a dispensing apparatus onto a platform to build a three dimensional model.    
     
     
         54 . The process of  claim 53  wherein the mixture is dispensed in the form of a bead.  
     
     
         55 . The process of  claim 54  wherein the bead comprises a slurry or a liquefied filament.  
     
     
         56 . The process of  claim 53  wherein the powder material comprises a refractory material.  
     
     
         57 . The process of  claim 56  wherein the refractory material comprises quartz,cristobalite, silica, leucite, zirconia, hafnia, zircon, alumina, magnesia, zircon, aluminosilicate, cordierite, mica, silicon nitride, silicon carbide, silica-alumina-nitrides, mullite, garnet, or mixtures thereof.  
     
     
         58 . A model used in the manufacture of a dental restoration manufactured by the process of  claim 53 .  
     
     
         59 . A process for forming a model used in the manufacture of a dental restoration comprising: 
 supplying investment material to a dispensing apparatus; and    dispensing the investment material from a dispensing apparatus onto a platform to build a three dimensional model.    
     
     
         60 . The process of  claim 59  wherein the investment material comprises a refractory material and a binder.  
     
     
         61 . The process of  claim 60  wherein the refractory material comprises quartz, cristobalite, silica, leucite, zirconia, hafnia, zircon, alumina, magnesia, zircon, aluminosilicate, cordierite, mica, silicon nitride, silicon carbide, silica-alumina-nitrides, mullite, garnet, or mixtures thereof.  
     
     
         62 . The process of  claim 60  wherein the binder comprises an inorganic material, an organic material, or mixtures thereof.  
     
     
         63 . The process of  claim 62  wherein the organic material comprises pyrrolidine, polyvinyl alcohol, polyvinyl acetate, polyvinyl chloride, polyvinyl butryal and polystyrene, or mixtures thereof.  
     
     
         64 . The process of  claim 62  wherein the inorganic material comprises magnesium oxide, ammonium phosphate, colloidal silica, calcium sulfate, magnesium phosphate, alkaline silicates, silica hydrosol, colloidal clays, or mixtures thereof.  
     
     
         65 . A model used in the manufacture of a dental restoration manufactured by the process of  claim 59 .  
     
     
         66 . A process for manufacturing a dental restoration comprising: 
 manufacturing a model by rapid prototyping;    applying ceramic, metal or composite material on the model to form a dental restoration.    
     
     
         67 . A process for manufacturing a model used in the manufacture of a dental restoration comprising: 
 (a) depositing a layer of a polymeric material; and    (b) repeating step (a) a number of times to produce a number of layers of the polymeric material which are bonded to one another to form a shape of the shell.    
     
     
         68 . The process of  claim 67  wherein the polymeric material comprises wax, plastic, rubber, composite material or mixture thereof.  
     
     
         69 . The process of  claim 68  wherein the wax material comprises a wax having a modulus of elasticity below about 10 GPa.  
     
     
         70 . The process of  claim 67  wherein the polymeric layer is cured before the deposition of another layer.  
     
     
         71 . The process of  claim 67  wherein the polymeric layers form a selected pattern.  
     
     
         72 . The process of  claim 67  wherein the selected pattern is based on a computer assisted design.  
     
     
         73 . A model used in the manufacture of a dental restoration manufactured by the process of  claim 67 .  
     
     
         74 . A process for manufacturing a dental restoration comprising: 
 manufacturing a master model by rapid prototyping; wherein the master model is fabricated of a polymeric material;    duplicating the master model to provide a working model, wherein the working model is fabricated of an investment material;    applying ceramic, metal or composite material on the working model to form a dental restoration.    
     
     
         75 . The process of  claim 74  wherein the investment material comprises a refractory material.  
     
     
         76 - 84  (canceled)