FILED OF THE INVENTION

This invention relates to dental implants, in particular to methods, systems and accessories useful in procedures relating to dental implants.

BACKGROUND OF THE INVENTION

Dental implants are widely used as artificial substitutes for the root portion of missing teeth, and allow a tooth prosthesis to be securely anchored to the jaw via a permanent abutment mounted to the implant. Endosseous implants generally comprise an externally threaded body, often self-taping into the bone tissues, and further comprise an internal chamber that is configured, typically internally threaded, for receiving and securing therein the anchoring stem of a permanent abutment therein.

Following implantation of an implant in the intra oral cavity and healing of the surrounding tissues, a physical model of the intra oral cavity is produced for facilitating design and manufacture of the permanent abutment and prosthesis or other restoration that is to be eventually mounted onto the implant. In one procedure, an impression abutment is mounted to the implant so that it projects into the intra oral cavity, and an impression is then obtained of the intraoral cavity using well known techniques and impression materials, for example PVS. The impression abutment may be of the pick-up type, to be embedded with the impression material and retained therein after the impression tray is removed. Alternatively the impression tray is removed without the impression abutment attached thereto, but nevertheless having a recess formed therein complementary to the outer shape of the impression abutment, enabling the transfer-type impression abutment to be mounted therein at a later time. Subsequently an analog, corresponding to the particular implant that is implanted in the patient, is attached to the abutment, which is in situ in the impression material, and plaster is poured into the impression tray including the analog to produce a positive plaster model of the intraoral cavity with the analog embedded. The analog, in particular the internal passage thereof which is substantially identical to the internal passage of the implant that is designed to receive, engage and secure the permanent abutment, is in a position and orientation in the plaster model corresponding to the position and orientation of the implant in the patient's intra oral cavity. The dental technician can now attach a permanent abutment, or custom design a permanent abutment to fit the implant, build a coping or bridge framework or prosthesis to fit into the intraoral cavity of the patient.

By way of general background, the following publications relate to implants:

U.S. Pat. No. 6,358,052 discloses a dental implant system and method for effecting a dental restoration using the same. The dental implant system having an implant fixture adapted to be deployed in a bone; an impression coping adapted to be selectively deployed on the implant fixture and in a dental impression; a laboratory analog adapted to be selectively deployed on the impression coping and in a dental cast; a spherical abutment adapted to be selectively deployed on the laboratory analog; and a multiaxis abutment adapted to be adjustably deployed on the spherical abutment; wherein the spherical abutment and the multiaxis abutment are used to generate a cast permanent abutment which may be received by the laboratory analog and the implant fixture.

US 2008/032262 discloses a dental implant system comprising an implant member, an abutment member and a transfer key with cooperatively engaging structures for ensuring proper alignment and orientation of an abutment assembled on the implant member and for preparing an accurate dental impression and mold which represents the implantation site and its relationship to adjacent teeth structures. A dental reconstruction method utilizing the dental implant system of the present invention is also disclosed.

US 2006/183078 discloses a one-piece, screw-receiving, externally-threaded endosseous dental implant that includes a body portion with external threading and, at its proximal end, an unthreaded, cylindrical portion including a retentive groove for engaging a complementary transfer component or comfort cap; a one- or two-piece screw-receiving implant abutment for attachment to a one or two-piece implant, including a retentive groove for engaging a complementary transfer component or comfort cap; and a fixture mount for insertion in a one-piece implant, that can be sectioned with the distal end used to extend the implant height.

SUMMARY OF THE INVENTION

The term virtual model is used herein synonymously with “numerical entity”, “3D model”, and other such terms, and relates to a virtual representation in a computer environment of a real object, for example a dentition or at least a part of intraoral cavity, or of a real model thereof, for example.

The term “scanning” refer to any procedure directed at obtaining 3D topographic data of a surface, particularly of a dental surface, and thus includes mechanical methods, typically based on 3D probes for example, optical methods, including for example confocal methods, for example as disclosed in WO 00/08415, the contents of which are incorporated herein in their entirety by reference, or indeed any other method.

The term “display” refer to any means or method for delivering a presentation, which may include any information, data, images, sounds, etc, and thus the delivery may be in visual and/or audio form.

According to a first aspect of the invention, there is provided a method and system for manufacturing a physical dental model. A virtual model is provided representative of at least a portion of the intra-oral cavity including at least one dental implant implanted therein, and the virtual model includes a virtual portion representative of each dental implant. The virtual spatial disposition of each such virtual portion is determined with respect to the virtual model, corresponding to a real spatial disposition of the respective implant with respect to the intra oral cavity. A physical model is then manufactured based on the virtual model, the physical model including a physical analog corresponding to each implant at a respective physical spatial disposition with respect to the physical model corresponding to the respective virtual spatial disposition of the respective virtual portion with respect to the first virtual model as already determined.

In some embodiments, a jig is provided configured for maintaining a desired physical spatial disposition between the physical analog and a cavity of the physical dental model at least until the physical analog is affixed in the cavity.

According to this aspect of the invention, there is provided a method for manufacturing a physical dental model, comprising

(a) providing a first virtual model representative of at least a portion of the intraoral cavity including at least one dental implant implanted therein, said first virtual model comprising a virtual portion representative of the or each said dental implant;

(b) determining a virtual spatial disposition of the or each said virtual portion with respect to the first virtual model corresponding to a real spatial disposition of the respective said implant with respect to said portion of the intra oral cavity; and

(c) manufacturing a physical model of said portion of the intra-oral cavity based on said first virtual model, said physical model including a physical analog corresponding to the or each said implant at a respective physical spatial disposition with respect to said physical model corresponding to the respective said virtual spatial disposition of said virtual portion with respect to the first virtual model based on said determination in step (b).

The first virtual model may be generated in any suitable manner—for example by scanning the intraoral cavity in vivo, or scanning a positive or negative physical model of the intraoral cavity that includes representations of the implant(s) and a part of the dentition in the vicinity the implant(s).

In at least some embodiments, step (b) comprises providing a second virtual model at least partially representative of the or each respective said physical analog, and incorporating said second virtual model with said first virtual model based on said determination of the respective said virtual spatial disposition, to generate a third virtual model, wherein in step (c), said manufacturing of said physical model is based on said third virtual model. For example, step (b) may comprise manipulating the or each said second virtual model into an aligned spatial disposition with respect to the respective said virtual spatial disposition, and generating said third virtual model based on the first virtual model and including a virtual cavity (i.e. a virtual representation of the cavity) for virtually receiving and accommodating the or each respective second virtual model therein in a manner corresponding to that required for the respective physical analog with respect to said physical model of the intra oral cavity.

Step (c) may comprise forming an outer model surface corresponding to dental surfaces of said portion of the intra oral cavity, and forming a recess in said physical model (corresponding to the virtual cavity) for accommodating a respective said analog at the respective said physical spatial disposition, said recess corresponding to the respective said virtual cavity.

In at least some embodiments, at least one said virtual cavity is generated having a form generally complementary to that of the respective said physical analog, such that the respective said recess formed in said physical model provides a friction fit with respect to the respective said physical analog to accommodate the respective said physical analog at the respective said physical spatial disposition.

In at least some other embodiments, at least one said virtual cavity is generated having a form generally complementary to that of the respective said physical analog including a jacket, such that the respective said recess formed in said physical model provides a significant clearance gap with respect to the respective said physical analog, wherein said respective physical analog comprises said jacket formed of suitable model material, said jacket having an external form substantially complementary to that of the respective said recess, to enable the respective physical analog including the respective jacket to be accommodated in the respective said recess at the respective said physical spatial disposition. The said external form for the respective said jacket may be configured for fixing the spatial disposition thereof in the respective said recess in six degrees of freedom. For example, the jacket may be formed by a casting process applied to the respective said physical analog, or by applying a layer of said model material on the respective physical analog, and CNC machining said layer to provide the respective said external form.

In at least some embodiments, at least one said virtual cavity is generated having a form generally complementary to that of the respective said physical analog, such that the respective said recess formed in said physical model provides a significant clearance gap with respect to the respective said physical analog, wherein a suitable filler material is applied to fill the clearance gap, to enable the respective physical analog including the respective jacket to be accommodated in the respective said recess at the respective said physical spatial disposition. For example, the filler material may comprise a suitable cementing material. A suitable jig may be used for maintaining a said physical spatial disposition between the respective physical analog and the respective cavity at least until the physical analog is affixed therein by means of the filler material. In at least some embodiments, the jig may comprise a base, that is mounted in fixed spatial relationship to the physical dental model, for example affixed to a portion of the physical model, at least until the physical analog is affixed therein. In at least some embodiments, said portion of the physical model does not include physical model representations of teeth adjacent to a said implant.

In at least some embodiments, step (c) comprises forming an outer model surface corresponding to dental surfaces of said portion of the intra oral cavity from a blank of model material, wherein said blank integrally includes the or each said physical analog in relative spatial dispositions to one another corresponding to the relative spatial dispositions of the or each dental implants with respect to one another in said portion of the intra oral cavity.

In at least some embodiments, step (d) comprises computer controlled manufacture of at least a portion of said physical model. For example, step (d) may comprise manufacturing said physical model via a material removal operation applied to a blank of material or a rapid prototyping process.

According to this aspect of the invention, there is also provided a dental model, manufactured according to the above method.

According to at least some embodiments, a physical model is manufactured with a hole for friction fit with the analog.

According to at least some other embodiments, the analog is embedded in a suitable material, which is milled for a close fit with the hole, which may be useful, for example, when the analog is of a shape that does not allow friction fitting.

According to at least some other embodiments, the model is manufactured with a relatively large cavity such as to provide a loose fit for the analog, which is cemented in place while held in a jig.

According to another embodiment, a plaster blank is cast with the analog embedded in a particular known position. The blank is then machined to ensure that the analogue is in the correct position/orientation with the other parts (e.g., model dental surfaces) of the finished physical model.

According to this aspect of the invention, there is also provided a system for manufacturing a physical dental model of an intra-oral cavity, comprising:

(A) scanning apparatus and computer system configured for providing a first virtual model representative of at least a portion of the intra-oral cavity including at least one dental implant implanted therein, said first virtual model comprising a virtual portion representative of the or each said dental implant, and for determining a virtual spatial disposition of the or each said virtual portion with respect to the first virtual model corresponding to a real spatial disposition of the respective said implant with respect to the intra oral cavity;

(B) a physical analog corresponding to the or each said implant;

(C) a manufacturing system for manufacturing a physical model of said portion of the infra-oral cavity based on said first virtual model, said physical model including a physical analog corresponding to the or each said implant at a respective physical spatial disposition with respect to said physical model corresponding to the respective said virtual spatial as determined by said computer system.

The manufacturing system is computer controlled. For example, the manufacturing system may be configured for manufacturing said physical model via a material removal operation applied to a blank of material, or via a rapid prototyping technique.

According to another aspect of the invention, there is also provided accessories including one or more of a physical tooth model and a jig.

In one embodiment, a jig is provided for maintaining a desired spatial disposition between a respective analog and the respective cavity of a physical model of an intra oral cavity at least until the analog is affixed therein, wherein the jig comprises a base configured for being mounted to a portion of the physical model not including portions representative of adjacent teeth with respect to an implant site.

According to another aspect of the invention, there is provided a method for modifying a physical dental model, comprising:

(A) providing a physical model representative of at least a portion of the intra-oral cavity including at least one dental implant implanted therein, said physical model comprising a model portion representative of the or each said dental implant;

(B) providing a first virtual model representative of at least a portion of the intra-oral cavity including at least one dental implant implanted therein, said first virtual model comprising a virtual portion representative of the or each said dental implant;

(C) determining a virtual spatial disposition of the or each said virtual portion with respect to the first virtual model corresponding to a real spatial disposition of

the respective said implant with respect to said portion of the intra oral cavity; and •

(D) modifying said physical model of said portion of the intra-oral cavity by including therein a physical analog corresponding to the or each said implant at a respective physical spatial disposition with respect to said physical model corresponding to the respective said virtual spatial disposition of said virtual portion with respect to the first virtual model based on said determination in step (C).

The method according to this aspect of the invention may comprise one or more of the elements and features as provided herein regarding the first aspect of the invention, mutatis mutandis.

According to another aspect of the invention there is provided an accessory in the form of a jig configured for maintaining a desired physical spatial disposition between a physical analog and a cavity of a physical dental model at least until the physical analog is affixed in said cavity.

The cavity is typically larger (wider and/or deeper than the part of the analog that needs to be embedded in the physical model providing a fellable clearance gap therebetween, and the analog is ultimately secured in the cavity via a suitable filler material, for example.

According to at least some embodiments, the jig may comprise a strut having a first end configured for being mounted with respect to the dental model at a first spatial disposition with respect thereto, and a second end configured for enabling the physical analog to mounted to the second end at a second spatial disposition with respect thereto, wherein said first end is at a third spatial disposition with respect to said second end, and wherein said first spatial disposition, said second spatial disposition and said third spatial disposition are chosen to provide said desired physical spatial disposition between the physical analog and the cavity when said strut is mounted with respect to the dental model and the physical analog is mounted to said strut.

In at least some embodiments, the jig may comprise a spacer member, wherein said strut comprises an elongate arm comprising said first end and said second end at opposed longitudinal ends of said elongate arm, wherein said first end comprises a strut base portion configured for being mounted to the dental model via said spacer member wherein to provide said first spatial disposition between said first end and the dental model.

Said strut base portion may be configured for enabling said spacer member to be mounted to said strut by engagement to the strut base portion. At least one of the strut base portion and said spacer member may comprise a first engagement arrangement to ensure that the spacer member may be mounted to the strut base portion in a spatial disposition with respect thereto that is fixed in six degrees of freedom. For example, the first engagement arrangement may comprise at least two laterally spaced pins projecting from a second spacer end of said spacer member and corresponding complementary wells formed in the strut base portion for receiving each said pin. Other alternative configurations for the first engagement arrangement may of course be provided.

The dental model may include a model base portion configured for enabling said spacer member to be mounted to the dental model by engagement to the model base portion. At least one of the model base portion and said spacer member may comprise a second engagement arrangement to ensure that the spacer may be mounted to the model base portion in a spatial disposition with respect thereto that is fixed in six degrees of freedom. For example, said second engagement arrangement may comprise at least two laterally spaced pins projecting from a first spacer end of said spacer member and corresponding complementary wells formed in the model base portion for receiving each said pin. Other alternative configurations for the second engagement arrangement may of course be provided.

In at least some embodiments, said spacer comprises a first spacer end and a second spacer end, wherein said first spacer end is configured for being mounted to said first end via said strut base portion in a spatial disposition with respect thereto that is fixed in six degrees of freedom, and wherein said second spacer end is configured for being mounted to the dental model via a model base portion of the dental model in a spatial disposition with respect to the model base portion that is fixed in six degrees of freedom.

The geometric form of the jig, in particular the specific spatial dispositions of the various parts thereof to properly mate with the physical dental model, can be based on the method provided according to the first aspect of the invention.

For example, the jig may be integrally produced from a suitable blank via a material removal operation or integrally produced via a suitable rapid prototyping operation, based on the geometric form previously determined.

According to this aspect of the invention there is also provided a jig particularly useful for dental implant procedures, comprising:

an arm having a first arm end and a second arm end spaced from said first arm end, said first arm end having a first engagement arrangement, and said second arm end being configured for releasably holding a physical analog;

a spacer element having a first spacer end and a second spacer end spaced from said first spacer end, said first spacer end being configured for engagement to said first arm end via said first engagement arrangement, and said second spacer end being configured for being mounted to a physical dental model representative of at least a portion of the real dentition of a patient, said dental model comprising a cavity

wherein in operation to maintain a desired physical spatial disposition between the physical analog and said cavity of the physical dental model, wherein the physical analog is at least partially received within the cavity, at least until the physical analog is affixed in said cavity.

As for other embodiments of the jig, said desired physical spatial disposition of the physical analog with respect to the dental model corresponds to a spatial disposition of a dental implant corresponding to the analog with respect to the real dentition that is being represented by the dental model.

According to this aspect of the invention there is also provided a kit particularly useful for dental implant procedures, comprising:

a physical dental model comprising a model dentition representative of a first real dentition of a patient, and further comprising a cavity configured for accommodating therein via a fellable gap a physical analog in a model spatial disposition with respect to said model dentition corresponding to a real spatial disposition of an implant with respect to said real dentition;

a jig configured for holding said physical analog in said model spatial disposition with respect to said cavity at least until the physical analog is affixed in said cavity.

In at least some embodiments, the jig may comprise a spacer member and a strut, said strut comprising a strut base portion configured for being mounted to said dental model via said spacer member, and a strut end configured for holding the physical analog thereat.

The dental model may comprise a model base portion configured for enabling said spacer member to be mounted to the dental model by engagement to the model base portion.

The spacer may comprise a first spacer end and a second spacer end, wherein said first spacer end is configured for being mounted to said strut via said strut base portion in a spatial disposition with respect thereto that is fixed in six degrees of freedom, and wherein said second spacer end is configured for being mounted to the dental model via said model base portion of the dental model in a spatial disposition with respect to the model base portion that is fixed in six degrees of freedom.

The model dentition is generally representative of a set of adjacent real teeth of a first dental arch of a patient, and may comprise a set of model teeth corresponding to a set of real teeth of at least a portion of a first dental arch of a patient, and wherein said cavity is located adjacent at least one said model tooth at a position corresponding to a missing tooth in the real dentition.

The kit may optionally further comprise an auxiliary dental model representative of a second real dentition of at least a portion of a second dental arch of the patient, wherein the second real dentition is occlusally opposed with respect to the first real dentition. The auxiliary dental model may be configured for being mounted with respect to said dental model in an occlusal relationship corresponding to that between said first real dentition and said second real dentition. This may be accomplished by mounting the two models to the spacer, or to a suitable articulator, for example.

