Patent Description:
The placement of a dental implant involves many operations, some of them being related to the manufacturing and handling of healing abutments and impression posts.

In some implant operations, when a dental implant is installed, it is convenient to place an adjacent scan post to provide external information about the evolution in the position and orientation of the dental implant, which is usually very difficult to obtain by external scan methods.

Scan posts are known to help dentists to calculate the location and orientation of a dental implant which has been installed in a patient's mouth. These scan posts are installed adjacent to a dental implant, and their shape is scanned by a device so that the orientation and the relative position of this scan post with respect of the rest of the teeth or another known reference is acquired. These data provide reliable information about the position and orientation of the dental implant which is not easily accessible.

Some documents provide ways of installing and measuring this information.

For example, in document <CIT>, a scanning member is provided, comprising a head portion with a flat top surface and a body portion which is non-rotationally coupled to the dental implant. The body portion is physically attached to a bottom surface of the head portion to form a generally "T" shape. This scanning member comprises at least two scan marks and also provides an internal through hole for receiving a screw to threadably couple with a threaded bore within the dental implant. By scanning the scanning member, the position and orientation of the hidden dental implant may be calculated. Anatomically shaped healing abutments that function as scan posts have been proposed such as the ones disclosed in <CIT>, or<CIT>.

The problem the clinicians face with these components is the fact that the orientation of the prosthetic connection of the implant in the jaw restricts the orientation of the anatomical component-body of these scan posts. Some known scan posts, such as the ones disclosed in documents <CIT> or <CIT> may allow more than one different assembly position between the core and the body. However, the disclosed features provide limitations on the degree of orientation correction that can be achieved. This is an important problem, since the anatomical piece must be oriented with extreme accuracy in the jaw in order to match the shape of the future implant prosthesis that will be installed onto the implant at the gingival level. If the prosthetic connection of the implant is not perfectly oriented, then this goal cannot be achieved, and the resulting soft tissue conditioning will be wrong; fact that can make the use of these components impossible or even dangerous. The mere use of different size or shape components in order to overcome the problem of proper fit is not an adequate solution since every particular implant site needs specific shape and size soft tissue conditioning that must not be compromised. The only way such a problem could be solved is by utilizing scan posts that comprise a non-engaging prosthetic connection, so that the whole system core and body can rotate in space. However, this would make the scanning process useless, since the orientation of the prosthetic connection of the implant will not be able to be identified and it must be identified during the scanning process and incorporated in the process for the final prosthesis design and fabrication. Moreover, the engagement between scan post and implant during a healing period is fundamental to allow stable fit and avoid micromovement between the two elements that lead to unfavourable hard and/or soft tissue recession.

An improvement in the orientation possibilities is therefore sought.

Document <CIT> discloses a dental system which can form an emergency profile similar to the state of an emergency natural tooth. The system of the present invention comprises a fixture combined with an alveolar bone and including an installation hole with the upper side opened; an abutment combined with the fixture through the installation hole; and a healing cap combined with the abutment to form an emergency profile on the gum. The healing cap is composed of a lower end part with circular exterior; an upper end part bigger than the lower end part and having a rectangular exterior; and a connection part connecting the lower end part and the upper end part, and is made of a synthetic resin material. The healing cap comprises an eccentric extension part extended toward at least one side over the lower end part to the upper end part.

Document <CIT> discloses a scan posts system with scan posts. Each scan post comprises a scan post core and a scan post body surrounding the core and resting in the shoulder of the core, wherein at least part of the scan post body is intended to be in contact with healing tissue. Each scan post body belongs to a group of scan post bodies comprising at least a combination of two different shapes with three different sizes and at least one height. Each scan post body comprises at least one scan mark suitable for providing information about the shape, size and height of the scan post to a scanning device, this information being useful for designing a dental implant prosthesis. The invention also provides a method of manufacturing a dental implant prosthesis using such a system.

However, none of them solves this problem as the present invention does.

The invention provides an alternative solution for this problem by means of a scan post according to claim <NUM>, and a scan post system according to claim <NUM>. Preferred embodiments of the invention are defined in dependent claims.

In a first inventive aspect, the invention provides a scan posts for being used in designing a dental implant prosthesis, the scans post comprising.

The fixing means comprises a securing screw which is configured to securely attach the scan post body to the scan post core and an auxiliary securing screw configured to securely attach the scan post core to an implant.

This scan post presents a customizing attachment between the scan post body and the scan post core. The scan post body is installed and may rotate freely until the fixing means fix the position of the body with respect to the core. The angular position may be chosen freely, not being restricted by a particular number of positions.

The solutions presented by the aforementioned previous art documents, alone or in combination, only allow for certain degrees of corrections, like for instance in steps of <NUM>° rotation. Thus, smaller (or intermediate) degrees of correction cannot be achieved. Even if a person skilled in the art increases the amount of engaging means present on the core or the body in the light of the aforementioned documents, the final effect can again not be the same with the one provided by the inventive scan post system since these engaging means must comprise certain dimensions in order to be able to function, where these dimensions will put a limit on the number of these means that can be added to the elements; Thus again they will provide for steps of orientation correction.

This fact make the scan post set of the invention suitable for helping the implant process occur in a more healthy way, since the scan post are intended to improve the healing process, since the ability of selecting the exact orientation of the scan post body with respect to the scan post core helps the tissue to grow in a more natural way, avoiding problems in further stages of this process. This scan post is helpful for manufacturing a dental implant prosthesis with anatomic sub-gingival and cervical profile. It is understandable that the central cavity of the scan post body can have alternative shapes, as will be defined later in particular embodiments, that will allow the desired function of the inventive scan post, such as a lunar shape, a cylinder with beveled walls, etc, these shapes being either symmetrical or asymmetrical. In some of the particular embodiments of the scan post, the minimum diameter of the scan post body is not larger than the maximum diameter of the shoulder of the scan post core.

The design of the proposed engaging means allows the reversible engagement between the two components and this provides the advantage of the same components to be re-used when needed; meaning if the scan body malfunctions then it can be disassembled from the core and the same core can be used with another body, or vice versa.

In particular embodiments, the scan post core further comprises a protrusion which protrudes a protrusion length from the pillar and the scan post body comprises a second portion which extends over at least <NUM>° and has a shape such that allows the movement of the protrusion along the second portion.

The scan post core comprises a protrusion and the scan post body comprises two portions: a first portion is intended to house the main circular portion of the scan post core and a second portion is intended to house the portion of the scan post core which comprises the protrusion. Hence, this customizing attachment provides a continuous angular customization between the rotation position of the body with respect to the core in a scan post. There is no limitation in the number of degrees that the scan post body should have with respect to the scan post core, any number between <NUM> and the extension of this second portion, which may be chosen by the dental practitioner. The fit between the first portion of the central cavity of the scan post body and the portion of a cylinder of the scan post core provides lateral stability between the scan post body and the scan post core, due to the fit between the portion of a cylinder of the scan post body and the first portion of the central cavity of the scan post core.

In some particular embodiments, the second portion of the central cavity of the scan post body extends over at least <NUM>°, particularly at least <NUM>°, particularly at least <NUM>°, particularly at least <NUM>°, particularly at least <NUM>°.

Any angular extension is suitable for the adjustment of the orientation of the scan post body with respect to the scan post core. The greater the extension angle, the easier this adjustment will be.

In particular embodiments, the second portion of the central cavity of the scan post body has a cylindrical shape with a diameter corresponding to at least the sum of the outer diameter and the protrusion length.

In these cases, the fit between the protrusion and the second portion of the central cavity cooperates with the fit between the portion of a cylinder of the scan post core and the first portion of the central cavity of the scan post body to provide lateral stability between the scan post body and the scan post core.

In some particular embodiments where the scan post core comprises a protrusion which protrudes a protrusion length from the pillar, the central cavity of the scan post body provides for a top and a bottom portion; where the bottom portion has a diameter smaller than the top portion and the bottom portion is intended to house the main circular portion of the scan post core that is located below the protrusion of the scan post core and the top portion is configured to house the portion of the pillar comprising the protrusion allowing the latter to freely rotate within this top portion. This bottom portion further comprises a recess configured to allow the free passing of the protrusion of the pillar. This recess allows the installation of the body on the core so that the protrusion of the pillar passes through the bottom portion until is finally located within the top portion of the central cavity, while at the same time the scan post body and the shoulder of the scan post core fit perfectly and form a continuous and derivable surface.

In some particular embodiments, the core mark provides the information for the three-dimensional location of the scan post core in space. This scan mark provides the information for the three-dimensional position and orientation of the core and thus of the three-dimensional position and orientation of the implant that is connected with, allowing the practitioner to freely position the body. In these cases, the scan mark of the scan post body is not necessary, or at least irrelevant to the implant position, since it only provides information for the scan post body orientation in space, which may be different from the orientation of the implant. In these embodiments, the scan post core may provide information about the position and orientation of the implant regardless the orientation of the scan post body, on the contrary to previous art documents, which disclose scan marks present on the body aiming to locate implant position and orientation and thus making impossible the functionality of such a scan post where the relationship between body and implant is not standardized.

Providing a scan mark on the core provides a very particular technical effect, because this is the element of the scan post system that has a constant relationship with the implant that is connected with. The core comprises a prosthetic connection that may have different geometry, depending on the implant systems. The prosthetic connection of the core matches with the connection of the implant in such a way that no rotation is allowed between the two elements. Thus, once the core is installed onto the implant, the resulting final assembly is standardized. The geometry of the prosthetic connection can allow different configurations which result in the same effect, since the geometry of the prosthetic connections is symmetrical. The scan mark on the core provides the information for this final three-dimensional configuration of assembly that includes the orientation and location of the implant's prosthetic connection and platform.

In some particular embodiments, the scan post core further comprises a cap, wherein the core mark is located in a position of the cap which depends on the position of the protrusion of the scan post core.

This makes the scan mark easier to be detected, since it is more available in the outer cap than directly located in the protrusion of the scan post core. It is understandable that the engaging means between the scan post core and the cap in particular embodiments could be different, meaning the core comprising a recess and the cap a protrusion, or any other surface geometry that can allow a stable, reproducible fit between the two elements.

The scan cap can be installed onto at least part of the core's pillar and within at least part of a housing of the scan post body, engaging at least part of the protrusion of the pillar. This scan cap comprises a scan mark that is located at the surface that engages the protrusion of the pillar. The scan mark of the scan cap has a stable relationship with the position of the protrusion when the scan post system is assembled. The goal of this scan cap is to "transfer" the scan mark of the core on a more coronal position that is easier to be identified and marked by the intra-oral scanner during the scanning process.

In some particular embodiments the scan marks present on the core, and, or the body and/or the cap are all identified and processed through suitable CAD-CAM software so that the final configuration, of the generated by the practitioner scan post after final assembly of all components, is achieved.

In the particular embodiments comprising a cap, the fixing means comprises a securing screw which is configured to securely attach the scan cap to the scan post body to the scan post core and an auxiliary securing screw configured to securely attach the scan post core to an implant.

Securing screws mean a reliable solution for this purpose. Since the scan post body may be freely rotated with respect to the scan post core, some fixing means are needed. One option is to use a sole screw for fixing the three, or four elements (body, core, or body, core cap and implant) and an alternative solution is to use one screw to fix the scan post body to the scan post core, or the scan cap to the scan body to the scan core and an auxiliary securing screw to attach the scan post core to an implant.

In some particular embodiments, the securing screw comprises an opening configured to allow the protrusion of the scan post core to be visible from outside the scan post.

In some particular embodiments, the protrusion of the scan post core stands out from the opening of the securing screw.

This allows the position of the protrusion to be visible by the practitioner. In those cases where the scan post core usually comprises a scan post mark, this embodiment is further advantageous since it provides the practitioner with the possibility to digitally scan the mark without removing the scan post body.

In some particular embodiments, the scan post further comprises glue or a friction fit connection between the scan post body and the scan post core.

In some particular embodiments, at least part of the scan post body and the shoulder of the scan post core form a continuous and derivable surface.

In each of the scan bodies, the surface formed by the shoulder and the scan post body is intended to be in contact with healing tissue when this tissue grows around the installed scan body. Hence, this scan post can further assist with proper shaping of the healing soft tissue according to the desired cervical and sub-gingival shape of the final prosthesis and accurately recording the latter through a digital intra-oral scanning process.

In some particular embodiments, the continuous and derivable surface formed by the scan post body and at least part of the scan post body comprises a convex portion and a concave portion, the concave portion being closer to the prosthetic connection than the convex portion.

This structure of convex and concave portions is natural for the healing tissue, thus contributing for a natural healing process.

In some particular embodiments, the pillar axis and the connection axis cut each other and form an angle comprised between <NUM> and <NUM>°. Once the scan post body is installed around the scan post core, the body axis will not be parallel to the connection axis, but will also form some angle, although it may be different from the angle formed between the pillar axis and the connection axis. These embodiments will be called "angulated" scan post installation and are useful when the shape of the edentulous space is not suitable for installing a straight scan post.

In some particular embodiments, the pillar axis and/or the connection axis is parallel to the body axis and is arranged at a distance between <NUM> and <NUM> therefrom. This will provide for an "off-set", or "eccentric" scan post installation.

In some particular embodiments, each scan post body further comprises second retention means and the scan post core comprises second reception means, the second retention means being arranged to abut against the second reception means to reversibly block the movement of the scan post body with respect to the scan post core in a direction parallel to the pillar axis, while at the same time allowing the free rotation of the scan post body with respect to the scan post core.

This provides stability between the body and the core, preventing a vertical movement between them.

In some particular embodiments, the second retention means comprises a protruding arc extended along a part of the second portion of the scan post body, and the second reception means comprises a recess performed in the protrusion of the scan post core, in such a way that the protruding arc has a height equal to the height of the recess.

In some particular embodiments, the second retention means comprises a recess extended along part of the first portion of the scan post body, and the second reception means comprises a second protrusion of the scan post core, in such a way that the second protrusion has a height equal to the height of the recess.

With these particular embodiments, the practitioner may install the body on the core and rotate until the second retention means engage with the second reception means, then the body may be freely rotated with respect to the core to reach the desired orientation. In this movement, the common height of the recess and the protruding arc will prevent the scan post body from moving in a direction parallel to the pillar axis.

In some particular embodiments, there is a cross section to the scan post body perpendicular to the body axis which cuts both the first portion and the second portion of the central cavity. In other embodiments, the central cavity of the scan post body comprises a beveled wall which connects the first portion and the second portion, so there is not any cross section perpendicular to the body axis which cuts both the first portion and the second portion of the central cavity, because the first portion and the second portion are separated by the beveled wall.

These are alternative options to achieve the technical effect of the invention. It is understood that the design of the proposed engaging means allows the reversible engagement between the body and the core and this provides the advantage of the same components being able to be disassembled and to be re-used when needed; meaning if the scan body malfunctions then it can be disassembled from the core and the same core can be used with another body, or vice versa. Moreover, the scan post core can be maintained installed onto the implant and the scan post body and/or cap can be uninstalled from the core and be replaced by the final implant prosthesis that will now be supported by the scan post core.

In some particular embodiments, the scan post body comprises two different parts attached to each other by means of mechanical and/or chemical retention means.

In some particular embodiments, these two parts are arranged one inside the other one, so that a first part reproduces the internal geometry of the scan post body while the second one reproduces the external geometry of the scan post body. These two parts may be produced by milling and then may be coupled and attached by means of mechanical and/or chemical bonding with, or without suitable bonding agent, such as glue. Alternatively, these parts may be produced by injection molding where the first part is installed onto the scan post core present in a suitable well of a mold that comprises wells with anatomical shape and a suitable material is injected within the well so that it covers at least part of the first part without engaging the scan post core. Once the material is set, it will form an anatomical external shape that has become one piece with the first part or a separate piece that will then be attached to the first part.

In a second inventive aspect, the invention provides a scan post system suitable for being used in designing a dental implant prosthesis, the scans post system comprising a plurality of scan post cores according to the first inventive aspect, wherein the system comprises at least four different scan post bodies with at least two different shapes with two different sizes and at least one height.

A set with a plurality of scan posts portions.

Such set does not form part of the claimed invention. Each scan post comprises one scan post core and one scan post body, but one single scan post core may be attached with different scan post bodies, there is no need that there is the same number of scan posts cores than of scan posts bodies. The scan post core of each scan post could be substantially the same: the scan post is characterized by the scan post body, which is different from the scan post body of a different scan post of the system. These scan bodies are selected from a group of scan bodies which comprises a combination of different features. For example, if the group of scan bodies comprises three different sizes, two different shapes and two different heights, the scan body system comprises <NUM> different scan posts. The scan post core of each one the <NUM> scan posts are substantially identical, but each scan post comprises a scan body which is selected from this group of <NUM> scan post bodies. As a consequence, the most suitable scan body may be selected to be part of the dental implant prosthesis design process, depending on the shape of the patient's jaw and natural dentition.

It is understandable that the above system could also be available in a more or less simplified format comprising a smaller or a greater number of components. The shapes and dimensions of anterior teeth and premolars are very similar, so the dental practitioner could prefer using a combo shape so that a set of three components (same shape but <NUM> different sizes) would be able to closely mimic these shapes in a satisfactory manner. The same applies for the shapes of maxillary and mandibular molars. Thus a system comprising six scan bodies (three for anterior and premolars with sizes small, medium, large and three for molars, small medium, large) could cover the basic needs of most clinical cases in an acceptable fashion, while reducing the number of components and thus the cost of the system for the dentist.

It is also understandable that the components of the system could be available in the market also as separate pieces so that a dentist can purchase when needed only the scan post in need for his clinical case. If for example one of the scan posts of the system is lost or malfunctions, then the dentist will be able to replace this specific scan post in need.

In some particular embodiments, the second portion extends over at least <NUM>°.

Providing this second portion with <NUM>° extension on the body covers all possible clinical cases since the core itself can be installed onto the implant in more than one positions as these possibilities relate to the geometry of its prosthetic connection. Thus, by doing so the final orientation of the body can be literally achieved in <NUM>° by simply installing the core in an opposite direction. This embodiment allows a controlled range of rotation. However, it is understandable that the second portion can always be increased further than <NUM>° if clinical needs dictate so in the future.

The proposed invention refers to scan posts that comprise a body with anatomical shape, meaning no cylindrical. This shape can vary, being symmetric or asymmetric, regular or irregular, in an effort to match the shape and dimensions of at least of part of the crown and, or the root trunk of the natural teeth as close as possible.

The inventive scan post could comprise one shape and, or size only, but it is understandable that in order to achieve a superior system that can cover all different clinical cases, a set of scan posts with different shapes and, or sizes is needed.

In some particular embodiments, the system comprises at least eighteen different scan post bodies with at least three different shapes with three different sizes and more than one height; and wherein each scan post body comprises at least one scan mark suitable for providing information about the shape, size and height of the scan post body to a scanning device, this information being useful for designing a dental implant prosthesis.

Scan bodies are therefore identified by the shape thereof in the portion with the maximum equivalent diameter, which is usually the top portion of the scan body, the portion which is farthest from the prosthetic connection. This way of identifying the main shape of the scan body is an easy way of choosing a preliminary shape for each particular type of tooth.

The shapes of a triangle with rounded edges, square with rounded edges, parallelogram with rounded edges or ovoid are a way of defining these shapes. As may be seen throughout the document, the "ovoid" shape has four curved sides with four rounded corners, but any other suitable shape may be chosen in order to adjust to the edentulous space.

The scan post bodies have a cross section which may vary in size and/or shape while advancing upwards from the shoulder, but all cross sections are oriented according to parallel planes, which are perpendicular to the pillar axis. These types of cross sections adapt to the dental pieces in a very good way. Triangles with round edges, squares with round edges and rectangles with round edges are examples of shapes which may adapt to the cervical portion of the patient's edentulous space.

In some particular embodiments, the height of the scan body of each scan post is defined by the distance between the cross section of the scan post with minimum equivalent diameter and the cross section of the scan post with maximum equivalent diameter, wherein the equivalent diameter is the maximum distance between two points belonging to said cross section, and particularly wherein this height is classified in ten different heights, namely <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM>. It should be understood that these heights are just a particular example based on currently available data and can be further adjusted or enriched if clinical needs in the future demand to do so.

The relevant height of a scan post is not always the total height thereof. The distance between the plane with maximum equivalent diameter and the plane with minimum equivalent diameter is a good indicator, since the maximum equivalent diameter defines the width of the scan post and the future dental implant prosthesis.

Depending on the features of patient's teeth, it will be suitable to choose a scan post belonging to one of these height categories.

In other particular embodiments, the height of the scan post system is defined from the height of the scan post core's shoulder.

These alternative embodiments are useful when an alternative methodology is used.

In some particular embodiments, the size of the scan body of each scan post is defined by the equivalent diameter of the cross section of the in a plane perpendicular to the pillar axis which crosses the scan post at its maximum equivalent diameter, wherein the equivalent diameter is the maximum distance between two points belonging to said cross section, this size being classified into at least three categories, the small one being comprised between <NUM> and <NUM>, the medium one being comprised between <NUM> and <NUM> and the big one being comprised between <NUM> and <NUM>.

The size of the scan post body is another key feature, which is chosen depending on the type of the tooth and on the patient itself. In particular cases, this size category depends on the shape of the scan post. For example, a triangular shape will be available in three sizes, a small size of <NUM>, a medium size of <NUM> and a large size of <NUM>. But another shape, such as a parallelogram size, may be available in a small size of <NUM>, a medium size of <NUM> and a large size of <NUM>.

In other particular embodiments, the size of the scan post system is defined from the size of the prosthetic connection and/or from the diameter of the scan post core's shoulder.

In some particular embodiments, at least some scan post bodies have different shapes at different cross sections perpendicular to the pillar axis, and wherein the scan marks comprise information about these different shapes and the distance of the perpendicular planes from the top of the scan post body.

The anatomical shape of a scan post may be therefore chosen, not only by the main shape, which is defined by the shape in the cross section with maximum equivalent diameter, but also by intermediate shapes, which may be different from this main shape. This information is encoded by the scan marks so that the dental practitioner may have complete information of the scan post which has been placed in the patient's mouth.

The root trunk is a portion of the tooth root which has a vertical dimension of several millimeters. The crown of the tooth has a portion called cervical margin, which is located at the level of the free gingival margin. The cervical portion usually has a vertical dimension between <NUM> and <NUM>. The scan posts of the invention are adapted to fit these two portions and can comprise a body with anatomical shape, which means different from a cylindrical shape, where this anatomical shape can be symmetric or asymmetric, regular or irregular.

A circular cross section in this location with minimum equivalent diameter, which is usually the portion which is closest to the shoulder, is advantageous, since the anatomical profile is mostly needed at the area of the gingival margin that will receive the cervical margin of the implant prosthesis. Below this area there is a transition zone which coincides with this zone with minimum equivalent diameter, wherein maximum tissue thickness is desired and a circular cylindrical shape is advantageous to provide the least diameter circumferentially in comparison to other shapes.

Scan marks help the practitioner when identifying scan posts which have this "combo shape", since the healing tissue may have grown to such a height that visual identification provides no help to determine the best shape for the dental implant prosthesis.

Accordingly, while embodiment can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed. On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate.

<FIG> shows a generic view of a scan posts system <NUM> according to the invention. This scan post system is suitable for being used in designing a dental implant prosthesis.

As will be shown below, each scan post belonging to the scan posts system comprises a scan post core and a scan post body. The scan post body is different for each scan post, while the scan post core is substantially the same for each scan post.

This system <NUM> comprises <NUM> scan posts <NUM>, which responds to the combination between four different shapes (rectangular with round edges, triangular with round edges, ovoid and square with round edges), three different sizes (small, medium and large) and three different heights (short, medium and long).

Every scan post <NUM> comprises several scan marks <NUM>, one of them containing information about the shape, the size and the height of the scan post <NUM>, which may be easily read and interpreted by a scanning tool. Further, other scan marks will be also useful for the scanning tool to provide position and orientation information of the scan post <NUM>.

<FIG> shows a vertical section view of a particular embodiment of a scan post <NUM> belonging to a scan posts system according to the invention.

This scan post <NUM> comprises a scan post core <NUM> and a scan post body <NUM>. The scan post core <NUM> comprises a prosthetic connection <NUM>, a pillar <NUM> defining a pillar axis 12a and a protruding shoulder <NUM> between the pillar <NUM> and the prosthetic connection <NUM>. The scan post body <NUM> in turn surrounds the pillar <NUM> and rests in the shoulder <NUM>. This scan post body <NUM>, or at least part of it, is intended to be in contact with healing tissue. The scan post <NUM> further comprises a retention screw <NUM> which is configured to provide a secure attachment between the scan post body <NUM> and the scan post core <NUM>. An auxiliary securing screw <NUM> is used to provide a secure attachment between the scan post core <NUM> and an implant (not shown in this figure). In yet different embodiments, other fixing means, such as glue or a friction fit connection is also used to attach these elements.

The lateral surface of the scan post body and the shoulder form a continuous and derivable surface. This surface comprises a convex portion <NUM> and a concave portion <NUM>, the concave portion <NUM> is closer to the prosthetic connection <NUM> than the convex portion <NUM>.

The height h of the scan body of this scan post is defined as the distance between the plane with minimum diameter and the plane with maximum diameter. In this figure, these planes are seen as lines <NUM>, <NUM>, since they are perpendicular to the pillar axis 12a.

<FIG> shows the same scan post <NUM> as the <FIG>, but to show different features.

In this figure, the pillar <NUM> comprises a portion of a cylinder 12b which has an outer diameter od and a protrusion <NUM> which protrudes a protrusion length pl from the pillar <NUM>. In this figure, the protrusion <NUM> is shown to the right, and comprises a protrusion mark <NUM> on top thereof.

As shown in <FIG>, the scan post body <NUM> comprises a central cavity with a first portion <NUM> having a cylindrical shape with a diameter substantially identical to the outer diameter of the cylinder of the pillar and a second portion <NUM> which extends over <NUM>° and has a cylindrical shape with a diameter corresponding to the sum of the outer diameter and the protrusion length. With this shape, the first portion <NUM> is suitable to receive the portion of a cylinder of the pillar while the second portion <NUM> is suitable for letting the protrusion (not shown in this figure) to freely rotate so that the scan post body <NUM> may be oriented in different orientations with respect to the scan post core <NUM>.

As is clearly shown in this picture, there is a cross section to the scan post body perpendicular to the body axis (i.e. a horizontal plane) which cuts both the first portion and the second portion of the central cavity, since both first and second portions are located at the same height of the scan post body.

This scan post <NUM> comprise one mark <NUM> located on top of the scan post body <NUM>, but any other location would be suitable as well. This scan mark <NUM> is capable of providing the necessary information for identifying the three dimensional position of the said scan post in the jaw, since the scan post body comprising a non-circular shape provides reference points due to its shape that, in combination with the scan mark, are enough to provide all the necessary information needed to the CAD-CAM station.

<FIG> shows a particular embodiment of a scan post <NUM> according to the invention, where the securing screw <NUM> comprises an opening <NUM> configured to allow the protrusion and the protrusion mark <NUM> of the scan post core to be visible from outside the scan post. This is useful so that there is no need to remove the scan post body <NUM> to scan the position of the protrusion mark <NUM>.

<FIG> shows a particular feature which may be comprised in any of the scan posts according to the invention.

In this figure, it may be seen how the scan post body comprises a protruding arc <NUM> and the scan post core comprises a recess <NUM>. The protruding arc <NUM> and the recess <NUM> are configured to match due to the fact that they have the same height (measured in the direction of the pillar axis), thus reversibly blocking the movement of the scan post body <NUM> with respect to the scan post core <NUM> in a direction parallel to the pillar axis, while at the same time allowing the free rotation of the scan post body <NUM> with respect to the scan post core <NUM>.

The protruding arc <NUM> extends only along a part of the second portion of the scan post body, leaving a free space <NUM> so that the protrusion is introduced. Once the protrusion is introduced, the protruding arc <NUM> and the recess <NUM> are at the same height and the blocking may take place by the rotation of the scan post body with respect to the scan post core.

<FIG> shows an alternative of the feature illustrated in <FIG>. In this case, the protruding arc <NUM> and the recess <NUM> are not located adjacent to the shoulder of the core, but at a height which is located approximately in the middle of the protrusion.

This makes the recess <NUM> to be fitted between two protrusions of the pillar, thus increasing stability.

<FIG> show different cross sections of this scan body <NUM>, the two of them being according to these aforementioned planes of maximum and minimum equivalent diameter. The cross section shown in <FIG> is made according to the plane <NUM> where the equivalent diameter is the maximum one, and in this case corresponds to the top portion of the scan post body. The cross section shown in <FIG> is made according to the plane <NUM> where the equivalent diameter is the minimum one, and in this case corresponds to the bottom portion of the scan post body.

The equivalent diameter is considered as the maximum distance between two points belonging to said cross section.

<FIG> shows the cross section of a particular example of a scan post where the shape in this maximum equivalent diameter section is an ovoid with rounded edges.

<FIG> shows in turn the cross section of the same scan post wherein the shape in this minimum equivalent diameter section is a circle.

The size of the scan body of each scan post is defined by the equivalent diameter of the cross section of the scan body in a plane perpendicular to the pillar axis which crosses the scan post at its maximum equivalent diameter. As a consequence, in this case, this scan post would be considered as an ovoid scan post. However, the rounded cylindrical shape in the bottom portion is advantageous, since maximum tissue thickness is desired in this zone and a circular cylindrical shape is advantageous to provide the least diameter circumferentially in comparison to other shapes.

This scan post starts with a cylindrical shape and then expands laterally upwards in a concave manner till it reaches its maximum diameter and at which point comprises a generally ovoid shape with rounded edges. The vertical location of the maximum diameter and thus the location of the anatomical shape may be different in the different groups and within the same group of shapes. The inventive custom scan posts comprise marks that additionally provide this information.

This size may be classified into at least three categories, the small one being comprised between <NUM> and <NUM>, the medium one being comprised between <NUM> and <NUM> and the big one being comprised between <NUM> and <NUM>.

<FIG> show the feature of a cap to be installed in a scan post according to the invention.

<FIG> shows a cap <NUM>. This cap <NUM> comprises a first recess <NUM> to match the protrusion of the scan post core and a second recess <NUM> which is located at the same angular position than the first recess <NUM>.

The scan cap can be installed onto at least part of the core's pillar and within at least part of the housing of the scan post body, engaging at least part of the protrusion of the pillar as seen in <FIG>. Since the scan mark of the scan cap and the one of the scan post core have a stable relationship to each other when the scan post system is assembled. The goal of this scan cap is to "transfer" the scan mark of the core on a more coronal position that is easier to be identified and marked by the intra-oral scanner during the scanning process. Therefore, it is understood that the protrusion of the pillar per se does not need to be a scan mark for the scan mark of the cap to maintain its functionality as a scan mark providing the information of the core and thus of the implant 3D position and orientation.

<FIG> and <FIG> show a particular example of a scan post body belonging to a scan post according to an embodiment of the invention.

In this case, the scan post body comprises two different parts <NUM>, <NUM> which are manufactured separately and then attached to each other by means of an adhesive.

<FIG> shows an exploded view of a scan post where the scan post body comprises these two parts <NUM>, <NUM>. The first part <NUM> reproduces the internal geometry of the scan post body. In this first part <NUM>, the relevant geometry is the internal one, which in this case reproduces the internal shape of the scan post of <FIG>.

The external geometry of this first part <NUM> is designed to match with the internal geometry of the second part.

The second part <NUM> reproduces the external geometry of the scan post body and is coupled to the first part to form a scan post according to the invention.

These two parts may be produced by milling and then may be coupled and attached by means of an adhesive. Alternatively, these parts may be produced by injection molding where the first part is installed onto the scan post core present in a suitable well of a mould that comprises wells with anatomical shape and a suitable material is injected within the well so that it covers at least part of the first part without reaching the scan post core. Once the material is set, it will form an anatomical external shape that has become one piece with the first part or a second piece that provides for the second part with anatomical shape that will then be attached to the first part.

The main advantage of splitting the manufacturing of the scan post body into these two pieces is that they can be used in an in-office tool, so that the anatomical shapes can be formed through injection moulding process by the dentist. The internal connection is therefore uncoupled from the manufacturing process of the anatomical external shape.

In an example of a manufacturing method, the dentist first installs the scan post core inside a mould. Then, the cap is installed on the pillar of the scan post core. Next step comprises introducing flowable composite material, to be cured by light. Thus, the cap and the composite become one piece with the desired shape. After this process, the scan post core and the customised cap may be used.

The abutment core is not affected by this process and the inner surface of the inventive cap that interacts with the core is not affected by the process either. Hence, the inventive scan post's function is not affected with its methodology of use.

Thus, the proposed embodiment allows a dentist to have a customisation mould to create different shapes and sizes of anatomical bodies without the need of different cores and caps available in their office.

Claim 1:
Scan post (<NUM>) suitable for being used in designing a dental implant prosthesis, the scan post (<NUM>) comprising
a scan post core (<NUM>) comprising a prosthetic connection (<NUM>) defining a connection axis (11a), a pillar (<NUM>) defining a pillar axis (12a), a shoulder (<NUM>) located between the pillar (<NUM>) and the prosthetic connection (<NUM>) and a core mark (<NUM>);
a scan post body (<NUM>) adapted to be installed around the pillar (<NUM>) of the scan post core (<NUM>) and resting in the shoulder (<NUM>) of the scan post core (<NUM>), the scan post body (<NUM>) defining a body axis (2a), wherein at least part of the scan post body (<NUM>) is intended to be in contact with healing tissue;
wherein
the pillar (<NUM>) comprises at least a portion of a cylinder which has an outer diameter;
the scan post body (<NUM>) comprises a central cavity with a first portion having a cylindrical shape with a diameter such to fit the portion of a cylinder of the pillar, so that when the body is installed around the pillar, the scan post body is allowed to freely rotate around the scan post core with lateral stability; and
the scan post further comprises a securing screw (<NUM>) which is configured to securely attach the scan post body (<NUM>) to the scan post core (<NUM>) when a desired position of the scan post body with respect to the scan post core is achieved; and
the scan post further comprises an auxiliary securing screw (<NUM>) configured to securely attach the scan post core (<NUM>) to an implant (<NUM>).