Assembly for carrying a dental prosthesis and a method of manufacturing the same

Abstract

The object of the invention is an assembly for carrying a dental prosthesis and a method of manufacturing the same, wherein the assembly for carrying a dental prosthesis comprises a dental implant (1 ), a fixation screw (2), and a pillar (3) for fixing the dental prosthesis, where the pillar (3) comprises a first end (4) of the pillar, a second end (5) of the pillar opposite the first end (4) of the pillar, and a cavity (6) of the pillar, wherein the cavity (6) of the pillar opens at both the first and second ends (4,5) of the pillar and the first end (4) of the pillar is adjacent to the dental implant (1 ), wherein at least a part of the fixation screw (2) is located in the cavity (6) of the pillar and the fixation screw (2) is connected to the dental implant (1 ), wherein the cavity (6) of the pillar comprises a first side (7) of the cavity comprising a first section (8) of the cavity and a second side (9) of the cavity comprising a second section (10) of the cavity, wherein the first side (7) of the cavity is located closer to the first end (4) of the pillar than the second side (9) of the cavity and the cross-section of the first section (8) of the cavity is larger than the cross-section of the second section (10) of the cavity, wherein the fixation screw (2) comprises a head (11 ) of the fixation screw that is located in the first side (7) of the cavity.

Description

[0001] Assembly for carrying a dental prosthesis and a method of manufacturing the same

[0002] Technical Field

[0003] The invention relates to an assembly for carrying a dental prosthesis, which solves problems associated with manufacture, assembly, and implantation of the assembly, in particular in relation to the loosening of a fixation screw from the cavity of a pillar, and furthermore an embodiment of the apex of the pillar that extends the clinical application of the invention.

[0004] Background of the Invention

[0005] In the current state of the art, there are known dental prostheses comprising a dental implant fixed in the jaw bone and a hollow pillar carrying the dental prosthesis, which are connected by means of a fixation screw, wherein the fixation screw is threaded through the hollow pillar and connected to an internal thread in a cavity of the dental implant. The embodiment of the pillar varies according to the type of the dental prosthesis. Maintaining the stiffness and strength of the assembled assembly of the dental implant, pillar, and fixation screw is crucial for the long-term durability of the assembly in the bone mass of the human jaw. If the force connection of the pieces of the assembled assembly is broken, the loose pieces may cause damage to the pieces of the assembly and the dental prosthesis, significantly reduce the safety of using the dental prosthesis, and may lead to damage to the health of the user - the patient. Repair of the damaged pieces of the installed assembly, including the dental prosthesis, is possible by replacing the loose defective pieces or by making a new dental prosthesis. If a dental implant that is integrated into the bone mass of the human jaw is damaged, surgical removal of the damaged implant is necessary, which entails health risks for the patient and economic costs for both the doctor and the patient.

[0006] One known solution for fixation of an assembly of a dental implant, pillar, and fixation screw is described in the document KR20090069402 A and consists in the use of a locking insert that is inserted into the pillar from the same side as the fixation screw, wherein the locking insert abuts the head of the fixation screw. The surface of the locking insert comprises a shaped protrusion that fits precisely into the shaped opening in the head of the fixation screw such that the elements fit tightly together and do not rotate relative to each other. This arrangement does not solve the possible axial displacement of the insert and therefore also of the fixation screw.

[0007] Other methods of preventing loosening of the fixation screw consist in using a locking screw insert that is inserted into the pillar from the same side as the fixation screw and abuts the head of the fixation screw, as described in the document KR20170029792 A. In the solution described in the document KR20090069402 A, the surface of the locking screw insert comprises a shaped protrusion that fits precisely into the shaped opening in the head of the fixation screw such that the elements fit tightly together and do not rotate relative to each other.

[0008] The document KR20090008785 A describes the use of a locking insert in the form of a screw, wherein the locking screw, in addition to the thread, also comprises a protrusion fitting into a corresponding opening in the head of the fixation screw. The fixation screw is thus connected to the dental implant and the pillar at the same time; however, in case of failure of the screw connection of the screw insert or the locking screw, there is still a risk of displacement of the fixation screw in the direction of the longitudinal axis of the implant.

[0009] A combination of the preceding solutions is described in the document KR102177377 B1 , which describes fixing of a fixation screw in the cavity of a pillar by means of an insert in the form of a locking screw, wherein both the head of the fixation screw and the head of the locking screw comprise an external thread that is connected to an internal thread in the cavity of the pillar. The face of the locking screw simply abuts the head of the fixation screw and its position is secured by cementation.

[0010] A disadvantage of all the above solutions is that in case of failure of function of the fixation screw or locking element, the displacement of the fixation screw in the cavity of the pillar in the direction of the longitudinal (axial) axis of the cavity, or complete loosening of the fixation screw from the pillar, is still possible. The dental implant, pillar, and fixation screw are applied separately during the implantation in the jaw, which increases the risk of damage, loss, or inhalation by the patient during handling and installation of the pieces as well as the overall complexity of assembling the assembly with the dental prosthesis. A further disadvantage lies in the fact that the diameter of the cavity of the pillar at its mouth, which is normally intended for the insertion of the fixation screw and to which the dental prosthesis is adjacent, is equal to or larger than the diameter of the head of the inserted fixation screw, and the pillar has a thin carrying wall at this place, which does not allow the use of these pillars for all prosthetic indications. These are e.g. dental prostheses that require small dimensions of the apical part of the pillar at the contact area with the dental prosthesis, which are designed for the frontal section of the dentition (i.e. in the incisor and canine anatomy). The large diameter of the cavity in the apical part of the pillar is also disadvantageous for dental prostheses of the distal section of the dentition (molars and premolars), which are subjected to the greatest pressure from chewing forces, because a larger volume of a high-strength material cannot be applied to the thin wall of the pillar in its apical part, which is necessary for sufficient strength of this dental prosthesis - the crown.

[0011] Summary of the Invention

[0012] The above shortcomings are eliminated by an assembly for carrying a dental prosthesis comprising a dental implant, a fixation screw, and a pillar for fixing the dental prosthesis, where the pillar comprises a first end of the pillar, a second end of the pillar opposite the first end of the pillar, and a cavity of the pillar, wherein the cavity of the pillar opens at both the first and second ends of the pillar and the first end of the pillar is adjacent to the dental implant, wherein at least a part of the fixation screw is located in the cavity of the pillar and the fixation screw is connected to the dental implant. The cavity of the pillar further comprises a first side of the cavity comprising a first section of the cavity and a second side of the cavity comprising a second section of the cavity, wherein the first side of the cavity is located closer to the first end of the pillar than the second side of the cavity and the cross-section of the first section of the cavity is larger than the cross-section of the second section of the cavity, wherein the fixation screw comprises a head of the fixation screw which is located in the first side of the cavity.

[0013] The dental implant is integrated in the bone mass of the jaw, wherein a pillar for carrying the dental prosthesis is attached to the dental implant by the fixation screw. The head of the fixation screw is housed in the first side of the cavity of the pillar, that is closer to the dental implant, where the first section of the cavity is also located. In the second side of the cavity closer to the second end of the pillar the second section of the cavity is located, wherein the section of the cavity means a place or a point on the longitudinal axis of the cavity where the cavity has a constant cross-section. Since the cross-section of the second section of the cavity is smaller than the cross-section of the first section of the cavity, the cavity closer to the second end of the pillar comprises a narrowing. This narrowing of the cavity of the pillar in the second side of the cavity ensures the integration of the fixation screw in the cavity of the pillar, which eliminates the axial displacement of the fixation screw relative to the pillar. Prior to the installation of the pillar to the dental implant, the fixation screw is already integrated into the cavity of the pillar and cannot be removed from the pillar, which eliminates the possibility of losing the fixation screw and increases safety when handling the pillar in the patient’s mouth. The narrowing of the cavity of the pillar on the second side of the pillar also allows the dimensions of the pillar to be reduced at the second end of the pillar, i.e. at the apical external part of the pillar to which the crown of the dental prosthesis is adjacent. The reduced dimensions of the external apical part of the pillar allow the pillar to be used for prosthetic indications of teeth that have a subtle shape topology (incisors, canines). Another advantage of the narrowed cavity closer to the apical part of the pillar is the possibility of increasing the thickness of the wall of the pillar and therefore increasing the strength of the pillar at the place of contact with the crown. Another advantage of the reduced external dimensions of the apical part of the pillar is the possibility of using a larger volume of a high-strength material used to make the crown - dental prosthesis for particularly stressed teeth (grinders, premolars, molars). The assembly for carrying a dental prosthesis with the pillar and fixation screw of the invention is a solution to increase the safety and functionality of the installation and use of many different types of dental prostheses in dental implant treatment.

[0014] In a preferred embodiment of the assembly for carrying a dental prosthesis of the invention, the diameter of the head of the fixation screw is larger than the diameter of the second section of the cavity. This embodiment further stabilizes the position of the fixation screw, especially the head of the fixation screw in the cavity, and completely prevents the fixation screw from being pulled out of the cavity of the pillar. If the head of the fixation screw or the second section of the cavity has an irregular (non-circular) cross-section, this definition means that the largest radial dimension of the head of the fixation screw is larger than the smallest radial dimension of the crosssection of the second section of the cavity.

[0015] In a preferred embodiment of the assembly for carrying a dental prosthesis of the invention, the cross-section of the cavity of the pillar in planes perpendicular to the longitudinal axis of the cavity of the pillar is circular, wherein the ratio of the diameter of the first section of the cavity Di to the diameter of the second section of the cavity D2 is larger than 1 , more preferably 1 .5 to 1 .65. This range is preferable with respect to the shaping and nominal dimensions of the fixation screws standardly used for dental prostheses.

[0016] In a preferred embodiment, the assembly for carrying a dental prosthesis further comprises a safety screw comprising a pin of the safety screw, wherein the head of the fixation screw comprises a handling opening, and the pin of the safety screw is in contact with the bottom of the handling opening. The safety screw is inserted into the second side of the cavity of the pillar and serves as a locking element that fixes the mutual position of the fixation screw and the pillar. The pin of the safety screw means the face of the safety screw, wherein the face of the safety screw is embedded in the handling opening in the head of the fixation screw and directly abuts the bottom thereof. By embedding the pin of the safety screw all the way to the bottom of the handling opening, force contact and better mutual cohesion of the fixation screw and the safety screw is achieved. The safety screw helps to prevent axial displacement of the fixation screw.

[0017] In a preferred embodiment of the assembly for carrying a dental prosthesis, the second side of the cavity comprises an internal thread of the pillar, wherein the safety screw comprises an external thread corresponding to the internal thread of the pillar. The external thread of the safety screw is in firm contact with the internal thread of the pillar after tightening the safety screw in the cavity of the pillar, wherein the position of the external thread of the safety screw after its tightening is precisely defined by the formation of the internal thread of the pillar in the second part of the cavity.

[0018] The method of manufacturing the assembly for carrying a dental prosthesis of the invention lies in the fact that the pillar is in its initial state a semi-finished product comprising a cavity of a uniform dimension and that it comprises a step of shaping the pillar around at least a part of the fixation screw and a subsequent step of connecting the fixation screw to the dental implant. In the first step of the manufacture, the initial (unfinished) semi-finished product of the pillar is used, in which an open internal cavity of a uniform dimension is made, into which the fixation screw is inserted such that the head of the fixation screw is in the first side of the cavity of the pillar and the shank of the fixation screw protrudes from the first end of the pillar. In the next step, the apical part of the pillar is shaped, in which the second section of the cavity is formed, i.e. the part of the cavity above the head of the fixation screw with a smaller dimension than the original dimension of the internal cavity for the insertion of the head of the fixation screw. This procedure ensures the integration of the fixation screw in the cavity of the pillar, in particular the housing of the head of the fixation screw in the first section of the cavity of the pillar, wherein the fixation screw and the pillar are then securely connected to the dental implant without the risk of the fixation screw falling out of the pillar.

[0019] The method of manufacturing the assembly for carrying a dental prosthesis preferably comprises a step of shaping the pillar performed by forming and machining technology. An advantage of the forming technology is an increase in the strength of the pillar, which has increased resistance to high-cyclic stresses. The method of manufacturing the assembly for carrying a dental prosthesis after the step of connecting the fixation screw to the dental implant further preferably comprises a step of inserting and tightening the safety screw relative to the fixation screw. The insertion of the safety screw acts as an additional locking method of securing the position of the fixation screw to the pillar, wherein the screw connection increases the cohesion of the safety screw and the pillar compared to simply inserting locking inserts.

[0020] In a preferred embodiment of the method of manufacturing the assembly for carrying a dental prosthesis, the internal thread of the pillar is made by chip machining or cold volume forming. By making the internal thread by volume forming, an internal thread can be manufactured with the smallest diameter smaller than the diameter of the original cavity with a smooth wall in which the internal thread is formed. By cold volume forming it is therefore possible to narrow the diameter of the cavity at the place of the internal thread.

[0021] Description of Drawings

[0022] A summary of the invention is further clarified using exemplary embodiments thereof, which are described with reference to the accompanying drawings, in which:

[0023] Fig. 1 shows a longitudinal section of an assembled assembly for carrying a dental prosthesis comprising a dental implant, pillar, fixation screw, and safety screw.

[0024] Fig. 2 shows a view of the assembly for carrying a dental prosthesis from an upper axonometric perspective.

[0025] Fig. 3 shows a view of the pillar from an upper axonometric perspective.

[0026] Fig. 4 shows a longitudinal section through the pillar.

[0027] Fig. 5 shows a side view of the pillar. Fig. 6 shows a view of the fixation screw from an upper axonometric perspective.

[0028] Fig. 7 shows a side view of the fixation screw.

[0029] Fig. 8 shows a longitudinal section of the fixation screw.

[0030] Fig. 9 shows a side view of the safety screw.

[0031] Fig. 10 shows a side view of the safety screw from an upper axonometric perspective.

[0032] Exemplary Embodiments of the Invention

[0033] The invention will be further clarified using exemplary embodiments with reference to the respective drawings. One exemplary embodiment is the assembly of a dental prosthesis shown in Figs. 1 to 8.

[0034] The assembled assembly for carrying a dental prosthesis shown in Fig. 1 and 2 comprises a dental implant 1, a pillar 3, a fixation screw 2, and a safety screw 13. The dental implant 1 means a surgical dental implant 1 that is firmly integrated in the bone mass of the human jaw during the dental implant treatment and comprises an internal opening 20 of the dental implant with a thread into which the hollow pillar 3 with the integrated fixation screw 2 is inserted. To connect the dental implant 1 and the inserted pillar 3, the fixation screw 2 is used, which is shown in Fig. 1 and further Figs. 6 to 8. The fixation screw 2 comprises a head 1 1 of the fixation screw with a handling opening 15, a shank 18 of the fixation screw with a smooth surface adjacent to the head 1 1 of the fixation screw, and an end thread 19 of the fixation screw, wherein the head 11 and the shank 18 of the fixation screw are located in the cavity 6 of the pillar and the end thread 19 of the fixation screw is connected to a thread in the internal opening 20 of the dental implant T The head 1 1 of the fixation screw has a cylindrical external shape and comprises the handling opening 15, wherein the handling opening 15 has the shape of a truncated hexagonal pyramid, which is particularly apparent from the view of the fixation screw 2 of Figs. 6 and 8.

[0035] The pillar 3 shown in Figs. 3 to 5 comprises a first end 4 of the pillar, a second end 5 of the pillar opposite the first end 4 of the pillar, and a cavity 6 of the pillar for the insertion of the fixation screw 2, which opens at both the first and second ends 4,5 of the pillar. The first end 4 of the pillar abuts the dental implant 1, wherein the external surface of the pillar 3 adjacent to the internal opening 20 of the dental implant 1 has an approximate shape of a truncated cone and comprises protruding ribs with shape precisely corresponding to the grooves on the internal opening 20 of the dental implant. A dental prosthesis (crown) is fixed to the second end of the pillar 5, also in the shape of a truncated cone, wherein the apical part of the pillar 3 comprises an n-gon on its external surface. The external shaping of the pillar 3, in particular the protruding ribs closer to the first end 4 of the pillar and the n-gon closer to the second end 5 of the pillar, can be seen in Fig. 3 and 5. The dental prosthesis is not an object of the invention and is therefore not shown in a figure, but in the context of the invention it is any type of prosthesis fixable to the pillar 3, which may be a crown, bridge, abutment, hybrid prosthesis, etc.

[0036] In the following part, the internal shaping of the pillar 3 will be described, i.e. the shaping of the cavity 6 of the pillar in which the fixation screw 2 is inserted in the assembled assembly for carrying a dental prosthesis. In the first exemplary embodiment of Fig. 4, the cross-section of the cavity 6 of the pillar is circular in planes perpendicular to the longitudinal axis 12 of the cavity of the pillar and the cavity 6 comprises a first side 7 of the cavity adjacent to the first end 4 of the pillar and a second side 9 of the cavity adjacent to the second end 5 of the pillar, wherein the first side 7 of the cavity houses the head 11 of the fixation screw and the shank 18 of the fixation screw. The cavity 6 of the pillar comprises, in the direction of the longitudinal axis 12 of the cavity 6, parts that differ in the diameter of the cavity 6 and in the shaping of the wall of the cavity 6, which is particularly evident from Fig. 4.

[0037] At the mouth of the cavity 6 at the first end of the pillar 4, the cavity 6 first comprises a cylindrical part 21 through which the shank 18 of the fixation screw is threaded in the case of the assembled assembly of a dental prosthesis. The cylindrical part 21 of the cavity is followed by an extension 22 in the shape of a truncated rotation cone and then the first section 8 of the cavity. The first section 8 of the cavity is then followed by a transition part 23 of the cavity, which takes the form of a continuous narrowing of the diameter of the cavity 6 towards the second end of the pillar 3, wherein the narrowest place of the transition part 23 is the second section 10 of the cavity. An end handling part 24 of the cavity is adjacent to the second end 5 of the cavity and is used to insert and fix the safety screw 13.

[0038] The first section 8 of the cavity is, in the first exemplary embodiment, the part of the cavity 6 between two limit points on the longitudinal axis 12 of the cavity, where one limit point is at the level of the larger base of the extension 22 of the cavity and the other limit point is at the level of the larger base of the transition part 23 of the cavity, which narrows towards the second end 3 of the pillar. In other words, the height of the first section 8 along the longitudinal axis 12 of the cavity is equal to the distance between the larger base of the truncated cone forming the extension 22 of the cavity and the base of the transition part 23 of the cavity. Throughout the height of the first section 8 (between these limit points), the diameter of the cavity 6 is constant and is adapted to house the head 1 1 of the fixation screw. Thus, the first section 8 of the cavity has the shape of a cylinder with a constant diameter, wherein the head 1 1 of the fixation screw is almost in contact with the wall of the first cavity section 8 along its entire circumference. The diameter of the first section 8 of the cavity (Di) is larger than the diameter of the head 1 1 of the fixation screw by a technological installation clearance (to allow the head 1 1 of the fixation screw to be rotated during tightening), wherein the diameter of the first section 8 of the cavity (Di) is larger than the diameter of the second section 10 of the cavity (D2). In the first exemplary embodiment, the diameter of the first section 8 of the cavity (Di) is larger than the diameter of the cavity 6 in all other parts of the cavity 6. In the first exemplary embodiment, the first section 8 of the cavity is followed by the transition part 23, which takes the form of a continuous narrowing of the diameter of the cavity 6 towards the second side 9 of the cavity.

[0039] The transition part 23 of the cavity is directly followed by the second section 10 of the cavity in the second side 9 of the cavity, wherein the second section 10 of the cavity is located closer to the second end 5 of the cavity than the first section 8 of the cavity. The diameter of the second section 10 of the cavity (D2) is smaller than the diameter of the first section 8 of the cavity (Di) and the diameter of the second section In the first exemplary embodiment, the second section 10 of the cavity is only one point on the longitudinal axis 12 of the cavity, which corresponds to the level of the narrowest place of the transition part 23 of the cavity. The narrowing of the diameter of the cavity 6 in the second section 10 compared to the first section 8 of the cavity and the head

[0040] 1 1 of the fixation screw is a key feature of the entire assembly of a dental prosthesis of the present invention, as it prevents the head 1 1 , and therefore the entire fixation screw 2, from moving relative to the pillar 3, and therefore prevents pulling (loosening) of the fixation screw 2 out of the pillar 3. Thus, the diameter of the head 1 1 of the fixation screw is larger than the diameter of the second section 10 of the cavity, wherein this definition means that the largest radial dimension of the head 1 1 of the fixation screw is larger than the smallest radial dimension of the cross-section of the second section 10 of the cavity. This relationship between the dimensions of the head 1 1 of the fixation screw and the second section 10 is important for possible alternative embodiments with a non-circular cross-section of the second section 10 of the cavity (or a non-circular cross-section of the head 1 1 of the fixation screw), which are shown further in alternative embodiments of the invention.

[0041] The ratio of the diameter of the first section 8 of the cavity and the diameter of the second section 10 of the cavity (D1 / D2) is preferably in the range of 1.5 to 1.65, which is derived from the nominal dimensions of the fixation screws 2 standardly used for assemblies of pillar and fixation screw in the case of screwed dental prostheses. Preferred combinations of the size of the head 1 1 of the fixation screw (diameter of the first section 8 of the cavity (Di)) and the diameter of the second section 10 of the cavity (D2) are given in the following table (Table 1 ).

[0042] Table 1 . The second side 9 of the cavity is adapted for installation of the safety screw 13 shown in Fig. 9 and 10, which serves to additionally secure the fixation screw 2. The safety screw 13 comprises a head of the safety screw, an external thread 17, and a pin 14, wherein the wall of the second section 10 of the cavity comprises an internal thread 16 of the pillar adapted to connect to the external thread 17 of the safety screw. If the second side 9 of the cavity comprises the internal thread 16 of the pillar, the diameter of the cavity 6 at the place of the internal thread 16 of the pillar is equal to the minor diameter of the safety screw 13 that is inserted into the internal thread 16 of the pillar. It is therefore the smallest possible dimension of diameter of the cavity 6 with the internal thread 16 of the pillar, as shown in Fig. 4, wherein the diameter of cavity 6 is equal to the diameter of the second section 10 of the cavity D2 at this place. In the first exemplary embodiment of the invention, the pin 14 of the safety screw has a smooth surface and the diameter of the pin 14 is smaller than the diameter of the external thread 17 of the safety screw, wherein after the assembly is assembled, the fixation screw 2 is tightened and the safety screw 13 is tightened, the pin 14 of the safety screw is embedded in the handling opening 15 of the head of the fixation screw and abuts the bottom of the handling opening 15. The handling part 24 of the cavity at the level between the internal thread 16 of the pillar and the second end 5 of the pillar, i.e. the part of the cavity 6 adjacent to the mouth of the cavity 6 on the second side 9 of the pillar, is used to handle and arrest the fixation and safety screws 2,13 to the other elements of the assembly.

[0043] In the following part, the method of manufacturing the pillar 3 of the assembly for carrying a dental prosthesis of the present invention will be described. The pillar 3 is made by a combination of forming and machining. The pillar 3 is in its initial state unfinished and is a semi-finished product with an open cavity 6 of a uniform dimension, which does not comprise the transition part 23 of the cavity and the second section 10 of the cavity, wherein subsequently the fixation screw 2 is inserted into the cavity 6 of the pillar such that the head 1 1 of the fixation screw is located in the first side 7 of the cavity at the place where the first section 8 of the cavity is expected to be formed. Subsequently, the shaping of the pillar 3 is finished around the fixation screw 2 housed in the cavity 6, in particular above the head 1 1 of the fixation screw. At this moment, the transition part 23 of the cavity and the second section 10 of the cavity are formed, whereby the fixation screw 2 is integrated into the body of the pillar 3, wherein it cannot be removed from the pillar 3.

[0044] The external shaping of the pillar 3 and cavity 6 is made by forming, which strengthens the material of the pillar 3 and increases the high-cyclic strength. Other possible methods of making the pillar 3 of the invention include e.g. hydroforming, casting, additive manufacturing technologies, and others. The use of forming is preferable in particular for the formation of the internal thread 16 of the pillar in the second section 10 of the cavity, which is carried out as follows: first, the original simple cavity 6 of the pillar with a smooth wall is formed, into which the internal thread 16 of the pillar is subsequently formed. The internal thread 16 of the pillar is not formed by cutting but by forming, wherein the part of the material forming the wall of the original simple cavity 6 is moved towards the axis of rotation (longitudinal axis 12 of the cavity) during the forming. The diameter of the cavity 6 of the resulting internal thread 16 of the pillar is, when this procedure is used, smaller than the diameter of the original simple cavity 6 of the pillar in the wall of which the internal thread 16 was formed.

[0045] The pair of the pillar 3 and the fixation screw 2 is subsequently connected together to the dental implant 1 by tightening the end thread 19 of the fixation screw in the thread of the dental implant 1. The step of connecting the fixation screw 2 to the dental implant 1 is followed by the step of inserting and tightening the safety screw 13 relative to the fixation screw 2, wherein the safety screw 13 is inserted into the cavity 6 of the pillar in the direction from the second end 5 of the pillar. The maximum tightening of the safety screw 13 relative to the internal thread 16 of the pillar and the fixation screw 2 is determined by the abutment of the pin 14 of the safety screw on the bottom of the handling opening 15 in the head 1 1 of the fixation screw.

[0046] In an alternative embodiment of the assembly of a dental prosthesis of the present invention, the shaping of the cavity 6 of the pillar may be modified. The transition part 23 of the cavity between the first and second sections 8,10 of the cavity, in which the narrowing of the cavity 6 occurs, may comprise any shaping, e.g. in the shape of a truncated cone or a general area. In another embodiment of forming the cavity 6, the transition part 23 may be omitted entirely, wherein the first section 8 of the cavity is directly followed by the second section 10 of the cavity. Thus, at the level of transition between the first and second sections 8,10 of the cavity, the diameter of the cavity 6 step changes, wherein the diameter of the cavity 6 between the second section 10 of the cavity and the second end 5 of the pillar may again be constant and the step is only at the place of contact between the first section 8 and the second section 10 of the cavity.

[0047] In another embodiment of the invention, the second section 10 of the cavity may comprise a protrusion in the wall of the second side 9 of the cavity around the circumference of the cavity 6, which makes the cross-section of the second section 10 of the cavity smaller than the cross-section of the first section 8 of the cavity and also prevents the head 1 1 of the fixation screw from being displaced, wherein the diameter of the cavity 6 between the second section 10 of the cavity and the second end 5 of the pillar may be equal to the diameter of the first section 8 of the cavity. In this embodiment, the second section 10 forms a kind of neck that prevents the head 1 1 of the fixation screw from being displaced towards the second end 5 of the pillar. The second section 10 can be made as an angular protrusion or as a rounded protrusion (in the case of a rounded protrusion, the cavity 6 has the smallest diameter D2 only at the apex of the protrusion). In another embodiment, the protrusion is not around the entire circumference of the cavity 6 at the place of the second section 10 of the cavity, wherein it takes the form of at least one pin or spike that protrudes from the wall of the cavity 6, wherein it makes the cavity 6 at the place of the second section 10 of the cavity smaller in cross-section than in the first section 8 of the cavity. This may be only one point or linear protrusion, more preferably several such protrusions regularly spaced around the circumference of the cavity (e.g. 2 protrusions opposite each other, 6 protrusions at regular intervals, etc.), which prevent the head 11 of the fixation screw from being displaced. In another embodiment of the invention, the second section 10 of the cavity may have a different irregular non-circular cross-section, wherein this cross-section of the second section 10 may have any shape, e.g. of an ellipse or an n- gon. However, in all these embodiments, the condition that the largest radial dimension of the head 1 1 of the fixation screw is larger than the smallest radial dimension of the cross-section of the second section 10 of the cavity must be met.

[0048] In another embodiment of the assembly of a dental prosthesis, the wall of the cavity 6 may be smooth on the second side 9 of the cavity, wherein the internal thread 16 of the pillar is formed directly by the external thread 17 of the safety screw only at the moment when the safety screw 13 is connected to the pillar 3. Although this embodiment of the pillar 3 without the internal thread 16 is simpler to manufacture, it is less accurate in terms of the position of the safety screw 13 when tightened to the internal thread 16 of the pillar.

[0049] In an alternative embodiment of the assembly for carrying a dental prosthesis, the additional securing of the position of the fixation screw 2 can be carried out entirely without the use of the safety screw 13, for example by using a simply inserted locking insert or by cementing the cavity 6 in the space between the head 1 1 of the fixation screw and the second end 5 of the pillar.

[0050] Industrial Applicability

[0051] The invention of an assembly for carrying a dental prosthesis with an integrated fixation screw can be used in a modification for other technical fields where it is preferable to integrate the fixation screw in another component, which allows handling of only the two elements at a time without the risk of their separation.

[0052] List of Reference Signs

[0053] 1 - Dental implant

[0054] 2 - Fixation screw

[0055] 3 - Pillar

[0056] 4 - First end of the pillar

[0057] 5 - Second end of the pillar

[0058] 6 - Cavity of the pillar

[0059] 7 - First side of the cavity

[0060] 8 - First section of the cavity

[0061] 9 - Second side of the cavity

[0062] 10 - Second section of the cavity

[0063] 11 - Head of the fixation screw

[0064] 12 - Longitudinal axis of the cavity

[0065] 13 - Safety screw

[0066] 14 - Pin of the safety screw

[0067] 15 - Handling opening

[0068] 16 - Internal thread of the pillar

[0069] 17 - External thread of the safety screw

[0070] 18 - Shank of the fixation screw

[0071] 19 - End thread of the fixation screw

[0072] 20 - Opening of the dental implant

[0073] 21 - Cylindrical part of the cavity

[0074] 22 - Extension of the cavity 23 - Transition part of the cavity

[0075] 24 - Handling part of the cavity

Claims

CLAIMS An assembly for carrying a dental prosthesis comprising a dental implant (1 ), a fixation screw (2), and a pillar (3) for fixing the dental prosthesis, where the pillar (3) comprises a first end (4) of the pillar, a second end (5) of the pillar opposite the first end (4) of the pillar, and a cavity (6) of the pillar, wherein the cavity (6) of the pillar opens at both the first and second ends (4,5) of the pillar and the first end (4) of the pillar is adjacent to the dental implant (1 ), wherein at least a part of the fixation screw (2) is located in the cavity (6) of the pillar and the fixation screw (2) is connected to the dental implant (1 ), characterized in that the cavity (6) of the pillar comprises a first side (7) of the cavity comprising a first section (8) of the cavity and a second side (9) of the cavity comprising a second section (10) of the cavity, wherein the first side (7) of the cavity is located closer to the first end (4) of the pillar than the second side (9) of the cavity and the cross-section of the first section (8) of the cavity is larger than the crosssection of the second section (10) of the cavity, wherein the fixation screw (2) comprises a head (1 1 ) of the fixation screw that is located in the first side (7) of the cavity. The assembly for carrying a dental prosthesis according to claim 1 , characterized in that the diameter of the head (1 1 ) of the fixation screw is larger than the diameter of the second section (10) of the cavity. The assembly for carrying a dental prosthesis according to claim 1 to 2, characterized in that the cross-section of the cavity (6) of the pillar is circular in planes perpendicular to the longitudinal axis (12) of the cavity of the pillar, wherein the ratio of the diameter of the first section (8) of the cavity Di to the diameter of the second section (10) of the cavity D2 is larger than 1 . The assembly for carrying a dental prosthesis according to claim 3, characterized in that the ratio of the diameter of the first section (8) of the cavity Di to the diameter of the second section (10) of the cavity D2 is 1.5 to5. The assembly for carrying a dental prosthesis according to claims 1 to 4, characterized in that it further comprises a safety screw (13) comprising a pin (14) of the safety screw, and that the head (11 ) of the fixation screw comprises a handling opening (15), wherein the pin (14) of the safety screw is in contact with the bottom of the handling opening (15).

6. The assembly for carrying a dental prosthesis according to claim 5, characterized in that the second side (10) of the cavity comprises an internal thread (16) of the pillar and the safety screw (13) comprises an external thread (17) corresponding to the internal thread (16) of the pillar.

7. A method of manufacturing the assembly for carrying a dental prosthesis according to claims 1 to 6, characterized in that the pillar (3) is in its initial state a semi-finished product comprising the cavity (6) of a uniform dimension and that it comprises a step of shaping the pillar (3) around at least a part of the fixation screw (2) and a subsequent step of connecting the fixation screw (2) to the dental implant (1 ).

8. The method of manufacturing the assembly for carrying a dental prosthesis according to claim 7, characterized in that the step of shaping the pillar (3) is performed by a forming and chip machining technology.

9. The method of manufacturing the assembly for carrying a dental prosthesis according to claims 7 and 8, characterized in that, after the step of connecting the fixation screw (2) to the dental implant (1 ), it comprises a step of inserting and tightening the safety screw (13) relative to the fixation screw (2).

10. The method of manufacturing the assembly for carrying a dental prosthesis according to claim 9, characterized in that the internal thread (16) of the pillar is made by chip machining or cold volume forming.

Images