Patent Application
20120214133
This is related to U.S. patent application Ser. No. 12/431,543, filed Apr. 28, 2009; and U.S. patent application Ser. No. 12/431,568, filed Apr. 28, 2009; which are herein incorporated by reference in their entirety.
1. Field of the Invention
The present invention relates generally to a method and a device for milling custom designed dental implant abutments.
2. Related Art
Computer Aided Design and Computer Aided Manufacturing (CAD/CAM) technology has had a big impact on the dental laboratory industry. Dental professionals can use these systems for designing a product and for controlling the manufacturing process. For example, once a dental prosthesis design has been produced with dental CAD software, CAM software controls the machines that construct the final product. The input information regarding the design of the dental prosthesis can either be created directly from the dentist's office based on a patient's intra oral image or can be created in dental laboratories based on a stone model image (or a milled or 3D printed model) which is reproduced by pouring into a dental impression or based directly on the dental impression.
So far, various CAD/CAM systems have been able to make frameworks and/or full contoured dental prosthesis for single crowns, bridges, inlays and onlays as well as custom implant abutments, and temporaries. These various CAD/CAM systems mill materials such as aluminous oxide, zirconium oxide, lithium disilicate glass ceramic, titanium, resin, feldspathic porcelain-based glass ceramics or resin-based composite blocks.
One example of a CAD/CAM made framework and/or a full contoured dental prosthesis in the dental laboratory includes making precise die models and articulated models using conventional modeling techniques which are then photographed with 3 dimensional dental optical scanners. The model is scanned in different positions and the scans are then used to calculate 3D image data. The bite record and tissue areas are also scanned. The data is processed to generate a precise 3D digital representation of the patient's mouth and/or teeth with an average marginal gap of 30 microns or under. Once all the data is calculated and the necessary 3D design of the prosthesis is done by a dental technician, it is transferred to a dental CNC milling machine.
Typical dental CNC milling machines are three dimensional mills that move a rotary cutter through an x, y, z axis envelope. A porcelain based raw material blank can be installed in a chuck or fixture within the envelope and the mill head can be moved around the blank to cut and form the blank into a desired shape. The desired shape is usually programmed into the CNC milling machine controller via a CAM based software program.
In certain situations, a patient's mouth may lack structure to support a dental prosthesis, such as a crown. In such situations, a dental implant can be secured in a hole drilled into the bone in the patient's mouth. An implant abutment is disposed on the dental implant. A coping or crown can then be affixed to the implant abutment. In the case where a coping is secured to the implant abutment, the crown can be secured to the coping. The implant and the implant abutment can be formed of titanium while the coping and crown can be formed of ceramic. A hybrid abutment can be formed of two pieces, namely a bottom of titanium and a top of ceramic.
Some implant abutments, known as stock abutments, can be factory premade. Premade implant abutments have limited ability for modification, namely manual hand grinding to reduce size to make an ideal shape tailored to each patient. Many cases, therefore, require a custom implant abutment. The custom milling of a custom titanium implant abutment can be a difficult and/or expensive proposition since the interface geometry of an implant abutment is of comparatively high precision and must be manufactured within a strict tolerance. Only a high precision, industrial machine can meet the challenge of milling the entire portion of a titanium custom implant abutment composed of the interface geometry, body portion and central hole.
There has not been a method or device that would facilitate the precision milling of customized titanium implant abutments within a simplified manufacturing process that can be carried out in the typical dental laboratory or dental office. It has been recognized that it would be advantageous to develop a device, system and/or method for custom milling an implant abutment. In addition, it has been recognized that it would be advantageous to develop a device, system and/or method for milling an implant abutment and a dental prosthetic, such as a crown or coping, on the same milling machine.
The invention provides a method for fabricating a custom implant abutment, the method comprising:
In addition, the invention provides a method for fabricating a custom implant abutment, the method comprising:
In addition, the invention provides an implant abutment connector device for securing a partial blank, having a prefabricated implant abutment interface geometry of an implant abutment, to a fixture of a milling machine. The implant abutment connector has a base end removably affixable directly to the fixture or affixable directly to a jig coupled to the fixture. The implant abutment connector has an attachment end having an implant interface geometry matable with the prefabricated implant abutment interface geometry of the partial blank. The implant abutment connector has a threaded bore capable of receiving a fastener through a bore of the partial blank and engaging the threaded bore to secure the partial blank to the attachment end of the implant abutment connector.
Furthermore, the invention provides an implant abutment connector in combination with a partial blank configured to be secured to a fixture of a milling machine. The partial blank comprises a prefabricated implant abutment interface geometry of an implant abutment and a bore therethrough. The implant abutment connector comprises a base end removably affixable directly to the fixture of the milling machine or affixable directly to a jig coupled to the fixture of the milling machine. The connector also comprises an attachment end having an implant interface geometry mated with the prefabricated implant abutment interface geometry of the partial blank. The connector further comprises a threaded bore with a fastener through the bore of the partial blank and engaging the threaded bore to secure the partial blank to the attachment end of the implant abutment connector.
Thus, the current invention solves the above identified challenge by providing a partially milled titanium blank, having a pre-fabricated implant abutment interface geometry to be used to make a custom implant abutment. This type of abutment also has a better fit than conventional custom abutments since the titanium mating surface was manufactured to fit very tightly. Well made dental implants have a very tight connection between the implant and the implant abutment. This can be very important for the long-term maintenance of the bone around the implant.
End users can simply secure this pre-fabricated blank to the holder and mill the custom created body portion of the implant abutment. Therefore, with this device and method it is possible to attain high precision accuracy as well as a shortened fabricated time.
Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention; and, wherein:
a is an exploded perspective view of the implant abutment connector and the partial blank of
b is an exploded perspective view of the implant abutment connector and the partial blank of
a is an exploded perspective view of the implant abutment connector and the implant abutment of
b is an exploded perspective view of the implant abutment connector and the implant abutment of
a-c are side schematic views of the partial blank with respect to the milling tool of
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.
The term “implant” is used herein to refer to all types of dental implants that are affixed in a patient's mount, often to the bone of the jaw. Such implants can provide a structure to which an implant abutment is affixed via an interface geometry.
The term “implant abutment” is used herein to refer to all types of implant abutment structures affixed to the implant and between the implant and a crown or coping. The implant abutment can be a single, monolithic structure, or can be formed by more than one piece. The implant abutment has an interface geometry that matches and/or mates with the interface geometry of the implant.
The term “partial blank” is used herein to refer to a blank of material from which an implant abutment will be milled, machined or fabricated; but which has a prefabricated implant abutment interface geometry that mates with the implant, and a millable blank portion which will be formed into a body of the implant abutment.
The term “coping” is used herein to refer to a substructure disposed on the implant abutment between the implant abutment and the crown.
The term “crown” is used broadly and interchangeably herein to refer to crowns, bridges, copings, etc.
The coping and crown are sometimes referred to as a superstructure or suprastructure.
The present invention provides a system and method for custom milling or fabricating custom implant abutments using an implant abutment connector to secure a partial blank with respect to a milling tool of a CNC milling machine. The implant abutment connector can have an implant interface geometry of an implant; and can be a pseudo implant or can mimic the implant or interface thereof that receives the implant abutment. The partial blank can have a prefabricated implant abutment interface geometry of the implant abutment; and can thus mate with the implant, and the implant interface geometry of the implant abutment connector. Therefore, the prefabricated implant abutment interface geometry of the partial blank is prefabricated to mate with the implant; while the implant abutment connector uses this same interface geometry to mate with the partial blank to secure and hold the partial blank for milling or fabrication.
The system and method of the present invention, and the implant abutment connector, can allow the partial blank to be milled in the same space or envelope of a CNC milling machine as dental blanks being milled to form crowns and/or copings. Thus, the present invention provides a system and method for milling, or alternately milling, both implant abutments and dental blanks in the same space or envelope of the CNC milling machine. The implant abutment connector can be affixed to either: 1) a primary fixture held by the CNC milling machine (such as in a cavity configured to hold a millable dental blank); 2) a jig held by the primary fixture (such as in the cavity configured to hold the millable dental blank), or 3) a secondary fixture that replaces the primary fixture in the CNC milling machine.
As illustrated in
In accordance with one aspect of the present invention, the CNC milling machine 22 can include a primary fixture 38. The primary fixture 38 can be a plate and can have opposite ends to be held in opposite chucks of the milling machine. The milling machine 22 and/or the primary fixture 38 can be configured for or adapted to receiving and holding a millable dental blank (not shown), such as a solid disc of constant material, such as zirconium dioxide, zirconium oxide ceramic, titanium, titanium alloy, acrylic polymer, plastic, wax, etc. The disc can be relatively large, such as 10 cm in diameter, and capable of having several crowns, bridges, copings, etc. milled therein. Thus, the primary fixture 38 can have a round or circular receptacle or cavity 42 therein to receive the disc. The receptacle or cavity can have a lower annular lip against which the large blanks or discs are received. A retaining ring can be secured over the opening or cavity to retain the large blank or disc. The primary fixture can remain in the milling machine while the retaining ring and larger blank or disc are removed and replaced. The milling machine can include one or more chucks or the like for securely holding the primary fixture 38, and one or more cutting or milling tools 46 tools to mill the disc or implant abutment. Thus, the larger millable dental blank received in the primary fixture 38 of the milling machine 22 can be capable of being machined to form a plurality of crowns, bridges, copings, etc.
In addition, an interchangeable jig 50 can be received in the cavity 42 of the primary fixture 38, and held by or carried by the primary fixture 38. The jig 50 can be wholly or partially sized and shaped as the larger millable dental blank so that it is interchangeable with the larger blank in the primary fixture 38. For example, the jig can be round to fit in the round or circular receptacle or cavity 42 of the primary fixture 38. The jig can be annular with a body that fits in the receptacle or cavity 42 of the primary fixture, and an annular flange on one end of the body that can abut to the plate of the primary fixture. The flange can have holes to receive fasteners to secure the jig to the primary fixture. The annular body of the jig can define an open center between an inner lateral face. The jig can be metal and can be formed by machining.
One or more implant abutment connector(s) 54 can be carried by the primary fixture 38. The implant abutment connector 54 can be removably affixed directly to the primary fixture 38, as shown in
Referring to
The implant abutment connector 54 in turn can carry and secure a partial blank 106 to the jig 50 and/or fixture 38 with respect to the milling tool 46 of the milling machine 22. The partial blank 106 (
Referring to
Securing the implant abutment connectors 54 to the jig 50 or the primary fixture 38 allows the primary fixture 38 to be used to secure both partial blanks 106 for fabricating custom implant abutments 18, and dental blanks for fabricating crowns 34 or copings. In addition, the same milling machine 22 can be used to fabricate both implant abutments 18 and crowns 34 or copings.
A method of using the above described system and the implant abutment connector 54 to fabricate a custom implant abutment 18 can include securing the implant abutment connector 54 with respect to the milling machine 22 and/or milling tool 46 thereof; or obtaining an implant abutment connector 54 secured with respect to the milling machine. As described above, the implant abutment connector 54 can be secured with respect to the milling machine 22 by affixing the connector directly to the primary fixture 38b (
The partial blank 106 is secured to the implant abutment connector 54 by mating the implant abutment interface geometry 110 (
An electronic model of at least a portion of a patient's mouth, including an implant, can be obtained. For example, the patient's mouth can be electronically scanned at a dental office. The dentist or oral surgeon can implant the implant 30 prior to scanning the patient's mouth. Alternatively, an impression can be made at the dental office from which a physical dental model can be made and then electronically scanned. A representation of the implant can be inserted in the physical model prior to scanning the physical model. An electronic model 132 of a body 136 of the implant abutment 18 can be created, as shown at 140 in
The millable blank portion 124 of the partial blank 106 can be milled based on the electronic model 132 to form the body 136 of the implant abutment 18, as shown at 144 in
Another or a subsequent electronic model of at least a portion of the patient's mouth, including the implant, can be obtained. For example, the patient's mouth can be electronically scanned at a dental office. Afterwords, the implant abutment can be secured to the physical dental model and then the physical model with the implant abutment can be scanned. An electronic model 164 of a crown 34 or coping can be created, as shown at 168 in
A dental blank can be milled based on the electronic model 164 to form the crown 34 or coping. For example, the electronic model can be imported to the CNC milling machine. The same milling machine that was used to mill the implant abutment can be used to mill the crown or coping. Thus, the implant abutment connector and the dental blank can be interchanged. The jig 50 can be removed from the primary fixture 38, or the implant abutment connector 54 can be removed from the primary fixture 38b, or the secondary fixture can be removed from the milling machine and replaced with the primary fixture. A dental blank can be secured with respect to the milling machine, such as secured in the cavity of the primary fixture. The dental blank can be milled with the milling tool of the milling machine based on the electronic model of the crown or coping.
While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.
