WO2012113083A1

WO2012113083A1 - Method and device for making a dental prosthesis with attachment system

Info

Publication number: WO2012113083A1
Application number: PCT/CA2012/050115
Authority: WO
Inventors: André ARCHAMBAULT; Gilbert Piccard
Original assignee: Innovation Tap Inc.
Priority date: 2011-02-25
Filing date: 2012-02-27
Publication date: 2012-08-30

Abstract

A jig for maintaining an orientation between a ball head implant component and a dental-prosthesis locking mechanism, comprises a body having a first side shaped to contact an outer surface of a casing of the locking mechanism. The first side defines a plug engaged into a portion of the casing for blocking movement between the body and the casing of the locking mechanism. A second side is shaped to contact a portion of the ball head implant component. The second side comprises an abutment surface for blocking some movement between the body and the ball head implant component. A passage in the body extends between the first side and the second side for the ball head of the ball head implant component to be received in the locking mechanism. A thickness of the body between sides is selected for the sides to respectively contact the locking mechanism and the ball head implant when the locking mechanism is interlocked to the ball head implant component.

Description

METHOD AND DEVICE FOR MAKING A DENTAL PROSTHESIS WITH ATTACHMENT SYSTEM

CROSS-REFERENCE TO RELATED APPLICATION ( S )

The present application claims priority on United States Provisional Patent Applications No. 61/446,526, and No. 61/446,585, both filed on February 25, 2011 and both incorporated herein by reference .

FIELD OF THE APPLICATION

The present application relates to dental prostheses (i.e., dentures), and more particularly to a method for making a dental prosthesis with attachment systems therein, as well devices related to the manufacturing of dental prosthesis. BACKGROUND OF THE ART

[0001] It is known to provide permanently fixed dentures which include implants anchored in the mandible or maxilla osseous portions and a denture including an artificial gum and teeth structure being fixed to the implants and/or existing teeth or roots.

[0002] United States Patent No. 7,785,108 discloses a denture attachment system that features a denture attachment mechanism that has a locking mechanism to releasably attach to a ball abutment implant. However, one of the challenges remains in fabricating a denture with such attachment system in such a way that the components of the denture attachment system are at the desired position and orientation, to optimize the interconnection between prosthesis and implants.

- l - SUMMARY OF THE APPLICATION

It is therefore an aim of the present disclosure to provide a device for maintaining an orientation between a ball head implant component and a dental-prosthesis locking mechanism during the manufacturing of a dental prosthesis incorporating the denture attachment system.

Therefore, in accordance with a first embodiment of the present application, there is provided a jig for maintaining an orientation between a ball head implant component and a dental-prosthesis locking mechanism, comprising a body having a first side shaped to contact an outer surface of a casing of the locking mechanism, the first side defining a plug engaged into a portion of the casing for blocking movement between the body and the casing of the locking mechanism, a second side shaped to contact a portion of the ball head implant component, the second side comprising an abutment surface for blocking some movement between the body and the ball head implant component, a passage in the body extending between the first side and the second side for the ball head of the ball head implant component to be received in the locking mechanism, a thickness of the body between sides being selected for the sides to respectively contact the locking mechanism and the ball head implant when the locking mechanism is interlocked to the ball head implant component .

Further in accordance with the first embodiment, the passage is a throughbore.

Still further in accordance with the first embodiment, the first side has a semi-cylindrical surface for contacting the casing of the locking mechanism .

Still further in accordance with the first embodiment, an axis of the throughbore is perpendicular to an axis of the semi-cylindrical surface. Still further in accordance with the first embodiment, the second side comprises a circular cavity, with the abutment surface comprising a periphery of the circular cavity.

Still further in accordance with the first embodiment, at least one marker groove is defined in the second side.

Still further in accordance with the first embodiment, an axis of the at least one marker groove is parallel to an axis of the semi-cylindrical surface.

Still further in accordance with the first embodiment, at least one lateral groove is in a lateral surface of the body for engagement of the jig into casting material.

Still further in accordance with the first embodiment, the jig is made with a resilient material.

Still further in accordance with the first embodiment, the resilient material is silicone.

In accordance with a second embodiment of the present disclosure, there is provided an assembly for making a dental prosthesis comprising: a casing of a locking mechanism of a dental prosthesis, the casing comprising a peripheral opening adapted to receive a ball head of a ball head implant component, and an end opening adapted to receive moving components of the locking mechanism for interlocking engagement with the ball head; and a jig for maintaining an orientation between the ball head implant component and the locking mechanism, the jig comprising a body having a first side shaped to contact an outer surface of the casing of the locking mechanism, the first side defining a plug engaged into the peripheral opening of the casing for blocking movement between the body and the casing of the locking mechanism, a second side shaped to contact a portion of the ball head implant component, the second side comprising an abutment surface for blocking some movement between the body and the ball head implant component, a throughbore in the body extending between the first side and the second side for the ball head of the ball head implant component to be received in the peripheral opening, a thickness of the body between sides being selected for the sides to respectively contact the casing and the ball head implant when the locking mechanism is interlocked to the ball head implant component.

Further in accordance with the second embodiment, the ball head implant component is a replica of a ball head implant abutment.

Still further in accordance with the second embodiment, the second side of the jig comprises a circular cavity, with the abutment surface comprising a periphery of the circular cavity, and the ball head implant component comprises a circular flange received in the circular cavity, the assembly of the casing, jig and ball head implant component forming a one-degree-of- freedom rotational joint about an axis of the ball head implant component.

Still further in accordance with the second embodiment, a dummy guillotine member is received in the end opening of the casing and adapted to interlock the casing to the ball head implant component.

Still further in accordance with the second embodiment, the first side of the jig has a semi- cylindrical surface for contacting the casing.

Still further in accordance with the second embodiment, an axis of the throughbore is perpendicular to an axis of the semi-cylindrical surface.

Still further in accordance with the second embodiment, at least one marker groove is defined in the second side of the jig. Still further in accordance with the second embodiment, an axis of the at least one marker groove is parallel to an axis of the semi-cylindrical surface.

Still further in accordance with the second embodiment, at least one lateral groove in a lateral surface of the body is provided for engagement of the jig into casting material.

Still further in accordance with the second embodiment, the jig is made with a resilient material.

Still further in accordance with the second embodiment, the resilient material is silicone.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is an assembly view of a locking mechanism for denture relative to a ball head implant abutment, in accordance with the prior art;

Fig. 2 is a perspective view of a positioning jig in accordance with the present disclosure;

Fig. 3 is an underside view of the positioning jig of Fig. 2;

Fig. 4 is a front perspective view of a master cast with the positioning jigs and casings of the locking mechanisms and dummy guillotine members;

Fig. 5 is an occlusal perspective view of the master cast with the positioning jigs and casings of the locking mechanisms and dummy guillotine members; and

Fig. 6 is a perspective view of a duplicate cast with a wax spacer, the positioning jigs, casings of the locking mechanisms and dummy guillotine members, prior to casting a splint thereon. DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to the drawings, and more particularly to Fig. 1, an implant abutment 12 is shown relative to a locking mechanism 14 of the type described in United States Patent No. 7,785,108. The implant abutment 12 has a ball head 20 at an end of a stem 21. The ball head 20 has a spherical geometry.

The stem 21 has a cylindrical body, with threading 22 on the outer surface or any other suitable surface for anchoring the stem 21 in the mandible or maxillary. An abutment flange 23 is adjacent to the ball head 20. The ball head 20 is separated from the abutment flange by a neck 24.

In other words, when the implant abutment 12 is received in the mandible, the stem 21 is screwed in the implant portion (not shown) implanted in the osseous material up to the abutment flange 23, which protrudes from the soft tissue of the mandible B. Accordingly, when the implant abutment 12 is anchored in the mandible, the ball head 20 is exposed.

Referring to Fig. 1, the locking mechanism 14 is typically housed in the acrylic base of a denture (a.k.a., dental prosthesis), such that a connection opening 40 thereof is exposed in a mandible receiving cavity of the denture (i.e., at the underside of the denture) . Moreover, a detent end 41 faces outwardly from the base of the denture. The detent end 41, comes in different lengths. For instance, it is considered to provide the detent end 41 in three different sizes, to accommodate a lingual, normal or buccal position of the denture teeth depending on the three classical jaw relations (i.e., prognathic, normal, retrognathic) .

The locking mechanism 14 has a hollow cylindrical casing 42. The cylindrical casing 42 has an open end 42A, through which a cavity of the casing 42 is accessed, and a closed end 42B. An opening 43 is defined in the peripheral surface of the cylindrical casing 42, which opening will be part of the connection opening 40 of the locking mechanism 14. A set screw 45, or any suitable fastener, may be used to retain the movable components of the locking mechanism 14 in place relative to the cylindrical casing 42.

A biasing member (not shown) is received at the closed end 42B of the cavity of the casing 42. The biasing member is typically a cushion of resilient material, or a spring. A hemispherical receptacle 51 is aligned with and faces toward the opening 43 in the casing 42.

Still referring to Fig. 1, a guillotine member 60 projects out of the cylindrical casing 42. The guillotine member 60 has an obround-shaped slot 61 (i.e., hockey-rink shape), as well as a generally pear- shaped slot 62 (e.g., with a circular portion and a throat portion) . The guillotine member 60 is the movable member of the locking mechanism 14. More specifically, when the guillotine member 60 is received in the casing 42, the set screw 45 passes through the obround-shaped slot 61. The elongated shape of the obround-shaped slot

61 enables the translation of the guillotine member 60 along the directions illustrated by C in Fig. 1, between a locking position, and a release position.

The guillotine member 60 is sized such that the detent end portion thereof extends out of the open end 42A of the casing 42, which end is visible in Fig. 1. Moreover, the guillotine member 60 is configured such that the biasing member biases the guillotine member 60 away from the closed end 42B, such that the guillotine member 60 has its end extending out of the open end 42A of the casing 42. The detent end portion of the guillotine member 60 will serve as detent to release the locking mechanism 14 from the implant abutment 12.

When the guillotine member 60 is in its release position, the larger end of the pear-shaped slot

62 is in register with the hemispherical receptacle 51. In the release position, the ball head 20 of the implant abutment 12 may access the hemispherical receptacle 51, so as to be lodged therein. In order for the guillotine member 60 to reach the release position, pressure must be exerted on the detent end portion of the guillotine member 60, against the biasing action of the biasing member. When the pressure on the detent end portion of the guillotine member 60 is released, the guillotine member 60 returns to its locking position.

When the guillotine member 60 is in its locking position, the narrower end of the pear-shaped slot 62 is in register with the hemispherical receptacle 51. In the locking position, the ball head 20 is held captive in the hemispherical receptacle 51 by the periphery of the narrower end of the pear-shaped slot 62. More precisely, the width of the narrower end of the pear-shaped slot 62 is less than the diameter of the ball head 20, such that the ball head 20 lodged in the hemispherical receptacle 51 is held captive therein with the neck 24 passing through the narrower end of the pair-shaped slot 62.

Referring concurrently to Figs. 2 and 3, a positioning jig in accordance with the present disclosure is generally shown at 70. The positioning jig 70 is used to maintain the implant abutment 12 (or replica thereof) and at least part of the locking mechanism 14 in a desired interlocking arrangement, during various steps of creation of a denture. The positioning jig 70 is typically made of a resilient and deformable polymeric material such as silicone. The jig 70 is used to interrelate the implant abutment 12 and the casing 42 in a reproducible and precise manner, and block movement in some degrees of freedom between the casing 12 and the implant abutment 12.

Accordingly, the jig 70 has a body comprising a locking-mechanism side 70A that has a surface adapted to conform to that of the cylindrical casing 42, and an implant-abutment side 70B that has a surface adapted to conform to that of the implant abutment 12. The jig 70 has a throughbore 72 that is shaped in such a way that the ball head 20 and neck 24 pass therethrough, when the jig 70 is seated on the abutment flange 23 of the implant abutment 12. As an alternative to the throughbore 72, the body of the jig 70 may define a clearance, a passage or the like allowing the neck 24 to extend beyond the jig 70, to come into engagement with the locking mechanism 14. In an embodiment, the diameter of the throughbore 72 ensures that the axis of the neck 24 is concentric with the center of the throughbore 72, namely along axis Y.

The throughbore 72 opens to a raised portion, forming a plug 74, in a semi-cylindrical channel 76. The channel 76 is shaped to receive the cylindrical casing 42 for concentric alignment therebetween, with the plug 74 received in the peripheral opening 43 (Fig. 1), and therefore abutting a perimeter of the opening 43. In Fig. 2, the plug 74 comprises wings 78 that would match an obround shaped for the opening 43 (although Fig. 1 shows a rectangular shaped opening 43), i.e., any appropriate shape is considered. Therefore, the plug 74 defines abutment surfaces that will contact edges of the opening 43 (Fig. 1), thereby blocking movement of the cylindrical casing 42 relative to the jig 70. In the illustrated configuration, the movements that are blocked are a rotation about and a translation along a longitudinal axis of the cylindrical casing 42. The locking-mechanism side of the jig 70 therefore blocks two rotational degrees of freedom of the cylindrical casing 42 when the same is installed thereon. Moreover, the plug 74 plugs the opening 43, generally preventing casting material to enter the cylindrical casing 42.

Referring to Fig. 3, the implant-abutment side

70B of the positioning jig 70 is shown in greater detail. A circular cavity 80 is defined in a main surface of the implant-abutment side 70B and is concentrically positioned relative to the throughbore 72. The circular cavity 80 is sized to receive the circular flange 23 (Fig. 1) of the implant abutment 12. Although a circular shape is shown for the cavity 80, any appropriate shape may be used as a function of the shape and configuration of the implant abutment 12.

Therefore, due to the abutment surfaces of the circular cavity 80, some movements between the positioning jig 70 and the implant abutment 12 are blocked when the positioning jig 70 is installed on the implant abutment 12. More specifically, the positioning jig 70 is prevented from moving in translation with the exception of moving in and out of engagement with the implant abutment 12 along an axis of the neck 24 of the implant abutment 12 (Fig. 1) . On the other hand, when the flange 23 is circular as in Fig. 1, the positioning jig 70 may rotate about the neck 24 (Fig. 1) . This may allow the adjustment of an orientation of the locking mechanism 14 (Fig. 1) relative to a myostatic line.

Referring to Fig. 4, the positioning jig 70 is illustrated as holding the locking mechanism 14 in its interlocking arrangement with the implant abutment 12. Due to the shapes of both sides of the positioning jig 70, respectively matching the shapes of portions of the implant abutment 12 and of the cylindrical casing 42, the positioning jig 70 allows to replicate the proper interlocking arrangement between the implant abutment 12 and the locking mechanism 14. As mentioned above, the locking mechanism 14 may however rotate about the neck axis, generally illustrated as Y in Fig. 4, whereby an orientation of the locking mechanism 14 may be adjusted. Therefore, the positioning jig 70 allows to block two of the three degrees of freedom permitted by the spherical joint formed between the implant abutment 12 and the locking mechanism 14.

Lateral grooves 82 may be provided in the positioning jig 70 to allow casting material to fix the jig 70 to various casts as described below. More specifically, during some casting steps, the casting material (e.g., wax) enters the lateral grooves 82 to render the jig 70 integral with the casts, thereby preserving the selected orientation of the casing 42. Marker grooves 84 (one or more) in the implant-abutment side 70B of the jig 70 may be provided to define markers. Hence, the marker grooves 84 are for instance parallel to an axis of the semi-cylindrical channel 76, such that bosses may be formed in wax blocking to indicate the desired orientation of the locking mechanism 14 (Fig. 1) relative to the Y axis, in one of the steps of forming the dental prosthesis. Tab 86 in the jig 70 is used to prevent infiltration of material in the tapped opening for the set screw 45 of the casing 42 (Fig. 1) .

A dummy guillotine member 90 may be inserted in the casing 42 to fix the positional arrangement between the implant abutment 12 and the cylindrical casing 42. The dummy guillotine member 90 interacts with the implant abutment 12 and the casing 42 in similar fashion to the various components of the locking mechanism 14 of Fig. 1, that are received within the casing 42, with the exception of the biasing action. Accordingly, the dummy guillotine member 90 comprises a channel of the throat portion of the pear-shaped slot 62 (Fig. 1), therefore cooperating with the ball head 20 and the neck 24, to block the cylindrical casing 42 from moving out of engagement with the implant abutment 12 (i.e., along the Y axis) . The guillotine member 90 also abuts a periphery of the open end 42A (Fig. 1) , thereby preventing infiltration of casting material into the casing 42 via the open end 42A. Slots 92 may be provided at the exposed end of the dummy guillotine members 90. The slots 92 are of the type being used with a screwdriver and may have other shapes then straight slots . As the dummy guillotine members 90 may adhere to casting or denture material, the slots 92 may be used to free the dummy guillotine members 90 from adhesion to the casting or denture material. The dummy guillotine members 90 are typically made of relatively porous brass .

Referring to Figs. 4 and 5, the positioning jig 70 may be used with replicas of the implant abutment 12, whose positioning is obtained by way of an impression (e.g., a multicolloid impression) featuring the geometry of the lower mandible and that of the exposed portions of the implants. The impression with implant replicas may be used to create a master cast 100. The master cast 100 is shown in Fig. 4, with the positioning jigs 70 holding the casings 42 in a desired interlocking arrangement to replicas of the implant abutments, with the dummy guillotine members 90 interlocking the casings 42 to the replica implant abutments. Replicas of cone implant abutments are shown at 102, and may also secured to the master cast 100. In Fig. 5, cone covers 104 are on the replicas of the cone implant abutments.

It is observed that the surface 70B is distanced from the mandible surface of the master cast 100, allowing a rotation of the locking mechanism 14 about the Y axis relative to the master cast 100, for instance relative to a myostatic line drawn on to the master cast 100. When a desired orientation of the casings 42 is reached, it may be set into place by wax blocking. As the wax blocking reproduces an impression of the casings 42 and of the cone covers 104, these may be removed when the wax blocking has been completed. The wax blocking will features bosses representing the marker grooves 84 (Figs. 2 and 3) indicating the selected orientation of the casings 42 relative to the mandible, as obtained using the jig 70 and master cast 100 as in Figs. 4 and 5.

During subsequent steps, a duplicate mold and a duplicate cast of the master cast 100 (Figs. 4 and 5) may be made and may incorporate the positioning jigs 70. Hence, the material of the positioning jigs 70 must be selected to be compatible with the casting material and denture material (e.g., poly(methyl methacrylate) , a.k.a. PMMA) . For instance, the jigs 70 may be used for steps of creation of the dental prosthesis, such as flasking, spruing, pouring and capping. Subsequently, further manufacturing steps may be performed, such as adding of sodium alginate after boil-out, deflasking, as well as applying various coatings with separators.

Referring to Fig. 6, a wax spacer 110 is on the mandible surface of one of casts. The denture will be cast on the wax spacer 110, thereby cooperating with the jigs 70 to reproduce the desired interlocking arrangement between the locking mechanisms 14 and the replicas of the implant abutments, ensuring that the locking mechanisms 14 are adequately oriented. The resulting splint or key will be a part of the dental prosthesis, with the master cast 100 (Figs. 4 and 5) being available to validate an orientation of the locking mechanisms. Once the casings 42 (Fig. 1) are integral with the splint or key, the positioning jigs 70 may be removed by deforming them out of engagement with the splint or key.

Because of the positioning jig 70 is made of a resilient material, it allows a bit of play between the locking mechanism 14 and the implant abutment 12 (or replica thereof) in any of the steps of creating a denture. The combination of the positioning jig 70 and dummy guillotine member 90 generally prevent infiltration of casting or denture material into the casing 42 (Fig. 1) during the steps of fabrication of the denture.

Claims

CLAIMS :

1. A jig for maintaining an orientation between a ball head implant component and a dental-prosthesis locking mechanism, comprising a body having a first side shaped to contact an outer surface of a casing of the locking mechanism, the first side defining a plug engaged into a portion of the casing for blocking movement between the body and the casing of the locking mechanism, a second side shaped to contact a portion of the ball head implant component, the second side comprising an abutment surface for blocking some movement between the body and the ball head implant component, a passage in the body extending between the first side and the second side for the ball head of the ball head implant component to be received in the locking mechanism, a thickness of the body between sides being selected for the sides to respectively contact the locking mechanism and the ball head implant when the locking mechanism is interlocked to the ball head implant component.

2. The jig according to claim 1, wherein the passage is a throughbore.

3. The jig according to any one of claims 1 and 2, wherein the first side has a semi-cylindrical surface for contacting the casing of the locking mechanism.

4. The jig according to claim 4 as dependent on claim 2, wherein an axis of the throughbore is perpendicular to an axis of the semi-cylindrical surface .

5. The jig according to any one of claims 1 to 4, wherein the second side comprises a circular cavity, with the abutment surface comprising a periphery of the circular cavity.

6. The jig according to according to any one of claims 1 to 5, wherein at least one marker groove is defined in the second side.

7. The jig according to claim 6 when dependent on claim 3, wherein an axis of the at least one marker groove is parallel to an axis of the semi-cylindrical surface .

8. The jig according to any one of claims 1 to 7, further comprising at least one lateral groove in a lateral surface of the body for engagement of the jig into casting material.

9. The jig according to any one of claims 1 to 8, wherein the jig is made with a resilient material.

10. The jig according to claim 9, wherein the resilient material is silicone.

11. An assembly for making a dental prosthesis comprising :

a casing of a locking mechanism of a dental prosthesis, the casing comprising a peripheral opening adapted to receive a ball head of a ball head implant component, and an end opening adapted to receive moving components of the locking mechanism for interlocking engagement with the ball head; and

a jig for maintaining an orientation between the ball head implant component and the locking mechanism, the jig comprising a body having a first side shaped to contact an outer surface of the casing of the locking mechanism, the first side defining a plug engaged into the peripheral opening of the casing for blocking movement between the body and the casing of the locking mechanism, a second side shaped to contact a portion of the ball head implant component, the second side comprising an abutment surface for blocking some movement between the body and the ball head implant component, a throughbore in the body extending between the first side and the second side for the ball head of the ball head implant component to be received in the peripheral opening, a thickness of the body between sides being selected for the sides to respectively contact the casing and the ball head implant when the locking mechanism is interlocked to the ball head implant component.

12. The assembly according to claim 11, further comprising the ball head implant component, the ball head implant component being a replica of a ball head implant abutment.

13. The assembly according to claim 12, the second side of the jig comprises a circular cavity, with the abutment surface comprising a periphery of the circular cavity, and the ball head implant component comprises a circular flange received in the circular cavity, the assembly of the casing, jig and ball head implant component forming a one-degree-of-freedom rotational joint about an axis of the ball head implant component.

14. The assembly according to any one of claims 11 to 13, further comprising a dummy guillotine member received in the end opening of the casing and adapted to interlock the casing to the ball head implant component.

15. The assembly according to any one of claims 11 to 14, wherein the first side of the jig has a semi- cylindrical surface for contacting the casing.

16. The assembly according to claim 15, wherein an axis of the throughbore is perpendicular to an axis of the semi-cylindrical surface.

17. The assembly according to according to any one of claims 11 to 16, wherein at least one marker groove is defined in the second side of the jig.

18. The assembly according to claim 17 when dependent on claim 15, wherein an axis of the at least one marker groove is parallel to an axis of the semi- cylindrical surface.

19. The assembly according to any one of claims 11 to 18, further comprising at least one lateral groove in a lateral surface of the body for engagement of the jig into casting material.

20. The assembly according to any one of claims 11 to 19, wherein the jig is made with a resilient material.

21. The jig according to claim 20, wherein the resilient material is silicone.