Computer-aided Fabrication Of A Removable Dental Prosthesis

Abstract

A method and system for fabricating a dental prosthesis are provided. High resolution digital scanned images of a patient's oral structures are acquired. Three dimensional (3D) cone beam X-ray images of hard and soft oral tissues are acquired. The scanned images are integrated with the 3D cone beam X-ray images in a 3D space to obtain combined three dimensional images of the oral structures. The occlusal relationship between upper and lower oral structures are digitally simulated using the combined three dimensional images. The dental prosthesis is digitally modeled for planning intra-oral positioning and structure of the dental prosthesis. The digital dental prosthesis model is refined based on simulated force tests performed for assessing interference and retention of the digital dental prosthesis model. A prospective dental prosthesis model is created based on the refined digital dental prosthesis model. The dental prosthesis is fabricated based on a verified prospective dental prosthesis model.

1 . A method for fabricating a dental prosthesis for a patient, comprising:
 acquiring one or more high resolution digital scanned images of one or more oral structures of said patient using one or more digital image scanning devices;   acquiring one or more three dimensional cone beam X-ray images of hard oral tissues and soft oral tissues of said patient using a cone beam X-ray image device;   integrating said one or more high resolution digital scanned images of said one or more oral structures with said one or more three dimensional cone beam X-ray images of said hard oral tissues and said soft oral tissues of said patient in a three dimensional space to obtain one or more combined three dimensional images of said one or more oral structures of said patient;   digitally simulating an occlusal relationship between upper oral structures and lower oral structures using said combined three dimensional images for digitally articulating said upper oral structures and said lower oral structures;   digitally modeling said dental prosthesis based on said digitally articulated upper oral structures and lower oral structures to generate a digital dental prosthesis model for planning intra-oral positioning and structure of said dental prosthesis;   refining said digital dental prosthesis model based on simulated force tests performed for assessing interference and retention of said digital dental prosthesis model;   creating a prospective dental prosthesis model based on said refined digital dental prosthesis model, wherein said prospective dental prosthesis model is tested for verifying predetermined functions of said prospective dental prosthesis model; and   fabricating said dental prosthesis based on said tested and verified prospective dental prosthesis model.   
     
     
         2 . The method of  claim 1 , further comprising subjecting said fabricated dental prosthesis to a milling process comprising:
 acquiring a three dimensional image, spatial location, and orientation of said fabricated dental prosthesis;   configuring an automated milling sequence based on a comparison between said acquired three dimensional image of said fabricated dental prosthesis and said refined digital dental prosthesis model; and   milling said fabricated dental prosthesis based on said milling sequence for gross cutting and fine detailing of said fabricated dental prosthesis.   
     
     
         3 . The method of  claim 1 , wherein said dental prosthesis is one of a removable complete denture dental prosthesis, a removable partial denture dental prosthesis, and a detachable fixed dental prosthesis anchored on one of natural oral structures and implanted oral structures. 
     
     
         4 . The method of  claim 1 , wherein said occlusal relationship between said upper oral structures and said lower oral structures is digitally simulated at different condylar positions for digitally reproducing bite registration, centric occlusion, and centric relation. 
     
     
         5 . The method of  claim 1 , wherein said digitally modeling of said dental prosthesis comprises establishing a preliminary digital model of said dental prosthesis using pre-scanned digital models from an image database of dental prosthesis design, wherein said preliminary digital model of said dental prosthesis is established by matching said pre-scanned digital models with jaw morphology and configuration of said patient obtained by characterizing arch form and size of upper and lower jaws, ridge height and form, and inter-jaw space and relation. 
     
     
         6 . The method of  claim 5 , wherein said preliminary digital model of said dental prosthesis is established by simulating and parameterizing elastic response of said soft oral tissues, occlusion force interaction between upper teeth and lower teeth, condylar guidance, lifting force of upper lip and lower lip, tongue motion, and oral muscles during primary motions of said oral structures of said patient. 
     
     
         7 . The method of  claim 1 , wherein said simulated force tests are performed for reducing interference and enhancing retention of said digital dental prosthesis model by simulating predetermined motions of said oral structures, and wherein refining said digital dental prosthesis model comprises modifying position, alignment and height of teeth of said digital dental prosthesis model. 
     
     
         8 . The method of  claim 1 , further comprising digitally modeling an acrylic base of said dental prosthesis based on said simulated force tests, wherein said acrylic base is configured for establishing a complete peripheral air tight seal with said hard oral tissues and said soft oral tissues to achieve suction based retention of said dental prosthesis. 
     
     
         9 . The method of  claim 1 , wherein said predetermined functions of said prospective dental prosthesis model comprise retention of said prospective dental prosthesis model, esthetics of said prospective dental prosthesis model, and occlusion and phonetics of said prospective dental prosthesis model. 
     
     
         10 . The method of  claim 1 , wherein said combined three dimensional images render low resolution images of upper jaw bones and lower jaw bones, roots of teeth, and temporomandibular joint complex, and high resolution images of coronal portion of said teeth and said soft oral tissues that potentially interface with said dental prosthesis. 
     
     
         11 . The method of  claim 1 , wherein said dental prosthesis is fabricated by one of casting metal into a preformed space of said prospective dental prosthesis model and molding acrylic material into a preformed space of said prospective dental prosthesis model. 
     
     
         12 . The method of  claim 1 , wherein said dental prosthesis is fabricated by rigidly attaching preformed prosthetic teeth to a predesigned abutment on an acrylic base of said dental prosthesis, wherein said base of said dental prosthesis is fabricated by precision milling of preformed blocks of high density and high strength acrylic material, and wherein each of said preformed prosthetic teeth has a shape of a dental crown. 
     
     
         13 . The method of  claim 1 , wherein said testing of said prospective dental prosthesis model comprises analyzing and incorporating modifications into said refined digital dental prosthesis model, creating a modified prospective dental prosthesis model, and verifying said modified prospective dental prosthesis model. 
     
     
         14 . The method of  claim 1 , further comprising modifying base and framework of a prefabricated dental prosthesis for maximizing retention and function of said prefabricated dental prosthesis by adapting said base to said soft oral tissues and providing anchorage with intra-oral dentition. 
     
     
         15 . A system for fabricating a dental prosthesis for a patient, comprising:
 one or more digital image scanning devices that acquire one or more high resolution digital scanned images of one or more oral structures of said patient;   a cone beam X-ray image device that acquires one or more three dimensional cone beam X-ray images of hard oral tissues and soft oral tissues of said patient;   an image integrator provided on a computing device, wherein said image integrator integrates said one or more high resolution digital scanned images of said one or more oral structures with said one or more three dimensional cone beam X-ray images of said hard oral tissues and said soft oral tissues of said patient in a three dimensional space to obtain one or more combined three dimensional images of said one or more oral structures of said patient;   a digital simulator provided on said computing device, wherein said digital simulator digitally simulates an occlusal relationship between upper oral structures and lower oral structures using said combined three dimensional images for digitally articulating said upper oral structures and said lower oral structures;   a digital modeler provided on said computing device, wherein said digital modeler:
 digitally models said dental prosthesis based on said digitally articulated upper oral structures and lower oral structures to generate a digital dental prosthesis model for planning intra-oral positioning and structure of said dental prosthesis; and 
 refines said digital dental prosthesis model based on simulated force tests performed for assessing interference and retention of said digital dental prosthesis model; 
   a three dimensional printer for creating a prospective dental prosthesis model based on said refined digital dental prosthesis model, wherein said prospective dental prosthesis model is tested for verifying predetermined functions of said prospective dental prosthesis model; and   a fabricator that fabricates said dental prosthesis based on said tested and verified prospective dental prosthesis model.   
     
     
         16 . The system of  claim 15 , wherein said digital modeler establishes a preliminary digital model of said dental prosthesis using said pre-scanned digital models from said image database, wherein said digital modeler establishes said preliminary digital model of said dental prosthesis by matching said pre-scanned digital models with jaw morphology and configuration of said patient by characterizing arch form and size of upper and lower jaws, ridge height and form, and inter-jaw space and relation. 
     
     
         17 . The system of  claim 15 , wherein said digital simulator digitally simulates said occlusal relationship between said upper oral structures and said lower oral structures at different condylar positions for digitally reproducing bite registration, centric occlusion, and centric relation. 
     
     
         18 . The system of  claim 15 , wherein said digital simulator performs said simulated force tests for reducing interference and enhancing retention of said digital dental prosthesis model by simulating predetermined motions of said oral structures. 
     
     
         19 . The system of  claim 15 , wherein said fabricator fabricates said dental prosthesis by rigidly attaching preformed prosthetic teeth to a predesigned abutment on an acrylic base of said dental prosthesis, wherein said base of said dental prosthesis is fabricated by precision milling of preformed blocks of high density and high strength acrylic material, and wherein each of said preformed prosthetic teeth has a shape of a dental crown. 
     
     
         20 . A computer program product comprising computer executable instructions embodied in a computer readable storage medium, wherein said computer program product comprises:
 a first computer parsable program code for integrating one or more high resolution digital scanned images of one or more oral structures with one or more three dimensional cone beam X-ray images of hard oral tissues and soft oral tissues of a patient in a three dimensional space to obtain one or more combined three dimensional images of said one or more oral structures of said patient;   a second computer parsable program code for digitally simulating occlusal relationship between upper oral structures and lower oral structures using said combined three dimensional images for digitally articulating said upper oral structures and said lower oral structures;   a third computer parsable program code for digitally modeling a dental prosthesis based on said digitally articulated upper oral structures and lower oral structures to generate a digital dental prosthesis model for planning intra-oral positioning and structure of said dental prosthesis; and   a fourth computer parsable program code for refining said digital dental prosthesis model based on simulated force tests performed for assessing interference and retention of said digital dental prosthesis model.