Custom Abutment

Abstract

To provide a custom abutment that achieves at least one of chucking stability during the processing step, holding precision of the connection part after milling, prevention of damage to the base part during processing, and good connection with a specific prosthesis. [Solution] A custom abutment 42 having a cylindrical milling block portion 44 and a fixture connection portion 46 connected to the milling block portion 44 for ensuring connection with a fixture, wherein the milling block portion 44 and the fixture connection portion 46 have a hole portion 48 passing through from the upper end to the lower end of the milling block portion 44 and the fixture connection portion 46, and the portion of the hole portion 48 present in the milling block portion 44 is located at the upper end of the milling block portion 44 and has a milling machine connection portion 50 having a shape corresponding to the milling machine connection portion for connection to the milling machine, and an internal thread structure portion 52 having an internal thread structure provided on the fixture connection portion 46 side of the milling machine connection portion 50.

Description

[Technical Field]

[0001] The present invention relates to custom abutments, such as pre-milled abutments, for use in dental implants. [Background technology]

[0002] JP 2023-551956 A describes a customized prefabricated abutment. This customized prefabricated abutment had room for improvement in terms of chucking stability during the processing process, retention accuracy of the connection part after milling, and prevention of damage to the base part during processing. Furthermore, although the outer surface of this customized prefabricated abutment could be processed, the inner surface had a specific structure, which made it difficult to connect to certain prostheses. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2023-551956 Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, the purpose of this invention is to provide a custom abutment that achieves at least one of the following: stable chucking during the processing process, accurate retention of the connection part after milling, prevention of damage to the base part during processing, and good connection with a specific prosthesis. [Means for solving the problem]

[0005] This invention relates to a custom abutment 42. The custom abutment 42 has a cylindrical milling block portion 44 and a fixture connection portion 46. The cylindrical milling block 44 is a portion that is milled using cutting or other methods to obtain the desired abutment shape. This portion becomes the abutment abutment, cuff, or the like. An example of the milling block 44 is a portion that is milled using a CAD / CAM method. An example of the milling block 44 is a cylindrical shape with a circle diameter of 7 mm to 20 mm and a cylindrical shape with a height of 10 mm to 20 mm. Note that the cylindrical shape refers to an example of the external shape, and even if a hole is formed in the center as described below, the external shape is cylindrical.

[0006] The fixture connection portion 46 is a portion that is connected to the milling block portion 44 so as to be coaxial with the milling block portion 44, for example, and that ensures connection with a fixture. An example of a fixture is an implant. The fixture connection portion 46 may be pre-machined to fit the fixture. In this case, the custom abutment 42 is also called a pre-milled abutment.

[0007] The milling block 44 and the fixture connection portion 46 have a hole 48 extending from the upper end to the lower end of the milling block 44 and the fixture connection portion 46, for example, in a region including the coaxial line. The portion of the hole 48 present in the milling block 44 has a milling machine connection portion 50 and an internal thread structure portion 52.

[0008] The milling machine connection part 50 is located at the upper end (prosthesis side) of the milling block part 44, and is a part for connecting to a milling machine, and has a shape corresponding to the connection part of the milling machine. The internal thread structure portion 52 is a portion having an internal thread structure provided on the fixture connection portion 46 side of the milling machine connection portion 50. The length of the internal thread structure portion 52 is, for example, 6 mm to 17 mm and is equal to or less than the height of the cylindrical shape of the milling block portion 44. [Effects of the Invention]

[0009] This device forms the milling machine connection part as one element of the hole in the upper part of the milling block part, which achieves stable chucking during the processing process, accurate retention of the connection part after milling, and prevention of damage to the base part during processing.In addition, this device provides an internal thread structure inside the hole that passes from the milling block part through the fixture connection part, making it possible to provide a custom abutment that can obtain a good connection with a specific prosthesis. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a conceptual diagram for explaining a dental abutment. [Figure 2] FIG. 2 is a diagram illustrating an example of a screw head. [Figure 3] FIG. 3 is a conceptual diagram showing how an abutment is removed by an abutment remover. [Figure 4] Figure 4 is a conceptual diagram showing the insertion of an access hole sealing rod into the hollow portion inside the abutment. Figure 4(a) is a conceptual diagram for explaining the access hole sealing rod. Figure 4(b) is a conceptual diagram (cross-sectional view) showing the state in which the access hole sealing rod and abutment are joined. Figure 4(c) is a conceptual diagram showing the state in which the access hole sealing rod is inserted into the abutment through a hole provided in the prosthesis. Figure 4(d) is a conceptual diagram after the shape of the access hole sealing rod has been adjusted. [Figure 5] Figure 5 is a conceptual diagram showing an example of an abutment in which the female thread portion is provided around the screw head housing portion. Figure 5(a) shows an external view of the abutment. Figure 5(b) shows an example of a conceptual cross-sectional view of the abutment. Figure 5(c) shows the state in which an access hole sealing rod has been inserted into the abutment. [Figure 6] Figure 6 is a conceptual diagram showing the designed abutment, where Figure 6(a) is an external view and Figure 6(b) is a partial cross-sectional view. [Figure 7]Figure 7 is a conceptual diagram showing how a prosthesis is sealed using an access hole sealing rod. Figure 7(a) shows the access hole sealing rod being inserted into the abutment. Figure 7(b) shows the access hole sealing rod protruding from the prosthesis after being inserted into the abutment. Figure 7(c) shows the access hole sealing rod being cut and then reshaped. [Figure 8] Figure 8 is a photograph, in lieu of a drawing, showing how a dental model was produced using a 3D printer and an implant was formed using an abutment. [Figure 9] FIG. 9 is a photograph, in place of a drawing, showing a dental model after the implant has been formed. [Figure 10] FIG. 10 is a conceptual diagram for explaining a custom abutment. [Figure 11] FIG. 11 is a conceptual diagram for explaining an example of the obtained abutment. [Figure 12] FIG. 12 is a conceptual diagram for explaining how to use the abutment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The custom abutment 42 according to the present invention relates to an abutment structure that connects a prosthesis and an implant body (hereinafter referred to as a fixture) in implant treatment, and is, for example, a pre-milled abutment that can be machined to an individual shape for each patient. The custom abutment 42 can also be considered a dental laboratory instrument or material used to fabricate the superstructure of a dental implant using a dental CAD / CAM system.

[0012] FIG. 10 is a diagram illustrating a custom abutment. FIG. 10(a) is an outline drawing of the custom abutment. FIG. 10(b) is a cross-sectional view of the custom abutment that serves as a reference. FIG. 10(c) is a top view of the custom abutment that serves as a reference. As shown in FIG. 1, the custom abutment 42 includes a cylindrical milling block portion 44 provided at the top and a fixture connection portion 46 provided at the bottom. For example, the milling block portion 44 and the fixture connection portion 46 are integrally formed coaxially and constitute the abutment body.

[0013] The milling block 44 has a cylindrical outer shape and is an unprocessed material portion used for forming the abutment shape specific to the patient, i.e., the abutment portion, cuff portion, etc., by CAD / CAM milling. This portion is designed to have a diameter of, for example, 7 to 20 mm and a height of 10 to 20 mm, and has dimensions that allow stable gripping and fixation in a processing machine.

[0014] The fixture connection part 46 is disposed below and continues from the milling block part 44 and has a fitting structure for realizing a secure mechanical connection with a predetermined fixture (e.g., an implant body). This connection part 6 has, for example, a machined hexagonal socket, a conical shape, an internal thread, or the like, and is structured to allow attachment with a torque-type screw.

[0015] Furthermore, an axial through-hole 8 is formed inside the custom abutment 42 from the upper end to the lower end, and this hole portion 48 includes a milling machine connection portion 50 and an internally threaded structure portion 52 inside the milling block portion 44. In the example shown in FIG. 1 , the milling machine connection portion 50 has a shape (in this example, a polygonal prism-like recess) corresponding to the connection element of the milling machine. Therefore, the connection element of the milling machine fits into the milling machine connection portion 50, stably connecting the milling block portion 44 to the milling machine. Furthermore, because the milling block portion 44 is cylindrical, the milling machine can easily grip the outside of the milling block portion 44. Note that one or more notches may be provided at the upper end of the milling block portion 44. The connection element of the milling machine fits into such notches, making the milling block portion 44 more stable.

[0016] The milling machine connection part 50 is provided at the upper end of the milling block part 44 and has a shape (e.g., D-shape, stepped cylinder, etc.) that is compatible with the dedicated chuck or adapter of the CAM milling device. This enables highly accurate positioning and stable gripping during processing.

[0017] The internal thread structure 52 is a female thread structure for screw insertion provided below the milling machine connection part 50, and allows the insertion of fixation screws for prostheses and trial screws. The length of the internal thread structure 52 is approximately 6 to 17 mm, and fits within the height of the milling block part 44.

[0018] Due to this structure, the custom abutment 42 of the present invention has excellent processing precision, retention stability, and mounting reliability, and can be directly used with existing CAD / CAM processing equipment, greatly improving immediacy and individual response in dental treatment settings.

[0019] The custom abutment 42 according to the present invention is designed to quickly and accurately manufacture an abutment suited to a patient through individual design using CAD / CAM and milling, and is used through the following process.

[0020] First, the patient's intraoral information is acquired from an intraoral scanner or a fabricated model, and the abutment shape is designed using CAD software based on this information. This design takes into account the margin position, cuff height, and axial inclination angle of the prosthesis.

[0021] Next, a dental milling machine that corresponds to the designed abutment shape is selected, and the custom abutment 42 (pre-milled blank) of the present invention is attached to the corresponding chucking jig. At this time, it is securely held in the jig via the milling machine connection part 50 of the milling block part 44.

[0022] The designed abutment data (CAD data) is imported into a dental milling machine via CAM software, and the initial position of the material (custom abutment 42) is confirmed to be aligned with the coordinate axis.

[0023] Machining parameters such as the machining range, cutting conditions, step over, spindle speed, etc. are set on the CAM software. If necessary, the machining area is adjusted to remove excess portions of the milling block 44.

[0024] Based on the set processing parameters, the dental milling machine cuts the milling block 44 to form the individually designed abutment and cuff parts. This processing forms the prosthetic shape while maintaining the connection structure of the fixture connection part 46.

[0025] The abutment that has been machined is removed and is try-in fitted to a fixture on the model. During try-in, a special screw is fastened using the internal thread structure 52 in the center of the abutment to fix the abutment to the model.

[0026] 11 is a conceptual diagram illustrating an example of the obtained abutment. This abutment has an abutment portion, a cuff portion located below the abutment portion, and a fixture connection portion located below the cuff portion.

[0027] 12 is a conceptual diagram for explaining how to use the abutment. This abutment can be used appropriately with a sealing rod or remover, which will be described later.

[0028] The custom abutment 42 of the present invention can be individually manufactured in this manner, quickly providing a highly accurate abutment structure that matches the patient's anatomical shape and prosthetic design.

[0029] An example of a dental abutment obtained using this custom abutment 42 will now be described.

[0030] FIG. 1 is a conceptual diagram illustrating a dental abutment. As shown in FIG. 1, the dental abutment 1 has a screw head receiving portion 3 and a female thread portion 5. In the example of FIG. 1, a relief groove portion 7 is present. In the example of FIG. 1, a hollow portion (access hole) is present that passes through the dental abutment 1 via the screw head receiving portion 3 and the female thread portion 5. This hollow portion functions as a passage that allows the screw to be easily inserted and removed. The dental abutment 1 has a hollow portion inside, and its exterior shape may be any known shape that is appropriate. Since the dental abutment 1 is typically used in dentistry, its size and other factors may be appropriately set taking into account the size of the tooth to which it is applied.

[0031] The dental abutment 1 is an element for connecting an implant (artificial tooth root) and a prosthesis (crown, bridge, denture, etc.). There are the following types of abutments, for example: screw-retained type (abutment that fixes the prosthesis with a screw), cement-retained type (abutment that bonds the prosthesis with cement, etc.), and custom abutment (abutment that is individually designed when a special shape is required). The abutment is made of, for example, titanium or zirconia. Abutments are already known, so elements of known abutments may be adopted as appropriate.

[0032] The screw head receiving portion 3 is an element for receiving the screw head 11. The screw head receiving portion 3 can securely hold the screw head 11. The example of a dental abutment 1 shown in Figure 1 has an abutment portion 4 for fixing a prosthesis from the inside, a cuff portion 2 located on the implant side of the abutment portion 4 for supporting the prosthesis, and a fixture connection portion 6 located on the implant side of the cuff portion 2 for connecting the implant and the implant abutment.

[0033] FIG. 2 is a diagram illustrating an example of a screw head. The screw head 11 of a dental implant is typically located at the top of the implant (artificial tooth root). The screw head 11 is typically designed with a cylindrical or tapered shape and serves to stabilize the connection between the implant body and the prosthesis (artificial tooth). Examples of materials for the screw head 11 include highly biocompatible materials such as titanium and zirconia. The screw head 11 shown in FIG. 2 includes a cylindrical body portion 13, a cylindrical head portion 15 located above the body portion 13 and having a larger diameter than the body portion 13, a threaded portion 17 located below the body portion 13, and a tip portion 19 located below the threaded portion 17. In this specification, a larger diameter may refer to a diameter that is, for example, 0.1 mm to 5 mm larger, 0.2 mm to 4 mm larger, 0.5 mm to 4 mm larger, or 1 mm to 3 mm larger.

[0034] The screw head receiving portion 3 in Fig. 1 has a shape suitable for receiving the screw head 11. The screw head receiving portion 3 has a body receiving portion, which is a portion for receiving the body portion 13 of the screw head 11 (a portion having a hole with a diameter equal to or slightly larger than the diameter of the body portion 13 and smaller than the diameter of the head portion 15), and a head receiving portion, which is located above the body receiving portion and is a portion for receiving the head portion 15 (a portion having a hole with a diameter equal to or slightly larger than the diameter of the head portion 15). Because of this shape, when the screw head 11 is inserted into the screw head receiving portion 3, it stops at an appropriate position.

[0035] The female thread portion 5 is an element provided around or on top of the screw head receiving portion 3 and has a root diameter larger than the diameter of the screw head 11. In the example of FIG. 1, the female thread portion 5 is provided on the top of the screw head receiving portion 3. That is, the internal hollow portion of the female thread portion 5 forms a female thread. The root diameter is larger than the internal diameter of the screw head receiving portion 3 (the diameter of the head receiving portion). This shape makes it easy to insert the screw head 11 through the female thread portion 5. The presence of the female thread portion 5 also makes it easy to adjust or remove the dental abutment 1 by inserting a remover or adjustment rod into this portion. Furthermore, the presence of the female thread portion 5 can also be used for sealing after the attachment of a superstructure. The implant body (artificial tooth root) and the abutment or the screw head are threaded together to precisely fix them. In this specification, the root diameter being larger than the internal diameter of the screw head receiving portion 3 (the diameter of the head receiving portion) may be equal to the diameter of the screw head receiving portion, or may be larger by 0.1 mm or more and 5 mm or less. As described above, the diameter may be within a range that does not affect the accommodation of the screw head.

[0036] The relief groove 7 is an element present in the upper part of the female thread portion and has an internal hole with a diameter larger than the root diameter of the female thread portion. The relief groove 7 may have a female thread formed therein, which allows the screw head 11 to be inserted and removed more smoothly, improving work efficiency.

[0037] FIG. 3 is a conceptual diagram showing how an abutment is removed with an abutment remover. The abutment remover 21 is used to remove a dental abutment 1. The abutment remover 21 includes a body portion 23 and a male thread portion 25 provided on the body portion 23. The male thread portion 25 has a thread shape that corresponds to the female thread portion 5. In the example of FIG. 3, the abutment remover 21 has a head portion 27 on its upper portion. As shown in FIG. 3( a), when removing an abutment 1 with the abutment remover 21, the abutment remover 21 is inserted into the abutment 1 from top to bottom. After the male thread portion 25 of the abutment remover 21 reaches the female thread portion 5 (the female thread inside the female thread) of the abutment 1, the abutment remover 21 can be coupled (screwed together) with the abutment 1 by rotating the abutment remover 21. 3(b) is a conceptual diagram showing the abutment remover and abutment coupled together. In this state, by rotating the abutment remover 21, the female thread of the abutment screws into the male thread of the abutment remover. Then, by lifting the abutment remover 21, the abutment 1 can be removed.

[0038] FIG. 4 is a conceptual diagram showing the insertion of an access hole sealing rod into the hollow portion inside the abutment. The access hole sealing rod 31 is used, for example, to seal the dental abutment 1. The access hole sealing rod 31 has a male thread portion 35 shaped to correspond to the female thread portion 5 (or the female thread of the undercut portion 7). By passing the access hole sealing rod 31 through the hollow portion (access hole) inside the abutment 1, it is expected to prevent the inflow of resin, wax, cement, etc. during wax-up, cementation, and verification index fabrication. The access hole sealing rod 31 may be made of a resin used in dentistry. An example of the resin is polyacetal resin. The access hole sealing rod 31 includes a body portion 33 shaped to fit into the access hole and a male thread portion 35 provided on the body portion 33. The male thread portion 35 has a thread shape corresponding to the female thread portion 5. In the example shown in FIG. 4(a), a tip portion 37 is formed at the bottom of the male thread portion 35.

[0039] When using the access hole sealing rod 31, the access hole sealing rod 31 is inserted into the abutment 1 from top to bottom. After the male thread portion 35 of the access hole sealing rod 31 reaches the female thread portion 5 (internal female thread) of the abutment 1, the access hole sealing rod 31 can be coupled (screwed) to the abutment 1 by rotating the access hole sealing rod 31. Figure 4(b) is a conceptual diagram (cross-sectional view) showing the state in which the access hole sealing rod 31 and the abutment are coupled. Figure 4(c) is a conceptual diagram showing the state in which the access hole sealing rod is inserted into the abutment through a hole in the prosthesis. Figure 4(d) is a conceptual diagram after the shape of the access hole sealing rod has been adjusted. In this example, the prosthesis was bonded to the abutment 1 in the oral cavity, and then the access hole sealing rod 31 was set, and the access hole sealing rod 31 was cut to the appropriate length and shaped. In this manner, an implant can be formed using this abutment 1.

[0040] FIG. 5 is a conceptual diagram showing an example of an abutment in which a female thread portion is provided around a screw head receiving portion. FIG. 5(a) shows an external view of the abutment. FIG. 5(b) shows an example of a cross-sectional conceptual diagram of the abutment. FIG. 5(c) shows the state in which an access hole sealing rod is inserted into the abutment. In this example, the female thread portion 5 is provided around the screw head receiving portion 3. As in this example, only a portion of the screw head 11 may be received in the screw head receiving portion 3. In the example shown in FIG. 5, the central axis of the internal cavity of the female thread portion 5 and the central axis of the internal cavity of the screw head receiving portion 3 are the same or nearly the same. In the example of FIG. 5, the female thread portion 5 is formed so as to surround the portion in which part of the screw head 11 is received. In addition, in this example, the access hole sealing rod 31 is threadedly engaged with the relief groove portion 7. [Example]

[0041] As an example, the milling block 44 of the custom abutment 42 is made of a titanium alloy cylinder with a diameter of 10 mm and a height of 15 mm. A stepped cylindrical milling machine connection part 50 is provided at the upper end of this block 44, allowing it to be attached to a CAM milling device.

[0042] The inner hole 48 is provided with an internal thread structure 52 extending 6 mm from the top, and is formed with a female thread that is compatible with an M1.6 screw.

[0043] The fixture connection portion 46 has an interface that is compatible with fixtures of the implant series, and is formed with a hexagonal anti-rotation structure and a conical mating surface.

[0044] This custom abutment 42 was fabricated by machining the block portion 44 with a three-axis milling machine according to the prosthetic shape designed based on the digital impression scan, forming the abutment and cuff portions, and then fixing it to the fixture with a screw.

[0045] As a result, precise connectivity to the implant body and a prosthetic shape tailored to each individual patient have been achieved, making it possible to instantly and highly accurately mount the prosthetic in clinical settings. [Example]

[0046] Figure 6 is a conceptual diagram showing the designed abutment. Figure 6(a) is an external view, and Figure 6(b) is a partial cross-sectional view. This dental abutment 1 has a screw head accommodating portion 3, a female thread portion 5, and an undercut portion 7. This abutment is a mechanism for separating the abutment from an implant fixture that is firmly fitted using a tapered joint. This abutment also serves as a hole sealing mechanism for creating a screw-retained superstructure. This abutment has an internal thread on its inner surface. This thread is thicker than the screw head and is large enough not to affect removal. A remover can be inserted here to remove the abutment from the fixture. This abutment can also be used for sealing after the superstructure is attached.

[0047] Figure 7 is a conceptual diagram showing how a prosthesis is sealed using an access hole sealing rod. Figure 7(a) shows the access hole sealing rod being inserted into the abutment. Figure 7(b) shows the access hole sealing rod protruding from the prosthesis after being inserted into the abutment. Figure 7(c) shows the access hole sealing rod being cut and then reshaped.

[0048] Figure 8 is a photograph, instead of a drawing, showing a dental model produced with a 3D printer and an implant formed using an abutment. Figure 9 is a photograph, instead of a drawing, showing the dental model after the implant has been formed. In this way, it has been demonstrated that the use of the dental abutment of this invention makes it easier to form the implant and remove the abutment. [Industrial Applicability]

[0049] The custom abutment of the present invention can be widely used in dental implant treatment, and contributes to improving the efficiency and success rate of implant treatment. [Explanation of symbols]

[0050] 1 Dental abutment 3 Screw head housing 5 Female thread 7 Undercut groove 11 Screw head 13 Torso 15 Head 17 Threaded section 19 Tip 21 Abutment Remover 23 Torso 25 Male thread 27 Head 31 Access hole blocking rod 33 Torso 35 Male thread 37 Tip 42 Custom Abutment 44 Milling block 46 Fixture connection 48 Hole 50 Milling machine connection part 52 Internal thread structure

Claims

1. a cylindrical milling block (44); and a fixture connection portion (46) connected to the milling block portion (44) for securing connection with a fixture. A custom abutment (42), The milling block (44) and the fixture connection portion (46) have a hole (48) extending from the upper end to the lower end of the milling block (44) and the fixture connection portion (46); The portion of the hole (48) present in the milling block (44) is a milling machine connection portion (50) located at the upper end of the milling block portion (44) and having a shape corresponding to a connection portion of a milling machine for connecting to a milling machine; an internal thread structure portion (52) having an internal thread structure provided closer to the fixture connection portion (46) than the milling machine connection portion (50); Custom abutment (42).

2. 2. The custom abutment (42) of claim 1, wherein the fixture connection portion (46) is a pre-milled abutment that has been pre-machined to fit the fixture.

3. 2. The custom abutment (42) of claim 1, wherein the milling block (44) is a portion milled using a CAD / CAM method.

4. 2. A custom abutment (42) as described in claim 1, wherein the milling block portion (44) has a cylindrical shape with a diameter of 7 mm or more and 20 mm or less, and a cylindrical shape with a height of 10 mm or more and 20 mm or less.

5. 2. The custom abutment (42) of claim 1, The custom abutment (42) has an internal thread structure (52) having a length of 6 mm to 17 mm and equal to or less than the height of the cylindrical shape of the milling block portion (44).

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