GB2502328A

GB2502328A - A dental implant moulded with a through hole

Info

Publication number: GB2502328A
Application number: GB201209144A
Authority: GB
Inventors: Stefan Jagelid; Simon Jegou; Nicolai Bernhard
Original assignee: Nobel Biocare Services AG
Current assignee: Nobel Biocare Services AG
Priority date: 2012-05-24
Filing date: 2012-05-24
Publication date: 2013-11-27
Also published as: WO2013174521A2; WO2013174521A3; GB201209144D0

Abstract

A method for manufacturing of a dental product (1, 10), comprising a glass-ceramic dental material intended to form a dental prosthesis (12, 12') for connection to a dental implant (9) with a first side (12a, 12'a) of the dental prosthesis facing towards the implant and an second side (12b, 12'b) of the dental prosthesis facing away from the implant. the method comprises the steps of providing the glass-ceramic dental material in a mouldable state, such as in a melted, viscous form or as a powder, arranging the mouldable glass-ceramic dental material around an elongated, heat-resistant and removable object or core (5, 5'), wherein the object is arranged to extend between the first (12b, 12'b) and second (12a, 12'a) sides of the dental prosthesis (12, 12') such as to form a channel (50, 50') for a screw through the dental prosthesis. The invention also concerns a dental product (1) comprising a cavity (50) provided with a flange (50b).

Description

Method for manufacturing of a dental product

TECHNICAL FIELD

This invention relates to a method for manufacturing of a dental product. In particular, the invention relates to manufacturing of a dental prosthesis comprising a glass-ceramic material and being intended for attachment to a dental implant. The invention also relates to a dental product of the above type.

BACKGROUND OF THE INVENTION

Dental implant products are well known and relates typically to a dental implant made of titanium screwed into the jawbone combined with a dental prosthesis fastened to the implant. The dental prosthesis contains often a shaped dental material in the form of a crown cap (coping) provided onto an abutment that in turn is fastened to the implant. Such an abutment comprises an upper part that extends inside the dental material and supports it, and a lower part provided with connection means, such as threads, for connection to the implant. A suitable dental material for such applications is glass ceramics.

A common glass ceramic material in dental applications is lithium disilicate as disclosed in e.g. US 6342458. Such a material is suitable for processing a shaped dental product, such as a crown cap (coping), and provides the dental prosthesis with suitable physical properties (tooth-like appearance, high bending fracture strength, high fracture toughness value, etc.).

There are different known ways of attaching the glass ceramic material onto the abutment. An example is to form the glass ceramic material directly onto an abutment using e.g. investment casting.

A glass ceramic material is desired in many dental applications but it is not used as often as desired because handling and forming of the material as well as attaching of glass ceramic copings properly onto abutments are relatively complicated and time-consuming processes. There is a need of

improvements in this field.

SUMMARY OF THE INVENTION

An object of this invention is to provide a dental product and a method for manufacturing of dental products that exhibit improved possibilities of making use of glass ceramic materials compared to conventional products and methods. This object is achieved by the method and product defined by the technical features contained in independent claim 1 and 20. The dependent claims contain advantageous embodiments, further developments and variants of the invention.

The invention concerns a method for manufacturing of a dental product, said product comprising a glass-ceramic dental material intended to form a dental prosthesis for connection to a dental implant with a lower side of the dental prosthesis facing towards the implant and an upper side of the dental prosthesis facing away from the implant, said method comprising the step of providing the glass-ceramic dental material in a mouldable state, such as in a melted, viscous form or as a powder.

The invention is characterized in that the method comprises the steps of: arranging the mouldable glass-ceramic dental material around an elongated, heat-resistant and removable object, wherein the object is arranged to extend between the upper side and the lower side of the intended dental prosthesis such as to be capable of forming a screw channel through the intended dental prosthesis upon removal; and forming a solid body of the mouldable glass-ceramic dental material around the elongated, heat-resistant and removable object.

This way it is possible to produce a glass-ceramic dental prosthesis with a pre-shaped screw channel that allows the prosthesis to be fastened to the implant by means of a screw. The screw channel is ready for use simply by removing the object from the solid body. To make such a screw channel cavity afterwards in an already solidified glass-ceramic dental material is very costly since it is both time-consuming and tool-damaging. Thus, the inventive method makes it possible in practice to make use of a whole crown glass-ceramic dental prosthesis, which is difficult to fasten properly to implants without screws. Such a dental prosthesis does not require any intermediate abutment. The inventive method can also be used to produce copings with preformed screw holes that can be fastened to abutments.

The solid body provided with the screw channel may be larger than the intended dental prosthesis and may be machined in a later step to a tooth-like shape suitable for the dental prosthesis. Alternatively, the solid body may directly take a shape suitable for the dental prosthesis, for instance by forming the body/dental prosthesis by investment casting using a model of a plastic or wax material that can be burned out when the mould has been created. A 3D-printed plastic model can be used.

In an embodiment of the invention the object has a part that allows gripping for pulling the object out of the solid body. This part can be a part of the object that protrudes out from the solid body. Such a protruding part can be a simple extension of the object but it can also comprise various items that facilitate gripping. As an alternative, or in combination, the part that allows gripping can be arranged inside the object, such as internal threads accessible from the end part of the object.

Preferably, the object has a circular cross section. This is suitable for a screw channel and it also simplifies removal of the object since it can be rotated before and during removal.

In an embodiment of the invention the object has a lower portion and an upper portion, wherein the lower portion is positioned closer to the lower side of the intended dental prosthesis, wherein the lower portion is more narrow than the upper portion, and wherein the object is provided with a flange that connects said portions. This provides a seat for a screw positioned in the screw channel for connecting the dental prosthesis directly or indirectly to the dental implant. This is an example of an embodiment wherein the shape and material of the object is configured such as to allow the object to be removed from the solidified glass-ceramic dental material by pulling it out in a direction towards the upper side of the intended dental prosthesis. It is also an example of an embodiment wherein the shape and material of the object is configured such as to prevent the object from being removed from the glass-ceramic dental material in a direction towards the lower side of the intended dental prosthesis without deforming the object and/or the glass-ceramic dental material.

Preferably, the object exhibits shape permanence in such a way that it has substantially the same shape before forming of the solid body as well as after removal of the object from the solid body. This means, for instance, that the object is a form of massive, integrated object that can be removed as a whole from the solid body. A suitable material for the object is metal. To facilitate removal of the object it is preferably provided with a layer of an agent that reduces the adhesion between the object and the solid body.

In an embodiment of the invention the mouldable glass-ceramic dental material is arranged also around a heat-resistant connecting member suitable for connection to the dental implant. Connecting members are commonly used to prevent rotation in relation to the dental implant (such that the screw to be placed in the screw channel only need press the prosthesis and implant together). Integrating the connecting member when forming the solid body is an efficient way of attaching the connecting member to the dental prosthesis. Preferably, the connecting member is fixed in the vicinity of the lower side of the dental prosthesis.

The invention also concerns a dental product comprising a solid body of a glass-ceramic dental material intended to form a dental prosthesis for connection to a dental implant with a lower side of the dental prosthesis facing towards the implant and an upper side of the dental prosthesis facing away from the implant, wherein the solid body comprises an internal cavity that extends between the upper side and the lower side of the intended dental prosthesis such as to form a screw channel for a screw connection between the dental prosthesis and the dental implant.

The inventive product is characterized in that the cavity has a lower portion and an upper portion, wherein the lower portion is positioned closer to the lower side of the intended dental prosthesis, wherein the lower portion is more narrow than the upper portion, and wherein the cavity is provided with a flange that connects said portions.

BRIEF DESCRIPTION OF DRAWINGS

In the description of the invention given below reference is made to the following figure, in which: Figs 1-4 show, in a schematic view, a first embodiment of the inventive method for production of a first type of dental product, Fig 5 show, in a schematic view, a variant of the method according to figures 1-4, Figs 6-8 show, in a schematic view, a second embodiment of the inventive method for production of the first type of dental product, Figs 9-1 1 show, in a schematic view, a second type of dental product, and Figs 12-13 show, in schematic views, dental products of the first and second type produced according to the inventive method.

DESCRIPTION OF EXAMPLE EMBODIMENTS OF THE INVENTION

Figures 1-4 show, in a schematic view, a first preferred embodiment of the inventive method for production of a first type of dental product 1.

Figure 1 shows, in a schematic view, a main mould 3 comprising a plurality of sub-moulds 4 each of which contains a metallic pin 5 screwed onto a metallic connector 6 that in turn is fastened onto a blank holder 7. A melted parent lithium silicate glass is poured into the mould 3 such as to fill each sub-mould 4 and surround the pin 5 and connector 6. As the glass material cools, a solid body 8 of the glass-ceramic dental material is formed around the pin 5, In this example, the pin 5 is made of stainless steel and the connector 6 is made of titanium. Such materials can withstand the contact with the solidifying glass melt and the further treatment of the solid body (see below) so that the shape, dimension and position of the pin 5 and the connector 6 will remain. Further, the material of the connector 6 is suitable for forming part of the dental product 1.

Since the pin 5 is intended to be removed in a later stage its surface is preferably treated such as to prevent or reduce adhesion to the glass ceramic material. On the other hand, the connector 6 is intended to form a connection to a dental implant 9 (see figure 12) and is therefore intended to be fastened (fused) to the glass ceramic material as to form an integral part of the solid body 8. The connector 6, or at least an upper part of it, is therefore preferably treated such as to enhance adhesion to the glass ceramic material.

The connector 6 has an upper part 6a intended to be fastened to the glass ceramic material and lower part 6b (see figure 4) forming a standard connector for various implants. Both parts 6a, 6b of the connector have a cross section that prevents rotation, i.e. a non-circular cross section, such as a polygonal cross section.

The solid body 8 is, by known means, heated to 650°C to form nuclei for further nucleation and crystallization of the glass ceramic material and, in this example where a lithium silicate material is used, to directly form a weak machinable lithium metasilicate phase.

Figure 2 shows a solid body 8 separated from its sub-mould 4 and supported by its blank holder 7. Besides the pin 5 and the connector 6, figure 2 indicates a shaped full-contour crown dental prosthesis 12 intended for connection to the dental implant 9 with a lower side 12a of the dental prosthesis facing towards the implant and an upper side 12b of the dental prosthesis facing away from the implant 9 (see figures 4 and 12).

The pin 5 is arranged to extend between the upper side 12b and the lower side 12a of the intended dental prosthesis 12 (where the lower side 12a in this case is immediately above the connector 6) such as to be capable of forming a screw channel/cavity 50 (see figures 4 and 12) through the intended dental prosthesis 12 upon removal.

As indicated in figure 3 the pin 5 has a lower portion 5a and an upper portion 5c, wherein the lower portion 5a is positioned closer to the lower side 12a of the intended dental prosthesis 12, wherein the lower portion 5a is more narrow than the upper portion 5c, and wherein the pin 5 is provided with a flange 5b or narrowing portion that connects the lower and upper portions 5a, 5c. Corresponding portions 50a-50c are formed in the screw channellcavity (see figures 4 and 12) The flange 5b generates a corresponding flange/narrowing surface 50b (see figure 12) in the glass ceramic material suitable for a head of a screw 15 to press onto when tightened for mounting the dental product 1 to the implant 9 (see figures 4 and 12).

Figure 3 shows a step of machining, using a grinding tool 16, the solid body 8 such as to form the full-contour crown dental prosthesis 12 out of the solid body 8. Such a machining process is known as such.

In a following step the pin 5 and the blank holder 7 are removed from the dental prosthesis 12, in this example by screwing and pulling.

In a following step the pre-crystallized full-contour dental prosthesis is heated to 850°C to crystallize to a final strong glass-ceramic phase (lithium disilicate if a lithium silicate material is used). Such a crystallization process is known as such.

Figure 4 shows a final dental product 1 comprising the full-contour crown dental prosthesis 12, the integrated connector 6 and the screw channel 50 resembling the shape of the removed pin 5. Further, it is shown the flange/narrowing surface SOb in the glass ceramic material generated in the screw channel 50 by the corresponding flange Sb of the pin 5. Figure 4 also shows a screw 15 to be used for fastening the dental product to the implant 9. A dental product 1 of this type screwed to an implant 9 is shown in figure 12. As can be seen in figure 12 the lower part 6b of the connector 6 connects into the implant 9 and the head of the screw 15 presses onto the flange SOb formed in the screw channel 50.

Figure 5 shows a variant of the above described method for manufacturing of a dental product 1. In this example, the melted parent glass is not poured into a mould containing the pin 5 and the connector 6. Instead melted parent glass is poured into a vessel and crushed into a fine powder (preferably c 45 pm) after the glass melt has hardened. The glass powder mixed with appropriate binder system is then pressed onto and around the pin 5 and the connector 6 by means of a cold isostatic pressing (CIP) process wherein the solid body 8' is formed (see figure 5). Such a process is known as such.

Remaining method steps as well as material and equipment used (shape of pin 5 etc). are similar as described in relation to figures 1-4.

Figures 6-8 show a second embodiment of the inventive method for manufacturing of a dental product. In similarity with the embodiment described above the second embodiment comprises the step of introducing the mouldable glass-ceramic dental material into a mould in which the removable object is positioned. However, in this case the mould has a shape and dimension substantially corresponding to that of the intended dental prosthesis 12. The method according to the second embodiment further comprises the steps of producing a plastic model/replica 21 (figure 6) that has a shape resembling that of the dental prosthesis 12 and forming the mould by arranging a refractory material around the plastic model.

Producing a three-dimensional plastic model 21 of the dental prosthesis 12 can be done by rapid prototyping (such as 3D-printing or stereo-lithography) or machining and is well known as such. The plastic model 21 used in the second embodiment is shown in figure 6. The plastic model 21 resembles a full-contour crown dental prosthesis 12 for connection to a dental implant 9 with a lower side 12a of the plastic model/dental prosthesis 21/12 facing towards the intended position of the implant 9 and an upper side 12b of the plastic model/dental prosthesis 21/12 facing away from the implant 9. The plastic model 21 comprises a pair of sprues 22 (figure 6) that, after having been burnt out in a later step, form channels 23 (figure 7) for use in the subsequent casting step for introducing hot pressed dental glass ceramic material into the mould. The number, shape and position of the sprues 22 may of course differ from what is shown here.

As shown in figure 6 the model is provided with an internal cavity 50, 60 that resembles the shape of the pin 5 and connector 6 used in the following casting step and is thus similar to the desired cavity in the final dental product shown in figure 8 (and in figures 4 and 12). An upper part 50 of the cavity is intended to form the screw channel and thus resembles the pin 5 (or at least the part of the pin 5 extending above the connector 6). A lower part 60 of the cavity, at the lower side 12a of the plastic model 21, resembles the upper part 6a (figure 4) of the connector 6. In similarity to what is described above, the screw channel cavity 50 has a lower portion 50a and an upper portion 50c, wherein the lower portion 50a is positioned closer to the lower side 12a of the intended dental prosthesis 12, wherein the lower portion 50a is more narrow than the upper portion 50c, and wherein the screw channel cavity 50 is provided with a flange 50b that connects the portions 50a, 50b (figure 6).

As described above, the purpose of the corresponding flange SOb in the dental product is to provide a surface onto which the head of the implant engagement screw 15 can press when engaging the dental product 1 to the implant 9.

When the plastic model 21 is finished, the pin 5 and connector 6 (which in this example are similar to what has been described above) are positioned in the cavity 50, 60 which then becomes completely filled. A mould is then formed in a conventional way by arranging a refractory investment material (plaster) 24 around the plastic model 21 containing the pin 5 and connector 6. The plastic model 21, including the sprues 22, is then burned out prior to hot pressing of the glass-ceramic at about 800°C -900°C.

Figure 7 shows the step of introducing the mouldable glass-ceramic dental material into a mould in which the object is positioned, in this case by hot-pressing a glass-ceramic ingot 28 (e.g. of the lithium disilicate-type) at about 900°C such as to generate a viscous flow through the sprue-channels 23 into the mould.

Thereafter, the casted dental crown, i.e. the solid body 8, is divested by sand blasting, the sprues 22 are cut and the pin 5 is removed to form the screw channel cavity 50, see figure 8. The connector 6 is now fused to the glass-ceramic dental material. If the lithium disilicate material is used the surface of the dental prosthesis is preferably acid etched with hydrofluoric acid to remove the thin (max 100 pm) reactive layer formed between the glass-ceramic material and a silica containing investment material.

Figures 9-1 1 show, in a schematic view, a second type of dental product 10 that can be produced by the inventive method, for instance by the embodiments described above. A difference compared to the first type of dental product 1 described previously is the shape of the cavity in the dental prosthesis (and in the corresponding cavity in the plastic model with regard to the second embodiment). Accordingly, also the shape of the removable object arranged in the mouldable glass-ceramic dental material differs.

Another difference is that the connector, which now has the form of an insert fitting (which includes parts commonly referred to as abutments), is not fused to the glass-ceramic dental material during manufacturing of the dental prosthesis. Instead the standard insert fitting is fastened to the dental material at a later stage, e.g. by fusing or cementing. The screw used to fasten such a dental product is introduced through a screw channel formed in similarity with the previous embodiments, but the screw head presses in this case onto an upper side of the insert fitting and not onto a flange in the glass-ceramic material.

Figure 9 shows schematically the dental prosthesis 12' hold by the holder 7.

In accordance with above, the dental prosthesis 12' has a lower side 12'a and an upper side 12'b. An object/pin 5' is arranged inside the dental prosthesis 12' and extends between the two sides 12'a, 12'b. What is shown in figure 9 corresponds roughly to what is shown in figures 3 and 8, i.e. a removable object 5, 5' arranged in a solid body having the shape of a full-contour crown dental prosthesis 12, 12'.

Figure 10 shows the second type of dental product 10 with its dental prosthesis 12' provided with a cavity 50' corresponding to the shape of the pin/object 5' shown in figure 9. Figure 10 also shows a standard insert fitting 26 to be inserted and fastened in the cavity 50'. The standard insert fitting 26 has a cavity 27 adapted to receive a screw inserted through the cavity 50' from the upper side 12'b of the dental prosthesis 12'. In this case the flange for the screw head is provided inside the fitting 26.

Figure 11 shows the dental product 12' with the standard insert fitting 26 inserted into the cavity 50' of the dental prosthesis 12'. The cavity 50' provides a screw channel through an upper part of the dental prosthesis 12' as well as room for the fitting 26.

As can be seen in figures 9-11 the removable object/pin 5' has in this case an elongated shape formed by a combination of a cylindrical pin provided onto (or screwed partly into) an item having the same shape as the fitting 26 (that occupies more space inside the dental prosthesis than the connector 6 shown in figures 1-8). What can be used as object 5' is thus a replica of the fitting 26 to be used together with an extended pin screwed into an upper screw hole of the replica. Alternatively, and as shown in figure 9, the removable object 5' can be an integrated one-piece part, for instance a machined silica-free material such as alumina. The fitting replica and the pin screwed into it can be made of stainless steel. Other suitable materials may be used for the pin 5'.

In case the second type of dental product 10 is to be manufactured by means of a plastic model as described in relation to figures 6-8, the plastic model is provided with a cavity similar to the cavity 50' of the dental prosthesis 12' shown in figure 10. The object to use in the subsequent casting step has, of course, a shape similar to that of the cavity it is intended to form. In the example shown here the object to use has a shape corresponding to the object 5' shown in figure 9. Remaining steps are similar what is described in relation to figures 6-8, except that no connection member is left in the glass-ceramic material after the investment casting.

The insert fitting 26 is preferably of standard type and is typically made of a titanium or zirconia based material and can be produced separately from the dental prosthesis 12'.

Not all method steps of the embodiment including a plastic model must be carried out at a production site. Typically, the plastic model and the object forming the cavity can be produced at a production site, whereas investment-casting, final treatment of the dental prosthesis and fastening of the insert fitting to the glass-ceramic material (if not fastened during the investment casting) can be made at a dental laboratory. A standard insert fitting is typically also produced at a production site but may be available from different suppliers.

Figures 12-13 show dental products 1, 10 of the first and second type manufactured according to the inventive method and fastened to dental implants 9.

Generally, the pin/object 5, 5' and the corresponding cavity/screw channel 50, 50' extend in a substantially straight direction between a central position of the upper side 12b and a central position of the lower side 12a of the intended dental prosthesis 12.

The object 5, 5' should have a certain internal strength so it does not break or fall apart when removed from the through-hole cavity. The Young's modulus for the material of the object 5, 5' should be at least 10 GPa, preferably at least 30 GRa, more preferably at least 50 GRa.

The invention is not limited by the embodiments described above but can be modified in various ways within the scope of the claims. For instance, the connector 6 does not necessarily have to be integrated in the dental prosthesis 12 as shown in figures 1-8, instead it could for instance be cemented to the lower side 12a of the dental prosthesis 12 after solidification of the glass-ceramic body 8, but integrating the connector 6 strengthens the adhesion and simplifies and improves the connection to the implant 9.

The term "plastic" refers in this case to any material that is useful for forming a plastic model of a dental prosthesis and that can be burnt-out in an investment casting process. For instance can wax be used. The term "model" refers to an item that corresponds substantially in shape and dimensions to the part it is intended to resemble. Some differences may exist though, such as the sprues.

The pin-shaped parts forming the screw channels may have a slightly increasing diameter in the same direction as they are intended to be pulled out in order to simplify removal.

The removable object 5, 5' making up the screw channel (and the space for the fitting 26) can be made of various heat-resistant and non-deformable metal, metal alloy or carbide alloy materials. The connector 6 is preferably made of titanium or a titanium alloy.

The (intended) dental prosthesis 12, 12' can have an outer shape that resembles more than one tooth, e.g. a bridge, since the inventive method and product are applicable to multi-abutment restorations.

That the connecting member 6 is ring-shaped means that it has a centrally located hole (that allows the screw 15 to fit through). It does not mean that the connecting member must have a circular shape.

The term (dental) implant refers in this context to a part or fixture intended to be fastened to the jawbone and/or other tissue whereas the term dental prosthesis refers to the glass-ceramic tooth-like part. The expression "a dental prosthesis for connection to a dental implant" means that the dental prosthesis can be connected directly or indirectly, e.g. via a fitting or a bridge, to the implant.

Claims

CLAIMS1. Method for manufacturing of a dental product (1, 10), said product comprising a glass-ceramic dental material intended to form a dental prosthesis (12, 12') for connection to a dental implant (9) with a lower side (12a, 12'a) of the dental prosthesis facing towards the implant and an upper side (1 2b, 1 2'b) of the dental prosthesis facing away from the implant, said method comprising the steps of: -providing the glass-ceramic dental material in a mouldable state, such as in a melted, viscous form or as a powder, characterized in that the method comprises the steps of: -arranging the mouldable glass-ceramic dental material around an elongated, heat-resistant and removable object (5, 5'), wherein the object is arranged to extend between the upper side (12b, 12'b) and the lower side (12a, 12'a) of the intended dental prosthesis (12, 12') such as to be capable of forming a screw channel (50, 50') through the intended dental prosthesis upon removal, and -forming a solid body (8) of the mouldable glass-ceramic dental material around the elongated, heat-resistant and removable object (5, 5').
2. Method according to claim 1, characterized in that it comprises the step of removing the object (5, 5') from the solid body (8).
3. Method according to claim 1 or 2, characterized in that it comprises the step of shaping, such as machining, the solid body (8) to the shape and dimension of the intended dental prosthesis (12, 12').
4. Method according to any of the above claims, characterized in that it comprises the step of introducing the mouldable glass-ceramic dental material into a mould in which the object (5, 5') is positioned.
5. Method according to claim 4, characterized in that the mould has a shape and dimension substantially corresponding to that of the intended dental prosthesis (12, 12').
6. Method according to claim 5, characterized in that it comprises the steps of -producing a plastic or wax model (21) that has a shape resembling that of the dental prosthesis (12, 12'), and -forming the mould by arranging a refractory material around the model (21).
7. Method according to any of the above claims, characterized in that the object (5, 5') has a part that allows gripping for pulling the object out of the solid body (8).
8. Method according to any of the above claims, characterized in that the object (5, 5') has a circular cross section.
9. Method according to any of the above claims, characterized in that the object (5) has a lower portion (5a) and an upper portion (Sc), wherein the lower portion (5a) is positioned closer to the lower side (12a) of the intended dental prosthesis (12), wherein the lower portion (5a) is more narrow than the upper portion (Sc), and wherein the object (5) is provided with a flange (Sb) that connects said portions (Sa, Sc).
10. Method according to any of the above claims, characterized in that the shape and material of the object (5) is configured such as to allow the object (5) to be removed from the solidified glass-ceramic dental material by pulling it out in a direction towards the upper side (12b) of the intended dental prosthesis (12).
11. Method according to any of the above claims, characterized in that the shape and material of the object (5) is configured such as to prevent the object (5) from being removed from the solidified glass-ceramic dental material in a direction towards the lower side (12a) of the intended dental prosthesis (12) without deforming the object (5) and/or the glass-ceramic dental material.
12. Method according to any of the above claims, characterized in that the object (5, 5') exhibits shape permanence in such a way that it has substantially the same shape before forming of the solid body (8) as well as after removal of the object (5, 5') from the solid body (8).
13. Method according to any of the above claims, characterized in that the mouldable glass-ceramic dental material is arranged also around a heat-resistant connecting member (6) suitable for connection to the dental implant (9).
14. Method according to claim 13, characterized in that it comprises the step of fixing the connecting member (6) in the vicinity of the lower side (1 2a) of the dental prosthesis (12).
15. Method according to claim 13 or 14, characterized in that the connecting member (6) is ring-shaped.
16. Method according to any of the above claims, characterized in that the object (5, 5') is made of metallic material.
17. Method according to any of the above claims, characterized in that the object (5, 5') is provided with a layer of an agent that reduces the adhesion between the object (5, 5') and the solid body.
18. Method according to any of the above claims, characterized in that the glass ceramic dental material is a lithium disilicate glass ceramic.
19. Method according to any of the above claims, characterized in that the dental prosthesis (12, 12') has an outer shape that resembles that of a tooth.
20. Dental product (1) comprising a solid body (8) of a glass-ceramic dental material intended to form a dental prosthesis (12) for connection to a dental implant (9) with a lower side (12a) of the dental prosthesis (12) facing towards the implant (9) and an upper side (1 2b) of the dental prosthesis (12) facing away from the implant (9), wherein the solid body (8) comprises a cavity (50) that extends between the upper side (12b) and the lower side (12a) of the intended dental prosthesis (12) such as to form a screw channel for a screw connection between the dental prosthesis (12) and the dental implant (9), characterized in that the cavity (50) has a lower portion (50a) and an upper portion (50c), wherein the lower portion (50a) is positioned closer to the lower side (12a) of the intended dental prosthesis (12), wherein the lower portion (50a) is more narrow than the upper portion (50c), and wherein the cavity (50) is provided with a flange (50b) that connects said portions (50a, 50c).
21. Dental product (1) according to claim 20, characterized in that the solid body (8) has an outer shape that resembles that of a tooth.
22. Dental product (1) according to claim 20 or 21, characterized in that it comprises a connecting member (6) for connection to the dental implant (9).
23. Dental product (1) according to claim 22, characterized in that the connecting member (6) is fixed to the solid body (8) in the vicinity of the lower side (1 2a) of the dental prosthesis (12).
24. Dental product (1) according to claim 22 or 23, characterized in that the connecting member (6) is ring-shaped.
25. Dental product (1) according to any of claims 22 to 24, characterized in that the connecting member (6) is made of metallic material.
26. Dental product (1) according to any of claims 20 to 25, characterized in that the glass ceramic dental material is a lithium disilicate glass ceramic.
27. Dental product (1) according to any of claims 20 to 26, characterized in that the cavity (50) forms a through hole and extends in a substantially straight direction from a central position of the upper side (12b) to a central position of the lower side (1 2a) of the intended dental prosthesis (12).