US20150374463A1

US20150374463A1 - System and method for manufacturing of dental crowns and crown components

Info

Publication number: US20150374463A1
Application number: US14/579,264
Authority: US
Inventors: Robert David Sager
Original assignee: Zircore LLC
Current assignee: Zircore LLC
Priority date: 2004-02-06
Filing date: 2014-12-22
Publication date: 2015-12-31
Also published as: US20170249418A1; US8751031B2; US20170231727A1; US20170231719A1; US20090319068A1; US20140297015A1; US20170196665A1; US20170300613A1

Abstract

A method of manufacturing custom crown coping and infrastructures is provided.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending U.S. application Ser. No. 14/300,856 filed on Jun. 10, 2014, which is a divisional application of then co-pending U.S. application Ser. No. 12/346,341 filed on Dec. 30, 2008 (now U.S. Pat. No. 8,751,031) and which claims priority pursuant to 35 U.S.C. 119(e) to then co-pending U.S. Provisional Patent Application Ser. No. 61/099,566, filed Sep. 24, 2008, and which is a continuation-in-part application of U.S. application Ser. No. 11/107,519 filed Apr. 15, 2005 (now U.S. Pat. No. 7,690,920) and of U.S. application Ser. No. 12/212,256 filed Sep. 17, 2008 (now U.S. Pat. No. 7,967,606), which is a continuation of U.S. application Ser. No. 11/023,950 filed Dec. 28, 2004 (now U.S. Pat. No. 7,445,449), which claims priority pursuant to 35 U.S.C. 119(e) to then co-pending U.S. Provisional Patent Application Ser. No. 60/631,102, filed Nov. 26, 2004, U.S. Provisional Patent Application Ser. No. 60/566,855, filed Apr. 30, 2004 and U.S. Provisional Patent Application Ser. No. 60/543,038, filed Feb. 6, 2004, the entire disclosures and claims of which are incorporated herein by reference.

FIELD OF THE INVENTION

Part A:
The present invention relates generally to prosthodontic systems, methods and apparatuses. More particularly, the present invention is concerned with a process for manufacturing custom dental crown copings and infrastructures which provides economy of manpower, time, materials and machine.
Part B:
The present invention relates generally to prosthodontic systems, methods and apparatuses. More particularly, the present invention is concerned with a process for manufacturing custom dental crown copings and infrastructures which provides economy of manpower, time, materials and machine.
Part C:
The present invention relates generally to prosthodontic systems, methods and apparatuses. More particularly, the present invention is concerned with a process for manufacturing custom dental crown cores and/or crowns which provides economy of manpower, time, materials and machine.
Part D:
The present invention relates generally to prosthodontic systems, methods and apparatuses. More particularly, the present invention is concerned with a process for manufacturing custom dental crown and bridge cores and/or crowns and bridges, which provides economy of manpower, time, materials and machine.

BACKGROUND OF THE INVENTION

Part A:
Prior to the advent of the instant invention, prosthodontic systems have been extremely labor intensive and time consuming, requiring a considerable amount of skilled labor to custom fit prosthodontics for each case. An example of a prior art prosthodontic system will be discussed below with respect to the Lava™ All Ceramic CAD/CAM System offered by 3M ESPE. The Lava™ System utilizes a standard two-piece Camlog Ti Ceramic abutment comprising a metal (titanium) portion and a ceramic portion. The metal portion of the abutment is implanted into the patient's mouth in the location in which a tooth replacement is necessary. The ceramic portion of the abutment, which is cemented to the metal portion, acts as a stump for mounting of a custom coping shaped to resemble the original tooth that is being replaced.
When a patient requires a tooth replacement, a three-dimensional model of the patient's mouth is prepared. Using the model of the patient's mouth, a lab technician will fit the metal portion of the abutment into the appropriate location in the model. The ceramic portion of the abutment is placed on the metal portion and the technician then modifies the ceramic portion by grinding down the ceramic portion so that it is appropriate for the location and orientation in which it will be positioned within the patient's mouth. Once the ceramic portion of the abutment is modified to its final shape, the abutment, which is located in the model, is scanned. Using data from the scan about the shape and orientation of the abutment, as well as the existing teeth surrounding the position of the abutment, the necessary shape of a crown coping is determined and the crown coping is manufactured. In the context of the Lava™ System, a Computer Numeric Control (CNC) Machine is utilized to manufacture the coping by milling a block to the shape of the crown; however, in many instances the coping is manufactured by hand. Once the coping is completed, the entire piece (coping and abutment) is ready for implant in the patient's mouth.
The prior art system described above is very time consuming, as it requires a considerable amount of labor and time to modify the abutment and then separately manufacture the coping based upon the shape of the modified abutment. In some cases, the ceramic portion of the abutment requires considerable modification due to its orientation within the patient's mouth such that a relatively small surface of the abutment remains for mounting of the coping. In addition, the prior art system results in substantial waste of materials as the ceramic abutment and the coping are manufactured independently. Therefore, it would be beneficial to provide a system for manufacturing a custom dental crown coping and infrastructure (abutment) which reduces the amount of labor, time and materials.
Part B:
Prior to the advent of the instant invention, prosthodontic systems have been extremely labor intensive and time consuming, requiring a considerable amount of skilled labor to custom fit prosthodontics for each case. Examples of a prior art prosthodontic systems include the Lava™ Zirconium CAD/CAM-CNC Crown Coping and Infrastructure System offered by 3M ESPE, and the Camlog Implant System's Ti-Ceramic Abutment. The Lava™ System utilizes a zirconia block which is CNC shaped in a greenware state that is then ceramic infused and heat sintered. The Camlog Implant System and other implant systems, utilize a two-piece abutment comprised of an upper sintered ceramic (zirconia) portion of the abutment that requires modification and a lower metal portion of the abutment that is screw affixed to the implant in the location in which a tooth replacement is necessary in the patient's mouth. The ceramic portion of the abutment, which is cemented to the metal portion in the lab prior to constructing the crown coping, simulates a laboratory analog of a prepared tooth stump base for fabrication of a custom crown coping, such as a Lava™ crown coping. It is noted that crown copings can also be fabricated from built-up powder as in the Vita/Vident Inceram/Zirconium System. It is noted also, all Ceramic crown systems at present require some type of ceramic base coping to be made first and then layered with porcelain to create the highly individualized likeness of the original tooth that is being replaced.
In the present system, when a patient requires a tooth replacement, a three-dimensional stone model of the patient's mouth is prepared from a master impression. If a two-piece abutment such as the Camlog Implant System's Ti-Ceramic Abutment described above is to be utilized, a lab technician will use the model of the patient's mouth to fit the metal portion of the abutment into the appropriate implant analog location in the model. The ceramic portion of the abutment is placed on the metal portion and the technician then modifies the ceramic portion by grinding down the factory sintered Zirconia ceramic piece so that its shape is appropriate for the location and orientation in which it will best support the final crown positioned within the patient's mouth. Once the ceramic portion of the abutment is modified to its final shape, the abutment, which is located in the model, is scanned. Using data from the scan about the shape and orientation of the abutment, as well as the existing teeth surrounding the position of the abutment, the necessary shape of a crown coping is determined and the crown coping is manufactured. In the context of the Lava™ System, a Computer Numeric Control (CNC) milling machine is utilized to manufacture the coping by milling a Lava™ block. Once the coping is completed, and built-up with porcelain to resemble a natural tooth, the entire piece (coping and abutment) is ready for placement in the patient's mouth. The crown coping/crown is cemented conventionally (like any crown to a tooth) to the installed abutment.
Part C:
Prior to the advent of the instant invention, prosthodontic systems have been extremely labor intensive and time consuming, requiring a considerable amount of skilled labor to custom fit prosthodontics for each case. Examples of a prior art prosthodontic systems include the Lava™ Zirconium CAD/CAM-CNC Crown Coping and Infrastructure System offered by 3M ESPE, and the Camlog Implant System's Ti-Ceramic Abutment. The Lava™ System utilizes a zirconia block which is CNC shaped in a greenware state that is then ceramic infused and heat sintered. The Camlog Implant System and other implant systems, utilize a two-piece abutment comprised of an upper sintered ceramic (zirconia) portion of the abutment that requires modification and a lower metal portion of the abutment that is screw affixed to the implant in the location in which a tooth replacement is necessary in the patient's mouth. The ceramic portion of the abutment, which is cemented to the metal portion in the lab prior to constructing the crown coping, simulates a laboratory analog of a prepared tooth stump base for fabrication of a custom crown coping, such as a Lava™ crown coping. It is noted that crown copings can also be fabricated from built-up powder as in the Vita/Vident Inceram/Zirconium System. It is noted also, all Ceramic crown systems at present require some type of ceramic base coping to be made first and then layered with porcelain to create the highly individualized likeness of the original tooth that is being replaced.
My prior inventions disclosed in U.S. Patent Application Ser. No. 60/566,855, filed Apr. 30, 2004 and 60/543,038 filed Feb. 6, 2004, the disclosures of which are incorporated herein by reference in their entirety, provide systems for simultaneously manufacturing a custom dental crown coping and ceramic infrastructure (abutment or ceramic portion of the abutment if two piece) to reduce the amount of labor, time and materials. My prior inventions can be used to manufacture pieces from a greenware stage prior to sintering, or alternatively from an already ceramic infiltrated sintered material, such as a Bio-HIP Y-TZP (High Heat and Isostatic Pressure formed ytrium stabilized zirconium dioxide block, which may be cut using a DCS machine). Notwithstanding, all prior art processes discussed above either mill crown core/crowns from a single block with a single axis machine, or mill a bridge from nuggets of 1-4 teeth in length with a single axis machine. This requires that a technician continuously attend the CNC crown core/crown machines to change blocks.
The maximum number of crown core/crowns that any system of the prior art can make from a single block is 8-14 (capable with a DCS machine), which can take in excess of 24 hours. Nevertheless, all other machines (other than a DCS machine) require the block to be changed for each crown/crown core, or at least one block change for each 3-4 crown/crown core units. All machines, other than a DCS machine, cut crown core/crowns from a non-sintered greenware stage. In such machines, the exchange of blocks is manual, and time consuming. Although the process is “computer numeric controlled” (CNC—meaning that a human does not have to manually make the piece), the production time and set up is such that the technician has to continuously monitor the machinery or at the least be mindful of the ticking clock and the end of the process. Thus, efficiency in the work place is difficult, if not impossible to obtain.
All prior art processes, except DCS, use non-sintered zirconium dioxide, and have to HEAT (sinter) the finished end product crown core/crowns to convert the zirconium dioxide to the tetragonal phase (strongest phase of the material). Although crown cores can be manufactured from non-sintered materials, in most processes crown cores are typically manufactured from metal materials for better durability. Unfortunately, all metals have trace materials that irritate some individuals soft tissues. Bio-HIP Y-TZP provides a non-metal option for manufacturing a crown core; however Bio-HIP Y-TZP is expensive, hard to work with, and so hard it eats diamond burs in the manufacturing process. Therefore, none of the processes of the prior art (whether cutting either non-sintered or sintered material) are efficient enough to make safe non-metal crown cores affordable for all people, and are intended primarily for small operation dental labs.
Using Bio-HIP Y-TZP and a DCS milling machine is the most accurate method and best material known to man to make a crown via CAD/CAM and CNC manufacturing as no variable result post production process is required (i.e. sintering). Notwithstanding, the prior art systems waste too much material (raw material and burs) and take too long, making what is the best material for crown core/crowns expensive. Thus, the use of Bio-HIP Y-TZP through prior art processes is not cost effective enough in production to make the best product available for all patients. Therefore, it would be beneficial to provide a process that increases the efficiency of using materials such as Bio-HIP Y-TZP for crown core/crowns so as to eliminate socio-economic discrimination in dentistry, and level the playing field in price and honesty of materials used.
Part D:
Prior to the advent of the instant invention, prosthodontic systems have been extremely labor intensive and time consuming, requiring a considerable amount of skilled labor to custom hand-make each prosthodontic unit for each case. Recent prior art CAD/CAM-CNC systems for manufacturing prosthodontic pieces require new skill sets and higher intellectual levels of skill than older systems, forcing the majority of labs in the USA (1-5 person small labs) to resist adopting advanced materials and methodologies and/or have to outsource such capabilities and subsequently label the result “premium” goods and services. Even through outsourcing, contemporary technological prior art prosthodontic systems are extremely inefficient, making the availability of high quality, cost-effective prosthodontic pieces nonexistent.
Examples of a prior art prosthodontic systems include the Lava™ two-stage zirconium dioxide system offered by 3M ESPE, and the Precident™ one-stage Bio-HIP Y-TZP (High Heat and Isostatic Pressure formed ytrium stabilized tetragonal zirconium polymorph) offered by DCS of Switzerland. The Lava™ System utilizes a zirconia dioxide block that is CNC milled in a greenware state then secondarily heat sintered. The Precident System mills directly from the harder presintered Bio-HIP Y-TZP block.
My prior inventions disclosed in U.S. Patent Application Ser. No. 60/566,855, filed Apr. 30, 2004 and 60/543,038 filed Feb. 6, 2004, the disclosures of which are incorporated herein by reference in their entirety, provide systems for simultaneously manufacturing a custom dental crown coping and ceramic infrastructure (abutment or ceramic portion of the abutment if two piece) to reduce the amount of labor, time and materials. My prior inventions can be used to manufacture pieces from a greenware stage prior to sintering, or alternatively from an already ceramic infiltrated sintered material, such as a Bio-HIP Y-TZP. Notwithstanding, all prior art processes discussed above mill crown and bridge cores/crowns and bridges from a single block of material with a single axis machine. All current systems require that a technician continuously attend the CNC crown and bridge core/crown and bridge machines to load and change blocks after a limited number of units are produced, and to manually separate finished units from the blocks to avoid trial and error “fit” re-identification.
The maximum number of crown core/crown pieces that any system of the prior art can currently make is 8-16 units/day (capable with a DCS machine, which can cut from 2 blocks before requiring shut down and material exchange), which can take in excess of 24 hours and which requires individual separation of the units from blocks by hand. All other machines (other than a DCS machine) require the block/lug to be changed for each crown/crown core, or at least one block change for each 3-4 crown or bridge core/crown and bridge units. For example, Hint-ELs® Zirconium TZP HIP, which comes in a disc (similar to a hockey-puck) shape for cutting bridges and a two-stage cylindrical (similar to a magic marker) shape for individual pieces, can be automatically feed into a milling machine such that multiple pieces can be cut without the requirement that an attendant mechanically remove the completed work and que-up materials from a hopper on the machine. Nevertheless, as each piece is unique, such machines must be shut down for removal of the pieces after they are cut to avoid confusion among multiple pieces. All machines, other than a DCS machine, cut crown core/crowns from a non-sintered greenware stage. In such machines, the exchange of blocks is manual, and time consuming. Although the process is “computer numeric controlled” (CNC—meaning that a human does not have to manually make the piece), the production time and set up is such that the technician has to continuously monitor the machinery or at the least be mindful of the ticking clock and the end of the process. Thus, true automation efficiencies in the work place are difficult, if not impossible to obtain.
All prior art processes recognize the TZP phase of zirconium to be the strongest of the metal-free materials. Unfortunately, all metals have trace elements that may irritate some individuals' soft tissues. Bio-HIP Y-TZP provides a non-metal hypo-allergenic option for manufacturing crown and bridge cores/crowns and bridges; however Bio-HIP Y-TZP is expensive, hard to work with, and so hard it eats diamond burs in the manufacturing process. Therefore, none of the processes of the prior art (whether cutting either non-sintered or sintered material) are efficient enough to make safe non-metal crown cores readily available and/or affordable for all people, and are intended primarily at present for affluent patients.
Using Bio-HIP Y-TZP via CAD/CAM and CNC manufacturing is known to offer the most precision. as no variable result post production process is required (i.e. sintering). Notwithstanding, the prior art systems waste too much material (raw material and burs) and take too long, making what is the best material for crown core/crowns expensive. Thus, the use of Bio-HIP Y-TZP through prior art processes is not cost effective enough in production to make the best product available for all patients. Therefore, it would be beneficial to provide a process that increases the efficiency of using materials such as Bio-HIP Y-TZP for individual crown cores/crowns so as to eliminate socio-economic discrimination in dentistry, and level the playing field in price and honesty of materials used.

SUMMARY OF THE INVENTION

Part A:
A principal object of the instant invention is to provide a system for manufacturing a custom dental crown coping and infrastructure (abutment) which reduces the amount of labor, time and materials.
The objects of the instant invention are accomplished through the use of a system that includes a two piece abutment similar to that described above. The metal insert portion of the abutment is a standard piece. The ceramic portion of the abutment is a custom-made piece, which is manufactured at the same time the coping is manufactured.
When a patient requires a tooth replacement, a three-dimensional model of the patient's mouth is prepared. Using the model of the patient's mouth, a lab technician will fit the metal portion of the abutment into the appropriate location in the model. The model will then be scanned. The scan provides data about the orientation of the metal insert within the model of the mouth and also data about the existing teeth surrounding the position of the abutment. The data from the scan, along with stored data about the standard shape of the metal insert to which the ceramic portion is to be mounted, is used to determine and design the appropriate shape for the ceramic portion of the abutment. At the same time, the shape of the coping is designed, using the data so that the coping will fit over the designed ceramic portion of the abutment.
The system of the instant invention allows both the coping at the ceramic portion of the abutment to be manufactured from a single block, significantly reducing the amount of material required. In addition, the inventive system significantly reduces the amount of labor necessary to manufacture the coping and the abutment. Because the abutment is custom manufactured, a superior mounting surface is achieved, regardless of the orientation of the metal insert with the mouth.
Part B:
A principal object of the instant invention is to provide a system for simultaneously or mechanico-sequentially fabricating a custom dental crown coping and infrastructure (abutment) to reduce the amount of labor, time and materials. The process is accomplished by integrating, sharing and interpreting stored Cad/Cam digital job information and CNC machining programs to achieve optimized custom milling results.
The objects of the instant invention are accomplished through the use of a system that includes a two piece abutment similar to that described above (until such time as the material and process allow one piece ceramic/zirconium abutments). The metal insert portion of the abutment is a standard piece. The ceramic portion of the abutment becomes a custom-made piece, which is manufactured at the same time the coping is manufactured.
When a patient requires a tooth replacement, a three-dimensional model of the patient's mouth is prepared. Using the model of the patient's mouth, a lab technician will fit the metal portion of the abutment into the appropriate location in the model. The model will then be scanned. The scan provides data about the orientation of the metal insert within the model of the mouth and also data about the existing teeth surrounding the position of the abutment. The data from the scan, along with stored data about the standard shape of the metal insert to which the ceramic portion is to be mounted, is used to determine and design the appropriate shape for the ceramic portion of the abutment. At the same time, the shape of the coping is internally designed, using the data so that the coping will fit over the designed ceramic portion of the abutment.
In one embodiment of the instant invention, the ceramic portion of the abutment and the coping are milled in a greenware stage and then sintered. In such an embodiment, it is necessary to shape the ceramic pieces as they are cut in the greenware stage so as to accommodate shrinkage that occurs during the sintering process and to result in a piece of the desired shape and size after sintering. As discussed with respect to the prior art, cutting the ceramic pieces in the greenware stage is much easier to accomplish than cutting once the pieces have been sintered. Nevertheless, the sintering process itself is an additional time consuming step that is required when working with greenware pieces. In an alternative embodiment, the ceramic pieces are milled from a factory sintered block (such as titanium, zirconium, inceram, plastic or any other suitable material now known or later discovered). Cutting of the factory sintered block is slower than cutting from a greenware block; however the additional sintering step is eliminated. The use of a factory sintered block provides additional advantages over the use of a greenware block, such as allowing larger pieces to be milled from a single block (i.e. full arches versus single crowns or bridges).
In a preferred embodiment of the instant invention, in which the ceramic portion of the abutment are milled from a factory sintered block, a custom crown core and custom crown coping is made for use with an off-the-shelf lower abutment portion, such as the lower metal portion (Ti-base) of the Camlog Implant System discussed above. Information regarding the size and shape of the off-the-shelf pieces are stored in a data file or library accessed by a milling machine (such as a DCS milling machine). The Ti-base is placed in a master model implant analog and the model is scanned to obtain data about the orientation of the base within the model and data about the existing teeth surrounding the position of the base within the model. The data from the scan is combined with the stored size and shape information regarding the Ti-base to design a custom crown core part to fit over the Ti-base and a custom crown coping to fit over the custom crown core. The custom crown core will be designed to have predetermined minimum dimensions based upon the size and shape of the Ti-base being used. In most instances however, the actual custom crown core will have dimensions greater than the library-stored “minimum”, thus the dimensions of the custom crown core will include a wax-up from the minimum dimensions. Once the final dimensions for the custom crown core and the custom crown coping are determined by wax-up software, the core and coping pieces are milled from a block of material.
In prior art systems, the custom dental crown coping and infrastructure (abutment) are manufactured from the ground up. The abutment is designed first and the coping is designed to fit the abutment. In the instant invention the custom dental crown coping and infrastructure can be manufactured from the ground up by first determining the shape and orientation of the abutment and then determining the shape and orientation of the coping.
Alternatively, the custom dental crown coping and infrastructure of the instant invention can be manufactured from the end product. In such a manner, the model is scanned and the shape and orientation of the final crown is determined or visualized. The thickness for the crown is subtracted to determine the shape and orientation of the coping. The thickness of the coping is then subtracted to form the shape and orientation of the abutment.
The system of the instant invention allows both the coping at the ceramic portion of the abutment to be manufactured from a single block, significantly reducing the amount of material required. In addition, the inventive system significantly reduces the amount of labor necessary to manufacture the coping and the abutment. Because the abutment is custom manufactured, a superior mounting surface is achieved, regardless of the orientation of the metal insert with the mouth.
Part C:
An object of the instant invention is to provide a system for utilizing materials such as Bio-HIP Y-TZP for manufacturing crown cores/crowns that is cost effective. Another object of the instant invention is to truly “automate” the crown core/crow making process, such that it can be largely unattended after CAD/CAM instructions are given to the CNC machinery. Yet another object of the instant invention is to provide a method of certifying and identifying custom pieces made by the automated process of the instant invention.
The objects of the instant invention are accomplished through the use of a continuous feed CNC machine for crown core/crown manufacture and Bio-HIP Y-TZP (High Heat and Isostatic Pressure formed ytrium stabilized zirconium dioxide) rods stock that is fed into the CNC machine. The rod stock of the instant invention may be formed in any and all cross sectional shapes (i.e., hex, round, square, christmas tree, etc.), and preferably will be available in a plurality of shapes and size to be used in the continuous feed crown core/crown machines for manufacturing pieces of varying shapes and sizes. The particular cross sectional shape and/or size utilized for a particular piece will be selected by the machine so as to minimize the amount of cutting and waste of material.
The process of the instant invention utilizes specialized software to interface between Cad/Cam design programs and CNC machines to enable the machine to use two cutting tools at one time which turn simultaneously and/or individually and sequentially about the rod stock to make a series of continuously produced crown cores/crowns.
The CNC machine of the instant invention also includes a laser engraving tool to provide a laser identity marking code on each crown core/crown manufactured by the process of the instant invention at the end of production. The marking on each piece is able to be subsequently scanned for sorting and positive identification and certification of process used.
The instant invention truly “automates” the crown core/crown making process, such that it can be largely unattended after CAD/CAM instructions are given to the machinery. The length of rod stock is loaded into the machine, and the machine requires no further user interaction until the rod stock is used up. In a preferred embodiment of the instant invention multiple CNC machines are loaded with multiple rods (of varying shapes and sizes) and multiple cutting tools. Much in the same way Henry Ford's assembly line automated the automobile industry, the instant invention allows the CNC process of the instant invention to be operated in a factory assembly-line style, rather than in “custom” small operation dental labs.
In a preferred embodiment of the instant invention, dentists (or their labs) only own scanners, and transmit via modem (or other data transmission device) the digital information obtained by the scanner to a central factory, or to one of multiple centers able to make the crown coping. Then the dentist and/or lab need only a finish porcelain technician, instead of the entire staff of technicians required to make the crown cores. Although similar “outsourcing” may be feasible for the manufacture of crown cores through prior art processes, the time and cost of Bio-HIP Y-TZP make the use of Bio-HIP Y-TZP zirconium a premium rather than a standard offering.
The laser engraver of the instant invention provides a method of certifying the origin, trademark (similar to the DeBeers marks for diamonds) of pieces, as well as a method of identifying pieces for tracking and/or sorting, by marking each crown core/crown manufactured from the rod stock with a laser marking after it is cut. Such markings are not feasible with prior art processes that require post production processes (i.e. sintering), as such processes would burn, melt or grind away the marking Individual crowns manufactured by prior art processes in which a crown is cut from a single block, may also be marked through the instant invention. Nevertheless, marking pieces manufactured from rod stock of the instant invention provides a particular advantage that is unnecessary in non-automated processes, as the mass production of pieces through the instant invention presents the possibility of disorganization and confusion of finished pieces.
As is discussed above, multiple CNC machines of the instant invention may be loaded with differing diameters of rod stock. In a preferred embodiment of the instant invention, all of the machines are controlled by a central control unit so that the control unit can automatically put the crown core/crown into production on the machine loaded with the most appropriate size rod stock, and thereby conserve both raw material and bur stock, as well as reduce the time it takes to cut away material by minimizes the amount of material that needs to be cut away. The rod stock of the instant invention may be of a variety of lengths, preferably anywhere from 1-8 feet, to optimize the versatility to small and big shops and or supply of the rod stock. The automatic feed of the rod stock to the machine minimizes user interaction, only requiring the technician to be an attendant to monitor the many machines, rather than having to constantly feed the machines with blocks of material and then restart them.
Part D:
An object of the instant invention is to provide a system for manufacturing prosthodontic pieces such as individual crown cores, crowns, or the like. Another object of the instant invention is to provide a system for utilizing materials such as Bio-HIP Y-TZP for manufacturing prosthodontic pieces such as individual crown cores, crowns, or the like that is cost effective. Another object of the instant invention is to truly “automate” the crown core/crown making process, such that it can be largely unattended after CAD/CAM instructions are given to the CNC machinery. Yet another object of the instant invention is to provide a method of certifying and identifying custom pieces made by the automated process of the instant invention. Still another object of the instant invention is to provide a continuous production crown core/crown making process that utilizes turning and multiple axis milling on a live center CNC machine.
The objects of the instant invention are accomplished through the use of a continuous feed live center CNC machine for crown core/crown manufacture and Bio-HIP Y-TZP rods stock that is fed into the CNC machine. The rod stock of the instant invention may be formed in any and all cross sectional shapes (i.e., hex, round, triangular, square, Christmas tree, etc.), and preferably is available in a plurality of shapes and sizes to be used in the continuous feed crown core/crown machines for manufacturing pieces of varying shapes and sizes. The particular cross sectional shape and/or size utilized for a particular piece will be programmed to be selected by the machine so as to minimize the amount of cutting and waste of material, and to expedite the manufacturing process.
The process of the instant invention utilizes specialized software, whether from prior art or by the instant invention, to interface between CAD/CAM design programs and CNC machines to enable the machine to use multiple cutting tools at one time simultaneously and/or individually and sequentially to continuously produce crown cores/crowns. In a preferred embodiment, the software is used by a central control unit that is connected to and controls a plurality of cutting machines.
The CNC machine of the instant invention also includes a high energy (i.e. laser, etc.) or mechanical engraving tool to provide an identity marking code on each crown core/crown manufactured by the process of the instant invention at the end of production. The marking on each piece is able to be subsequently scanned for sorting and positive identification and certification of process used. The identification mark on each piece can be scanned by an electronic scanning device, such as a bar code scanner, and pieces can then be rapidly hand sorted or automatically sorted by machinery connected to the scanning device. It is noted because the individual crown cores are manufactured and totally separated from a rod, with the final cut off occurring at a single point on the external occlusal/incisal surface, minimal hand finishing will be required, and the identity marking code may then be placed anywhere on the external surface. Such opportunity is not possible on any other prior art, requiring subsequent finishing and/or material altering processes.
The instant invention truly “automates” the crown core/crown making process, such that it can be largely unattended after CAD/CAM instructions are given to the machinery, and that the core requires the minimum of manual finishing and handling during and after manufacture. The rod stock is loaded into the machine, and the machine requires no further user interaction until the rod stock is used up. In a preferred embodiment of the instant invention multiple CNC machines are loaded with multiple rods (of varying shapes and sizes) and multiple cutting tools. Much in the same way Henry Ford's assembly line automated the automobile industry, the instant invention allows the CNC process of the instant invention to be operated in a highly automated “factory” style, rather than primarily custom “small shop” style.
In a preferred embodiment of the instant invention, dentists (or their labs) may only own scanners, and transmit via modem (or an other data transmission device) the digital information obtained by the scanner to a central factory, or to one of multiple centers able to make the crown coping. Then the dentist and/or lab need only a finish porcelain technician, instead of the entire staff of technicians required to make the crown cores. Although similar “outsourcing” may be feasible for the manufacture of crown cores through prior art processes, the time and cost of Bio-HIP Y-TZP make the use of Bio-HIP Y-TZP zirconium a premium rather than a standard offering.
The high energy (i.e. laser, etc.) or mechanical engraver of the instant invention provides a method of certifying the origin and material, trademark (similar to the DeBeers marks for diamonds) of pieces, as well as a method of identifying pieces for tracking and/or sorting, by marking each crown core/crown manufactured from the rod stock with a marking after it is cut. It is noted at present, there is no federal, state or local educational or licensure requirement for dental laboratory technicians, and no federal, state or local requirement for materials used in dental prostheses, such as crowns and bridges. By marking the units, the instant invention offers the first opportunity for certification of material, material lots and processes through to completed dental prostheses. Such markings are less feasible with prior art processes that require post production processes (i.e. sintering), as such processes would burn, melt or grind away the marking. Individual crowns manufactured by prior art processes in which a crown is cut from a single block, may also be marked through the instant invention. Nevertheless, marking pieces manufactured from rod stock of the instant invention provides a particular advantage that is unnecessary in non-automated processes, as the mass production of pieces through the instant invention presents the possibility of disorganization and confusion of finished pieces.
As is discussed above, multiple CNC machines of the instant invention may be loaded with differing diameters and/or shapes of rod stock. In a preferred embodiment of the instant invention, all of the machines are controlled by a central control unit so that the control unit can automatically put the crown core/crown into production on the machine loaded with the most appropriate size rod stock, and thereby conserve both raw material and bur stock, as well as reduce the time it takes to cut away material by minimizing the amount of material that needs to be cut away. The rod stock of the instant invention may be of a variety of lengths, preferably anywhere from 3 cm to 3 meters, to optimize the versatility to small and big shops and or supply of the rod stock. The automatic feed of the rod stock to the machine minimizes user interaction, only requiring the technician to be an attendant to monitor and periodically change and/or spot check calibration of tools of the many machines, rather than having to constantly feed the machines raw material blocks/purge from the machines of finished pieces and then restart manually them.
In the preferred embodiment of the instant invention, rod stocks are a Bio-HIP Y-TZP (High Heat and Isostatic Pressure formed ytrium stabilized tetragonal zirconium polymorph) material. Nevertheless, it will be appreciated that other suitable materials, such as titanium or modern synthetics, that do not require post production processes may be utilized to manufacture pieces without departing from the spirit and scope of the instant invention. It will further be appreciated that certain features of the instant invention may also be utilized with materials that require post production processes without departing from the spirit and scope of the instant invention.
The foregoing and other objects are intended to be illustrative of the invention and are not meant in a limiting sense. Many possible embodiments of the invention may be made and will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof. Various features and subcombinations of invention may be employed without reference to other features and subcombinations. Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention and various features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention, illustrative of the best modes in which the applicant has contemplated applying the principles, are set forth in the following description and are shown in the drawings/photos and are particularly and distinctly pointed out and set forth in the appended claims.

Part A and Part B:

FIG. 1 demonstrates the prior art system including 1) purchase of the two piece abutment, 2) modification of the ceramic portion of the abutment, 3) scanning of the modified portion of the abutment, and 4) manufacturing of the crown coping.

FIG. 2 demonstrates the system of the instant invention including 1) scanning of the metal portion of the abutment within the model, 2) manufacturing the ceramic portion of the abutment, and 3) manufacturing the coping. Part B:

FIGS. 2A and 2B are partial front views of a master model implant analog utilized in accordance with an embodiment of the instant invention.

FIG. 3 shows a front view of an implant base portion and a top view of a plurality of implant base portions, each having a different diameter.

FIG. 4 shows a ceramic abutment portion coupled to an implant base portion, the abutment and base portion being used in accordance with an embodiment of the instant invention.

FIG. 5 shows the ceramic abutment portion and the implant base portion of FIG. 4 and a Core positioned on the ceramic abutment portion.

FIGS. 6A and 6B show a DCS frame used in accordance with an embodiment of the instant invention.

Part D:

FIG. 7 is a schematic diagram of a preferred embodiment system for continuously making a plurality of prosthodontic pieces such as crowns, crown cores, or the like, of the instant invention.

FIG. 8A is a perspective view of a cylindrical rod stock of the instant invention, the view showing broken lines indicating prosthodontic pieces made from the rod stock in accordance with the instant invention.

FIG. 8B is a perspective view of a cylindrical rod stock of the instant invention, the view showing broken lines indicating prosthodontic pieces made from the rod stock in accordance with the instant invention.

FIG. 8C is a perspective view of a Christmas-tree rod stock of the instant invention, the view showing broken lines indicating prosthodontic pieces made from the rod stock in accordance with the instant invention.

FIG. 8D is a perspective view of a hexagonal rod stock of the instant invention, the view showing broken lines indicating prosthodontic pieces made from the rod stock in accordance with the instant invention.

FIG. 8E is an end view of a quadrilateral rod stock of the instant invention, the view showing broken lines indicating a prosthodontic piece made in accordance with the instant invention, the prosthodontic piece being made generally perpendicularly to the rod axis.

FIG. 8F is an end view of two cylindrical rod stocks of the instant invention, the view showing broken lines indicating prosthodontic pieces made in accordance with the instant invention.

FIG. 9 is a front view of a prosthodontic piece made in accordance with the instant invention, including identification marks in accordance with several embodiments of the instant invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

As required, a detailed embodiment of the present invention is disclosed herein; however, it is to be understood that the disclosed embodiment is merely exemplary of the principles of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
As required, a detailed embodiment of the present inventions is disclosed herein; however, it is to be understood that the disclosed embodiment is merely exemplary of the principles of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.
Referring to FIG. 7 a preferred embodiment of a system of the instant invention is shown in which a plurality of cutting machines 110 a, 110 b and 110 c are connected to central control unit 120. Control unit 120 is connected to scanner 130. Each of machines 110 a, 110 b and 110 c include cutting tools 112, laser engraving units 14, and automatic rod stock feeders 116. Rod stocks of varying cross-sectional shapes and sizes are loaded into machines 110 a, 110 b and 110 c. In the embodiment shown in FIG. 7 each of machines 110 a, 110 b and 110 c is fed a rod stock having a different cross-sectional shape and/or size from the rod stocks in the other of machines 110 a, 110 b and 110 c. For example, machine 110 a utilizes rod stock 140 a having a circular cross-sectional shape of a first diameter, d1, for cutting larger pieces such as molars; machine 110 b utilizes rod stock 140 b having a circular cross-sectional shape of a second diameter, d2, smaller than the first diameter, d1, for cutting smaller pieces such as incisors; and machine 110 c utilizes rod stock 140 c having a Christmas-tree cross-sectional shape for cutting crowns.
In operation, control unit 120 receives specifications for a piece that is to be cut from scanner 130. Scanner 130 may be located in close proximity to control unit 120 and machines 110 a, 110 b and 110 c. Alternatively, scanner 130 may be located remote from control unit 120, such as in a dental office or lab, and control unit 120 and machines 110 a, 110 b and 110 c may be located in a central factory or manufacturing center. In the embodiment shown in FIG. 7, scanner 130 is a stand alone scanner already available in the art and may include appropriate CAD/CAM software for obtaining specifications for a piece that is to be cut (either internally to the scanner or in a computer to which the scanner is connected). In such an embodiment, the dental professional will use the scanner to obtain specifications for the piece that is to be manufactured and transmit the specifications electronically (such as via modem) to the central factory.
The use of different cross-sectional shapes and sizes in each of machines 110 a, 110 b and 110 c allows a rod stock to be selected for cutting a particular piece 150 so as to minimize the amount of material that must be cut away from the rod stock to make the piece. This decreases cutting time, saves material and minimizes wear on the machine. Once controller 120 obtains specifications for piece 150 from scanner 130 control 120 will determine from the variety of rod stock available the shape and size most appropriate for piece 150. As is shown in FIGS. 8A-8F, the rod stock (referred to generally as reference number 140) can available in a variety of different shapes and sizes to allow many different shapes and sizes of pieces to be cut while resulting in minimal waste of material and maximizing efficiency of the cutting process. Rod stock 140 shapes and sizes include, but are not limited to, circular cross-section rod stock 140 a having diameter d1 for cutting larger pieces such as molars; circular cross-section rod stock 140 b having a smaller diameter d2 for cutting smaller pieces such as incisors; Christmas tree rod stock 140 c for cutting pieces such as crowns; hexagonal cross-section rod stock 140 d; and quadrilateral cross-section rod stock 140 e. Referring to FIG. 8F in particular, it can be seen that the circular rod stock 140 b having diameter d2 is a more appropriate cross sectional size for piece 150 than rod stock 140 a having larger diameter d2, as the larger cross section diameter of 140 a results waste of material and requires considerably more cutting than rod stock 140 b.
In most rod stock shapes and sizes, it is preferred that pieces be cut along the axis of the rod stock, such that bottom 158 and top 159 of each piece 150 are both located on the axis of the rod stock, as is shown in FIGS. 8A-8D. Nevertheless, it will be appreciated that pieces may also be cut in which that hollowed bottom 158 and top 159 are located off of the axis of the rod stock (i.e. the piece is cut generally perpendicular to the axis—see 140 e of FIG. 8E).
Once the appropriate machine having the desired rod stock shape and size is selected, controller 120 will activate feed mechanism 116 on the appropriate machine to feed rod stock 140 into machine 10 for cutting by cutters 112 and marking by laser marking unit 114, both of which are controlled by controller 120. The automatic feed mechanism 116 of machine 10 can be made in any manner now know or hereafter discovered for automatically moving rods, tubes and the like in an axial direction.
In a preferred embodiment of the instant invention cutting machines 110 a, 110 b and 110 c are live center CNC machines that each include two cutting tools 112. The live center and two cutting tools allow a plurality of individual prosthodontic pieces to be sequentially cut from a continuous rod stock along multiple axes as the rod stock is continuously fed into the cutting machine without any human operator assistance.
As the instant invention allows a plurality of pieces to be cut from a single continuous rod stock without operator interaction to replace the material for each new piece, confusion between pieces may occur. Therefore, machines 110 a, 110 b and 110 c of the instant invention include laser marking units 114 to provide an identification mark on each piece after it is cut. As is shown in FIG. 9, the identification mark on piece 150 may include a certification mark 152 identifying the source and signifying the quality of piece 150, as well as a unique identification code for tracking and identifying the specific piece 150 which is most likely a customized prosthodontic piece. The unique identifying code of the instant invention may include piece identification number 154 and/or bar code 156, or any other identification code now known or hereafter discovered. It will be appreciated that although the marking unit of the preferred embodiment discussed herein is a laser-engraving unit, other marking units such as ink jets, etching, manual/mechanical engraving, etc., may be utilized without departing from the spirit and scope of the instant invention.
It will be appreciated that although the marking of prosthodontic pieces such as crowns, crown cores, or the like, made in accordance with the instant invention is sometimes referred to herein as being accomplished “after” the piece is cut, the actual marking can take place as part of the cutting process. In such instance, the marking of the piece is referred to as being accomplished “after” the cutting of the piece as the marking is initiated “after” the cutting has been initiated. Accordingly, the completion of the cutting may precede, coincide with or even succeed completion of the marking without departing from the spirit and scope of the instant invention.
The steps of a preferred embodiment of the present invention include milling a custom crown core and a custom crown coping from a single block of material using a DCS milling machine. The custom crown core is designed to attach to a base of an off-the-shelf implant such as the Ti-base portion of the Camlog Implant System.
Some embodiments use a unique frame in a single axis milling machine, such as a DCS milling machine, to accomplish milling of custom crown cores. The frame includes a molded/milled polymer base that holds a threaded base to which a blank for the custom crown core is attached. The frame is placed within the milling machine, and one of three angled blanks is chosen by control software of the machine depending upon the desired shape of the custom crown core that is to be machined. This allows for undercutting of the blank which may be necessary for custom crown cores that will be located at a variety of angled orientations. Implants having a generally orthogonal orientation will generally utilize the 0 degree blank for milling. As the orientation angle increases to about 10 degrees from an orthogonal orientation, the 10 degree blank will be utilized. As the orientation angle increases to about 20 degrees from an orthogonal orientation, the 20 degree blank will be utilized. Because additional material is needed to provide the “minimum” dimension of the custom core in angled orientations, the diameters of the blanks increase as the angle increases (i.e. 10 degree blank is larger diameter than 0 degree blank, and 20 degree blank is larger diameter than 10 degree blank).
In the foregoing description, certain terms have been used for brevity, clearness and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the description and illustration of the inventions is by way of example, and the scope of the inventions is not limited to the exact details shown or described.
Although the foregoing detailed description of the present invention has been described by reference to an exemplary embodiment, and the best mode contemplated for carrying out the present invention has been shown and described, it will be understood that certain changes, modification or variations may be made in embodying the above invention, and in the construction thereof, other than those specifically set forth herein, may be achieved by those skilled in the art without departing from the spirit and scope of the invention, and that such changes, modification or variations are to be considered as being within the overall scope of the present invention. Therefore, it is contemplated to cover the present invention and any and all changes, modifications, variations, or equivalents that fall with in the true spirit and scope of the underlying principles disclosed and claimed herein. Consequently, the scope of the present invention is intended to be limited only by the attached claims, all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.
Having now described the features, discoveries and principles of the invention, the manner in which the invention is constructed and used, the characteristics of the construction, and advantageous, new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts and combinations, are set forth in the appended claims.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Claims

What is claimed is:

1. A method of creating digital job information for at least one component to be manufactured selected from the group consisting of a crown, multi-tooth unit, bridge, coping, crown coping, core, abutment and infrastructure, the method comprising the steps of:

obtaining a three-dimensional model of a patient's mouth;

determining an outer shape of a dental restoration based on the three-dimensional model of the patient's mouth;

determining a manufacturing parameter for a component of the dental restoration to be manufactured based upon the determined shape of the dental restoration;

wherein the determined manufacturing parameter is selected from a plurality of preset parameter options; and

creating the digital job information based upon the determined manufacturing parameter.

2. The method as claimed in claim 1 wherein the preset parameter options include a variety of material classification options from which the component is designed to be manufactured.

3. The method as claimed in claim 2 wherein the material classification options include a material shape, size, configuration and/or consistency.

4. The method as claimed in claim 1 wherein the preset parameter options include a variety of manufacturing methods.

5. The method as claimed in claim 4 wherein one of the variety of manufacturing methods includes utilizing multiple manipulations at one time simultaneously.

6. The method as claimed in claim 5 wherein the utilizing multiple manipulations comprises utilizing multiple tools.

7. The method as claimed in claim 6 wherein at least one of the tools comprises a cutting tool.

8. The method as claimed in claim 4 wherein one of the variety of manufacturing methods includes utilizing multiple manipulations at one time individually and sequentially.

9. The method as claimed in claim 8 wherein the utilizing multiple manipulations comprises utilizing multiple tools.

10. The method as claimed in claim 9 wherein at least one of the tools comprises a cutting tool.

11. The method as claimed in claim 4 wherein one of the variety of manufacturing methods includes utilizing one of a plurality of machines.

12. The method as claimed in claim 1 wherein the determining step comprises organizing a material and a manufacturing method.

13. A method of automating manufacture of at least one component selected from the group consisting of a crown, multi-tooth unit, bridge, coping, crown coping, core, abutment and infrastructure, the method comprising the steps of:

obtaining digital job information for a plurality of the components to be manufactured at one or more computer automated machines;

manufacturing the plurality of components by the one or more computer automated machines;

tracking an identity of at least one component during manufacturing; and

maintaining a record of the identity of the at least one component.

14. The method as claimed in claim 13 wherein the step of maintaining a record of the identity of the component includes placing a unique identification mark in association with the component.

15. The method as claimed in claim 14 wherein the unique identification mark is placed on the component.

16. A method of creating digital job information for manufacturing a custom coping, the method comprising the steps of:

preparing a three-dimensional model of a patient's mouth;

selecting an implant abutment insert and inserting it into the model;

scanning the model with the implant abutment insert inserted in the model;

utilizing the resulting scan of the model with the implant abutment insert to design a coping to fit over the implant abutment insert; and

creating the digital job information comprising the implant abutment insert selection and coping design information for use in manufacturing the custom coping.

17. A method of creating digital job information for manufacturing a custom coping, the method comprising the steps of:

receiving a scan of a three-dimensional model of a patient's mouth having an implant abutment insert therein;

utilizing the received scan of the model with the implant abutment insert to design a coping to fit over the implant abutment insert; and

18. A custom coping manufactured by the steps of:

preparing a three-dimensional model of a patient's mouth;

selecting an implant abutment insert and inserting it into the model;

scanning the model with the implant abutment insert inserted in the model;

utilizing the resulting scan of the model with the implant abutment insert to design a coping to fit over the implant abutment insert;

creating the digital job information comprising the implant abutment insert selection and coping design information for use in manufacturing the custom coping; and

milling the custom coping using the digital job information.