CROSS-REFERENCE TO RELATED APPLICATIONS

66,821,238May, 2013Schuler, et al.14,272,566May, 2014Schulter, et al

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC

Not Applicable

DESCRIPTION

Field of the Invention

Dental prosthetics having individual crowns placed on top of a framework is becoming more popular due to improved aesthetics of individual crowns and the ability to replace and repair an individual crown when chipped, broken, or otherwise damaged as opposed to having to replace or repair the entire prosthesis as a unit. However, the process for the development of the framework has several challenges, namely that it only utilizes a portion of the spatial dimensions of a patient's mouth, it requires technicians to purchase copings and screws to generate, and is extremely time intensive. A need exists for a method in which one can easily and readily identify the correct position and orientation of the crown copings and minimize the trial and error process and rework currently needed to produce an individual crown dental prosthetic.

Background of the Invention

This application is a divisional of U.S. patent application Ser. No. 14/272,566 filed May 8, 2014, which is a conversion from an original Provisional Patent Application No. 66/821,238 filed May 9, 2013. The benefit of the earlier filing dates of the aforementioned U.S. patent application Ser. No. 14/272,566 and Provisional Patent Application No. 66/821,238 are hereby claimed.

Current individual crown prosthetics are fabricated by a process, herein referred to as the “copymill” process, where an acrylic pattern of the framework is first fabricated, then duplicated in titanium or another material. This process has several challenges, namely that it only utilizes a portion of the spatial dimensions of a patient's mouth, it requires technicians to purchase copings and screws to generate, and is extremely time intensive.

The current “copymill” process will begin in very much the same way that a traditional cast framework is created. The dentist or technician will create a stone cast and diagnostic wax up from the impression and clinical measurements taken at the time of the impression. Implant analogs will be included in the stone cast providing replicas of the implant and/or abutment mating geometries found in the patient's mouth. The diagnostic wax up will provide the appropriate position of the denture teeth that will be incorporated into the design of the final prosthesis. Once the denture teeth positions have been deemed acceptable by the patient and doctor, the technician will create a facial index of the denture tooth set up. Utilizing this facial index as a guide, the technician will attach a series of copings to the implant analogs and utilizing either wax or an acrylic material begin fashioning by hand the design of the framework to support the individual crowns. The technician is somewhat limited in designing the individual crown framework as he/she only has the facial boundary of the diagnostic wax up to utilize as a guide. The technician will be extremely limited in being able to visualize the correct position of the framework in the occlusal and lingual dimensions for the case. There will also be limits in determining the position of the margins where each individual crown will mate with the framework. This process requires a highly skilled technician who will have to utilize his/her experience and talent in order to appropriately fashion an acceptable design.

Once the wax/acrylic pattern of the individual crown framework has been generated, the technician can choose to either cast the framework or submit the wax/acrylic pattern to a milling company who will duplicate the design by milling the structure out of a single piece of titanium. This duplication milling process is commonly termed “copymill”.

The casting technology traditionally used in fabricating the framework is fraught with errors and usually results in the framework having to be cut and soldered in order to properly mate with the implants in the patient's mouth. This cutting and soldering process results in additional visits for the patient and weakens the overall strength and integrity of the framework.

The copymill process provides improvements to the fit of the individual crown framework to the implants in the patient's mouth, but there are limits associated with tool access in cutting many of the finer geometries the dental technician incorporated in the design of the framework. During the manufacturing process of the copymill individual crown framework, there will be radiuses, tool marks, and additional material left over due to the limits of the tool diameter or tool access. These radiuses, tool marks, and additional material will have to be removed by hand by the technician. This issue of excess material is especially problematic in dealing with the margins where the individual crowns will mate to the framework. Refining the milled framework is once again an extremely time intensive task requiring a highly trained technician.

Once the framework has been checked for fit, refined, and deemed acceptable by both the doctor and technician, the individual crowns can be fabricated. An impression of the framework on the stone cast is taken and a new stone cast of the framework is made. The stone cast of the framework is pinned, based, and sectioned to allow for each of the individual support posts and margins that will support the crowns to be scanned. The technician will refine the margin for each individual support post by hand and provide a clear delineation which can be captured by the scanner. Once all of the margins have been refined, the technician will scan the stone cast of the framework with all of the individual support posts appropriately placed along with the opposing arch. The technician will then scan each individual support post separately and define the location of the margin. From this point, the technician can begin designing each individual crown on the basis of the opposing dentition. Once all of the crowns have been designed, the technician can load the design file into a milling machine where they can be fabricated from several different materials (i.e. Zirconia, Wax, Titanium, etc. . . . ). The technician can also use a number of other manufacturing processes in addition to milling, such as 3D Printing, Laser Sintering, Ceramic Pressing, Casting or EDM.

The manufactured crowns are then assessed for their fit against the copymill individual crown framework. Sometimes slight modifications/adjustments will have to be made to ensure the crown has the appropriate passive fit relative to the margin. The crowns are also checked for appropriate occlusion against the opposing arch. At this point, the technician or dentist may choose to perform a framework try in, where the framework and crowns are placed on the implants in the patient's mouth and the design is reviewed by the dentist and patient. Depending upon any critiques from the patient, the technician may need to adjust portions of the framework or crowns to accommodate these aesthetic demands.

Finally, the framework and crowns can be finished with applying the appropriate acrylic or porcelain materials for the pink gingiva and the crowns can be stained glazed or have porcelain added to provide the appropriate aesthetic finish.

One can appreciate the time, skill, and potential rework associated with this process in order to achieve an acceptable framework with crowns that meet the clinical needs of the dentist and aesthetic demands of the patient. A need exists for a method in which one can easily and readily identify the correct position and orientation of the crown copings and minimize the trial and error process and rework currently needed to produce an individual crown dental prosthetic.

In U.S. Provisional Patent Application 66,821,238 Schulter et al. claims an “Individual Crown Dental Framework Method and Prosthesis,” for which this application claims the benefit.

In U.S. Pat. No. 8,100,692 Diagenlo, et al., teaches a dental framework that is attached to dental anchors, such as dental implants which are secured to the patient's mandible or maxilla, where the framework may be fabricated based on the dimensions and surface contours of a stone cast and diagnostic wax up created from an impression of the patient's mouth.

In U.S. patent application Ser. No. 11/876,450 Karlsson teaches of the utilization of a dental scanning unit commonly found in the market place.

SUMMARY OF THE INVENTION

In accordance with the first embodiment of the invention, a dental prosthesis is disclosed consisting of a dental implant framework and series of crowns that are intended to mate with a series of implants and abutments in a patient's mouth and reestablish the patient's loss dentition. The crowns are a part of an assembly consisting of a crown and support post and consist of known dimensions. The support post possesses a margin where the crown will ultimately mate. These assemblies are aligned in a proper orientation to replace the patient's missing dentition and are easily editable to provide flexibility at the time of design in meeting any clinical or aesthetic demands of the patient. Bridging structures are used in connecting the support posts and the fittings that will mate with the implants and abutments. The combination of bridging structures, support posts, and fittings will provide the completed design of the dental implant framework. The crowns can be combined together into a bridge and even have gingiva contours added per the discretion of the operator. As the dimensions of the crown and support post assemblies are known, the dental implant framework and crowns (bridges, if preferable) can be designed and manufactured simultaneously.

In accordance with a second embodiment of the invention, a method for designing a dental implant framework and series of crowns is provided. Through the use of digital data the location and orientation of the proposed position of the crowns is determined. A second set of digital data is used in identifying the location of the implants and abutments in the patient's mouth. On the basis of these digital data sets fittings and crown/support post assemblies are aligned appropriately and provide the basis for designing the dental implant framework and crowns for the dental prosthesis. The design of the crowns and dental implant framework are conducted simultaneously and the resulting CAD models are used in fabricating the crowns and dental implant framework out of the preferred material and manufacturing methodology. Gingival contours can be applied to the dental implant framework and crowns by means of acrylic, composite, porcelain, or another preferred material being processed to the dental implant framework and crowns. The gingival contours can also be incorporated into the design of the dental implant framework and crowns and manufactured at the same time as the dental implant framework and crowns.

In accordance with the third embodiment of the invention, a CAD library of crowns and support posts is disclosed. This CAD library and crowns is used in the design process in fabricating a dental implant framework and series of crowns for a dental prosthesis. The crowns and support posts of the CAD library can be based on the dimensions of the teeth that they are intended to be replaced. They can also be based on denture teeth that are commonly available in the market place or on the basis of crown and tooth libraries commonly found in many of the design software systems available in the market. The crown and support post models are completely parametric and dependent upon one another, where edits can be easily made to these models per the clinical aesthetic demands of the patient and changes in features of one will result in automatic updating of the second dependent body. This crown and support post CAD library provides one with a rapid design process for the fabrication of a dental implant framework and crowns for a dental prosthesis.

