DE102009015358B4 - Screw, screwing tool and their use for the manufacture of dental prostheses - Google Patents

Abstract

Screw (3) consisting of a screw head (29) and a screw shaft, wherein the screw head (29) comprises a conical chamber (32) for receiving a screwing tool (1), characterized in that the chamber of alternating, conically downwardly extending first guide surfaces (31) and with respect to these undercut, also conically downwardly extending second or further guide surfaces (34), which with the corresponding antagonistic first guide surfaces (11) and second guide surfaces (14) of the screwing tool (1) non-positively and cooperate positively, wherein the first and second guide surfaces (31, 34) of the chamber (32) of the screw head (29) laterally formed force transmission surfaces (26), which with the corresponding antagonistic force transmission surfaces (6) of the screwing tool (1) when applying a torque frictionally and positively cooperate n.

Description

The present invention relates to a screw having an improved connection geometry for interaction with a screwing tool.

The invention finds use in the field of mechanics, dental technology, electromechanics and orthopedics. Finally, as an application, the invention also describes a dental implant in which the implant is attached to the abutment via an abutment screw, the abutment screw and / or the implant having a screw head profile according to the invention.

Dental implants consist of an implant that is surgically inserted into the jawbone, an abutment and a tooth attachment (eg crowns). The abutment is connected to the implant by means of an abutment screw. The abutments can compensate for inclinations of the implants implanted in the jawbone.

It must be ensured that the abutment is designed to be rotationally secure relative to the implant in order to prevent twisting of the abutment and implant when screwing in or removing the abutment screw. Also, the abutment screw should be tight, otherwise it can lead to a relaxation of the structure. Usually, abutments are screwed into the implant via abutment screws and tightened with a defined torque by means of a torque wrench. The screwing tools and abutment screw used are standard hexagon or slot screwdrivers. Implant and abutment are either as a common component or as separate units. Such implant systems are for example in the DE 10 2006 005 667 A1 , of the DE 198 03 172 A1 , of the DE 10 2006 005 147 A1 as well as the EP 0 801 544 A1 described.

The screw head geometry of conventional abutment screws does not differ significantly from those of conventional screws, as they are used in mechanical engineering or tool making. The screw head of previously used in the art abutment screws therefore consists of the usual slot, polygonal, and toothed shaft geometries.

Depending on the position of the implants in the jawbone, a distinction is made between diverging and converging implants. Diverging implants are still more difficult to handle. For adaptation or renewal of implants, it is often necessary to remove an already adapted in the jaw bone dental implant system again. For this purpose, all abutment screws of the prosthesis must be loosened and unscrewed from the screw channel, so as to separate the abutment of the implant. Since the abutment screw is usually buried in a narrow, very difficult to access screw channel of the abutment, it turns out after successful loosening regularly difficult to pry the small screw with the usual tools from the channel and reach. In addition, the abutment screw and / or the screw channel are often contaminated with saliva, blood, or fillings, which further complicates dislodging, levering, and gripping the abutment screw out of the screw channel. The dental practitioner is therefore regularly reliant on auxiliary tools, such as fine needles or probes, with which he can pry the abutment screw from the screw channel, sometimes quite cumbersome. With additional tweezers he has to grab the screw in time. Frequently, the abutment screw slips back into the screw channel during such manipulations or even falls into the mouth region of the patient. Due to the large number of screws used in dental prostheses, this mechanical process is very time-consuming and cumbersome.

In the case of divergent implant systems, it is aggravating that the implants are anchored in different defined X, Y, Z positions in the jawbone. Accessibility in the mouth area is extremely limited in such implant systems. If the screw channel of the abutment is additionally contaminated with bodily fluids or fillings, even auxiliary tools such as probes or needles can no longer lever out the abutment screw. The dental practitioner will therefore have to regularly spend a lot of time and patience to solve the individual abutment screws from the screw channel and lever out of the channel.

Similar problems also exist with the gingivaformer, which is used during the healing phase for forming soft tissue. The gingivaformer is screwed into the implant and tightened. At the foot of the healing abutment a screw thread is formed, which is screwed into the corresponding mating thread of the implant.

If a screw known from the prior art is turned with the screwdriver, a force is created which causes the screwdriver to slide out of the screw head. This effect is enhanced by saliva, blood or other contaminants in the screw channel. It comes to a slipping of the screwing tool. Furthermore, the internal geometry of the screw head or the Wrench itself damaged or even destroyed.

In order to avoid the loosening of screws or other connection components from a screwing tool, various solutions are generally known in the prior art. So will in the DE 198 06 662 A1 describes a coupling for connecting a screwing tool with a screw, wherein locking elements are provided on the screwing tool and the screw head, which engage with each other when attaching the screwing with the screw head. The disadvantage here, however, that with the engagement of a high material wear is connected to press the spherical projection into the receptacle of the screw head. Also, these designs do not withstand the torques occurring with abutment screws. In the DE 40 31 363 A1 In addition, the tool must be spread apart to effect a corresponding positive connection. This is impractical with the small screws used in the dental implant field. The screwdriver can slip off and break the screw head.

In the U.S. Patent 5,353,667A a screw is described with a screw profile, but due to the geometry requires a larger screw head. Also, this solution would be impractical with miniature screws such as abutment screws, which require a defined torque and would not cause the desired form fit. Similar solutions are also in the GB patent specification 2 368 016 A and the U.S. Patent 5,868,049 described.

Screw head profiles with conical design and / or force transmission surfaces are for example in the EP 0 928 165 B1 . WO 97/06930 A1 or the US Pat. No. 5,868,049 described. A disadvantage of these solutions is that they sometimes have to record quite high punctual moments of force when turning the screwing tool, which can be problematic especially for small screws or even for those screws that are used in dental prostheses.

In the screws known in the prior art, the rotational forces first act on the outer edge of the screw head and cause a minimal rotation of the screwing tool or a slight deformation of the screw head geometry, until a full-surface contact is given. The screw head and the screwdriving tool act like a torsion spring. By a slight deviation relative to the central axis of rotation, the contact surfaces slide apart causing erroneous functions resulting in deformation of the structure and loss of function.

For secure attachment of the screwdriver in the screw head, the dentist by design must push the screwdriver firmly into the chamber of the screw head. The applied force is not defined and leads to damage in the threads and the screw head. This leads to a self-loosening of the screw, resulting in a loosened crown structure. The function of the denture is no longer given.

Besides the deformation of the screw head during the load due to the effect of the torque, another disadvantage of the abutment screws known from the prior art is that the force in the cooperation of the screwing tool with the screw head geometry represents an uncontrolled variable. This can lead to damage to the thread substance in the implant and the screw. Another disadvantage is to see in the unsafe handling during use, because the screw can not be securely connected to the screwing. The screw can come loose and slip the screwdriver out of the screw head.

It is therefore an object of the present invention to provide a screw profile which eliminates the aforementioned disadvantages.

This object is achieved by a screw having the features of claim 1.

The screw according to the invention consists of a screw head and a screw shaft. The term "screw" should not be construed as limiting in this context. This term includes all connection arrangements in which a first component with a further component must be positively and positively connected to defined torques.

In one embodiment of the invention, this is preferably an abutment screw with a screw head chamber designed according to the invention. In another aspect, it is an implant with a connection geometry designed according to the invention for attaching the abutment formed antagonistically at the foot. Another aspect of the invention relates to a healing abutment with a screw head profile according to the invention.

The geometry described here can also be used for other connection arrangements, in particular in areas in which miniature screws are used, for example in prostheses, in computer production or in electrical engineering. Possible areas of use are therefore next to the dental technology, the mechanics, the Electromechanics and the production of prostheses in orthopedics.

The screw head profile according to the invention consists of a central recess or chamber for receiving a screwing tool, wherein the chamber is conical. Due to the conical shape, it is possible to obtain a gap-free positive connection with torque-transmitting surfaces, which would not be possible with a cylindrical course. Also achieved by the conical shape optimal for the intended purpose joining tolerance between the screwing and the screw head. In the chamber, a plurality of conically downwardly extending guide surfaces and laterally of the guide surfaces arranged force transmission surfaces for receiving the torque acting upon rotation of the screw are formed according to the invention. The second and further guide surfaces are differently undercut in the chamber of the screw head. "Undercuts" in this context means that the guide surfaces are different degrees incorporated into the material of the screw head. The distance between two opposing guide surfaces is the greater the further they are cut into the material of the screw head. These guide surfaces cause a screwing of the screwing tool into the central chamber of the screw head. Preferably, several differently undercut guide surfaces are provided in the screw head, which define the screw head geometry and give a characteristic profile. The guide surfaces are used to guide the technical cone of the antagonistic counter-geometry of the screwing and safe and easy assembly of the functional parts of the screwing or screw head similar to the key-lock principle. Both the guide surfaces and the lateral force transmission surfaces of the screw head geometry contribute to the support of the screwing tool and must be in positive engagement during the power transmission. The lateral force transmission surfaces are arranged at any angle of> 0 degrees with respect to the (top) surface of the guide surfaces. An angle of 90 degrees is preferred.

The counter-geometry of the screwing tool essentially corresponds to a technical cone with a conically tapered geometry at the end. On this cone are the corresponding counter-geometries corresponding to the screw, d. H. first and further guide surfaces and force transmission surfaces, which cooperate with the first and weitren guide surfaces and power transmission surfaces of the screw head. In this context, it is also possible to speak of antagonistic guide surfaces or force transmission surfaces of the screwing tool to the screwing head, since these interact with the corresponding guide surfaces or force transmission surfaces of the screw head positively and non-positively or cooperate.

The lateral force transmission surfaces and the guide surfaces are preferably arranged symmetrically at the screw head or screwing tool, d. H. the two surface elements lie opposite one another along an axis of symmetry. Depending on the degree of undercut of the surfaces in the screw head, the distance between the opposing surfaces is greater or smaller.

The screw head geometry or screw head geometry according to the invention has both a retention function and a force transmission function. Due to the inventive design of the guide surfaces and power transmission surfaces and the different angular dimensions of the conical shape of the guide surfaces can be self-centering screw and screw together. This ensures a defined, detachable, but at the same time firm connection between the screwing tool and the screw head. Slipping of the screw when loosening from the screw channel is thereby prevented.

About additional locking grooves or locking cams, a locking connection between the screwing and the screw head is made in a further preferred embodiment, so as to avoid accidental release of the screwdriver from the screw when levering out of the screw channel. The resilient locking legs slide over inclined planes of the screw head in the provided for them locking grooves, where they finally lock. Preferably, the resilient locking leg is designed hook-shaped at the head end. Due to the spring function, however, this connection can also be easily released at the same time. This results in defined joining or releasing forces. In a further embodiment, locking grooves are in the screw head and the locking cams on the screwing tool, d. H. the locking elements are reversed. In one embodiment, the locking groove may also be formed circumferentially on the screwdriver or in the chamber.

In a further embodiment, an additional clamping function is achieved in that the guide surfaces have an L-shaped clamping leg at the foot end. This clamping leg on the technical cone of the screwing tool engages positively in the corresponding L-shaped undercuts formed at the foot of the guide surfaces of the chamber of the screw head. Preferably, those are in the screw head formed undercuts counterclockwise radially narrowed. The L-shaped clamping legs of the guide surfaces fit with a counterclockwise rotation of the screwing tool in the undercuts of the chamber and jammed with defined predetermined force on the side walls and the upper and lower surfaces of the undercuts. This additionally secures the connection of the screw to the screwing tool after loosening the screw (counterclockwise rotation). In an alternative embodiment, this clamping function can be represented in a corresponding counter-symmetry, so that it also fulfills its function clockwise.

The power transmission function when turning the screw (left or right rotation) is mainly produced by the lateral force transmission surfaces. The force transmission surfaces absorb the forces when screwing or loosening the screw (clockwise or counterclockwise rotation) and transmit them to the body substance of the individual functional parts of the screw head geometry. For this purpose, the force transmission surfaces are preferably arranged at right angles (90 degrees) to the central axis. The conical shape leads to a rejuvenation of the force transmission surfaces. Preferably, these are additionally formed radially and parallel to the diameter plane offset with different angles of attack. This results in inclined planes with different angular dimensions. From these inclined planes ultimately self-locking moments that prevent loosening of the joined parts under load.

As already mentioned, the force transmission surfaces can be parallel-symmetrical with different angular dimensions on the cone of the screwing tool to the foot. However, you can also define a clamping leg, which engage in the corresponding undercuts of the chamber of the screw head. When tightening the screw by turning the screw clockwise, such a clamping function is not required. Therefore, it is preferred that here the force transmission surfaces extend symmetrically downwards (i.e., to the foot end). If no clamping legs are provided, the connection between the screwing tool and the screw head via the aforementioned locking elements can take place when the screw is loosened counterclockwise. Additionally or alternatively, the L-shaped designed clamping legs can engage in the undercuts of the screw head by turning the screwing tool to the left. Due to the conical shape of the guide surfaces and the force transmission surfaces, the screwing tool is additionally locked with the screw via a clamping closure acting over the surfaces. The occurring torques can be optimally transmitted by the contacting surfaces.

In a further embodiment, one or more additional, symmetrically arranged guide surfaces may be provided, which also contribute to the power transmission and the positive connection. In this case, the cone tip of the screwing tool is rather elongated and has viewed from the bottom of a jagged geometry. The chamber of the screw head has a corresponding corresponding counter-geometry.

The screw head profile according to the invention can be used in any arbitrary arrangement, in which a stable, but at the same time releasable connection between a first component to be made with a second component. In a first aspect of the invention is therefore an abutment screw with a screw head according to the invention and an associated screwing tool. In a further embodiment, the screw is an implant having a conically extending chamber formed therein with the guide surfaces and force transmission surfaces configured according to the invention. In this chamber, the corresponding corresponding foot of the abutment is inserted and positively and non-positively connected. In a further aspect, the screw is a gingivaformer with a chamber embodied therein designed in accordance with the invention in the screw head. In a preferred embodiment, a horizontal, circumferential groove is formed at the head end of the healing abutment, in which a locking ring is positively inserted. The locking ring causes a locking of the locking elements and thus avoids accidental jumping out of the resilient locking leg of the corresponding groove. Through the groove a clearance for the spring region in the screw head is created vertically. The spring region is the area in which the spring detents are located. Here, the geometry of the screw head undergoes a rejuvenation, from which a certain elasticity arises.

In a further embodiment, an additional stable implant arrangement can be created by forming interlocking tooth geometries on the abutment and on the implant. Due to the interlocking of individual surfaces, a positive connection is achieved, which contributes to additional stability.

Due to the geometry according to the invention, the screw head can be kept small, which benefits the miniature architecture of the abutment screws or gingiva formers and implants. Due to the conical configuration of the screw head and the defined transmission of force on the individual surfaces also gives a defined clamping force and a defined positive connection. Because the space in the screw head with abutment screws is very limited and only a narrow range of stress and strain is available, allows the inventive screw head geometry in small dimensions, a torque of up to 60 Ncm on the screw head. In this case, dimensions of 2.2 mm in diameter and a height of 2.3 mm are readily possible, and without damaging the geometry of the screw head by the operation of the screwing. Decisive in the system according to the invention is that the power transmission does not take place as in the prior art in the region of the screw head edge, but is oriented towards the center of the screw head to the screw shaft. Due to the cone geometry, this provides more "material" for absorbing the forces acting in the screw head. As a result, the required forces can be transmitted without deformation even with these small dimensions.

The occurring forces and the distribution of forces on the forces acting in the screw head with the screwing tools were confirmed by the finite element method (FEM). The analyzes showed that the occurring forces are optimally distributed over the acting surfaces. There is no deformation of the screw head geometry, as is the case with known screws when applying a torque. The clamping function and locking function according to the invention further prevents the screwing tool from slipping out of the screw head when the screw is being removed from the screw channel. Due to the geometry of the invention, the occurring force is further defined precisely, which acts on the assembly of the screwing with the screw head. As a result, damage to the thread substance in the implant and the screw can be avoided. The handling by the dental practitioner is greatly facilitated. The screw can not loosen on its own and can also be easily loosened and handled with "Tilt" implants and "All an Four" implants.

Due to the high possible torques, the preferred materials in the dental implant area such as titanium for the screw and high-performance steel for the screwdriver can be used. Another advantage is that the screw profile according to the invention enables self-centering of the screwing tool in the screw head. The screwdriver sits firmly in the chamber of the screw head. The applied force is defined and avoids damage in the threads and the screw head. Self-loosening of the screw with the consequence of a loosened crown structure is prevented.

The invention will be explained in more detail in the following drawings. Show it:

1 a first embodiment of an abutment screw with associated screwing tool,

2 another embodiment of an abutment screw with associated screwing tool,

3 various embodiments of the screwing tool head of in 2 described embodiment,

4 another embodiment of an abutment screw,

5 a variant for a gingivaformer,

6 an enlarged detail of different wrench heads,

7 the functioning of the latching closure,

8th a locking of the latching closure by a locking ring,

9 a form-fitting profile for abutment and implant.

10 a dental prosthesis consisting of abutment and implant.

In 1 recognizes a first embodiment of the screw according to the invention. In 1A you recognize an abutment 2 with an abutment screw inserted in the screw channel 3 with the screw head 29 trained screw head profile with a conical chamber 32 , The screwing tool 1 with the cone 12 trained counter profile can also be seen. The mating profile of the screwing fits according to the key-lock principle in the present invention formed corresponding screw head profile. In the chamber 32 the screw head can be seen the individual, symmetrically opposite arranged and different undercut, conically downwardly extending guide surfaces 31 . 34 , The guide surfaces 31 . 34 are of lateral power transmission surfaces 26 limited, which absorb the torques of the screwing tool when turning the screw. At the cone 12 of the screwing tool 1 Furthermore, one recognizes the corresponding corresponding antagonistic force transmission surfaces 6 and guide surfaces 11 . 14 , The guide surfaces 11 . 14 of the cone 12 of the screwing tool 1 cooperate with the antagonistic guide surfaces 31 . 34 the abutment screw 3 , The transmission surfaces 6 of the screwing tool 1 cooperate with the antagonistic transmission surfaces 26 the abutment screw 3 ,

Due to the offset parallel to the diameter plane arrangement of the power transmission surfaces 6 . 26 (Moment load surfaces) creates a divergence between the axis orientation of these surfaces with respect to the central axis and the angles of inclination of the individual conical surfaces. This will be the screwing tool 1 clamped and secured against tensile forces. All surfaces in the chamber 32 of the screw head 29 , Which are in surface contact with the corresponding antagonist surfaces of the screwing, exercise leadership and support functions. The transmission surfaces 6 of the screwing tool 1 as well as the power transmission surfaces 26 of the screw head 29 additionally exercise the function of a moment-load power transmission. In 1B the entire implant structure is shown. On the implant 4 becomes the abutment 2 plugged in and via an abutment screw 3 screwed. The screwing tool 1 can from the top into the screw channel of the abutment 2 be introduced. In 1C you can see the configuration of the cone 12 of the screwing tool 1 , In 1D is a detail enlargement of the cone 12 shown. Clearly visible are the different undercut, symmetrically and conically downwardly extending guide surfaces 11 . 14 of the cone 12 of the screwing tool 1 , The individual guide surfaces 11 . 14 taper at different angles as inclined planes down conically. The lateral power transmission surfaces 6 are opposite the guide surfaces 11 . 14 Arranged at right angles and tapering in the course. The tip of the cone 12 is designed in the embodiment shown around. Furthermore, one recognizes the on the guide surface 11 at the foot trained clamping leg 13 , The clamping leg 13 accesses the corresponding undercuts 33 of the screw head 29 ,

In 2 one recognizes a further embodiment of the screw head geometry according to the invention. In 2A It is easy to see how the individual surfaces cooperate with each other in a positive and non-positive manner. As a result, defined joining and releasing forces for the screwing 1 and the screw 3 possible. The resilient locking leg 27 forms with the cone 12 a sloping plane 25 , Wherein the interfaces touch each other positively and non-positively. The locking cams 30 of the locking leg 27 glide over the inclined plane 25 in the locking groove 10 ,

At the bottom is a small gap 28 recognizable, which is necessary to allow the lateral surfaces of the inclined plane 25 touch. In 2 B is the entire structure, consisting of screwing tool 1 , Abutment 2 , Abutment screw 3 and implant 4 shown. The at the screwing tool 1 trained locking groove 10 cooperates with those on the screw head 29 trained cams 30 , which in the embodiment shown on the guide surfaces 34 the screw head profile are formed. In 2C are the screwing tool 1 and the transmission surfaces 6 as well as the guide surfaces 11 . 14 shown in more detail. The L-shaped clamping legs are also clear 13 the guide surface 11 as well as the locking groove 10 to see. In 2D you can see a magnification section of the cone just described 12 , The individual guide surfaces 11 . 14 tapered down at different angles. The angular dimension of the guide surfaces 14 of the screwing tool 1 is greater than the conical shape of the guide surfaces 11 of the screwing tool 1 , In 2E is again an enlarged detail of the screwing tool 1 to see.

In 3 Further illustrations of the embodiments just described are shown. In 3A is the screwing tool 1 with the abutment screw 3 positively and positively connected. In 1B and 1C you recognize screwing tools 1 with different geometries of the cone 12 , In 1B and 1C be different screwing tools 1 shown. In 1B is an example of a tool for tightening the screw clockwise shown. The guide surfaces 11 . 14 run conically downwards at different angles. At the guide surface 11 are Rastnuten 10 educated. The lateral power transmission surfaces 6 taper from bottom to top according to the conical shape. In 1C is the screwing tool 1 for counterclockwise anti-clockwise rotation to loosen the screw 3 shown. Here have the guide surfaces 11 at the foot clamping legs 13 , These clamping legs 13 grab the corresponding undercuts 33 the chamber 32 of the screw head 29 , The associated screw head 29 is in 1D shown. The with the guide surfaces 11 . 14 of the screwing tool 1 cooperating guide surfaces 31 . 34 are also visible. At the foot of the guide surfaces 31 is the undercut 33 to recognize, in the clamping leg 13 of the screwing tool 1 positive and positive sliding in left turn.

In 4 a further embodiment of the screw head geometry according to the invention is shown. In 4A you can recognize the screwing tool again 1 , the abutment screw 3 , the abutment 2 and the implant 4 , In the embodiment shown is an additional guide surface 5 on the screwing tool 1 or another corresponding guide surface 35 in the chamber 32 the abutment screw 3 shown. In 1B you recognize the guide surfaces again 11 . 14 of cone 12 of the screwing tool 1 , The corresponding counter-geometry on the screw head 29 allows self-centering of the screwing tool 1 , In 1C you can see the cone 12 from its bottom. The additional guide surfaces 5 run conically downwards at a greater angle and are opposite the guide surfaces 11 . 14 further undercut. This creates an elongated, jagged geometry of the tip of the cone 12 , In 1D can be seen in detail the screw head profile. The individual first guide surfaces 31 . 34 as well as additional guide surfaces 35 . 36 are recognizable.

In 5 Finally, another embodiment in the form of a healing abutment is shown. Clearly visible are the chamber 32 and the already discussed areas. In 5A is a longitudinal section of the healing abutment according to the invention with the chamber 32 to see. In 5B you can see the chamber structure of the chamber 32 with the individual guide surfaces 31 . 34 . 35 . 36 and the undercut 33 , In 5C one recognizes a longitudinal section through the gingivaformer. In 5D you can see the screw head profile in plan view. The individual guide surfaces 31 . 34 . 35 . 36 are symmetrical along the axis of symmetry A in the screw head 29 arranged. Also cooperating with circumferential locking grooves locking cams 30 are recognizable. In 5E you can see the structure of the chamber 32 with more details. At the guide surface 34 there are locking cams 30 , which with corresponding circumferential locking grooves 10 cooperates with the screwing tool. Furthermore, the circumferential horizontal groove is also 16 in the head of the gingiva former 3 to recognize. The groove 16 serves the formation of the environment around the gingiva former 3 located screw head 29 , Through the groove 16 vertical is a free space for the spring region in the screw head 29 created. The spring region is the area in which the spring detents are located. In this area learns the geometry of the screw head 29 a rejuvenation, from which a certain elasticity arises. At the same time, this groove 16 for receiving a locking ring 17 serve to prevent springing back of the spring detents (see. 8th ). Clearly visible is the undercut 33 the guide surface 31 at the foot of it. The additional guide surface 35 is less undercut than the guide surface 31 , and these in turn undercut less than the guide surface 34 , The individual guide surfaces 31 . 34 . 35 . 36 are arranged so that the torque when operating the screwing 1 acts simultaneously on all surface points and the screwing tool 1 in the screw head 29 is involved. Due to the inclined planes, which come about by different angular dimensions of the individual surfaces in the conical shape, defined interfaces, which absorb the lateral torques arise. This slides the screwing tool 1 in the center of the screw head 29 , The torque acts on all surfaces and in particular of the power transmission surfaces 26 added.

In 6 one recognizes different embodiments of the cone 12 of the screwing tool 1 , In 6A Again, the different undercut guide surfaces 11 . 14 . 15 as well as the lateral force transmission surfaces 6 shown. Clearly visible is the cone-shaped cone tip. The cone 12 is in the embodiment shown at the head of a retention surface 9 includes. As a result, the vertical guidance of the screwing tool 1 in the screw head 29 specified. In 6B one recognizes a further embodiment in which the individual clamping legs 13 the guide surfaces 11 can be clearly seen. Also, the conically tapering power transmission surfaces 6 are clearly visible. The tip of the cone 12 forms a star-shaped geometry. The locking groove 10 runs over the entire width of the guide surface 11 ,

In 7 you can see the interaction of the resilient locking leg 27 with the locking cam 30 and a circumferential locking groove 10 of the screwing tool 1 , The locking leg 27 forms with the screwing tool 1 a sloping plane 25 , This forms a gap 28 at the bottom of the screw head 29 out. The additional locking will loosen the screw 3 from the screwing tool 1 avoided. By the resilient locking leg 27 can the screwing tool 1 if necessary, easily back off the screw 3 be solved.

In 8th you can see the head of a gingiva former 3 in which the screw head profile according to the invention is formed. On the outer thigh 18 of the gingiva former 3 is a U-shaped groove 16 incorporated into which the corresponding foot 19 a locking ring 17 can engage positively and accurately. As a result, the resilient locking leg 27 to the screwing tool 1 in the locking groove 10 pressed and locked in this position. Only when removing the lock ring 17 can the locking leg 27 from the locking groove 10 spring back and the screwing tool 1 from the gingiva former 3 be solved.

In 9 recognizes the connection profile according to the invention as a design for connecting an implant 4 with an abutment 2 , The chamber according to the invention 32 is at the head end 22 of the implant 4 educated. In this chamber 32 engages positively and non-positively the antagonistic trained foot 23 of the abutment 2 , The geometries are perfectly matched to each other. To recognize the form close to the Facing the abutment 2 with the implant 4 , creating a gap 20 as well as a lip 21 it becomes apparent which one in the gap 20 of the foot end 23 of the abutment 2 attacks. At the end of the lip 21 is a hook or wedge-shaped structure formed around an additional latching with a corresponding locking groove on the abutment 2 to effect. This geometry leads to a stable, but also defined coupling of the abutment 2 with the implant 4 , At the same time the mentioned disadvantages of the prior art are avoided. Cavities in which bacteria can nest are avoided. In the embodiment shown, the chamber has 32 on the implant 4 In addition, a thread profile in which the threaded portion of the abutment screw 3 from above the abutment 2 can be screwed.

In 10 you can see the overall structure of a dental prosthesis consisting of implant 4 and abutment 2 , On the abutment 2 is the structure with an abutment screw according to the invention 3 screwed. The connection profile according to the invention is formed on two components of the implant. The implant 4 and the abutment screw 3 have the same chamber geometries in the screw head in the embodiment shown 29 the abutment screw 3 or at the head end 22 of the implant 4 , In the chamber 32 are the individual guide surfaces 31 . 34 to see. The screw head 29 interacts with the technical cone 12 of the screwing tool 1 , Another variant of the profile according to the invention is at the head end 22 of the implant 4 shown. Again, a chamber of the invention 32 with individual conical guide surfaces 31 . 34 educated. In the variant shown is in the implant 4 a threaded hole in the chamber 32 provided in which the abutment screw 3 over the abutment 2 is screwed, ie the threaded portion of the abutment screw 3 gets through the hole in the abutment 2 guided. Furthermore, one recognizes the already described lip 21 which are in the corresponding gap 20 of the foot end 23 of the abutment 2 positive and non-positive engages. The abutment 2 In this way it can be twist-proof with the implant 4 get connected. Due to the conical design of the chamber 32 Cavities in which bacteria can implant are avoided.

For the skilled person further embodiments taking into account the teaching of the invention can be seen. The advantages of the present invention are to be summarized in that a high torque can be distributed to individual guide surfaces or force transmission surfaces in a confined space. Furthermore, the torque on the screw can be applied without deformation, without the screw geometry is damaged or even destroyed. Also, a defined assembly and separation of the screwing from the screw with defined forces. This also leads to the protection of the threaded parts. Ultimately, this facilitates the self-centering of the screwing tool in the screw head and allows for safe removal of the screw from the narrow abutment screw channel. "Tilt" implants and "All an Four" implants are easier to handle.

The profile according to the invention can be used anywhere where it depends on a defined but releasable connection. An example is the notebook construction, in which individual printed circuit boards or the housing are screwed on long screw channels. Even in these screw channels, it is very difficult to grab the screw. Therefore, in a further aspect, the invention relates to the use of the inventive connection profile for the production of dental prostheses.

LIST OF REFERENCE NUMBERS

1

Wrench

2

abutment

3

screw

4

implant

5

Guide surface screwing tool

6

Power transmission surface Screwing tool

9

retention area

10

locking groove

11

first guide surface screwing tool

12

cone

13

clamping leg

14

second guide surface screwing tool

15

further guide surface screwing tool

16

Nut gingivaformer

17

Lock ring gingivaformer

18

Outer thigh gingivaformer

19

Foot lock ring

20

gap

21

lip

22

Head implant

23

Foot end abutment

25

inclined plane screw

26

Power transmission surface screw

27

resilient locking leg screw

28

Gap technical cone

29

screw head

30

locking cam

31

first guide surface screw

32

Chamber screw head

33

undercut

34

second guide surface screw

35

additional guide surface screw

36

additional guide surface screw

Claims (14)

Screw ( 3 ), consisting of a screw head ( 29 ) and a screw shaft, wherein the screw head ( 29 ) a conically shaped chamber ( 32 ) for receiving a screwing tool ( 1 ), characterized in that the chamber consists of alternating, conically downwardly extending first guide surfaces ( 31 ) and with respect to these undercut, also conically downwardly extending second or further guide surfaces ( 34 ), which with the corresponding antagonistic first guide surfaces ( 11 ) or second guide surfaces ( 14 ) of the screwing tool ( 1 ) cooperate positively and positively, wherein the first and second guide surfaces ( 31 . 34 ) the chamber ( 32 ) of the screw head ( 29 ) laterally formed power transmission surfaces ( 26 ) which correspond to the corresponding antagonistic force transmission surfaces ( 6 ) of the screwing tool ( 1 ) cooperate with application of a torque frictionally and positively. Screw according to claim 1, characterized in that the first and second guide surfaces ( 31 . 34 ) of the screw head ( 29 ) in the chamber ( 32 ) are arranged symmetrically. Screw according to claim 1 or 2, characterized in that the first guide surfaces ( 31 ) Undercuts ( 33 ), which with antagonistic L-shaped clamping legs ( 13 ) of the first guide surface ( 11 ) of the screwing tool ( 1 ) co-operate positively and positively. Screw according to one of claims 1 to 3, characterized in that the first and second guide surfaces ( 31 . 34 ) taper conically downwards at different angles and form inclined planes. Screw according to one of claims 1 to 4, characterized in that the force transmission surfaces ( 26 ) in the chamber ( 32 ) taper conically along the axis of rotation. Screw according to one of claims 1 to 5, characterized in that in at least one guide surface ( 31 . 34 ) the chamber ( 32 ) a locking cam ( 30 ) is formed, which with one on the cone ( 12 ) of the screwing tool ( 1 ) formed locking groove ( 10 ) cooperates. A screw according to claim 6, characterized in that the locking grooves ( 10 ) on the screwing tool ( 1 ) and locking cams ( 30 ) at the screw head ( 29 ) are formed. Screw according to claim 7, characterized in that the locking cams ( 30 ) on a resilient latching leg ( 27 ) formed with the cone ( 12 ) of the screwing tool ( 1 ) laterally an inclined plane ( 25 ). Screw according to one of claims 1 to 8, characterized in that the lateral force transmission surfaces ( 26 ) the chamber ( 32 ) at right angles to the first and second guide surfaces ( 31 . 34 ) are formed. Screw according to one of claims 1 to 9, characterized in that at least one further guide surface ( 35 . 36 ) in the chamber ( 32 ) of the screw head ( 29 ) formed with at least one further corresponding antagonistic guide surface ( 5 . 7 ) on the cone ( 12 ) of the screwing tool ( 1 ) cooperates. Screw according to one of claims 6 to 10, characterized in that the latching groove ( 10 ) is circumferential. Screw according to one of Claims 1 to 11, characterized in that the screw is an abutment screw ( 3 ) or a gingivaformer ( 3 ) is an inventively designed connection geometry. Screwing tool comprising a handle and a cone ( 12 ), characterized in that on the cone ( 12 ) one opposite the screw head ( 29 ) according to one of claims 1 to 11 corresponding antagonistic counter-profile is formed. Use of a screw according to one of claims 1 to 12 for the production of dental prostheses.

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