WO2012141703A1

WO2012141703A1 - Universal dental crown and system and method of restoring a tooth using a universal dental crown

Info

Publication number: WO2012141703A1
Application number: PCT/US2011/032380
Authority: WO
Inventors: Simon P. Mcdonald; Adam Doudney
Original assignee: Triodent Holdings Limited; Triodent Corporation
Priority date: 2011-04-13
Filing date: 2011-04-13
Publication date: 2012-10-18

Abstract

A coping having an interior cavity having the form of a portion of a tooth is provided. The coping is filled with a filling agent and placed over a prepared tooth to form a mounting fixture on the prepared tooth. The coping is then removed. The mounting fixture provides the profile of a portion of the tooth. A universal dental crown is then secured to the mounting fixture. The exposed prepared tooth, mounting fixture and universal dental crown blend together to provide a profile of a tooth.

Description

UNIVERSAL DENTAL CROWN AND SYSTEM AND METHOD OF RESTORING

A TOOTH USING A UNIVERSAL DENTAL CROWN

FIELD OF THE INVENTION

The present invention relates to a universal dental crown and system that enables a dental professional to create and bond a dental crown in place without an impression or laboratory procedure.

BACKGROUND OF THE INVENTION

Traditionally, porcelain or ceramic dental crowns have been made by a dental technician using a model of the tooth that was cast from an impression. This process generates very accurate and successful crowns but the process is costly and requires at least two patient visits with a gap between, with sufficient time for the dental technician to complete the laboratory work.

More recently, a CAD/CAM process has been developed whereby digital data from a 3D scan of the tooth is imported into a CAD/CAM program and a ceramic crown is designed and milled from a block of material using a sophisticated CNC milling machine. The alternative to a porcelain or ceramic crown for a patient with limited financial means is a composite resin crown. These are ordinarily created directly in the mouth and are awkward for the dental professional to create and are more likely to fracture or otherwise fail.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide dentists and their patients with an alternative type of dental crown/restoration that is strong, easily fitted in one appointment and costs less than the laboratory or CAD/CAM crown. The present invention addresses these goals, amongst others. The present invention provides a system for restoring a prepared tooth. The system includes a coping having a sidewall and closed end which define a cavity, and an open end which provides access to the cavity, the closed end having an internal surface with a defined shape, the sidewall having an internal surface which generally resembles a portion of the sides of a tooth, the cavity adapted to receive a portion of a prepared tooth wherein a space is defined between the internal surfaces and the prepared tooth, and a universal dental crown having an exterior surface configured to resemble a tooth, and a cavity having an internal surface which presents a defined shape corresponding to the defined shape of the coping.

The present invention further provides a method of restoring a tooth with a dental crown. The method includes the steps of preparing the tooth to be restored, selecting a coping and a universal dental crown, wherein the a coping includes a sidewall and closed end which define a cavity, and an open end which provides access to the cavity, the closed end having an internal surface with a defined shape, the sidewall having an internal surface which generally resembles a portion of the sides of a tooth, wherein the universal dental crown includes an exterior surface configured to resemble a tooth, and a cavity having an internal surface which presents a defined shape corresponding to the defined shape of the coping, providing a filling agent in a cavity in the coping, fitting the coping and filling agent to the prepared tooth, wherein a space is defined between the internal surfaces and the prepared tooth to allow the filing agent to take shape to the coping and form a mounting fixture, removing the coping from the prepared tooth after the filling agent has cured, and securing the universal dental crown to the mounting fixture.

The present invention also provides a kit for restoring a tooth. The kit includes a plurality of copings, each coping includes a sidewall and closed end which define a cavity, and an open end which provides access to the cavity, the closed end having an internal surface with a defined shape, the sidewall having an internal surface which generally resembles a portion of the sides of a tooth, and a plurality of universal dental crowns, each universal dental crown includes an exterior surface configured to resemble a tooth, and a cavity having an internal surface which presents a defined shape corresponding to the defined shape of the coping.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of a universal dental crown according to the present invention;

Figure 2 is an elevation view of the universal dental crown of Figure 1 according to the present invention;

Figure 3 is a perspective view from below of the universal dental crown of Figure 1 according to the present invention;

Figure 4 is a perspective view of a coping according to the present invention;

Figure 5 is an elevation view of the coping of Figure 4 according to the present invention;

Figure 6 is a bottom view of the coping of Figure 4 according to the present invention;

Figure 7 is a perspective view of a prepared tooth according to the present invention; Figure 8 is a perspective view of an inverted combined universal dental crown and coping according to the present invention;

Figure 9 is a perspective view of a coping mounted to a prepared tooth according to the present invention,

Figure 10 is a partial cross-sectional view of a universal dental crown and coping filled with composite resin, mounted to a prepared tooth according to the present invention; and

Figure 1 1 is a partial cross-sectional view of a universal dental crown bonded to the cured composite resin mounting, bonded to a prepared tooth according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

1. Definitions Restoring a tooth is a method for returning a damaged tooth to its normal anatomy ensuring that the tooth is able to function in a normal manner.

A dental crown refers to an artificial ceramic or metal structure that sits on top of the damaged tooth to mimic a normal tooth.

A coping refers to a mold that mimics the shape and size of a normal tooth.

The mesial surface refers to mid-line (or towards the front of the mouth) and the distal surface refers to the back surface of the tooth. The buccal and lingual sides are the cheek and tongue surfaces of the tooth, respectively. The occlusal surface is the biting or top surface of the tooth.

Restorative materials traditionally used to restore a damaged tooth include, but are not limited to: composite resin, cement, silver, gold, porcelain, amalgam, alloy, wax.

2. Description of Preferred Embodiments

A universal dental crown and system in accordance with the present invention comprises two primary components, namely a dental crown 10 and a coping 12, as shown in the accompanying drawings. Referring specifically to the embodiment of the present invention shown in Figures 1-3, the dental crown 10 is shown. Noting that teeth are of different anatomical shapes and types, the respective dental crowns 10 are available for each tooth type. The dental crown 10 is a universal component that is manufactured in a range of shades, tooth-types and sizes. The dental crown 10 is preferably composed of ceramic, metal, plastic or resin material formed using conventional means for working with these materials, such as plastic injection molding, pressing molten glass or injecting ceramic powders into molds and then consolidating the powders in a furnace. The dental crown 10 generally includes an occlusal surface 16 and side surfaces consisting of a buccal surface 18, lingual surface 20, distal surface 22, and mesial surface 24. Figure 3 also shows an internal cavity 26 configured to receive a portion of the prepared tooth in a manner as more fully described below. The dental crown 10 further includes a lower edge or apical margin 28. In addition, the cavity 26 of the dental crown 10 is defined by an upper interior surface or ceiling 30 and a generally conical shaped inclined wall 32 extending between the ceiling 30 and the lower edge 28. Alternatively, the conical shaped inclined wall 32 may consist of four inclined walls which generally define a conical shaped inclined wall 32. It will be understood from the disclosure herein that the wall 32 may have other geometric shapes and still not depart from the invention.

As shown in Figures 1-3, the tooth anatomy of the dental crown 10, namely, the circumferential dimensions and configuration of the occlusal surface 16, buccal surface 18, lingual surface 20, distal surface 22, and mesial surface 24, are selected to mimic the shapes and sizes of normal teeth in an adolescent or adult human.

The coping 12 is shown in Figures 4-6. In one embodiment, the coping 12 is made of plastic and may be vacuum formed. Further, in one embodiment, the coping material is transparent. The sidewalls of the coping 12 consist of a buccal portion 38, lingual portion 40, distal portion 42, and mesial portion 44. A raised portion 48 extends upwardly from the coping 12. The raised portion 48 substantially conforms to the cavity 26 of the dental crown 10. In one embodiment, the raised portion 48 includes a generally conical shaped inclined wall 50 extending upward to an upper coping surface 52. A substantially flat annular perimeter pad 54 is located at the base of the wall 50. Alternatively, the inclined wall 50 may consist of four inclined walls meeting at curved corners and which generally define a conical shaped inclined wall 50. It will be understood from the disclosure herein that the wall 50 may have other geometric shapes and still not depart from the invention. However, the wall 50 will generally conform to the wall 32 of the dental crown 10. Similarly, the upper coping surface 52 will generally conform to the upper interior surface or ceiling 30 of the dental crown 10, and the pad 54 will generally conform to and receive the lower edge or apical margin 28 of the dental crown 10. The sidewalls 38, 40, 42 and 44 of the coping 12 are generally shaped to match the normal anatomical form of the respective tooth. The sidewalls extend from the substantially flat annular perimeter pad 54 to the tooth's prepared margin by approximately 1 to 4 millimeters. The extended sidewalls are designed to be trimmed by the dentist to match and provide a seamless interface with the prepared tooth. The coping 12 is made of a material that will accommodate such trimming by the dentist. In one embodiment, the walls of the coping 12 have a thickness between 10 and 100 microns to provide a coping which may be trimmed yet has satisfactory strength for the intended purpose. For example, the coping 12 must be made of a material which will retain its shape. In particular, as noted above, it is important that the coping 12 conform to the dental crown 10.

The plastic coping sidewall may comprise at least a first perforation or vent 56 disposed in the sidewall, preferably the buccal portion 38 or lingual portion 40, to facilitate the escape of excess amounts of a filling agent, as will be more fully describe below. In addition, the coping 12 may include one or more concave depressions or dimples 58, preferably in the inclined wall 50, such as shown in Figure 10.

In one embodiment, the method of restoring a tooth in accordance with the present invention includes initial selection of a matching coping 12 and universal dental crown 10. The coping 12 and universal dental crown 10 are selected based on the tooth type as well as the tooth size and shading. The tooth is prepared in a manner as generally known in the art. However, the tooth should be prepared in anticipation of receiving a particular coping 12 as more fully described herein. For example, Figure 7 shows a prepared tooth 60. The selected coping 12 is trial fitted to the prepared tooth 60, prior to preparation, during preparation, as well as after preparation of the tooth. Further, the selected coping 12 and selected universal dental crown 10 may be temporarily fitted together, such as via a press interference fit or via a tacky temporary adhesive, or the like. See Figure 8 as an example of a universal dental crown 10 temporarily fitted with a respective coping 12. It will be understood that the coping 12 and universal dental crown 10 must be a matched set. Further, the coping 12 and universal dental crown 10 must be selected to conform to the prepared tooth and the adjacent teeth. During the trial fitting of the coping 12 with the prepared tooth 60, the sidewalls of the coping 12 may be trimmed by the dentist as appropriate.

Once the dentist is satisfied with the selection of the coping 12 and universal dental crown 0, the coping 12 is removed from the prepared tooth 60 and the universal dental crown 10. The coping 12 is sufficiently filled, as will be understood from the description herein, with a filling agent which may consist of an auto-cured or light cured composite resin or cement. The agent is selected or tinted to match the shading of the surrounding teeth.

Prior to the composite resin curing, the coping 12 is then fitted to the prepared tooth 60.

As the coping 12 is pressed against and fitted to the prepared tooth 60, any excess composite resin will be forced out of the coping 12 at the interface between the lower edge 62 of the coping 12 and the prepared tooth 60, and likely primarily at the buccal and lingual sides. The optional at least one or more perforation or vents 56 may also be included in the sidewalls of the coping 12 to provide additional means of the composite resin to escape the coping 12. The perforations or vents 56 also enable the dental professional to work any air bubbles out of the filling agent to ensure a maximum amount of filling agent per volume available is utilized. The excess composite resin is removed prior to light curing of the resin. The excess composite resin may be removed with a hand tool, for example.

Figure 9 depicts the coping 12 mounted to the prepared tooth 60 with the composite resin cured.

It will be appreciated that with the coping 12 positioned in place with the prepared tooth 60, it is important that there are no air pockets between the coping 12 and the prepared tooth 60. The disadvantage of air pockets will be readily appreciated by one skilled in the art. Thus, a satisfactory amount of composite resin must be provided within the coping 12 prior to placement upon the prepared tooth 60. It will also be appreciated that a transparent coping 12 will assist the dentist in confirming that air pockets are not present. The transparent feature of the coping 12 will also be beneficial during the selection, trimming and trial fitting of the coping 12 to the prepared tooth 60.

After the composite resin has cured, the coping 12 is removed from the prepared tooth 5 60. For example, the coping 12 may be split utilizing a blade or similar tools. The composite resin will be left in place providing the universal dental crown mounting fixture 70. The interface between the lower edge 62 of the coping 12 and the prepared tooth 60 may be further finished using the appropriate tools, as necessary. The mounting fixture 70 will provide a profile similar to the form of the coping 12, such as shown in Figure 11. As seen in Figure 11 , the mounting

10 fixture 70 includes a mounting fixture top surface 72, generally conical shaped side walls 74, a substantially flat annular perimeter pad 76, mesial portion 78, distal portion 80, and lingual portion 82 and buccal portion 84 (both shown in Figure 9), as well as the optional concave depressions or dimples 86.

The universal dental crown 10 is now secured to the mounting fixture 70 via luting

15 cement, bonding agent or the like. The luting cement will flow into the dimples 86 and, when hardened, will form an additional physical lock between the mounting fixture 70 and the dental crown 10. After setting, the occlusal surface 16 of the dental crown 10 may be further finished, as necessary, to provide a satisfactory bite.

It is important that the coping 12 be fitted to the prepared tooth 60 such that the coping ίθ 12 is spaced from the prepared tooth 60 at an appropriate distance or height such that when the universal crown 10 is later secured to the prepared tooth 60, the occlusal surface 16 of the universal dental crown 10 will be at the correct spacing from the prepared tooth 60 to provide an ideal patient bite and avoid malocclusion. In addition, care must be given to provide appropriate rotational alignment of the coping 12 to the prepared tooth 60. Correct alignment of the

'5 universal dental crown 10 will be dependent on several factors, including the preparation of the geometry of the prepared tooth 60, selection of the combination coping 12 and universal dental crown 10, and trimming of the coping 12 during trial fitting. Additional adjustments may be available after curing of the composite resin by means of replacing the selected dental crown 10 with another similar dental crown but having a slight variation in height and/or rotational alignment of the occlusal surface 16. Ultimately, if necessary, additional finishing of the universal dental crown 10 may be necessary.

In practice, it is contemplated that a dental professional will obtain a kit comprising a set of universal dental crowns 10 and copings 12 for multiple tooth anatomies and sizes and shades, wherein each universal dental crown 10 and coping 12 includes at least one matching coping 12 and dental crown 10, respectively.

While the present invention has been described in connection with a specific application, this application is exemplary in nature and is not intended to be limiting on the possible applications of this invention. It will be understood that modifications and variations may be effected without departing from the spirit and scope of the present invention. It will be appreciated that the present disclosure is intended as an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated and described. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims.

Claims

I claim:

1. A system for restoring a prepared tooth, the system comprising:

a coping having a sidewall and closed end which define a cavity, and an open end which provides access to the cavity, the closed end having an internal surface with a defined shape, 5 the sidewall having an internal surface which generally resembles a portion of the sides of a tooth, the cavity adapted to receive a portion of a prepared tooth wherein a space is defined between the internal surfaces and the prepared tooth; and

a universal dental crown having an exterior surface configured to resemble a tooth, and a cavity having an internal surface which presents a defined shape corresponding to the defined 10 shape of the coping.

2. The system of Claim 1 wherein the sidewall of the coping extends approximately 1 to 4 millimeters, and the coping is formed of a trimmable material having a thickness between 10 and 100 microns, wherein the sidewall is trimmed and shaped to match the normal anatomical form of a tooth.

15 3. The system of Claim 1 wherein the sidewall of the coping includes a buccal portion, a distal portion, a lingual portion and a mesial portion, and the coping is formed of a transparent plastic.

4. The system of claim 1 , wherein the coping further includes a raised portion extending generally above the sidewall, the raised portion includes an inclined wall having a

10 base and extending upward from the base to an upper coping surface, and a substantially flat annular perimeter pad located at the base of the inclined wall.

5. The system of claim 4, wherein the inclined wall of the coping includes at least one dimple, and the sidewall of the coping includes at least one vent.

6. The system of claim 1 , wherein the universal dental crown includes a buccal ',5 surface, a lingual surface, a distal surface, a mesial surface and an occlusal surface.

7. The system of claim 4, wherein the internal surface of the dental crown includes an inclined wall and an upper interior ceiling surface, and the dental crown further including a lower edge which conforms to the annular perimeter pad of the coping.

8. A system for restoring a prepared tooth, the system comprising:

a filling agent;

a coping having a sidewall and closed end which define a cavity, and an open end which provides access to the cavity, the closed end having an internal surface with a defined shape, the sidewall having an internal surface which generally resembles a portion of the sides of a tooth, the cavity adapted to receive a portion of a prepared tooth wherein a space is defined between the internal surfaces and the prepared tooth to allow the filing agent to take shape to the coping and cure; and

a universal dental crown having an exterior surface configured to resemble a tooth, and a cavity having an internal surface which presents a defined shape corresponding to the defined shape of the coping, the cavity of the universal dental crown adapted for receiving the cured filling agent in a mating engagement.

9. The system of claim 8 wherein the cured filling agent forms a mounting fixture and includes a sidewall having a buccal portion, a lingual portion, a distal portion and a mesial portion, and the sidewall of the mounting fixture is flush with the exterior surface of the universal dental crown and the prepared tooth, the mounting fixture further includes a mounting pad generally above the sidewall, an inclined wall extending up generally from the mounting pad to a top surface, and the internal surface of the universal dental crown includes an inclined wall and an upper interior surface, the universal dental crown further including a lower edge.

10. The system of claim 8 further comprising an adhesive which secures the universal dental crown to the cured mounting fixture.

1 1. The system of claim 10, wherein the inclined wall of the coping includes at least one dimple, and the mounting fixture includes a respective at least one dimple, and wherein the adhesive is formed in the dimple and provides a physical lock between the mounting fixture and the universal dental crown.

12. The system of claim 9, wherein the sidewall of the coping is formed of a trimmable material having a thickness between 10 and 100 microns, wherein the sidewall is trimmed and shaped to match the normal anatomical form of a tooth.

13. The system of claim 8, wherein the coping is made of a transparent plastic.

14. A method of restoring a tooth with a universal dental crown, the method comprising the steps of:

a) preparing the tooth to be restored;

b) selecting a coping and a universal dental crown, wherein the a coping includes a sidewall and closed end which define a cavity, and an open end which provides access to the cavity, the closed end having an internal surface with a defined shape, the sidewall having an internal surface which generally resembles a portion of the sides of a tooth, wherein the universal dental crown includes an exterior surface configured to resemble a tooth, and a cavity having an internal surface which presents a defined shape corresponding to the defined shape of the coping;

c) providing a filling agent in the cavity in the coping;

d) fitting the coping and filling agent to the prepared tooth, wherein a space is defined between the internal surfaces and the prepared tooth to allow the filing agent to take shape to the coping and form a mounting fixture; d) removing the coping from the prepared tooth after the filling agent has cured; and

e) bonding the universal dental crown to the mounting fixture.

15. The method of claim 14, further comprising the step of trimming the sidewalls of the coping to match the anatomical form of the prepared tooth.

16. The method of claim 14, wherein the step of securing the universal dental crown includes applying an adhesive between the internal surface of the universal dental crown and

5 the mounting fixture.

17. The method of claim 14, wherein the step of selecting a coping includes the step of selecting a transparent coping, and wherein the step of fitting the coping and filling agent to the prepared tooth includes eliminating air pockets from the filling agent.

18. The method of claim 14, wherein the step of fitting the coping and filling agent to 10 the prepared and bonded tooth includes positioning the coping with the proper orientation with respect to the adjacent teeth.

19. A kit for restoring a tooth, the kit comprising:

a plurality of copings, each coping includes a sidewall and closed end which define a cavity, and an open end which provides access to the cavity, the closed end having an internal 15 surface with a defined shape, the sidewall having an internal surface which generally resembles a portion of the sides of a tooth; and

a plurality of universal dental crowns, each universal dental crown includes an exterior surface configured to resemble a tooth, and a cavity having an internal surface which presents a defined shape corresponding to the defined shape of the coping.

•0

20. The kit for restoring a tooth of claim 19, wherein the plurality of coping are in differing sizes and tooth types.

5 21. The kit for restoring a tooth of claim 19, wherein the plurality of universal dental crowns are in differing sizes, tooth types and shading.

22. The kit for restoring a tooth of claim 19, wherein each universal dental crown includes at least one matching or corresponding coping.