Patent Application
20180263739
The present invention relates generally to the field of restorative implant dentistry, and more particularly to apparatus, systems and methods of production and use of a dental model including one or more integral dental implant analogs, and further to enhanced thread engagement and retention within a dental implant analog.
Dental implants are commonly used in restorative dentistry to affix a dental prosthesis to the jaw of a human or animal patient. Typically, a dental practitioner installs an externally threaded implant into an aperture formed in the bone of the patient's jaw, to which an artificial tooth, crown, or other dental prosthesis will be attached. After placement of the implant, the surrounding bone tissue is allowed to heal and an abutment mount upon which the dental prosthesis is fabricated is secured to the implant. Typically, an abutment screw is used to attach the prosthesis to the implant via an anchoring bore through the abutment and into an internally threaded bore in the implant. Optionally, a temporary crown or healing abutment may be attached to the implant during healing and fabrication of a permanent prosthesis.
A physical model of the patient's intraoral cavity may be utilized to facilitate design and manufacture of the dental prosthesis to be mounted to the implant. Traditionally, the model was produced by impression molding using a dental impression tray and impression material to cast a replica of the patient's intraoral structure (an “analog” process of producing a model). More recently, models have been made using an electronic intraoral scanner to generate a digital model, from which a physical model can be created by 3D printing, CNC milling, or other computer aided manufacture technique (a “digital” process of producing a model). The models or casts are typically formed from dental plaster or gypsum stone, acrylic, or polymeric resins, and may be of a full or partial dental arch of one or both of the patient's upper and lower jaw dentition.
The location and orientation of a dental implant that has been placed in the patient's jaw is transferred to the physical dental model by use of an impression coping engaged in the implant (using an analog modeling process), or by a scan body engaged in the implant (using a digital modeling process). Traditionally, an implant replica or analog of the actual implant is then placed into the physical model in the indicated location and orientation. The practitioner (or a lab technician at the direction of the practitioner) then uses the physical model with the implant analog placed therein to design and manufacture an abutment and crown prosthesis configured to be engaged with the implant and fit the patient's surrounding dentition and bite. Once the prosthesis has been fit and tested on the model and its implant analog, the practitioner will fit, adjust and install the prosthesis to the actual implant within the patient's mouth.
Precise and accurate placement of the implant analog within the dental model can be difficult, however, due to a variety of reasons, including manufacturing tolerances, and/or errors or inconsistencies at any stage of the process. Inaccuracies in placement of the implant analog within the dental model can result in improper fit of the prosthesis to the patient, and/or additional “chair time” for the patient while the dental practitioner adjusts and fits the prosthesis. Also, for unitary models, the materials from which the physical dental model and/or the implant analog are constructed may lack sufficient thread-holding strength to withstand more than light engagement of the abutment screw when mounting the abutment and prosthesis to the implant analog when fitting and adjusting the prosthesis to the model during manufacture. Over-tightening of the abutment screw may strip threads or otherwise damage the model or the implant analog, detach the implant analog from the model, or improperly alter the position of the implant analog within the model; whereas under-tightening may position the prosthesis differently on the model than when installed in the patient's mouth, resulting in a less accurate and precise fit.
Accordingly, it can be seen that needs exist for improved apparatus, systems and methods of production and use of a dental model including one or more dental implant analogs, and further to enhanced thread engagement and retention with a dental implant analog and dental model. It is to the provision of improved apparatus, systems and methods meeting these and other needs that the present invention is primarily directed.
In example embodiments, the present invention provides improved apparatus, systems and methods of production and use of a dental model including one or more dental implant analogs (an analog or model of an actual dental implant), and further to enhanced thread engagement and retention with a dental implant analog and dental model. In example forms, the invention provides a physical dental model having an integral implant analog directly formed as a unitary and monolithic part of the model, and corresponding directly or in a functionally analogous manner to the position and geometry of the actual dental implant that has been placed in the patient. In this manner, tolerances between parts and/or inaccuracies in installation of a separate implant analog into a dental model are substantially reduced or eliminated, resulting in more precise modeling, manufacture and fit of a dental prosthesis. In further example forms, a thread-retention portion or body formed of metal or other high-strength material is embedded in the physical dental model in alignment with the implant analog, to allow tighter engagement of the abutment screw to more closely match actual placement conditions of the prosthesis into the patient's mouth, and eliminate or substantially reduce stripping threads or otherwise damaging the model and/or implant analog during manufacture and fitting of the prosthesis using the model.
In one aspect, the present invention relates to a dental model. The dental model preferably includes an implant analog and modeled dentition surrounding the implant analog. The implant analog models an actual dental implant in the mouth of a patient and the modeled dentition models actual dentition surrounding the actual dental implant in the mouth of the patient. The implant analog and modeled dentition preferably comprise an integrally formed monolithic body.
In another aspect, the invention relates to a system for dental modeling and delivery of a dental prosthesis to a patient. The system preferably includes a dental implant for implantation in the mouth of the patient, a dental prosthesis comprising an abutment mount configured for cooperative engagement with the dental implant, and an abutment screw configured for engagement through the abutment mount and into engagement with the dental implant to retain the dental prosthesis in place on the dental implant. The system preferably also includes a dental model comprising an implant analog and modeled dentition surrounding the implant analog. The implant analog models the dental implant and the modeled dentition models actual dentition in the mouth of the patient. The implant analog and modeled dentition preferably comprise an integrally formed monolithic body.
In still another aspect, the invention relates to a method of dental modeling for installation of a dental prosthesis in a patient's mouth. The method preferably includes the steps of providing a dental implant for placement at an implant site in the patient's mouth adjacent to surrounding dentition; generating a digital dental model by scanning the implant site and the surrounding dentition, wherein the digital model comprises data corresponding to at least one characteristic of the dental implant; fabricating a physical dental model based on the digital dental model, the physical dental model comprising at least one implant analog modeling the dental implant and modeled dentition modeling the surrounding dentition, wherein the implant analog and modeled dentition comprise an integrally formed monolithic body; preparing a dental prosthesis using the physical dental model; and affixing the dental prosthesis to the dental implant in the patient's mouth.
These and other aspects, features and advantages of the invention will be understood with reference to the drawing figures and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawings and detailed description of example embodiments are explanatory of example embodiments of the invention, and are not restrictive of the invention, as claimed.
The present invention may be understood more readily by reference to the following detailed description of example embodiments taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention. Any and all patents and other publications identified in this specification are incorporated by reference as though fully set forth herein.
Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment.
With reference now to the drawing figures, wherein like reference numbers represent corresponding parts throughout the several views,
The implant analog 20 of the model 10 comprises a generally cylindrical external geometry 22, and an internal hexagonal recess 24 extending from the top of the analog down through the material of the model and into communication with a lower recess 26 formed into the bottom surface of the model. The top rim of the implant analog defines a generally flat annular abutment contact surface 28, optionally having a small recessed relief portion surrounding the hexagonal recess. In alternate embodiments, the internal recess of the implant analog may be functionally analogous to a hexagonal recess, but defining a square, triangular, or other polygonal or otherwise shaped female recess configuration compatible with a hexagonal or otherwise configured male engagement profile of a corresponding dental prosthesis abutment mount, as described in greater detail below with reference to
In example embodiments, the dental model 10 is produced using a digital modeling process wherein a dental practitioner uses an intraoral optical or computed tomography (CT) scanner to create a three-dimensional digital model of the patient's dentition, including the location, configuration, and orientation of one or more dental implants placed in the patient's jaw, and surrounding teeth and gum tissue. Optionally, a digital scan body may be temporarily installed in the implant in the patient's mouth during the scan to facilitate precise capture of the location and orientation of the implant relative to the patient's surrounding dentition in the three-dimensional digital model. In alternate embodiments, the dental model 10 may be produced using an analog modeling process, for example using impression material within an impression tray, pressed over the patient's dentition, and cured and removed to form a mold. In example embodiments, the internal geometry of the actual physical dental implant in the patient's mouth, including the hexagonal recess for engagement of a dental prosthesis abutment mount, is directly reproduced in the digital model by importing or building a set of digital files corresponding to one or more dental implant geometries into a dental design software system (such as for example the 3Shape Dental System of 3Shape A/S of Copenhagen Denmark).
The physical dental model 10 may then be fabricated from the three-dimensional digital model generated by the scan, for example by 3D printing, CNC milling, or other computer aided manufacturing (CAM) digital fabrication process. Alternatively, in an analog fabrication process, the impression mold may be used to cast the physical model from dental modeling plaster, gypsum stone or resin. The dental implant analog 20 is a modeled representation of an actual dental implant that has been implanted in the patient's mouth, and the model 10 further comprises one or more modeled teeth, gum tissue, and/or other modeled features accurately representing the size, shape, location and orientation of corresponding actual features in the patient's mouth. The implant analog 20 is preferably fabricated as a unitary integral part of the model 10 in a monolithic body, for example by a continuous 3D printing process, or by milling the model including the implant analog(s) from a single workpiece of material. By directly forming the physical dental model 10 (including the implant analog portion 20 and its internal geometry) as a monolithic body from the digital model generated from the scan of the patient's dentition, positional inaccuracies and tolerance stacking resulting from the modeling process and/or from installation of a separate implant analog into a previously formed physical dental model are substantially reduced or eliminated, resulting in a physical model that more accurately represents the actual physiology of the patient's mouth.
In further embodiments, the physical dental model 10 optionally further comprises a thread-retention portion or body on or within the model, and positioned in operative alignment with the implant analog 20, to resist or prevent stripping of threads in the physical model during manufacture and test-fitting of a dental prosthesis using the model. In example embodiments, the thread-retention portion comprises an insert of metal, ceramic, high-strength polymer or other thread-retention material having a greater thread-holding capacity than the base material from which the implant analog and surrounding dentition portions of the physical dental model are formed, and preferably having sufficient hardness and toughness to engage and retain a threaded connection at typical insertion forces and torques used in attachment of a dental prosthesis to a dental implant in standard implant dentistry. For example, in the depicted embodiment the thread-retention insert comprises a steel nut 40 having a hexagonal exterior profile and an internally threaded bore extending therethrough. The nut 40 is inserted into a correspondingly configured hexagonal recess 50 formed in the underside of the model 10, opposite the implant analog portion 20. The threaded internal bore of the nut 40, when the nut is positioned within the lower recess 50, is coaxially aligned with the hexagonal recess 24 of the implant analog 20, and the lower recess 50 extends through the model into communication with the internal recess 24 of the implant analog. In example embodiments, the recess 50 is sized to receive the nut 40 with a close sliding, interference or press fit, to hold the nut in place upon insertion. Alternatively, the nut 40 can be held in place by adhesive, mechanical couplings or other attachment means. In alternate embodiments, the thread-retention portion or body may comprise a threaded insert of differing geometry, an embedded body of thread-retaining material co-molded or co-printed with the model 10, or be otherwise inserted, embedded or formed within the model, as a separately attached component or integrally formed as part of the model.
In example modes of use, a dental practitioner, lab technician or other user of the physical dental model 10 may fabricate and test fit a dental prosthesis using the model, in order to minimize chair-time and discomfort to the patient that might otherwise be necessary if the prosthesis were produced and fitted directly into the patient's mouth without use of a model. For example, a prosthetic tooth T (shown in broken lines in
The invention further comprises a workflow process or method, which in example embodiments may include steps selected from:
While the invention has been described with reference to example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/472,071 filed Mar. 16, 2017, the entirety of which is hereby incorporated herein by reference for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 62472071 | Mar 2017 | US |
