METHOD OF FABRICATING A DENTURE

Abstract

A method of making a denture comprised of fabricating a mold form, including a mold surface corresponding to an external surface of the denture; casting a liquid mold block material against the mold surface of the mold form, and curing the liquid mold block material to form a solid mold block including a second mold surface corresponding to the external surface of the denture. Denture teeth are placed in the tooth sockets of the mold block. Denture base material is delivered against the denture base surface portion of the second mold surface and bases of the denture teeth. The liquid denture base material is cured into a solid state to form a denture base block including embedded denture teeth. The denture base block is placed in a milling fixture; and milled to form the internal surface of the denture.

Claims

1. A method of making a denture comprised of a denture base and denture teeth, and having an external surface and an internal surface, the method comprising: a) fabricating a mold form, including a first mold surface corresponding to the external surface of the denture; b) casting a liquid mold block material against the first mold surface of the mold form, and curing the liquid mold block material into a solid or semi-sold state to form a mold block including a second mold surface corresponding to the external surface of the denture, the second mold surface including denture tooth sockets contiguous with a denture base surface portion; c) placing denture teeth in the tooth sockets of the mold block; d) delivering liquid denture base material against the denture base surface portion of the second mold surface and against bases of the denture teeth, and curing the liquid denture base material into a solid state to form a denture base block including embedded denture teeth; and e) milling the denture base block to form the internal surface of the denture.

2. The method of claim 1, further comprising creating a three dimensional digital CAD model of the denture, which includes data defining the external surface of the denture usable to define the first mold surface of the mold form.

3. The method of claim 1, further comprising obtaining an impression of a patient's dentition, and using the impression to define the three dimensional digital CAD model of the denture.

4. The method of claim 1, wherein the mold form is made by milling mold form material from a mold form material starting block.

5. The method of claim 1, wherein the mold form is made by 3D printing.

6. The method of claim 1, wherein the mold form is bounded by a cylindrical perimeter and wherein the mold form is placed in a cylindrical mold fixture prior to casting the liquid mold block material.

7. The method of claim 1, wherein the mold form is comprised of an annular flange surrounding the first mold surface.

8. The method of claim 1, wherein following forming the mold block, the mold block is removed from a mold fixture, inverted, and replaced in the mold fixture.

9. The method of claim 1, wherein milling the denture base block includes removing upper portions of the embedded denture teeth.

10. The method of claim 1, further comprising removing support material from the denture base following the milling the denture base block.

11. A method of making a denture comprised of a denture base and denture teeth, and having an external surface and an internal surface, the method comprising: a) creating a three dimensional digital CAD model of the denture, which includes data defining the external surface of the denture usable to define a first mold surface of a mold form; b) fabricating the mold form, including a first mold surface corresponding to the external surface of the denture, by milling mold form material from a mold form material starting block; c) casting a liquid mold block material against the first mold surface of the mold form, and curing the liquid mold block material into a solid or semi-sold state to form a mold block including a second mold surface corresponding to the external surface of the denture, the second mold surface including denture tooth sockets contiguous with a denture base surface portion; d) placing denture teeth in the tooth sockets of the mold block; e) delivering liquid denture base material against the denture base surface portion of the second mold surface and against bases of the denture teeth, and curing the liquid denture base material into a solid state to form a denture base block including embedded denture teeth; and f) milling the denture base block to form the internal surface of the denture.

12. A method of making a denture comprised of a denture base and denture teeth, and having an external surface and an internal surface, the method comprising: a) creating a three dimensional digital CAD model of the denture, which includes data defining the external surface of the denture usable to define a first mold surface of a mold form; b) fabricating the mold form, including a first mold surface corresponding to the external surface of the denture, by 3D printing mold form material; c) casting a liquid mold block material against the first mold surface of the mold form, and curing the liquid mold block material into a solid or semi-sold state to form a mold block including a second mold surface corresponding to the external surface of the denture, the second mold surface including denture tooth sockets contiguous with a denture base surface portion; d) placing denture teeth in the tooth sockets of the mold block; e) delivering liquid denture base material against the denture base surface portion of the second mold surface and against bases of the denture teeth, and curing the liquid denture base material into a solid state to form a denture base block including embedded denture teeth; and f) milling the denture base block to form the internal surface of the denture.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present disclosure will be provided with reference to the following drawings, in which like numerals refer to like elements, and in which:

[0025] FIG. 1 is a side cross-sectional view of a mold form including a first mold surface corresponding to the external surface of the denture, the mold form contained in a molding fixture;

[0026] FIG. 2 is a top view of the mold form contained in the molding fixture of FIG. 1;

[0027] FIG. 3 is a side cross-sectional view of the mold form and molding fixture of FIG. 1, depicting the step of fabricating a mold block of colloid material within the molding fixture;

[0028] FIG. 4 is a side cross-sectional view of the molding fixture as shown in FIG. 3, but with the mold fixture inverted, and with the mold form of FIG. 1 removed;

[0029] FIG. 5 is a side cross-sectional view of the molding fixture as shown in FIG. 4, with denture teeth placed in tooth sockets and fixture covers positioned to form a denture base mold cavity;

[0030] FIG. 6 is a side cross-sectional view of the molding fixture as shown in FIG. 5, following the delivery of denture base material into the denture base mold cavity;

[0031] FIG. 7 is a side cross-sectional view of a denture base block with embedded denture teeth removed from molding fixture at the start of milling of the denture base;

[0032] FIG. 8 is a side cross-sectional view of a nearly completed denture, at a point near completion of the milling of the denture base; and

[0033] FIG. 9 is a side cross-sectional view of a completed denture; and

[0034] FIG. 10 is a flow chart of a method of making a denture in accordance with the present disclosure.

[0035] The present invention will be described in connection with certain preferred embodiments. However, it is to be understood that there is no intent to limit the invention to the embodiments described. On the contrary, the intent is to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION

[0036] For a general understanding of the present invention, reference is made to the drawings. In the drawings, like reference numerals have been used throughout to designate identical elements. The drawings are to be considered exemplary, and are for purposes of illustration only. The dimensions, positions, order and relative sizes reflected in the drawings attached hereto may vary.

[0037] In the following disclosure, certain components may be identified with the adjectives top, upper, bottom, lower, left, right, etc. These adjectives are provided in the context of the orientation of the drawings. The description is not to be construed as limiting the methods of the present disclosure to use in a particular spatial orientation. The methods and related apparatus may be used in orientations other than those shown and described herein.

[0038] It is also to be understood that any connection references used herein (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily imply that two elements are directly connected and in fixed relation to each other.

[0039] The terms preferred and preferably refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the inventive scope of the present disclosure.

[0040] The term providing, such as for providing a molding fixture and the like, when recited in the claims, is not intended to require any particular delivery or receipt of the provided item. Rather, the term providing is merely used to recite items that will be referred to in subsequent elements of the claim(s), for purposes of clarity and ease of readability.

[0041] The term semi-solid material as used herein is meant to indicate a material that behaves as a solid, i.e., no deformation of the material occurs, until a threshold stress is applied. At or above the threshold stress, the material deforms irreversibly, i.e., the material flows or creeps. When the stress at or above the threshold is removed, the semi-solid material reverts to a non-flowing solid state.

[0042] A method of making a denture in accordance with the present disclosure will now be described. It is to be understood that the denture in the following disclosure is an exemplary complete denture comprised of mandibular teeth. It is to be understood that the method described herein is not limited to mandibular dentures. The method is also applicable to maxillary dentures and partial dentures.

[0043] Referring first to FIG. 9, an exemplary complete denture 10 is comprised of a denture base 12 and denture teeth 14. The denture 10 has an exposed external (lingual and labial) surface 11, which includes the surfaces of teeth 14 and exposed surfaces of the denture base 12, which are contacted by saliva and food during chewing, and which may be visible within the mouth. The denture 10 has an internal surface 19, which, when in use, is contacted with and adhered to the tissue of the patient's mouth (not shown).

[0044] Referring to FIG. 10, in the method 100 shown therein, certain preparatory/denture design steps 110 are performed prior to fabrication of a mold form in step 120 that includes a denture external surface. In step 112, an impression of the patient's dentition is obtained. The impression (or model of the impression) and occlusal registration of the complete denture (and opposing arch, if any) may then be digitally scanned. From this data, a digital 3D CAD model of denture may be created in step 114. In step 116, a replica of the finished denture is fabricated by additive (e.g., 3D printed using a plastic) or subtractive (e.g., milling) methods, and a trial fit in the patient is performed. The dentist checks for proper occlusion, speech, lip support, smile line, tooth position and general esthetics. The dentist will note changes, if any, and return the replica denture to the denture fabrication laboratory. If changes are requested, the lab will revise the 3D model in step 118 and fabricate a new denture for a second trail fit in the patient.

[0045] Once the desired final dimensions of the denture are determined, a mold form is fabricated in step 120. Referring to FIGS. 1 and 2, the mold form 20 includes a region 22 corresponding to the external surface of the denture. The mold form 20 is further comprised of an annular flange 21 having a horizontal flange surface 24 bounded by an inner edge 23 and an outer edge 25. The mold form 20 may be fabricated by a suitable 3D additive or subtractive method. In one embodiment (not shown), the mold form 20 may be fabricated as a solid block. In the embodiment shown in FIG. 1, the mold form 20 is fabricated with the external surface of the denture and the annular flange formed as a shell 26, and with supports 28 joined to the shell 26. When fabrication of the mold form 20 is complete, it is placed in a cylindrical mold flask or fixture 30 with the supports 28 disposed on a solid cover 32 that is fitted to the fixture 30. The outer edge 25 of the flange 21 is substantially equal in diameter to the inside diameter of a cylindrical fixture 30 so as to enable a sliding fit therein. Referring also to FIG. 10, the mold form 20 is placed in the mold fixture 30 in step 130. In certain embodiments, the mold fixture 30 may be about 98 millimeters (mm) in diameter, and the height of the flange 21 may be about 20 mm.

[0046] In step 140, a liquid or semi-solid mold block material is delivered into the molding fixture and cast against a first mold surface of the mold fixture, which is comprised of the region 22 corresponding to the external surface of the denture and the horizontal flange surface 24. Referring to FIG. 3, the mold block material 40 may be delivered through an opening 36 in a mold cover 34 that is fitted to the mold fixture 30. Alternatively, the mold block material 40 may be delivered into the mold fixture 30 through an open top thereof. The mold cover 34 may then be placed on the mold fixture 30. Any excess mold block material 40 can escape through the opening 36 in the mold block cover 34.

[0047] Following delivery of the mold block material 40 into the mold fixture 30, the mold block material 40 is cured to a solid or semi-solid state. In certain embodiments, the mold block material 40 may be a silicone material. In other embodiments, the mold block material 40 may be a reversible hydrocolloid impression material such as alginate. The hydrocolloid material, which may be delivered into the mold fixture in a heated state, solidifies into an elastic gel after cooling and cross linking.

[0048] Referring to FIG. 4, after forming the mold block material 40 in the mold fixture 30, the covers 32 and 34 are removed from the mold fixture 30, the mold form 20 is removed from the mold fixture 30, and the mold fixture 30 is inverted so that the mold block material 40 is in the bottom of the mold fixture 30. The mold block material 40 includes a mold surface 42 with tooth sockets 43, and an annular flange surface 44. Referring to FIG. 5, in step 150, denture teeth 14 that were selected in the denture fabrication steps 110 are placed in the tooth sockets 43 of the mold block 40. The covers 32 and 34 are fitted to the mold fixture 30, forming a denture base cavity 38 therein.

[0049] Referring to FIG. 6, in step 160, liquid denture base material is delivered into the denture base cavity and cast against the denture base surface portion 42 of the mold block material 40 and against bases of the denture teeth 14. In step 170, the liquid denture base material is crosslinked and cured into solid denture base block 50, within which are embedded the denture teeth 14. In certain embodiments, the denture base block 50 may be made of an auto-polymerizing material, such as polymethyl methacrylate. In certain embodiments, the molding fixture 30 may be placed in a pressure pot (not shown), and heat and pressure may be applied to accelerate the cross linking and solidification of the denture base block 50. The auto-polymerizing material of the denture base block 50 chemically bonds to the bases of the denture teeth 14, thereby forming a strong bond between the teeth 14 and the solid denture base material.

[0050] In step 180, the denture base block 50 with embedded denture teeth 14 is removed from the molding fixture 30. Referring to FIG. 7, the denture base block 50 in the form of a cylindrical disk is placed in a standard milling fixture (not shown) of a mill (not shown). The mill is preferably a computer numerically controlled (CNC) mill, in which the digital denture date obtained in steps 110 can be uploaded. In step 190, the mill rotates a milling bit 2 and articulates the bit 2 around multiple axes and along multiple pathways, and removes all of the material of the denture base block 50 except for the material of the denture base 12, thereby forming the intaglio (tissue) side, i.e., the internal surface 19 of the denture. During the milling step, any excess height of teeth 14 will also be automatically removed, i.e., an upper portion 15 of teeth 14 will be removed by the mill bit 2. Advantageously, the removal of the upper portion 15 of teeth 14 solves one of the main problems with conventional digital dentures, which is that the vertical height of the teeth 14 must be adjusted to conform to the available vertical space (VDOvertical dimension of occlusion) in the mouth of the patient.

[0051] Referring to FIG. 8, it can be seen that most of the denture base block 50 and the upper portion 15 (FIG. 7) of the teeth 14 have been removed by the mill bit 2, and that only some support material 17 remains to be removed from the denture base 12 at the conclusion of the milling step 190. This material 17 may be removed using an abrasive cut-off disc or bur. The denture may then be polished using conventional pumice and polishing compounds. The resulting completed denture 10, as described previously, is shown in FIG. 9.

[0052] Referring again to FIG. 10, an alternative embodiment of the method may begin by performing the denture design steps 110. However, instead of performing step 120 to produce the mold form 40 as depicted in FIG. 3, the mold form 40 may be produced using an additive process such as 3D printing. Such a process may be performed using a Model Eden 260VS 3D printer, or a Model Dental Prime 3D printer manufactured and sold by Stratasys Ltd. of Edina MN. Such 3D printers are capable of printing elastic support materials. Making the mold form 40 from an elastic material is preferable so as to enable the placement of denture teeth 14 into the tooth sockets of the mold form 40. Following the fabrication of the mold form 40 by 3D printing, the method proceeds with steps 130-190 as described previously to produce the complete denture. Advantageously, it is anticipated that making the mold form 40 from an elastic support material will reduces denture fabrication time and cost. The elastic support material is less costly than the 3D printed plastic resin described previously.

[0053] It is therefore apparent that there has been provided, in accordance with the present disclosure, a method of making a denture. The foregoing description of technology and the invention is merely exemplary in nature of the subject matter, manufacture, and use of the invention and is not intended to limit the scope, application, or uses of any specific invention claimed in this application or in such other applications as may be filed claiming priority to this application, or patents issuing therefrom. The following definitions and non-limiting guidelines must be considered in reviewing the description.

[0054] The headings in this disclosure (such as Background and Summary) and sub-headings used herein are intended only for general organization of topics within the present technology, and are not intended to limit the disclosure of the present technology or any aspect thereof. In particular, subject matter disclosed in the Background may include novel technology and may not constitute a recitation of prior art. Subject matter disclosed in the Summary is not an exhaustive or complete disclosure of the entire scope of the technology or any embodiments thereof. Classification or discussion of a material within a section of this specification as having a particular utility is made for convenience, and no inference should be drawn that the material must necessarily or solely function in accordance with its classification herein when it is used in any given composition.

[0055] To the extent that other references may contain similar information in the Background herein, said statements do not constitute an admission that those references are prior art or have any relevance to the patentability of the technology disclosed herein. Any discussion in the Background is intended merely to provide a general summary of assertions.

[0056] The description and specific examples, while indicating embodiments of the technology disclosed herein, are intended for purposes of illustration only and are not intended to limit the scope of the technology. Moreover, recitation of multiple embodiments having stated features is not intended to exclude other embodiments having additional features, or other embodiments incorporating different combinations of the stated features. Specific examples are provided for illustrative purposes of how to make and use the compositions and methods of this technology and, unless explicitly stated otherwise, are not intended to be a representation that given embodiments of this technology have, or have not, been made or tested.

[0057] Unless otherwise specified, relational terms used in the present disclosure should be construed to include certain tolerances that those skilled in the art would recognize as providing equivalent functionality. By way of example, the term perpendicular is not necessarily limited to 90.00, but also to any variation thereof that those skilled in the art would recognize as providing equivalent functionality for the purposes described for the relevant member or element. Terms such as about and substantially in the context of configuration relate generally to disposition, location, and/or configuration that is either exact or sufficiently close to the location, disposition, or configuration of the relevant element to preserve operability of the element within the invention while not materially modifying the invention. Similarly, unless specifically specified or clear from its context, numerical values should be construed to include certain tolerances that those skilled in the art would recognize as having negligible importance, as such do not materially change the operability of the invention.

[0058] As referred to herein, all compositional percentages are by weight of the total composition, unless otherwise specified. As used herein, the words comprise, include, contain, and variants thereof are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that may also be useful in the materials, compositions, devices, and methods of this technology. Similarly, the terms can and may and their variants are intended to be non-limiting, such that recitation that an embodiment can or may comprise certain elements or features does not exclude other embodiments of the present technology that do not contain those elements or features.

[0059] Although the open-ended term comprising, as a synonym of non-restrictive terms such as including, containing, or having, is used herein to describe and claim embodiments of the present technology, embodiments may alternatively be described using more limiting terms such as consisting of or consisting essentially of. Thus, for any given embodiment reciting ingredients, components or process steps, the Applicants specifically envision embodiments consisting of, or consisting essentially of, such ingredients, components or processes excluding additional ingredients, components or processes (for consisting of) and excluding additional ingredients, components or processes affecting the novel properties of the embodiment (for consisting essentially of), even though such additional ingredients, components or processes are not explicitly recited in this application. For example, recitation of a composition or process reciting elements A, B, and C specifically envisions embodiments consisting of, and consisting essentially of, A, B, and C, excluding an element D that may be recited in the art, even though element D is not explicitly described as being excluded herein.

[0060] Having thus described the basic concept of the invention, it will be apparent to those skilled in the art that the foregoing detailed disclosure is intended to be presented by way of example only, and is not limiting. Various alterations, improvements, and modifications will occur to those skilled in the art, though not expressly stated herein. These alterations, improvements, and modifications are intended to be suggested hereby, and are within the spirit and scope of the invention. Additionally, the recited order of processing elements or sequences, or the use of numbers, letters, or other designations therefore, is not intended to limit the claimed processes to any order except as may be expressly stated in the claims.