Dental screw and dental fastening tool

Abstract

The present disclosure provides a dental screw (10) for securing dental components (1, 2) to each other, the dental screw having a proximal end (11), a distal end (12) and a longitudinal axis (LS), wherein the dental screw further comprises a screw head (13) comprising a tool engagement interface (20) for engaging a fastening tool (30) at the proximal end and a screw shank (14) distal of the screw head, the screw shank comprising a torque limiting portion (15) and a threaded portion (16) distal of the torque limiting portion for engaging a dental component (1, 2, 3), wherein the dental screw is configured to transmit a minimum torque of 26 Ncm from the tool engagement interface to the threaded portion and the torque limiting portion is configured to limit the transmittable torque to a maximum torque for preventing damage to the threaded portion. The present disclosure further provides a dental fastening tool, a dental fastening device and a dental support device.

Description

[0001] This application is a divisional application of application number 202080042052.9, with an entry date of December 7, 2021, entitled "Dental Screws and Dental Fastening Tools". Technical Field

[0002] This invention relates to dental screws, dental fastening tools, dental fastening devices, and dental prosthesis support devices. Background Technology

[0003] Dental prostheses anchored within a patient's mouth using dental implants have proven to be a highly successful solution for replacing one or more teeth. Currently, numerous dental techniques are available that allow for the aesthetic integration of dental prostheses into a patient's dentition. Furthermore, from a functional point of view, these prostheses are essentially identical to the one or more natural teeth they replace, resulting in minimal changes to the patient compared to their healthy natural counterpart.

[0004] To provide patients with customized and cost-effective solutions for dental restorations, dental restorations are typically modular in design. Therefore, by selecting a combination of dental components that deliver the desired replacement outcome, these restorations are tailored to individual patients. This combination of dental components can be as simple as a dental implant directly attached to the prosthesis. More commonly, it is a combination of an abutment, a dental implant, and a prosthesis, with the abutment positioned between the implant and the prosthesis. Such abutments are available as single-piece or multi-piece abutments. Other components that may be present in a dental restoration include bridging elements, caps, etc.

[0005] One of the most common techniques for assembling dental components is the use of dental screws. Dental screws allow for the assembly and disassembly of dental restorations. This is particularly advantageous for adjusting dental restorations in the dental laboratory and in the chair position of a dental clinic. Furthermore, the use of screws makes revisions of at least some parts of a dental restoration much easier compared to, for example, using dental adhesives to connect these components. Such dental screws have been described in WO 2018 / 091515 A1, WO2017 / 070335 A1, and US 8,029,282 B2.

[0006] However, an increasing number of components require smaller dental screws to optimize the fit of dental restorations. Smaller dental screws also offer greater flexibility in dentition areas where space is quite limited, such as the anterior teeth.

[0007] These dental screws are used to assemble and secure dental components relative to each other, where chewing forces are primarily transmitted through the dental components. Therefore, the primary function of a dental screw is to hold the components in place. Furthermore, the smaller the dental screw, the more material can be specified for the dental components to increase their strength against chewing forces. Summary of the Invention

[0008] In view of the foregoing, one object of this disclosure is to provide dental screws with a design that allows for further reduction in their size. However, the smaller the screw, the more difficult it becomes to manipulate. Therefore, another object of this disclosure is to enhance the manipulation of such small dental screws. Furthermore, the reduced size of these dental screws carries the risk of damage to the screw or dental component, particularly when transmitting torque during tightening. Therefore, yet another object of this disclosure is to improve torque transmission between fastening tools, screws, and / or dental components. The inventors have also considered the cost-effective manufacture of these dental screws, screwdrivers, and dental components.

[0009] To address these objectives, this disclosure provides a dental screw for securing dental components to each other. The dental screw has a proximal end, a distal end, and a longitudinal axis. The dental screw also includes a screw head comprising a tool engagement interface for engaging a fastening tool at the proximal end, and a screw shank distal to the screw head. The screw shank includes a torque-limiting portion and a threaded portion distal to the torque-limiting portion for engaging the dental components. The dental screw is configured to transmit a minimum torque of 26 Ncm, and the torque-limiting portion is configured to limit the transmittable torque to a predetermined maximum torque to prevent damage to the threaded portion, particularly under maximum tensile and / or shear stress.

[0010] If the maximum torque is exceeded, particularly under maximum tensile and / or shear stress, the torque-limiting portion, which is part of the screw shank, causes the screw shank to fail. In other words, the material at the torque-limiting portion of the dental screw cannot withstand the shear force caused by torque exceeding the maximum torque and applied via the tool engagement interface. However, dental screws are constructed to transmit a minimum torque of 26 Ncm in order to securely fasten dental components to each other.

[0011] Therefore, the torque-limiting portion prevents damage to the threaded portion of the dental screw and the threaded portion of the dental component to which the dental screw engages. For example, the dental component can be a dental implant, so the dental screw prevents damage to the implant. Thus, it also provides the patient with the benefit that this configuration of the dental screw prevents implant revision due to such damage.

[0012] Typically, a dental screw threads onto a first dental component to fasten a second dental component to the first. Due to a predefined failure at the torque-limiting section of the dental screw, the second dental component to which the screw is intended can be easily removed. Furthermore, the section of the screw that remains engaged with the first dental component after failure can also be easily removed using a tool such as pliers. Therefore, the first dental component remains intact and does not need to be replaced. In fact, the only part that must be replaced is the dental screw.

[0013] The torque-limiting portion is preferably arranged (in a portion) adjacent to the screw head such that, after the torque-limiting portion fails, the main portion of the shank that engages with the dental component remains in the dental component, with which the dental screw engaged before failure. This facilitates the removal of the remaining shank of the dental screw from the dental component. In other words, the torque-limiting portion is preferably located in the coronal (proximal) portion of the screw.

[0014] Because of the torque limiting section, the size of the dental screw can be further reduced without the risk of failure at sections of the dental screw that could potentially damage the dental component.

[0015] To weaken the dental screw at the torque-limiting section, the torque-limiting section may have a minimum section modulus along the rod.

[0016] Therefore, the cross-section of the torque-limiting portion is designed to have minimal resistance to torque, and thus, if the applied torque exceeds the maximum torque that the torque-limiting portion is designed to transmit, it will break first. In other words, the section modulus of the torque-limiting portion is less than the section modulus of the rest of the rod, including the threaded portion. The section modulus is also preferably less than any section of the screw head designed to transmit torque applied via the tool engagement interface.

[0017] Alternatively or additionally, the torque limiting portion may include at least one notch for inducing failure, and may be made of different materials and / or have different material properties.

[0018] Preferably, the maximum torque that can be transmitted at the torque limiting section is 38 Ncm, 36 Ncm, 34 Ncm, or 32 Ncm. Applying torque exceeding the torque value selected for the design of the dental screw will cause the torque limiting section to fail, and thus the dental screw to fail.

[0019] Furthermore, the torque limiting portion can be configured to withstand a maximum tensile force in the range of 300N to 500N, and preferably in the range of 350N to 450N.

[0020] The application of torque results in a tensile force acting along the screw shank between the screw head and the threaded portion, also along the torque-limiting portion. Exceeding the maximum tensile force designed for the dental screw, especially during torque application, is configured to cause the screw shank to break at the torque-limiting portion, and thus lead to screw failure.

[0021] The tool engagement interface may include a torque transmission region having a cross section perpendicular to the longitudinal axis of the dental screw, the cross section including a profile having four or five convex segments and / or planar segments alternating with four or five concave segments respectively.

[0022] These concave and convex sections form a wavy profile around the longitudinal axis of the dental screw. This enhances torque transmission via the tool engagement interface. This is primarily due to the torque transmission between the corresponding dental fastening tool and the dental screw on the contact surface extending in a more radial direction. Furthermore, during the application of torque to fasten the dental screw to the dental component, it is not necessary to apply a force along the longitudinal axis of the dental screw to maintain engagement between the fastening tool and the dental screw.

[0023] Furthermore, having four or five convex segments and / or planar segments alternating with four or five concave segments enables a design with a smaller screw head having sufficiently thick walls to transmit a predetermined torque, while allowing for a compact screw design. It also allows for screwdrivers with smaller diameters. A greater number of segments requires a larger screwdriver, which results in an increase in the screw head size and / or a thinner screw wall. The tool engagement interface is preferably formed as a recess.

[0024] It has been found that a larger number of concave and convex and / or planar sections primarily weaken the screw head, while a smaller number of concave and convex / planar sections show adverse effects related to torque transmission.

[0025] Preferably, the convex and / or planar and concave segments are connected or merged at transition points, and at each transition point, the angle between the tangent of the concave segment's profile and the tangent of the convex segment is in the range of 90° to 180° or 160°, preferably 95° to 150°.

[0026] Achieving an angle at the transition point within the range listed above in the design of dental screws has been shown to provide smooth and efficient torque transfer.

[0027] The transition point between alternating concave and convex and / or planar segments can be a point along the contour of the tool engagement interface, where the two alternating segments transition continuously or smoothly from one to the other. In this case, the transition point represents the point where the curvature changes sign with a continuous change in slope. Therefore, when based on adjacent concave segments or adjacent convex and / or planar segments, the tangent at this transition point has the same slope.

[0028] Alternatively, a transition point can also be a point where alternating segments transition discontinuously from one to another. In this case, the curvature changes sign or direction with a sudden shift in the slope. Therefore, a tangent at the transition point based on an adjacent concave segment results in a different slope than a tangent based on an adjacent convex segment and / or planar segment.

[0029] The convex and / or planar and concave sections may form longitudinally engaging protrusions extending radially from a circle with the largest inner diameter toward the longitudinal axis. The engaging protrusions preferably have a chamfer at their proximal ends.

[0030] These longitudinal engagement protrusions are configured to engage the fastening tool and receive torque from it. In other words, they form at least a portion of the torque transmission zone. A chamfer at the proximal end of the engagement protrusion makes it easier for dental professionals to engage the fastening tool with the dental screw. More specifically, a chamfer, preferably located at the entrance to the tool engagement interface, guides the engagement of the fastening tool.

[0031] The tool engagement interface may include a pickup area that tapers along the direction from the proximal to the distal end of the dental screw. The pickup area is preferably located near, proximal to, and / or at least partially along the torque transmission area.

[0032] The tapered shape of the pickup area allows the dental screw to be held to the dental fastening tool via friction. In other words, the dental fastening tool can be inserted into the pickup area. Sufficient pressure is then applied to press the dental fastening tool into the pickup area. This establishes a frictional fit that can be easily reversed. For this reversible frictional fit, the angle of the tapered shape is preferably chosen to be in the range of 5° to 12°, particularly 6° to 9°, or essentially 7°. Alternatively, it can be in the range of 10° to 12° or essentially 11°.

[0033] Specifically, if the pickup area extends at least partially along the torque transmission area—that is, the torque transmission area and the pickup area at least partially overlap or are identical—the tapered configuration results in the advantage of continuous and effective torque transmission even in the presence of wear. More specifically, if the tool engagement interface of the dental fastening tool and / or dental screw undergoes wear, the dental fastening tool will simply be inserted further into the tapered torque transmission area. Thus, the torque transmission remains essentially unchanged because the structure in which torque transmission occurs remains substantially the same despite wear.

[0034] On the one hand, if the torque transmission zone and the pickup zone overlap at least partially, this allows for a more compact design of the screw head and the fastening tool along their longitudinal axis. On the other hand, if the pickup zone and the torque transmission zone do not overlap, wear can be reduced and a more precise fit between the dental screw and the fastening tool can be achieved due to the functional and spatial separation of the two zones.

[0035] The tool engagement interface may also include a verification area for verifying the type of dental screw. The verification area is preferably located at the distal end of the tool engagement interface.

[0036] Based on the verification zone, dental professionals can verify whether a dental screw is the appropriate screw to be used with a dental fastening tool or dental component. For example, if a dental professional cannot fully insert the fastening tool into the tool engagement interface and / or engage the fastening tool with the tool engagement interface, this indicates that the incorrect screw or the incorrect dental component has been selected for assembly. Therefore, such a verification zone prevents damage to the dental component or dental screw if the configuration of the dental component or dental screw is not complementary to each other.

[0037] In addition to or besides a verification area, the proper combination of dental components and dental screws can also be ensured by constructing the two dental components such that they can only be assembled using dental screws that are correctly positioned and oriented relative to each other. This is specifically addressed in the international application also filed by the applicant under number PCT / EP2018 / 071797. Figure 5 The application is incorporated herein by reference in a detailed description.

[0038] Furthermore, this disclosure provides a dental fastening tool. The dental fastening tool has a proximal end, a distal end, and a longitudinal axis. The dental fastening tool includes a screw engagement interface at the distal end for engaging a dental screw (particularly a dental screw as described above), and a torque limiting portion proximal to the screw engagement interface. The torque limiting portion is configured to limit the transmittable torque to a maximum torque for preventing damage to the screw engagement interface.

[0039] The advantages of dental fastening tools that include a torque-limiting portion are similar to those achieved by utilizing a torque-limiting portion integrated into a dental screw. More specifically, if the torque transmitted by the dental fastening tool exceeds a predefined maximum torque, the torque-limiting portion is configured to fail. This failure prevents damage to the dental screw. After failure, the portion of the dental fastening tool that separates at the torque-limiting portion can be easily removed, allowing the assembly or removal of the dental screw to be performed using another dental fastening tool, for example, to investigate the cause of the failure. In any case, the torque-limiting portion of the dental fastening tool prevents damage at the height of dental components such as dental implants or abutments.

[0040] As discussed above, the torque limiting section also allows for a smaller design of the dental screw. This reduces the safety factors typically included to prevent damage to or failure of the dental screw or the dental component to which it engages or is fastened. Instead of attempting to prevent any damage, damage is controlled by the predetermined failure of the dental screw. In other words, the safety provided by safety margins is at least partially replaced by a safety mechanism based on controlled failure.

[0041] The torque limiting portion can be configured to withstand a maximum torque of 35 Ncm or less, preferably in the range of 27.5 Ncm to 34 Ncm, and more preferably in the range of 28 Ncm to 33 Ncm.

[0042] The higher values ​​in these ranges, such as 30 Ncm to 34 Ncm, are preferably used for dental fastening tools that also allow torque to be transmitted when the longitudinal axis of the dental fastening tool and the longitudinal axis of the dental screw are tilted relative to each other. The lower values ​​in these ranges, such as 27.5 Ncm to 29 Ncm, are sufficient for dental fastening tools that do not allow such tilting during torque transmission.

[0043] The screw engagement interface may include a torque transmission zone having a cross-section perpendicular to the longitudinal axis, the cross-section comprising four or five convex segments and / or planar segments alternating with four or five concave segments. The convex and / or planar segments and concave segments form an engagement structure around the longitudinal axis of the dental fastener.

[0044] The advantages of this configuration of the torque transmission zone have been discussed with respect to the corresponding zone of the dental screw. Regarding dental fastening tools, it should be noted that if the dental fastening tool is designed to transmit torque also at the aforementioned angle to the dental screw, then the use of five concave sections alternating with five convex and / or planar sections is particularly advantageous.

[0045] A dental fastening tool that allows for angular torque transmission between the longitudinal axis of the dental fastening tool and the longitudinal axis of the dental screw preferably has a curved profile in the section along the longitudinal axis (longitudinal section).

[0046] The curved profile preferably extends at an angle in the longitudinal section, allowing torque transmission between the dental fastener and the dental screw, while the relative angle between their longitudinal axes is in the range of 0° to 25°. Therefore, the curved profile can extend over a range of at least 25°.

[0047] The concave section preferably has a curved profile in a cross-section perpendicular to the longitudinal axis of the dental fastening tool. Conversely, the convex section may have a curved profile, particularly a circular profile, or may include both curved and straight (linear) profiles. This corresponds to convex and planar sections along the circumference of the screw engagement interface. As previously mentioned, planar sections may also be used instead of convex sections. Those skilled in the art will understand that a planar section is represented by a straight line in a cross-section of the fastening tool perpendicular to its longitudinal axis.

[0048] Preferably, the convex and / or planar and concave segments are connected or merged at transition points, and at each transition point, the angle between the tangent of the concave segment's profile and the tangent of the convex segment is in the range of 90° to 180° or 160°, preferably 95° to 150°.

[0049] Similar to dental screws, achieving an angle at the transition point within the range listed above in the design of dental fastening tools has been shown to provide smooth and efficient torque transmission.

[0050] Smaller angles, ranging from 90° to 110° and especially from 96° to 104°, particularly enhance torque transmission between the tool engagement interface of the dental screw and the screw engagement interface of the dental fastening tool.

[0051] Larger angles, in the range of 130° to 180° and particularly in the range of 142° to 148°, can advantageously be combined with a greater number of the aforementioned concave and convex segments and / or planar segments, particularly five per segment. Angles within these ranges still provide efficient torque transmission. They further allow the configuration of the screw engagement interface to transmit torque even when the longitudinal tool axis and the longitudinal screw axis are misaligned (i.e., tilted relative to each other).

[0052] The angle at the transition point of the dental screw's profile preferably matches substantially the angle at the transition point of the dental fastening tool.

[0053] The transition point between alternating concave and convex and / or planar segments can be a point along the contour of the screw-joint interface, where the two alternating segments transition continuously or smoothly from one to the other. In this case, the transition point represents the point where the curvature changes sign with a continuous change in slope. Therefore, when based on adjacent concave segments or adjacent convex and / or planar segments, the tangent at this transition point has the same slope.

[0054] Alternatively, a transition point can also be a point where alternating segments transition discontinuously from one to another. In this case, the curvature changes sign or direction with a sudden shift in the slope. Therefore, a tangent at the transition point based on an adjacent concave segment results in a different slope than a tangent based on an adjacent convex segment and / or planar segment.

[0055] The screw engagement interface may include a pickup area for retaining the dental screw, which is preferably located near, proximal to and / or at least partially along the torque transmission area.

[0056] The presence of a pickup zone facilitates the manipulation of dental screws, as they can be manipulated while attached to a dental fastening tool. This is also advantageous because it prevents contamination of the dental screw during manipulation.

[0057] The pickup area can be conical, especially if torque transmission can only be achieved when the longitudinal axes of the dental screw and the dental fastener are aligned with each other.

[0058] Alternatively, the pickup area may also have a curved profile in the longitudinal section, as described above regarding the curved torque transmission area of ​​a dental fastening tool. Such a pickup area can also serve at least partially as a torque transmission area.

[0059] In any case, the pickup area will be able to interact with, for example, a dental screw with a tapered tool engagement interface in order to establish pickup and retention functions via friction.

[0060] The screw engagement interface may also include a verification area for verifying the type of dental screw when engaging the dental screw. The verification area is preferably located at the distal end of the tool engagement interface.

[0061] As described above in relation to dental screws, the verification area serves to verify the proper use of dental fastening tools, for example, when used with corresponding dental screws. Therefore, unintentional use of dental fastening tools can be prevented.

[0062] This disclosure also provides a dental fastening device. The dental fastening device includes a dental screw, particularly a dental screw according to one of the aforementioned configurations. The dental fastening device also includes a dental fastening tool, particularly a dental fastening tool constructed as described above. Both the dental screw and the dental fastening tool each include a torque-limiting portion, wherein the torque-limiting portion of the dental screw is configured to withstand a maximum torque higher than the maximum torque that can be transmitted via the torque-limiting portion of the dental fastening tool.

[0063] To transmit torque, dental fastening tools and dental screws correspond to each other. More specifically, the tool engagement interface of the screw and the screw engagement interface of the dental fastening tool correspond to each other.

[0064] Due to the aforementioned relationship between the torque-limiting portion of the dental fastening tool and the torque-limiting portion of the dental screw, failure during the use of the dental screw and dental fastening tool is designed to occur first on the fastening tool side. This prevents damage to the dental screw or dental component. Designing the fastening device to cause failure further away from the dental component (e.g., dental implant) that engages with the dental screw makes it easier to replace any of these dental components, dental screws, or dental tools.

[0065] The dental screw of the dental fastening device may include a tool engagement interface, wherein the tool engagement interface includes a torque transmission region having a cross-section comprising alternating convex and / or planar segments with concave segments, wherein the convex and concave segments preferably have curved profiles. In order to transmit torque in the engaged state of the dental screw and the dental fastening tool, at least a middle section of each of the convex and / or planar segments of the dental screw faces the profile of the concave segment of the tool engagement interface at a distance.

[0066] Due to this distance, the convex and / or flat sections of the dental fastening tool do not engage with the dental screw. This prevents torque from being transmitted from the dental fastening tool to the dental screw at locations where the profile would otherwise be quite inefficient. Torque transmission can also lead to increased wear due to the unfavorable influence of the contact surfaces on the orientation of torque transmission, as will be described in more detail below. In other words, with this configuration, torque transmission occurs primarily at the transition points between the concave and convex and / or flat sections of the screw engagement interface of the dental fastening tool and the tool engagement interface of the dental screw.

[0067] This configuration also reduces wear on the convex and / or flat sections of the dental fastening tool. Wear can be further reduced by using steel as the material for the dental fastening tool and preferably titanium or titanium alloys as the material for the dental screw.

[0068] The torque transmission zone of the dental screw and the torque transmission zone of the dental fastening tool have rotational clearance when they engage with each other, particularly in the range of 1° to 3.5° and preferably in the range of 1.5° to 3°.

[0069] In other words, the cross-sectional profiles of the torque transmission zones of the dental screw and the dental fastening tool correspond to each other, but are not necessarily perfectly matched, so that they are configured to provide such rotational clearance. This rotational clearance serves as tactile feedback for the dental professional to determine the initiation of torque transmission. In particular, the dental professional can easily initiate torque transmission when contact is established between the profile of the dental fastening tool and the dental screw during rotation. The rotational clearance also facilitates the insertion of the dental fastening tool. This is especially useful if the dental fastening tool is configured to allow torque transmission (only) when the longitudinal axes of the dental fastening tool and the dental screw are aligned with each other.

[0070] Dental screws and dental fastening tools may also each include a pickup area configured to engage with each other by friction. As mentioned above, such a pickup area facilitates manipulation of the dental screw and prevents contamination, especially since dental professionals do not have to hold the dental screw directly.

[0071] Dental screws and dental fastening tools may also each include a verification zone configured to allow the torque transmission zone of the dental fastening tool to engage with the torque transmission zone of the dental screw when the dental fastening device is fully engaged.

[0072] In other words, torque transmission can only be truly achieved when the verification areas of the dental screw and the dental fastening tool are fully engaged. Without full engagement, torque transmission is at least difficult to achieve, and preferably impossible. As discussed above, this prevents damage to the dental fastening tool, dental screw, and dental components that are not intended for combined use.

[0073] In addition, this disclosure provides a dental prosthesis support device including a dental screw, particularly a dental screw according to the above configuration, and dental components, wherein the dental components are specifically dental implants, abutments, and / or dentures.

[0074] In this combination, the smaller design of the dental screws allows for increased strength and / or reduced size of the dental prosthesis support device.

[0075] A dental screw may include a support surface. The support surface may be inclined relative to the longitudinal axis of the dental component. Therefore, the dental component includes a screw seat. The screw seat may be inclined at an angle relative to the longitudinal axis of the dental screw such that, at least in the pre-tightened state, the contact between the support surface of the dental screw and the screw seat is typically established by line contact. During contact between the screw seat and the support surface, the longitudinal axis of the screw seat is aligned with the longitudinal axis of the support surface.

[0076] The angular relationship between the support surface of a dental screw and the screw seat of a dental component, at least initially resulting in line contact between the support surface and the screw seat, has the advantage that this contact is more predictable than surface contact, which leads to better predictability of the tightening process. Therefore, this helps to predetermine the flow of forces within the screw and thus improves the predictability of failure. The line contact is preferably located at or near the outer diameter of the screw head.

[0077] When tightened, the angular clearance between the support surface of the dental screw and the screw seat of the dental component can be at least partially closed. Therefore, the increase in torque is suppressed at the end of tightening. Dental professionals can more easily predict the end of tightening. Therefore, damage to the dental screw, dental fastening tool, or dental component is less likely.

[0078] The screw seat and the support surface are preferably both formed as conical angle surfaces.

[0079] The dental screw includes a threaded portion, and the dental component includes a threaded hole. In the tightened state, the threaded sides of the threaded portions that are in contact with each other are in contact with the threaded sides of the threaded hole for at least 70% of their profile length in the radial direction.

[0080] In other words, when the contact between the two sides of the threads of the dental screw and the dental component is observed in the profile of the longitudinal section of the screw in a tightened state, the two thread profiles are in contact with each other along at least 70% of their respective lengths. More specifically, the proximal side of the threaded portion of the dental screw and the distal side of the threaded hole of the dental component are in contact along the threaded sides along at least 70% of their respective lengths in a radial direction relative to the longitudinal axis of the dental screw.

[0081] The advantage of this configuration is that it enhances the surface contact between the dental screw and the dental component compared to standard threads (such as metric ISO threads), resulting in a more uniform distribution of force within the threaded hole used to fasten the dental screw into the dental component. It also allows for the accumulation of the necessary tensile force for tightening with fewer turns and therefore faster tightening, and enables a shorter thread design. This allows for a smaller design for both the dental screw and the threaded hole in the dental component. The strength of the dental prosthesis support can be increased and / or its overall size can be reduced. Attached Figure Description

[0082] The following figures illustrate preferred embodiments of the invention. These embodiments should not be construed as limiting, but are merely intended to enhance the understanding of the invention within the context of the following description. In these figures, the same reference numerals refer to features having the same or equivalent functions and / or structures throughout. For the sake of brevity, repeated descriptions of these features are generally omitted.

[0083] Figure 1 It is a cross-sectional view along the longitudinal axis of the dental screw, and in particular the longitudinal axis of the tool engagement interface of the dental screw.

[0084] Figure 2 yes Figure 1 A plan view of the tool engagement interface of the dental screw shown;

[0085] Figure 3 a and Figure 3 b is perpendicular to Figure 1 and Figure 2 The cross-sectional view shown is a longitudinal axis view of a dental screw, which shows the engagement of the tool engagement interface with the screw engagement interface of the dental fastening tool.

[0086] Figure 4 yes Figure 3 a and Figure 3 Partial side view of the dental fastening tool shown in b;

[0087] Figure 5 It is perpendicular to the height of the torque transmission section of the fastening tool. Figure 3 and Figure 4 A cross-sectional view of the longitudinal axis of the dental fastening tool shown;

[0088] Figure 6 a and Figure 6 b is a cross-sectional view along the longitudinal axis of the dental screw at the height of the tool engagement interface and when engaged with the dental fastening tool;

[0089] Figure 7 This is a three-dimensional view of a dental screw according to another embodiment;

[0090] Figure 8 It is for fastening according to another implementation scheme. Figure 7 A three-dimensional view of the dental screw fastening tool shown;

[0091] Figure 9 yes Figure 8 Detailed view of the screw engagement interface of a dental fastening tool;

[0092] Figure 10 a and Figure 10 b illustrates the function of the verification area at the screw engagement interface;

[0093] Figure 11 This is a side view of another embodiment of the screw engagement interface of a dental fastening tool;

[0094] Figure 12 yes Figure 11 A front view of the screw engagement interface of the dental fastening tool shown;

[0095] Figure 13 It is a schematic cross-sectional view of the threaded engagement between a dental screw and a dental implant; and

[0096] Figure 14 It is a cross-sectional view along the longitudinal axis of the dental screw, abutment, and implant during engagement, according to yet another embodiment. Detailed Implementation

[0097] Figure 1 A sectional view along the longitudinal axis LS of the dental screw 10 according to the embodiment is shown. Hereinafter, the section along the longitudinal axis is also referred to as the longitudinal section. Figure 1 A longitudinal section of the dental screw 10 shows a portion of the screw head 13 and the screw shank 14. The screw head 13 includes a tool engagement interface 20. Figure 1 As shown, the tool engagement interface 20 is preferably formed as a recess.

[0098] To transmit torque, the tool engagement interface 20 includes an engagement structure. This engagement structure includes convex sections 21 and concave sections 22. The convex sections 21 and concave sections 22 alternate. An equal number of convex sections 21 and concave sections 22 are present. As shown, these sections are arranged on the inner circumferential wall of the tool engagement interface 20 and form a torque transmission zone 25b.

[0099] Figure 2 An exemplary embodiment of the dental screw 10 includes a tool engagement interface 20 comprising five convex segments 21 and five concave segments 22. As seen in a section perpendicular to the longitudinal axis LS of the dental screw 10 (hereinafter also referred to as the vertical section), the convex segments 21 and concave segments 22 form longitudinal engagement protrusions 24 extending from a circle 26. This circle is defined by the maximum inner diameter of the tool engagement interface 20. With respect to the tapered tool engagement interface 20, as further described below, the diameter of the circle 26 decreases from the proximal end to the distal end of the dental screw 10.

[0100] To achieve a compact and durable design for the dental screw 10, it has been found advantageous to provide four or five concave and convex segments for the tool engagement interface 20. Preferably, the screw engagement interface of the dental fastening tool includes a number of concave and convex segments corresponding to the number of concave and convex segments of the dental screw to be engaged.

[0101] As will be described in more detail below, for fastening tools that allow for effective and angular application of torque (i.e., torque applied via angle), five convex sections and five concave sections are preferred.

[0102] It has been found that for combinations of dental screws and fastening tools whose longitudinal axes are aligned during torque application, having four concave and four convex segments is particularly advantageous. In such an implementation, the geometry of the engagement structure results in very precise engagement and efficient torque transmission.

[0103] In the exemplary embodiment of the dental screw and fastening tool shown in the figure, the concave segment 22 and the convex segment 21 have curved profiles. However, and as previously mentioned, the convex segment 21 can also be planar. The concave segment 22 and the convex segment 21 form a joint structure. Along the profile of the joint structure in a vertical section, the concave segment 22 and the convex segment 21 connect at a transition point 23. Figure 2 In the implementation scheme, the transition between the concave section 22 and the convex section 21 is continuous.

[0104] However, and as mentioned above, the transitions between these segments can also be discontinuous. Figure 5 An example of a discontinuous transition along the contour of the engagement structure is shown for the fastening tool 30. Here, the transition point 43 of the screw engagement interface 40 of the fastening tool 30 is discontinuous in terms of slope change. Due to this discontinuity, the transition point 43 represents a corner along the contour of the screw engagement interface 40, as seen in a vertical section relative to the longitudinal axis LT of the dental fastening tool 30. In the engagement structure 44, this transition point 43 of the contour creates a longitudinal edge (see...). Figure 4 ).

[0105] At transition point 23, torque transmission from the fastening tool 30 to the dental screw 10 is most efficient. The tangent to the profile of the tool engagement interface 20 at this transition point 23 extends in the direction closest to the radial direction. Therefore, the torque applied by the fastening tool at this point produces a maximum force component perpendicular to the surface of the tool engagement interface 20 and a minimum force component parallel to that surface along the engagement profile. Thus, torque transmission between the dental fastening tool and the dental screw 10 is very efficient at this point, with relatively low wear. Therefore, it is advantageous to transmit torque between the fastening tool and the dental screw 10 at and near transition point 23.

[0106] The dental fastening tool 30 for transmitting torque to the dental screw 10 includes a engagement structure 44 corresponding to the engagement structure 24. Figure 5An exemplary embodiment of a dental fastening tool 30 is shown, which has an engagement structure 44 in a vertical section relative to the tool's longitudinal axis LT. The engagement structure 44 of the dental fastening tool 30 is part of a torque transmission region 45b (see [link to documentation]). Figure 4 Corresponding to the dental screw 10, the cross-sectional profile of the engagement structure 44 includes a convex segment 41 and a concave segment 42. The convex segment 41 and the concave segment 42 merge or transition into each other at a transition point 43. Similar to the transition point 23 of the torque transmission region 25b of the dental screw 10, the transition point 43 can be continuous or discontinuous. As described above, Figure 5 The transition point 43 of the dental fastening tool 30 shown is a discontinuous transition point.

[0107] Furthermore, the concave section 42 is preferably curved. The convex section 41 may be curved and / or planar. Figure 5 In the exemplary embodiment shown, the convex segment 41 is curved, and more specifically, has a circular shape.

[0108] As described above, the angle between the tangent of the convex section 41 and the tangent of the concave section 42 at the transition point 43 is preferably in the range of 90° to 180° or 160°, preferably 95° to 150°. The closer this angle is to 90°, the more effective the torque transmission from the dental fastening tool 30 to the dental screw 10 at the transition point 43. At 90°, the torque transmission occurs substantially in the circumferential direction. There is essentially no force component acting in a direction parallel to the surface (which extends radially) of the engagement structure 44, thus substantially preventing wear on this surface caused by torque transmission. For example, Figures 8 to 11 The dental fastening tools 130 and 230 shown are designed for such efficient torque transmission.

[0109] Figure 3 A dental fastening tool 30 is shown that has been inserted into the dental screw 10 (see [link]). Figure 3 a). Then the dental fastening tool 30 rotates about its longitudinal axis LT, such that the engagement structure 44 of the dental fastening tool 30 engages with the engagement structure 24 of the dental screw 10 (see Figure 3 b). As described above, this rotational clearance provides tactile feedback to dental professionals and facilitates the insertion of the screw engagement interface 40 of the fastening tool 30 into the tool engagement interface 20 of the dental screw 10. The screw engagement interface 40 extends within the tool engagement interface 20 around aligned longitudinal axes LT and LS. Figure 3 The middle position in a Figure 3The rotation of the engagement position in b is about 0.5 times that of β. As described above, the rotational clearance β between the rotational engagement orientations (i.e., the engagement orientation for tightening and the engagement orientation for loosening) is preferably 1° to 3.5°, and more preferably 1.5° to 3°.

[0110] Once engaged, the torque is transmitted across the concave section 42 of the dental fastening tool 30 to the convex section 21 of the dental screw 10. This is in Figure 3 In diagram b, this is schematically indicated by a thick black line. More specifically, torque is transmitted along the contours of the engagement structures 24, 44 between transition points 23, 43 to an intermediate position, preferably along the concave section 42 of the fastening tool 30 and the convex section 21 of the dental screw 10. In other words, there is essentially no torque transmission along the contours in the region of the convex section 41 of the fastening tool 30 and the convex section 21 of the dental screw 10. This is because there is a gap between the convex section 41 and the concave section 22, which face each other, when in the engagement state. Therefore, no wear is caused in this region. Furthermore, torque is provided efficiently at and near the transition points. Torque transmission also occurs in regions further from the outer wall of the dental screw 10, i.e., in regions with higher wall thickness. As a result, and with the torque transmission along the curved concave section 42 and the correspondingly curved convex section 21, stress concentration is avoided. Therefore, these features also enable a more compact design for the dental screw.

[0111] Figure 4 A partial view of the dental fastening tool 30 is shown in longitudinal section. The dental fastening tool 30 is further referenced below. Figure 6 The image is shown in a longitudinal section. For example... Figure 4 As shown, the torque transmission region 45b of the screw engagement interface 40 is curved. More specifically, it is at least partially circular in shape. Furthermore, at the distal end 32, the dental fastening tool 30 preferably has a rounded tip 33. This geometry allows the dental fastening tool 30 to be tilted while transmitting torque from the dental fastening tool 30 via the screw engagement interface 40 to the tool engagement interface 20 of the dental screw 10. This is, for example, in… Figure 6 As shown, the longitudinal axis LS of the dental screw is inclined relative to the longitudinal axis LT of the fastening tool 30. Furthermore, the aforementioned curved and rounded configuration of the screw engagement interface 40 prevents damage or scratching to the surface of the engagement structure 24, which could otherwise reduce the strength of the dental screw 10. Similar to the dental screw 10, the torque transmission region 45b also serves as the pickup region 45a, as will be described in further detail below.

[0112] Figure 4The dental fastening tool also includes a torque limiting portion 35 proximal to the screw engagement interface 40. Preferably, a rod 36 is arranged between the screw engagement interface 40 and the torque limiting portion 35 such that the dental fastening tool 30 will not break within the tool engagement interface 20 of the dental screw 10 during failure. This facilitates the removal of portions of the dental fastening tool 30, including a portion retained within the tool engagement interface 20.

[0113] As described above, if the applied torque exceeds a predefined maximum value, the torque limiting portion 35 is configured to fail. Preferably, the torque limiting portion is configured to withstand a maximum torque of 35 Ncm or less, and more preferably in the range of 27.5 Ncm to 34 Ncm, and more preferably in the range of 28 Ncm to 33 Ncm.

[0114] like Figure 4 As shown, the torque limiting portion 35 can be designed with a reduced cross-section, resulting in reduced strength at that cross-section. In other words, the torque limiting portion 35 has the lowest section modulus along the dental fastening tool 30. Therefore, the section modulus of the torque limiting portion 35 is lower than the section modulus of the waist portion adjacent to the screw engagement interface 40 and the shank 36.

[0115] like Figure 1 As shown, the convex segment 21 of the tip of the longitudinal engagement protrusion 24 of the tool engagement interface 20 is chamfered at its proximal end, i.e., at the entrance of the dental fastening tool to the tool engagement interface 20. The resulting chamfer 27 facilitates the insertion of the dental fastening tool. On the one hand, they allow for the initial insertion of the dental fastening tool, even when the engagement structure 44 of the dental fastening tool 30 is not properly aligned with the engagement structure 24 of the dental screw 10 in the direction of rotation. On the other hand, the longitudinal axis LS of the dental screw 10 may initially have too much inclination relative to the longitudinal axis LT of the fastening tool 30. Here, the chamfer 27 has a guiding function.

[0116] also, Figure 1 The dental screw 10 includes a tapered tool engagement interface 20. More specifically, the tool engagement interface 20 becomes narrower in the direction from the proximal end 11 to the distal end of the dental screw 10. In other words, the tool engagement interface 20 may have a substantially conical shape. Due to the tapered shape, the tool engagement interface 20 forms a pickup area 25a for picking up and retaining the dental screw. In this exemplary embodiment of the dental screw and as... Figure 1 , Figure 2 and Figure 6 As shown, the pickup area 25a and the torque transmission area 25b overlap each other.

[0117] The following will refer to Figure 6 Explain the picking function in more detail. For example... Figure 6As shown in Figure a, when the fastening tool 30 is inserted into the recess of the tool engagement interface 20 along the longitudinal axis LS, the fastening tool 30 engages the dental screw 10 through friction. Because the tool engagement interface 20 is tapered, the pickup function is achieved through friction caused by the insertion of the fastening tool 30. More specifically, the dental screw 10 can be held by the fastening tool 30.

[0118] As described above, the angle of the taper is preferably selected in the range of 5° to 12°, particularly 6° to 9°, or substantially 7°. Alternatively, it can be in the range of 10° to 12° or substantially 11°. These values ​​allow the dental screw to be securely held while simultaneously allowing the connection between the fastening tool 30 and the dental screw 10 to be easily released. Therefore, these angles also prevent unwanted wear.

[0119] In addition to its pickup function, the tapered shape of the tool engagement interface 20 ensures optimal engagement between the dental fastening tool 30 and the dental screw 10. This is in Figure 6 a and Figure 6 This is illustrated schematically in b. Figure 6 In step a, the dental fastening tool 30 has its initial dimensions, meaning it has not yet undergone wear. Therefore, the engagement between the dental fastening tool 30, or more specifically, the screw engagement interface 40, occurs proximal to the tool engagement interface 20 of the dental screw 10.

[0120] Preferably, the dental fastening tool 30 is configured for reusability and is preferably made of metal, particularly steel. Therefore, wear occurs during continued use and repeated use of the tool. Wear occurring at the engagement structure 44 of the dental fastening tool 30 results in a reduction in the size of this structure. However, since the tool engagement interface 20 of the dental screw 10 is tapered, the dental fastening tool 30 can be easily pushed further into the tool engagement interface 20. This achieves the same engagement quality, thereby ensuring efficient torque transmission. This in Figure 6 As shown in b, the worn dental fastening tool 30 now engages the tool engagement interface 20 of the dental screw 10 on the more distal side.

[0121] Figure 7 Another embodiment of the dental screw 110 is shown. (See example...) Figure 7 As shown, the dental screw 110 includes a torque-limiting portion 115 directly adjacent to the screw head 113. Those skilled in the art will understand that... Figure 1 In the embodiment of the dental screw 10 shown, such a torque limiting portion 115 may also exist along the screw shank 14, either at the same location along the screw shank 14 or at a different location.

[0122] Similar to the torque limiting portion 35 described relative to the dental fastening tool 30, the torque limiting portion 115 has a minimum section modulus along the portion of the body of the dental screw 110 that transmits torque (i.e., the portion of the body that experiences increased shear and tensile stress during the tightening of the dental screw 110).

[0123] The torque limiting portion 115 is part of the screw shank 114 and is arranged along the screw shank. At the end of the screw shank 114, i.e., at the distal end 112 of the dental screw 110, is a threaded portion 116. The threaded portion 116 is used to engage dental components, such as dental implant 401 or abutment 402 (see [link to documentation]). Figure 14 For example, dental screw 110 can be used to attach abutment 402 to dental implant 401.

[0124] As defined above, the minimum torque that the torque-limiting portion 115 of the dental screw 110 should withstand and transmit is preferably 26 Ncm. When the maximum torque value is exceeded, the torque-limiting portion 115 should specifically prevent failure of any portion of the dental screw 110 distal to the torque-limiting portion 115, particularly failure of the threaded portion 116. Controlling the failure of the dental screw in this way ensures that the dental component engaged with the dental screw 110 remains intact. This is particularly advantageous when the dental component is a dental implant anchored within the patient's bone tissue, as it prevents implant revision.

[0125] Figure 8 Another embodiment of the dental fastening tool 130 is shown. The screw engagement interface 140 at the distal end 132 of the dental fastening tool 130 further includes a convex segment 141 and a concave segment 142 forming a circumferential engagement structure 144. The dental fastening tool 130 is configured for a dental screw, which preferably includes an engagement structure having a corresponding number of convex and concave segments. As mentioned above, the convex segments may also be at least partially planar.

[0126] However, the dental fastening tool 130 differs from the dental fastening tool 30 in the previous figures, particularly in the screw engagement interface 140. Specifically, the screw engagement interface comprises four convex segments and four concave segments, instead of five.

[0127] Go to Figure 9 The screw engagement interface 140 of the dental fastening tool 130 differs from the previous embodiment in that the pickup area 145a is separate from the torque transmission area 145b. More specifically, the torque transmission area 145b is located near and distal to the pickup area 145a. In other words, the pickup area 145a does not overlap with the torque transmission area 145b. The pickup area 145a is substantially conical in shape for engaging with the corresponding pickup area of ​​the dental screw by friction to facilitate manipulation of the dental screw, as described above.

[0128] although Figure 9 The torque transmission region 145b of the dental fastening tool 130 has a concave shape similar to the pickup region 145a, but it can alternatively have a cylindrical form, such as... Figure 11 and Figure 12 Another embodiment of the dental fastening tool 230 is shown and further described below.

[0129] In addition to the pickup area 145a and the torque transmission area 145b, the dental fastening tool 130 includes a verification area 145c adjacent to its distal end 132. In one aspect, this verification area 145c serves to prevent engagement with a tool engagement interface 120b that does not include a dental screw 110b having a correspondingly shaped verification area (see [link to tool engagement interface 120b]). Figure 10 b). Furthermore, the absence of a corresponding verification area in the dental screw 110b can also prevent engagement of the pickup area 145a, since it is impossible to insert the dental fastening tool 130 into the tool engagement interface of the dental screw 110b far enough to engage these areas.

[0130] On the other hand, if the dental screw 110a includes a corresponding verification area, such as Figure 10 If a dental screw 110a is in a, then the dental fastening tool 130 can engage the tool engagement interface 120a of the screw.

[0131] Figure 11 and Figure 12 Another embodiment of a dental fastening tool 230 is shown, which has a screw engagement interface 240 similar to the screw engagement interface 140 of a previous embodiment. However, unlike the previous embodiment, the dental fastening tool 230 does not include a verification area. Instead, the screw engagement interface 240 may only include a pickup area 245a and a torque transmission area 245b. Although in Figure 11 The illustrated embodiment of the dental fastening tool 230 and in Figure 10 In the embodiment of the dental fastening tool 130 shown, torque transmission regions 145b and 245b are located near and distal to pickup regions 145a and 245a, respectively; however, those skilled in the art will understand that this order can also be reversed. Therefore, pickup regions 145a and 245a may be located distal to torque transmission regions 145b and 245b. Furthermore, pickup regions 145a and 245a and torque transmission regions 145b and 245b need not be adjacent to each other, but can be spaced apart.

[0132] For cost-effective production, the concave section 242 is machined in a proximal direction beyond the screw engagement interface 240. Therefore, the pickup area 245a essentially has a conical shape interrupted by the concave section. However, this is functionally unnecessary, but it provides more defined friction between the pickup area 245a and the corresponding dental screw. This also applies to the dental fastening tool of the previous embodiment.

[0133] Figure 12 A front view of the dental fastening tool 230 as seen from the distal end 232 is shown. As shown, the screw engagement interface 240 includes four convex segments 241 alternating with four concave segments 242. As indicated with respect to previous embodiments, the convex segments 241 may also be planar segments. In this exemplary embodiment, the convex segments 241 are curved and, in particular, have a circular shape, as seen in the vertical section relative to the longitudinal tool axis LT.

[0134] like Figure 12 As illustrated in the example, the angle α between the tangent of the convex section and the tangent of the concave section is at least close to the optimal angle of approximately 90° for transmission as described above. In other words, the angle α is in the lower range indicated above. Therefore, the configuration of the torque transmission zone 245b of the screw engagement interface 240 provides efficient torque transmission and is not prone to wear during continuous and repeated use. To keep the wear of the dental fastening tool of this disclosure low, at least the screw engagement interface and preferably the fastening tool are made of metal, particularly steel.

[0135] Unlike the dental fastening tool 30 in the previous figures, the screw engagement interface 240 can only engage with the tool engagement interface of the dental screw if the longitudinal tool axis LT and the longitudinal axis are substantially aligned. As described above, this alignment is facilitated by providing a chamfer at the entry point to the tool engagement interface of the dental screw.

[0136] Figure 13 This is a schematic longitudinal section of the threaded engagement between a dental component (particularly dental implant 301) and a dental screw 310. Naturally, this configuration is applicable to any combination of dental components and dental screws.

[0137] In the tightened state, the distal side 303 of the threaded portion of the dental implant is in close contact with the proximal side 318 of the threaded portion 316 of the dental screw. Therefore, the force provided by tightening the dental screw 310 to secure another dental component to the dental implant 301 is transmitted as the contact force between the threaded sides 303 and 318.

[0138] In the configuration disclosed herein, the dimensions of the threaded hole of the implant 301 and the external thread of the dental screw 310 are designed such that... Figure 13The overlap of the tooth flanks, indicated by the continuous black line, is at least 70% of the radial length of each of the thread flanks. The radial length of the thread flank is defined as the length between the tip of the thread and its root, which allows force to be transmitted in the longitudinal direction of the threaded shaft of a dental screw or the threaded hole of a dental component. For comparison, standard threads, such as those according to ISO standards, have only at least 60% overlap.

[0139] Furthermore, the overlap of the threaded connection according to this embodiment is as high as 90%, 93%, and preferably 96%. Nevertheless, compared to ISO threads, the difference in minimum overlap of 10% allows for a significantly increased thread strength. This result enables a more compact design for the dental screw 310 because compressive forces are transmitted more efficiently within the threaded connection.

[0140] Figure 14 A partial cross-sectional view along the longitudinal screw axis LS in the longitudinal direction is shown. It shows the abutment 402 fastened to the dental implant 401 via the dental screw 410. As described above, the torque-limiting portion of the dental screw according to this disclosure is sized to transmit at least a minimum amount of torque. Furthermore, the dental screw is configured for controlled failure at torque values ​​exceeding the maximum torque value.

[0141] When Figure 14 When the dental screw 410 is fastened to the dental implant 401, the support surface 417 of the screw head 413 at the distal end of the screw head 113 presses against the screw seat 404 of the dental abutment 402. Due to the contact established between the support surface 417 and the screw seat 404, a portion of the torque transmitted from the dental fastening tool (not shown) via the tool engagement interface 420 of the dental screw 410 is transmitted to the abutment 402.

[0142] Similarly, Figure 14 As shown, the screw seat 404 and the support surface 417 have conical shapes. The conical shapes of the screw seat 404 and the support surface 417 have different cone angles from each other. Preferably, the cone angle of the support surface 417 is larger than the cone angle of the screw seat 404. However, it is alternatively possible for the cone angle to be designed in a configuration where the cone angle is smaller than the screw seat 404. The difference between the cone angles of the support surface 417 and the screw seat 404 is represented by γ. Figure 14 As shown in the image.

[0143] Due to this angle γ, the contact between the support surface 417 and the screw seat 404 is essentially established via line contact. This is advantageous in one respect because such line contact results in less torque being transmitted from the dental screw 410 to the base 402. On the other hand, the torque transmitted but not used for tightening the threaded connection can be more precisely determined. These two advantages allow for more predictable behavior of the torque-limiting portion of the dental screw 410. In other words, this configuration makes the failure of the dental screw 410 at the torque-limiting portion more reliable and thus contributes to a more compact design of the dental screw 410.

[0144] As previously described, the gap created by the difference γ between the cone angles can be at least partially closed at the end of the tightening process of the dental screw 410. This closure of the gap is caused by the deformation of the screw seat 404 and the support surface 417, and further reduces the amount of torque transmitted toward the threaded portion of the dental screw 410 relative to the amount of torque transmitted to the abutment 402. This change in the transmission ratio has a damping effect during the application of torque and makes it possible to more precisely adjust the maximum torque at the end of the threaded connection between the dental screw 410 and the dental implant 401. Therefore, these features of the screw seat 404 and the support surface 417, and their configuration in the dental assembly, also enable a more compact design for the dental screw 410.

[0145] Figure Labels

[0146] The last two digits of the reference numerals used in the specification and drawings are listed below. Throughout the drawings, these numerals indicate features having the same or equivalent function and / or structure. The preceding numerals indicate embodiments.

[0147] 1 Dental implants

[0148] 2 abutments

[0149] 3. Side of threaded hole

[0150] 4 screw seats

[0151] 10 dental screws

[0152] 11 Proximal

[0153] 12 remote

[0154] 13 screw heads

[0155] 14 screw rod

[0156] 15 Torque Limiting Section

[0157] 16 threaded portion

[0158] 17 Support Surface

[0159] 18 The side of the threaded portion

[0160] 20 Tool Integration Interface

[0161] 21 convex sections

[0162] 22 concave sections

[0163] 23 Transition Points

[0164] 24 Dental Screw Engagement Structure

[0165] 25a Pickup Area

[0166] 25b Torque Transmission Zone

[0167] 25c verification area

[0168] 26. Circles with the largest inner diameter

[0169] 27 chamfer

[0170] 30 Fastening Tools

[0171] 31 proximal end

[0172] 32 remote

[0173] 33 rounded tip

[0174] 35 Torque Limiting Section

[0175] 36 strokes

[0176] 40 screw joint interface

[0177] 41 Convex Section

[0178] 42 concave sections

[0179] 44 Fastening tool engagement structure

[0180] 45a Pickup Area

[0181] 45b Torque Transmission Zone

[0182] 45c verification area

[0183] Longitudinal axis of LS screw

[0184] Longitudinal axis of LT fastening tool

[0185] α is the angle at the transition point between the tangent of the convex segment and the tangent of the concave segment.

[0186] β Rotational clearance between the dental screw and the fastening tool

[0187] The taper angle difference between the support surfaces of the γ screw seat and the screw head.

Claims

1. A dental prosthesis support device, the dental prosthesis support device comprising a dental screw and a dental component, the dental screw having a proximal end, a distal end, and a longitudinal axis, wherein the dental screw further comprises a screw head and a screw shank, the screw head including a tool engagement interface for engaging a fastening tool at the proximal end and a support surface at the distal end of the screw head, the screw shank being disposed distal to the screw head, the screw shank including a torque limiting portion and a threaded portion distal to the torque limiting portion for engaging the dental component, wherein the torque limiting portion includes: (i) a smaller cross-section than the rest of the dental screw, (ii) a material different from the rest of the dental screw, or (iii) at least one notch, such that the dental screw is configured to transmit a minimum torque of 26 Ncm to prevent damage to the threaded portion, wherein the dental component includes a screw seat for engaging a support surface of the screw head, wherein the support surface and the screw seat have a conical shape, and wherein the cone angles of the support surface and the screw seat are different from each other.

2. The dental prosthesis support device according to claim 1, wherein the maximum torque that can be transmitted at the torque limiting portion is 38 Ncm, 36 Ncm, 34 Ncm or 32 Ncm.

3. The dental prosthesis support device according to claim 1, wherein the torque limiting portion is configured to withstand a maximum tensile force in the range of 300N to 500N, and preferably in the range of 350N to 450N.

4. The dental prosthesis support device according to claim 1, wherein the tool engagement interface includes a torque transmission region having a cross section perpendicular to the longitudinal axis, the cross section including a profile, wherein at least one of four or five first segments of the profile of the cross section alternates with at least one of four or five second segments, wherein the first segments are convex or planar, and wherein the second segments are concave.

5. The dental prosthesis support device according to claim 4, wherein the first section is convex, wherein the convex section and the concave section form a longitudinal engagement protrusion extending radially from a circle having the largest inner diameter toward the longitudinal axis, the longitudinal engagement protrusion preferably having a chamfer at its proximal end.

6. The dental prosthesis support device of claim 4, wherein the first section is convex, wherein the tool engagement interface includes a recess, the recess including a tapered pickup area along the entire length of the recess in a direction from the proximal end to the distal end of the dental screw, the pickup area preferably being located near the torque transmission area, proximal to the torque transmission area, or at least partially along the torque transmission area.

7. The dental prosthesis support device according to claim 1, wherein the tool engagement interface further includes a verification area for verifying the type of the dental screw, the verification area preferably being located at the distal end of the tool engagement interface.

8. The dental prosthesis support device according to any one of claims 1-7, wherein the dental component is a dental implant, abutment, and / or denture.

9. A dental fastening tool having a proximal end, a distal end, and a longitudinal axis, wherein the dental fastening tool includes a screw engagement interface at the distal end for engaging a dental screw, and a torque limiting portion proximal to the screw engagement interface, wherein the torque limiting portion is positioned such that, in a state where the screw engagement interface engages within a tool engagement interface of the dental screw, the dental fastening tool will not break within the tool engagement interface of the dental screw during failure, the torque limiting portion being configured to limit transmittable torque for preventing damage to the screw engagement interface, wherein the screw engagement interface includes a torque transmission zone having a cross-section perpendicular to the longitudinal axis, the cross-section including at least one of four or five first segments alternating with at least one of four or five second segments, wherein the first segments are convex or planar and the second segments are concave.

10. The dental fastening tool of claim 9, wherein the torque limiting portion is configured to withstand a maximum torque of 35 Ncm or less, preferably in the range of 27.5 Ncm to 34 Ncm, and more preferably in the range of 28 Ncm to 33 Ncm.

11. The dental fastening tool of claim 9, wherein the first segment and the second segment form an engagement structure around a longitudinal axis of the dental fastening tool, the engagement structure having a curved profile in a cross-section along the longitudinal axis, wherein the first segment is convex or planar, and wherein the second segment is concave.

12. The dental fastening tool of claim 11, wherein the first segment and the second segment are connected at a transition point, and at each transition point, the angle between the tangent of the profile of the second segment and the tangent of the first segment is in the range of 90° to 180° or 160°, preferably 95° to 150°.

13. The dental fastening tool of claim 9, wherein the screw engagement interface includes a pickup area for retaining the dental screw, the pickup area preferably being located near, proximal to, or at least partially along the torque transmission area.

14. The dental fastening tool of claim 9, wherein the screw engagement interface further includes a verification area for verifying the type of the dental screw when engaging the dental screw, the verification area preferably being located at the distal end of the screw engagement interface.

15. A dental fastening device comprising: A dental screw, wherein the dental screw includes a screw head and a screw shank, the screw head including a tool engagement interface for engaging a fastening tool at a proximal end of the dental screw and a support surface at a distal end of the screw head, the screw shank being disposed distal to the screw head, the screw shank including a torque limiting portion and a threaded portion distal to the torque limiting portion for engaging a dental component, wherein the torque limiting portion includes: (i) a smaller cross-section than the remainder of the dental screw, (ii) a material different from the remainder of the dental screw, or (iii) at least one notch; A dental component, wherein the dental component includes a screw seat for engaging a support surface of a screw head, wherein the support surface and the screw seat are conical in shape, and wherein the cone angles of the support surface and the screw seat are different from each other; and Dental fastening tools, The dental fastening tool includes a torque limiting portion, wherein the torque limiting portion of the dental screw is configured to withstand a maximum torque higher than the maximum torque that can be transmitted through the torque limiting portion of the dental fastening tool.

16. The dental fastening device according to claim 15, The dental screw includes a tool engagement interface, wherein the tool engagement interface includes a torque transmission region having a cross-section comprising alternating convex and / or planar segments with concave segments; and The dental fastening tool includes a screw engagement interface, wherein the screw engagement interface includes a torque transmission region having a cross-section comprising alternating convex and / or planar segments with concave segments. In the engaged state of the dental screw for transmitting torque and the dental fastening tool, at least the middle section of each of the convex section and / or the planar section of the dental screw faces the contour of the concave section of the tool engagement interface at a certain distance.

17. The dental fastening device according to claim 15 or 16, wherein the torque transmission region of the dental screw and the torque transmission region of the dental fastening tool have rotational clearance when engaged with each other, particularly in the range of 1° to 3.5° and preferably in the range of 1.5° to 3°.

18. The dental fastening device of claim 15 or 16, wherein the dental screw and the dental fastening tool each include a pickup area configured to engage with each other by friction.

19. The dental fastening device of claim 15 or 16, wherein the dental screw and the dental fastening tool each include a verification area configured to allow the torque transmission area of ​​the dental fastening tool to engage with the torque transmission area of ​​the dental screw when the dental fastening device is fully engaged.

Images