Patent Application
20200214808
The present disclosure relates generally to dental implant systems. More particularly, the disclosure relates to a dental implant assembly from which an impression can be taken of a patient's mouth (either using impression material or by digital scanning, for example) in order to design a dental prosthesis for that patient.
The process of providing a patient with a dental prosthesis requires a number of stages that may vary depending on the type of treatment, indication, clinician's preference, etc. Generally in the first stage, an incision is made through the gingiva to expose the underlying bone so that a dental implant can be placed in the jawbone. A second component, commonly known as a healing abutment, is then attached to the coronal end of the dental implant (for example by screw-fit or press-fit) so that, during healing of the gingiva and as the dental implant integrates with the bone, the coronal end of the implant does not become covered by the gingiva.
The healing abutment has to be temporarily removed in order to take an adequate impression which is used to transfer the implant's positional information to a model from which the final prosthesis can be created. During this step, the healing abutment is replaced by a third component, commonly known as an impression coping or scan abutment, which is attached to the coronal end of the dental implant, and from which the impression can be obtained.
Impression material can be used to create a negative imprint of the impression coping (“an impression”) in a well-known manner. Alternatively, it is possible to create a digital impression by scanning a scan abutment or similar using, for example an intra-oral scanner such as the 3Shape™ TRIOS described at http://www.3shape.com/products/trios/intraoral-scanners. Regardless of the impression-taking technique and scan technology used, the transfer of the implant's positional information from the patient to the model (stone or digital or other) requires accurate recording of positional information such as height, orientation, axis angulation, and centering, among others. Therefore, all components used in the method must be manufactured to a high tolerance and the technique itself must be performed with a high degree of accuracy.
Once the impression has been taken, the impression coping or scan abutment is removed and the healing abutment is normally reattached to the coronal end of the dental implant and left in place until healing and osseointegration is complete.
When it is desired to attach the final prosthesis made from the impression, the healing abutment is once again removed so that the prosthesis and its abutment can be attached.
As can be seen from the above, several of these stages involve removing and reattaching components to the dental implant which disrupts the healing process of the soft tissue and potentially also the underlying bone and thereby potentially affecting the implant treatment success from both a functional and aesthetic point of view. Each of these stages is generally done under local anaesthesia and requires skilled medical personnel.
The known techniques record the position of the implant but not the geometry of the soft tissue emergence profile created by the healing abutment. One reason that this has been acceptable is that the generally used healing abutments are simply cylindrical and do not generate anatomically relevant shapes, whose positional information needs to be recorded. Another reason is that the soft tissue emergence collapses so quickly that a proper impression of it, digital or otherwise, cannot be taken using conventional techniques.
There are other less common techniques known involving placing a provisional or permanent abutment on the implant without using a healing abutment at all. An impression is taken by mounting an impression cap on the provisional or permanent abutment. These techniques can impair the outcome of the implant as the tall post will transfer mastication forces down to the implant during the most delicate healing phase, just after placement of the implant and before the impression has been taken. These techniques also do not record a proper soft tissue profile, nor does the provisional or permanent abutment have an ideal emergence profile as they are positioned before swelling is gone and healing is completed.
The invention is defined in the appended claims.
In accordance with an aspect of the present invention there is provided a dental implant assembly comprising:
Recording positional information without having to remove the healing component from the implant has numerous advantages including reducing the number of surgical steps involved.
Advantageously, the impression component can not only record the position of the implant but also indirectly record the soft tissue emergence profile surrounding the implant.
In an embodiment, said impression component has an outer surface, an upper portion and a lower portion,
In this embodiment, said shoulder may engage with an apical end surface of the impression component to provide said axial locator. The formation on said inner surface of said bore of the healing component may comprise a groove and said formation on said outer surface of the impression component comprises a protrusion. Alternatively, said formation on said inner surface of said bore of the healing component comprises a protrusion and said formation on said outer surface of the impression component comprises a groove.
In another embodiment, said healing component has an outer surface, an upper portion and a lower portion,
In this embodiment, said shoulder engages with an apical end surface of the healing component to provide said axial locator. The formation on said inner surface of said bore of the impression component may comprise a groove and said formation on said outer surface of the healing component comprises a protrusion. Alternatively, said formation on said inner surface of said bore of the impression component comprises a protrusion and said formation on said outer surface of the healing component comprises a groove.
In an embodiment, said groove is an axially-extending groove. Optionally, said protrusion is a lug protruding radially into or out of said bore.
The healing component may comprise PEEK or titanium.
The impression component comprises a material and/or a textured surface compatible with digital scanning.
In an embodiment, the dental implant assembly further comprises a press-fit feature between the impression component and the healing component. The press-fit feature may comprise a localised narrowing of the internal bore of the healing component and/or a localised widening of the external diameter of the lower portion of the impression component.
In an embodiment, the dental implant assembly further comprises a centering feature for centering the impression component in the bore of the healing component. The centering feature may comprise a chamfered coronal edge on the bore of the healing component and/or a recess on an external surface at the apical end of the impression component or vice versa.
Preferably, said positional information includes any of:
In an embodiment, the upper portion of said impression component includes a cone or pyramid or other shape at its coronal end, whose tip and/or corners and/or faces can be used as a marker for positional information during digital scanning thereof.
In an embodiment, the upper portion of said impression component includes a substantially horizontal surface and/or a substantially vertical surface which can be used as a marker for positional information during and/or after digital scanning thereof.
In an embodiment, when said axial locator is engaged, the impression component and healing component combined have a predetermined height dependent upon the dimensions of the impression component and/or healing component selected.
The predetermined height may be measured from said substantially horizontal surface on said impression component. Preferably, said predetermined heights are stored in a digital library which can be referred to during digital scanning and design.
In an embodiment, the healing component has a substantially planar or conical surface at its apical end for engaging the coronal end of the dental implant.
The healing component may preferably have an anatomical shape. According to another aspect of the invention there is provided a dental implant kit comprising the dental implant assembly of any of the preceding paragraphs and a plurality of said healing components, each healing component having an anatomical shape representing different anatomical positions such as different teeth positions, for example a pre-molar, a canine, a central incisor. The different anatomical shapes may be stored in and compared or matched with a digital library which can be used during or after digital scanning and/or during design of a final prosthesis.
According to another aspect of the invention, there is provided a method of obtaining a dental impression recording positional information about a dental implant, the method comprising the steps of:
The method may further comprise the step of centering the impression component in the bore of the healing component before the step of inserting.
The method may further comprise the step of rotationally aligning the impression component in the bore of the healing component using said rotational locator before the step of inserting.
The method may further comprise the step of comparing the digital scan with a digital library containing the geometry of the healing component to determine a soft tissue emergence profile created by that specific healing component. The soft tissue emergence profile may be used during design of a final prosthesis.
Embodiments of the invention are further described hereinafter, by way of example only, with reference to the accompanying drawings, in which:
In the present disclosure, the following terms may be understood with reference to the explanations below:
The term “dental implant” includes a dental implant per se, to which the healing component defined below may be attached directly and also includes an assembly comprising a dental implant and an abutment or spacer, wherein the healing component defined below may be attached to the abutment or spacer.
The term “healing component” may mean a healing abutment, tissue former, provisional abutment, final abutment or other component attachable to a dental implant during healing of the gingiva.
The term “impression component” may mean an impression coping, scan abutment, scan peg, or other component from which an impression may be taken either by using impression material or by using digital scanning.
The term “upper” or “coronal” refers to the direction towards the crown of the tooth.
The term “lower” or “apical” refers to the direction towards the root of the tooth.
The term “attachable” may mean directly attachable or indirectly attachable with one or more intermediate components therebetween.
The term “bore” may have a substantially constant diameter or may have a varying diameter along its length and/or may have localised formations on an internal surface thereof.
The terms “axial locator” and “rotational locator” may mean components which limit axial and rotational (respectively) movement of one component in relation to another.
The term “anatomical shape” may mean a shape which resembles or mimics a natural anatomical structure. The anatomical shape may resemble an emergence profile, for example, whose actual cross-sectional shape at the level of the gingiva margin depends on the type of tooth (e.g. round in the case of an incisor, more triangular or square in the case of others).
Referring to
The impression component comprises a material and/or a textured surface compatible with digital scanning. The material and/or textured surface should be non-reflective, or at least one with minimal reflection which can be achieved for example by roughening the surface or using optically matt materials.
An impression coping suitable for digital scanning requires distinct geometrical features that can be used as markers and recorded by the scanner and subsequently identified by the software to identify rotation, centre, height and angulation relative the implant and the implant axis. With reference to
An optional pyramid formation 23 on the top of the upper portion can be used as marker during a digital scanning process. Other shapes are possible for the marker, for example a line, cone or other shape having a defined tip, plane, point or corner. Undercuts and other more complex shapes are not required for digital scanning as these undesirably add complexity during capturing of the shape during the scan and during processing by the software.
The lower portion 22 of the impression component is provided with a formation 24 that can be used as a rotational locator to rotationally align the impression component with a healing component as the two are assembled together. The formation 24 may be a longitudinally-extending protrusion or lug.
Referring to
The upper portion 11 includes a formation 14 that can be used as a rotational locator to rotationally align the healing component with an impression component as the two are assembled together. In the illustrated embodiment, the formation 14 is a longitudinally-extending groove into which the protrusion 24 of the impression component can be located.
Further axial downward movement of the impression component cannot occur until the protrusion 24 is rotationally aligned with the groove 14 in the healing component (see
To further improve and secure centering of the impression component 20 in the healing component 10, a press-fit feature is provided in the form of, for example, a localised narrowing 18 or ridges in the internal bore 13 positioned below the upper portion 13. The press-fit feature can engage with the outer surface, including the lower portion 27, of the impression component 20. To improve the start of the press-fit, a recess 26 of the impression component can be incorporated to delay the press-fit engagement until a more axially stable interaction between the two components has been reached.
Now preferably under press-fit, yet further downward axial movement of the impression component eventually causes the apical end surface 25 to reach and come to rest on the shoulder 16 as shown in
Once the impression component has been fully engaged with the healing component, the impression can be taken in a conventional way, either using impression material or by using digital scanning. A digital library may be provided containing positional data about the various available combinations of impression components and healing components.
Once the impression has been taken, it is easy to remove the impression component from the assembly when it is no longer needed, leaving the healing component undisturbed for healing to continue.
Although the above-described example has the impression component engaged in a bore of the healing component, an alternative embodiment is envisaged in which the healing component is engaged in a bore of an impression component.
Use of the dental implant assembly described herein offers significant advantages over the known prior art. In particular, the number of stages can be reduced, saving cost and resource, and disrupting the healing process less, and providing a means to make an accurate impression of the soft tissue emergence profile before it collapses. Although the above-described example involves a temporary healing abutment which can later be replaced with a provisional or final abutment associated with a prosthesis, it is alternatively possible for the provisional or final abutment itself to perform the function of the claimed healing component if it has the appropriate anatomical shape for healing.
Some implant systems have a small number of implant-to-abutment connections, for example one or two major, for a wide range of implant diameters 3, 5-8 mm and different geometries like straight and tapered. In such an implant system, if the anatomical shape of the healing component matches the shapes of the abutments in the implant system (possibly made in different materials, or shapes in a digital library or both), then a very effective working process flow can be achieved whereby any implant size can be treated, using only one impression component, matching the final prosthesis (either a stock abutment or an individually designed abutment created from a digital library) with the marginal shape of the healing component thus improving aesthetics, minimizing pain and decreasing cost for the treatment.
The prior art techniques typically require three surgical interventions over the following eight steps (surgical intervention I for step a, surgical intervention II for steps b-f and surgical intervention III for steps g-h):
The technique described herein completely eliminates two of these stages (b and f) and one surgical intervention (II). Instead only two surgical interventions are required over the following six steps (surgical intervention I for step a and surgical intervention II for steps e-f):
Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.
Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1712780.4 | Aug 2017 | GB | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/GB2018/052265 | 8/9/2018 | WO | 00 |
