The present disclosure relates generally to a manufacturing system and, more particularly, to a system and method for manufacturing dental workpieces including prostheses, support structures, and drill or surgical templates.
Additive manufacturing is a process of creating three-dimensional components by depositing overlapping layers of material, typically under the guided control of a computer. One technique of additive manufacturing is known as direct metal laser sintering (DMLS). The DMLS technique uses a laser to direct a high-energy beam into a powdered metal medium at precise locations corresponding to features and dimensions of the component to be manufactured. As the energy beam contacts the powdered metal, the powdered metal is caused to melt and weld together and to previously melted layers of the component.
In some situations, a component created only via DMLS is complete and in final form. In other situations, however, for example in situations where tight tolerances on size and/or form are required, other manufacturing steps (e.g., subtractive steps) may be taken. These steps can include creation of a base component (e.g., via milling and/or lathing) on which the printed component can subsequently be fabricated. The base component may have tight external tolerances in critical areas that cannot be achieved via additive manufacturing.
DMLS and conventional subtractive manufacturing operations have been used together to create dental prostheses. For example, U.S. Pat. No. 8,778,443 of Uckelmann et al. that issued on Jul. 15, 2014 (“the '443 patent”) describes a method for manufacturing an abutment for a dental implant. The method includes mounting a generic base member previously prefabricated via milling onto a platform. The method then includes laser-sintering a customized main body onto the base member in a layer-by-layer manner.
Although, the method described in the '443 patent may be used to produce high-quality dental prostheses, the method may still be less than optimal in some circumstances. For example, because the method of the '443 patent uses a generic base member, the completed implant abutment may not match well the contours of a specific patient's mouth. This may be particularly true when the implant abutment spans multiple tooth sites. An abutment that does not match the contours of the patient's mouth may be uncomfortable, unhygienic, and unreliable.
The disclosed system and method are directed to overcoming one or more of the problems set forth above and/or other problems of the prior art. In particular, the invention is directed towards a system according to claim 1, a method according to claim 8 and dental device according to claim 15. Advantageous embodiments are the subject of the dependent claims. They may be combined freely unless the context clearly indicates otherwise.
In one aspect, the present disclosure is directed to a system for manufacturing a dental device. The system may include a subtractive machine configured to manufacture a base of the dental device from a material blank, and an additive machine configured to manufacture a top of the dental device by adding material onto a surface of the base. The system may also include a controller in communication with the subtractive machine and the additive machine. The controller may be programmed to receive digital data corresponding to a mouth of a particular patient, and to control operation of the subtractive machine to customize the base based on the digital data.
In yet another aspect, the present disclosure is directed to a method for manufacturing a dental device. The method may include receiving digital data corresponding to a mouth of a particular patient and, based on the digital data, subtractively manufacturing from a material blank a base of the dental device. The method may also include additively manufacturing a top of the dental device on a surface of the base.
In particular, a system for manufacturing a dental device comprises:
a subtractive machine configured to manufacture a base of the dental device from a material blank;
an additive machine configured to manufacture a top of the dental device by adding material onto a surface of the base; and
a controller in communication with the subtractive machine and the additive machine, the controller being programmed to:
receive digital data corresponding to at least one of a mouth of a particular patient and the dental device; and
control operation of the subtractive machine to customize the base based on the digital data.
In an embodiment of the system the controller is further configured to control operation of the additive machine to customize the top based on the digital data.
In another embodiment of the system the controller is further configured to:
In another embodiment of the system the plane passes through multiple features of the dental device.
In another embodiment of the system:
the plane is a first plane; and
the controller is further configured to:
determine in the virtual model of the dental device a third location of at least one feature having geometry that can be fabricated by the subtractive machine;
determine in the virtual model of the dental device a fourth location of at least one feature having geometry that can be fabricated by the additive machine; and
determine in the virtual model a location of a second plane separating the third location from the fourth location, wherein the second plane forms a virtual boundary at least partially defining the base and the top.
In another embodiment of the system the first location corresponds with tight-tolerance and high-precision; and
the second location corresponds with complex freeform geometry.
In another embodiment of the system the dental device is one of a superstructure, a substructure used for mounting of the superstructure, and a template used to install the superstructure or substructure in a mouth of a particular patient.
In another embodiment of the system the subtractive machine is configured to manufacture a reference feature associated with the material blank for use in at least one of placing the base of the dental device inside the additive machine and detecting an orientation of the base of the dental device inside the additive machine.
In another embodiment of the system it further includes a transfer machine configured to transfer the base from the subtractive machine to the additive machine based on a location of the reference feature.
In another embodiment of the system the additive machine is configured to sinter the top from a powdered metal.
In another embodiment of the system select surfaces of the base correspond to one of an implant abutment face, a threaded bore, or a cusp surface.
In particular, a method for manufacturing a dental device comprises: receiving digital data corresponding to at least one of a mouth of a particular patient and the dental device; subtractively manufacturing from a material blank a base of the dental device based on the digital data; and additively manufacturing a top of the dental device on a surface of the base.
In an embodiment of the method, additively manufacturing the top of the dental device includes additively manufacturing the top based on the digital data.
In another embodiment the method further includes: determining in a virtual model of the dental device a first location of at least one feature having geometry that can be fabricated by subtractive manufacturing;
determining in the virtual model of the dental device a second location of at least one feature having geometry that can be fabricated by additive manufacturing; and
determining in the virtual model a location of a plane separating the first location from the second location, wherein the plane forms a virtual boundary at least partially defining the base and the top.
In another embodiment of the method the plane passes through multiple features of the dental device.
In another embodiment of the method the plane is a first plane and the method further includes:
determining in the virtual model of the dental device a third location of at least one feature having geometry that can be fabricated by subtractive manufacturing;
determining in the virtual model of the dental device a fourth location of at least one feature having geometry that can be fabricated by additive manufacturing; and
determining in the virtual model a location of a second plane separating the third location from the fourth location, wherein the second plane forms a virtual boundary at least partially defining the base and the top.
In another embodiment of the method the first location corresponds with tight-tolerance and high-precision; and the second location corresponds with complex freeform geometry.
In another embodiment of the method the dental device is one of a superstructure, a substructure used for mounting of the superstructure, and a template used to install the dental device in a mouth of a particular patient.
In another embodiment the method further includes subtractively manufacturing a reference feature associated with the material blank for use in placement of the base prior to additively manufacturing the top.
In another embodiment of the method additively manufacturing the top includes sintering the top from a powdered metal.
In another embodiment of the method select surfaces of the base correspond to one of an implant abutment face, a threaded bore, or a cusp surface.
The invention is also directed towards a dental device manufactured via a method according to the invention.
Machine 20 may embody any type of machine known in the art that is used to remove (i.e., “subtract”) material from select surfaces of material blank 27. In the disclosed exemplary embodiment, machine 20 is a general or specific-use milling machine having a computer-controlled rotary cutter 44 that is configured to cut away chips of material from surfaces of material blank 27. In particular, one or more actuators 46 may be connected to cutter 44 and configured to spin cutter 44 about its own axis while also advancing teeth (not shown) of cutter 44 into the surfaces of material blank 27 at desired locations. The relative spinning and/or translating between cutter 44 and material blank 27 may be precisely controlled (e.g., via controller 26) based on the digital data defining dental device 10, material blank 27, and/or cutter 44. It is contemplated that machine 20 could form a portion of a larger machining center, if desired, and have access to one or more automatic tool changers, tool carousels, coolant systems, debris collection, and/or enclosures. It is contemplated that another type of machine, for example a laser ablation or milling machine could also or alternatively be used to remove material from the surfaces of material blank 27, if desired.
In the disclosed exemplary embodiment, machine 20 includes a holder 48 configured to receive and secure material blank 27 during the material-removal process performed by cutter 44 and described above. In the disclosed example, a recess 50 is formed within holder 48 and designed to receive material blank 27 of a standard size, shape, and/or configuration. In the disclosed exemplary embodiment, recess 50 is shown as a generally cylindrical socket having a diameter and depth specifically associated with material blank 27 and/or the manufacture of dental devices 10. Recess 50 may be accessible to cutter 44 from one side or opposing sides, as desired. For example, holder 48 may have windows therein that allow cutter 44 to pass through and access material blank 27 over a large area and/or from a wide range of angles. Holder 48 may be movable to allow the desired access (e.g., holder 48 may be configured to flip over) and/or cutter 44 may be moved to the side(s) of material blank 27 requiring cutting, as desired. A flange 53, clamp, fastener, clip, or other similar device may be used to retain material blank 27 inside recess 50 of holder 48.
Machine 22 may take many different forms. In the disclosed exemplary embodiment, machine 22 is a sintering type of machine having a build chamber 30, a material chamber 32, a recoater 34, and an energy source 36. Recoater 34 may be configured to push powdered material from material chamber 32 into build chamber 30 (in a direction indicated by an arrow 38) and on top of base 28, and energy source 36 may be selectively activated to sinter (e.g., to melt) a pattern in the powder (e.g., by way of a laser beam 39) and thereby produce layers of solidified material on base 28 that form top 29. After each layer of material is solidified, a platform 40 in build chamber 30 (along with base 28 and any already fabricated layers of top 29) may be incrementally lowered; a platform 42 in material chamber 32 (along with the powdered material) may be incrementally raised; and recoater 34 may push a new layer of powdered material over the solidified layer for sintering of a new layer of top 29. It is contemplated that machine 22 could embody another type of additive machine (e.g., a vat photo-polymerization machine, a material jetting machine, a binder jetting machine, a material extrusion machine, a directed energy deposition machine, or another machine), if desired.
The placement of material blank 27 (or at least knowledge of the placement) inside of holder 48 may affect material removal from blank 27 and/or subsequent material additions to base 28. For example, cutter 44 of machine 20 may be guided by controller 26 based on known geometry of material blank 27 and also based on a known or assumed relative location between cutter 44 and material blank 27. For this reason, machine 20 may be equipped with a way to locate and/or detect the location of material blank 27 during and/or after placement within recess 50. This may include, for example, one or more reference features 54 formed in material blank 27 and/or holder 48 (e.g., within and/or around recess 50) that are configured to engage material blank 27 in a particular manner so as to precisely locate and/or orient material blank 27. Alternatively or additionally, a scanner, imaging device, and/or measurement probe (not shown) may be used by machine 20 to detect the location of feature(s) 54 and/or material blank 27 after placement within holder 48. In one example, reference feature 54 is a cylindrical depression or hole formed at a center of material blank 27. Reference feature(s) 54 may be prefabricated within material blank 27 or machined into material blank 27 by machine 20 during manufacture of base 28. It is contemplated that feature(s) 54 may be used in one or both of machines 20, 22 to properly position, orient, machine, and/or build up layers of dental devices 10. Other methods may also be used, if desired.
In the disclosed exemplary embodiment of
Controller 26 may embody a single processor or multiple processors that include a means for controlling an operation of system 12. Numerous commercially available processors may perform the functions of controller 26. Controller 26 may include or be associated with a memory for storing data such as, for example, the digital data associated with dental device 10 and/or blank 27, operating conditions of machines 20-24, design limits, performance characteristics or specifications, operational instructions, etc. Various other known circuits may be associated with controller 26, including power supply circuitry, signal-conditioning circuitry, solenoid driver circuitry, communication circuitry, and other appropriate circuitry. Moreover, controller 26 may be capable of communicating with other components of system 12 (e.g., with each of machines 20-24) via either wired or wireless transmission and, as such, controller 26 could be connected directly to machines 20-24 or alternatively disposed in a location remote from machines 20-24 and indirectly connected (e.g., wirelessly).
In some exemplary embodiments, controller 26 may rely on sensory information when regulating operations of machines 20-24. This sensory information may include, for example, a detected location and/or orientation of material blank 27 within recess 50 of work holder 48, a detected location and/or orientation of base 28 within build chamber 30, and a tracked location and/or orientation of transfer machine 24 (e.g., a grasping hand of machine 24). The sensory information may be provided by way of one or more sensors 52, for example a proximity sensor, an actuator sensor, a measurement probe, a camera, etc. Signals generated by sensor(s) 52 may be directed to controller 26 for processing.
As described above and shown in the exemplary embodiment of
Base 28 and top 29 may be fabricated by different machines and/or processes due to the specific tolerances and geometric requirements of each of these components. For example, base 28 may include features intended to engage other devices or existing dentistry in the patient's mouth and, therefore, requires tighter tolerances and/or finer surface finishes that are best achieved by machine 20. These features may include, for example, abutment faces, threaded bores, and/or cusp surfaces (not shown). Abutment faces may mate tightly against faces of corresponding implants and, accordingly, accurate contours at these faces may be required for proper engagement. Threaded bores may receive screws or other fasteners that are used to anchor dental devices within the patient's mouth. Accordingly, proper alignment of the bores and crisp threading may be required to ensure a desired placement in relation to existing contours surrounding dental devices 10. The cusp surfaces may need to be accurate in order to ensure that damage to dental devices 10 and/or the surrounding dentistry does not occur during use. Top 29 may be additively manufactured by machine 22 to create complex geometries not otherwise possible via traditional subtractive processes and/or rougher surfaces that can improve bonding with cosmetic veneers or other similar outer covers. The complex geometries can include, for example, curving passages and imbedded fasteners.
A virtual model of dental device 10 may be created for a particular patient (e.g., based on the digital data described above), and then divided into base 28 and top 29 along at least one plane 56. In the embodiment of
Dividing the virtual model of dental device 10 into base 28 and top 29 may allow use of a thinner material blank 27, as compared to subtractively producing the entirety of dental device 10. This may reduce the amount of material to be subtractively removed, saving manufacturing time and reducing waste. Such waste may not be recyclable in all cases, leading to increased cost of a fully subtractively manufactured dental device 10.
In an alternative embodiment shown in
In some embodiments, during subtractive manufacturing, machine 20 may co-form a support structure with base 28 from material blank 27. The support structure may include, for example, an outer frame 60 (shown only in
It is contemplated that a single dental device 10 or multiple dental devices 10 may be fabricated inside a single outer frame 60. For example, multiple dental devices 10 may be nested inside each other and inside of outer frame 60. By fabricating multiple dental devices 10 inside the same outer frame 60, greater efficiencies may be achieved. In some exemplary embodiments, the particular dental devices 10 formed within the same outer frame 60 may correspond with the same patient and/or the same surgical procedure. For example, a kit may be created by co-forming one or more superstructures 14, substructures 16, and/or templates 18 (referring to
The disclosed system and method may be used to manufacture a wide range of well-fitting dental devices in an accurate manner. The dental devices manufactured by the disclosed system may conform well to a patient's mouth because most (if not all) parts of each dental device are customized for each patient. Accuracy may be achieved through the combined use of subtractive and additive manufacturing processes, such that areas of high-precision and also areas of high-complexity can be produced within required tolerances. Operation of system 12 will now be described in detail.
At a start of a manufacturing event, digital data regarding a dental device 10 to be produced may be electronically loaded into controller 26 (referring to
Once machining of base 28 has been completed, any chip material around base 28 may be removed (e.g., brushed away, vacuumed up, etc.). Transfer machine 24 may then transport base 28 from machine 20 to machine 22, and place base 28 in a desired location inside of build chamber 30. In some exemplary embodiments, base 28 may need to be oriented in a particular way before sintering can begin. This may include, for example, aligning particular reference features 54 of base 28 (and/or holder 48) with corresponding features in build chamber 30. In another example, base 28 may be loaded into build chamber 30 in any desired manner, but the resulting location and/or orientation may need to be detected thereafter.
The digital data described above may then be used to control operation of build chamber 30, material chamber 32, recoater 34, and energy source 36. For example, platform 40 may be lowered in an amount corresponding to a desired thickness of a first layer of top 29 on base 28. At about the same time, platform 42 may be raised by at least this same thickness. Thereafter, recoater 34 may be driven by associated actuator(s) to push material protruding from material chamber 32 above a lower edge of the corresponding recoater into build chamber 30 and on top of base 28. The material may be spread across platform 40 in a relatively consistent and well-distributed manner. Thereafter, energy source 36 may be activated to sinter the powdered material in a pattern corresponding to the size, shape, and/or contour of top 29 at the particular height above platform 40. Platform 40 may then be lowered by a thickness of a second layer of top 29, and the process may be repeated. It should be noted that, in some embodiments (e.g., embodiments, where plane 56 passes through only a single feature of dental device 10 and is surrounded by other taller features), a different method of additive manufacturing (e.g., vat photo-polymerization, material jetting, binder jetting, material extruding, or directed energy depositing) may be required. Once all layers of top 29 have solidified, any powdered material around dental device 10 may be removed (e.g., brushed away, vacuumed up, etc.). Dental device 10 may thereafter be installed within the corresponding patient's mouth. In some embodiments, outer frame 60 and/or the associated connectors may first need to be cut away from dental device 10 prior to installation.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed system and method. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed system and method. For example, when referring the “mouth” of a particular patient, such reference is intended to encompass only part (e.g., only soft tissue, only hard tissue, a particular combination of soft and hard tissues, etc.) or all of the mouth. It is intended that the specification and examples be considered as exemplary only.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2018/056534 | 3/15/2018 | WO | 00 |
Number | Date | Country | |
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62473794 | Mar 2017 | US |