Implant body

Abstract

To provide an implant body capable of observing a state that dental pulp is regenerated inside the implant body.SOLUTION: Implant body 900 includes an implant body 100 and a closure member 200. The implant body is formed with a throughbore 160 extending therethrough. A cell holding chamber 140 for holding cells is provided below the through-hole. The upper end of the through-hole is provided with an upper opening 110 for injecting human stem cells into the cell retention chamber. A fixing hole 120 for inserting and fixing an abutment is provided below the upper portion of the opening. An insertion hole 130 for inserting a sealing member is provided below the fixing hole. The cell retention chamber is located below the insertion hole. The closing member is detachably attached to the insertion hole.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a dental implant body that is implanted into a jawbone when, for example, a permanent tooth has lost its root. [Background technology]

[0002] Currently, there are three main types of prosthetic treatment for missing teeth: dentures, bridges, and implants. Of these, implant treatment has the advantage of being superior to dentures and bridges in terms of restoring bite force and being able to be performed without cutting down adjacent teeth, and has been reported to have a high five-year success rate of 95.5% for the upper jaw and 95.2% for the lower jaw.

[0003] However, because implants are directly bonded to bone and lack the periodontal ligament, they are more susceptible to infection and periodontal disease (peri-implantitis) than natural teeth. Therefore, the success rate depends heavily on post-treatment maintenance. Furthermore, because implants lack the pressure-breaking properties of the periodontal ligament, there is a difference in the amount of pressure displacement during occlusion between implants and natural teeth. Therefore, connecting implants to natural teeth with prosthetic devices is not recommended. This narrows the range of prosthetic treatment options. Furthermore, when the opposing tooth (the tooth that occludes an implant) is a natural tooth, the periodontal ligament of the natural tooth bears a greater occlusal force, making the opposing tooth more susceptible to periodontitis due to occlusal trauma. Given the current average lifespan of teeth, which is said to be 57 years, and the current super-aging society, the development of implants that can improve the prognosis of implant treatment for tooth loss and expand prosthetic treatment options is crucial.

[0004] Currently, clinical periodontal tissue regeneration involves the GTR method, which mechanically prevents the invasion of epithelial-derived cells and promotes the attachment and regeneration of connective tissue-derived cells, and the Emdogain method, which induces cementum induction using enamel matrix proteins, primarily amelogenin, extracted from immature porcine tooth germs. The GTR method is technically difficult, and the success rate varies greatly depending on the surgeon. While the Emdogain method is technically simple, it has a narrow range of indications, is difficult to control postoperative regeneration, and, although its safety has been established, is still viewed with resistance due to its porcine origin. Furthermore, while both methods achieve more reliable recovery than previous methods, regeneration is still far from normal.

[0005] At the clinical research stage or preclinical stage, attention is being paid to a method in which a cell sheet is applied to the bone defect area and then transplanted together with a filler.

[0006] Previously, it has been reported that periodontal tissue regeneration can be achieved in periodontal disease by adding periodontal ligament stem cells, their culture supernatant, or bFGF to alveolar bone defects. Periodontal ligament cells, dental pulp cells, and even adipocytes have been used as cell sources, and regeneration has been confirmed in all cases. There have also been reports of regeneration achieved by using b-FGF, PTFβ, or supernatant on collagen sheets. These studies focused on the trophic effects of cells or these factors, such as their migration, proliferation, and angiogenesis. In clinical practice, in cases of severe periodontal disease, pulp removal and root canal filling are often performed before periodontal surgery to prevent inflammation from spreading to the root canal.

[0007] Techniques such as surface treatment of implant bodies and attachment of stem cells have been reported to improve osseointegration between implant bodies and bone and to regenerate periodontal tissue around implant bodies, and surface treatments such as carbon removal and acid treatment have been reported to improve the adhesion of osteoblasts and other cells and improve mechanical properties. As a method for attaching stem cells, periodontal tissue regeneration and attachment using the aforementioned cell sheets and bone fillers as scaffolds have been reported, but the probability of regenerating cementum-like tissue and periodontal ligament-like tissue similar to that of normal teeth is low at 10%, and the amount of mineralized material formed in bone around the tooth root is insufficient.

[0008] It has been reported that an implant body can reproduce the microenvironment of periodontal tissue by transplanting dental pulp stem cells into a fixation hole that penetrates the inside of the implant body, resulting in the regeneration and attachment of periodontal tissue (Patent Document 1).

[0009] With this implant body, once the regeneration of the dental pulp has been completed inside the implant body, treatment is finally completed by placing an artificial tooth on top of the implant body.

[0010] However, it takes time for the dental pulp to regenerate, and it takes about six months to a year for the dental pulp to regenerate inside the implant. In addition, the regenerative ability of the dental pulp varies depending on the individual's constitution, age, and other conditions, and the period of time for the dental pulp to regenerate can vary greatly depending on the person receiving treatment.

[0011] For this purpose, it is preferable to periodically check whether dental pulp is being regenerated inside the implant body from the time dental pulp stem cells are transplanted inside the implant body until dental pulp is regenerated inside the implant body.

[0012] However, in the above-mentioned implant body, the abutment is inserted and fixed after dental pulp stem cells are transplanted into the fixation hole, making it difficult to confirm whether dental pulp is being regenerated inside the implant body. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] Patent No. 6338214 Summary of the Invention [Problem to be solved by the invention]

[0014] The present invention has been made in view of the above problems, and has as its object to provide an implant body that allows periodic and accurate observation of the state of dental pulp regeneration inside the implant body. [Means for solving the problem]

[0015] The implant body of the present invention is an implant body for generating dental pulp and periodontal ligament, characterized in that the implant body has a through-hole formed therethrough, and has a cell holding chamber located at the bottom of the through-hole for holding cells, an upper opening located at the upper end of the through-hole for injecting human stem cells into the cell holding chamber, a lower opening located at the lower end of the through-hole, and a closure member inserted from the upper opening for closing the upper end of the cell holding chamber, wherein the closure member is detachable. [Effects of the Invention]

[0016] After the implant is fixed, human stem cells can be reliably injected through the through-hole. In addition, by making the structure openable and closable after injection, it is possible to check the regeneration of the dental pulp later. By making the opening and closing device out of a transparent material, visual confirmation is possible without the need for opening and closing operations. If there is a problem with the condition of the stem cells, maintenance can be carried out through the opening. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a diagram illustrating an implant body 900 according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a view illustrating a state in which a blocking member 200 is attached to the implant body 900 according to the first embodiment of the present invention. [Figure 3] FIG. 1 is a view illustrating a state in which an artificial tooth is attached to the upper part of the implant body 900 according to the first embodiment of the present invention. [Figure 4] FIG. 1 is a view illustrating a state in which the implant body 900 according to the first embodiment of the present invention is a one-piece type implant and an artificial tooth is attached to the upper part of the implant body. [Figure 5] FIG. 1 is a diagram illustrating an implant body 900 according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a view illustrating a state in which a blocking member 200 is attached to an implant body 900 according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a diagram illustrating an implant body 900 according to a third embodiment of the present invention. [Figure 8] FIG. 10 is a view illustrating a state in which a blocking member 200 is attached to an implant body 900 according to a third embodiment of the present invention. [Figure 9] 1A to 1C are diagrams illustrating a mode of use of an implant body 900 according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, these embodiments are intended to facilitate understanding of the principles of the present invention, and the scope of the present invention is not limited to the following embodiments. Other embodiments in which a person skilled in the art appropriately replaces the configuration of the following embodiments are also included in the scope of the present invention.

[0019] (Embodiment 1) 1 is a diagram illustrating an implant body 900 according to a first embodiment of the present invention. The implant body 900 according to the present invention is an implant body 900 for generating dental pulp and periodontal ligament. The implant body 900 has an implant main body 100 and a closing member 200.

[0020] A through-hole 160 is formed inside the implant body 100 as an opening. A cell retention chamber 140 for retaining cells is provided at the bottom of the through-hole 160. An upper opening 110 for injecting human stem cells into the cell retention chamber 140 is provided at the upper end of the through-hole 160. The outer diameter of the implant body 100 is, for example, φ3.0 mm to φ6.0 mm.

[0021] During treatment, human stem cells are injected through the insertion hole 130 .

[0022] A fixing hole 120 for inserting and fixing an abutment is provided below the upper opening 110. An insertion hole 130 for inserting an encapsulation member 200 is provided below the fixing hole 120. A cell retention chamber 140 is located below the insertion hole 130. A lower opening 150 is provided below the cell retention chamber 140 and is located at the lower end of a through-hole 160. The outer surface of the implant body 900 preferably has a side surface shape of an ellipsoid of revolution of 6 to 7:1 so that it can be appropriately embedded in a hole drilled in the alveolar bone.

[0023] The closing member 200 is inserted from the upper opening 110 to close the upper end of the cell holding chamber 140. The closing member 200 is detachably attached to the insertion hole .

[0024] In the first embodiment, the closing member 200 is, for example, substantially cylindrical in shape. The insertion hole 130 is, for example, substantially cylindrical in shape. The outer diameter of the closing member 200 is approximately the same as or slightly smaller than the inner diameter of the insertion hole 130. The inner diameter of the insertion hole 130 is, for example, φ1.6 mm to φ2.0 mm, and preferably φ1.8 mm. The outer diameter of the closing member 200 is, for example, φ1.5 mm to φ1.9 mm, and preferably φ1.7 mm. The shape of the cell retention chamber 140 is, for example, substantially cylindrical, and its inner diameter is, for example, φ1.8 mm to φ2.2 mm, and preferably φ2.0 mm.

[0025] FIG. 2 is a diagram illustrating the state in which the closing member 200 is attached to the implant body 900 according to the first embodiment of the present invention. As shown in FIG. 2 , in this first embodiment, after human stem cells are injected into the cell-retention chamber 140, the closing member 200 is pushed into the insertion hole 130, whereby the closing member 200 is attached to the insertion hole 130 by frictional force. In the attached state, the upper portion of the closing member 200 is exposed from the insertion hole 130. To observe whether dental pulp is regenerating in the cell-retention chamber 140 after waiting for several months, the closing member 200 can be removed from the insertion hole 130 by pulling the upper portion of the closing member 200 with a physical force exceeding the frictional force. This allows the state of dental pulp growth in the cell-retention chamber 140 to be periodically observed. The growth of dental pulp in the cell-retention chamber 140 can be confirmed by, for example, checking the blood flow with a Doppler blood flowmeter (φ1.5) or visually observing with an endoscope.

[0026] The implant body 100 and the blocking member 200 are made of a base material made of a biocompatible metallic material. The biocompatible metallic material is not particularly limited, but examples include pure titanium, titanium alloys, cobalt-chromium alloys, and copper. The base material is preferably made of pure titanium or a titanium alloy. Examples of titanium alloys include Ti-6Al-4V alloy, Ti-6Al-7Nb alloy, and Ti-15Mo-5Z4-3Al alloy.

[0027] The implant body 100 and the closing member 200 may also be made of a base material made of a biocompatible ceramic material. The biocompatible ceramic material is not particularly limited, but examples include zirconia (zirconium oxide), alumina (aluminum oxide), yttrium oxide, hafnium oxide, silicone oxide, magnesium oxide, and cerium oxide. Preferably, the base material is made of zirconia (zirconium oxide). Using zirconia as the base material improves aesthetics. To improve cost, zirconia may be combined with carbon, resin, glass, or the like. The zirconia (zirconium oxide) content of the base material should be 10% by mass or more by volume.

[0028] When the closing member 200 is made of a base material made of a biocompatible ceramic material, it can also be made of a transparent or translucent ceramic material. If the closing member 200 is transparent, the state of growth of the dental pulp in the cell retention chamber 140 can be roughly observed while the closing member 200 is attached to the insertion hole 130, and when the state of growth of the dental pulp needs to be observed in detail, the closing member 200 is removed from the insertion hole 130. The composition of the transparent ceramic material is not particularly limited, but for example, it contains 50 to 90 mass % alumina and 10 to 50 mass % zirconia.

[0029] The human stem cells held in the cell holding chamber 140 are preferably human dental pulp stem cells, such as human deciduous tooth pulp stem cells. When using human dental pulp stem cells, deciduous teeth or wisdom teeth extracted during treatment can be effectively used.

[0030] Human dental pulp stem cells are, for example, dental pulp stem cells that express CD29, CD73, CD90, CD105, or CD166. Human dental pulp stem cells are introduced into the cell holding chamber 140 in the form of a solution containing dental pulp stem cells, for example, with a syringe. The concentration of dental pulp stem cells in the solution containing dental pulp stem cells is not particularly limited, but may be, for example, 8×10 7 cells / mL ~ 2 × 10 8 cells / mL.

[0031] Human stem cells can also be held together with an extracellular matrix in the cell holding chamber 140. The extracellular matrix is ​​not particularly limited and may include, for example, at least one of collagen, artificial proteoglycan, gelatin, hydrogel, fibrin, phosphophoryn, heparan sulfate, heparin, laminin, fibronectin, alginic acid, hyaluronic acid, chitin, PLA, PLGA, PEG, PGA, PDLLA, PCL, hydroxyapatite, β-TCP, calcium carbonate, titanium, and gold.

[0032] In the present embodiment 1, the closing member 200 can also be attached to the insertion hole 130 by using a biocompatible adhesive. When observing whether the dental pulp is regenerating in the cell retention chamber 140, the closing member 200 can be removed from the insertion hole 130 by melting the adhesive or by pulling the upper part of the closing member 200 with a force greater than the physical force required to fix it with the adhesive.

[0033] 3 is a diagram illustrating the state in which an artificial tooth is attached to the upper part of an implant body 900 according to the first embodiment of the present invention. In this embodiment, the implant body 900 is a two-piece type implant. If confirmation is required, the state of the dental pulp in the cell retention chamber 140 is observed, and after confirmation, the closure member 200 is inserted and fixed in the insertion hole 130, and then the abutment 300 is inserted and fixed in the fixing hole 120. Thereafter, the artificial tooth 400, which is the upper structure, is placed over the abutment 300. This completes the implant treatment.

[0034] 4 is a diagram illustrating the case where the implant body 900 according to the first embodiment of the present invention is a one-piece type implant. The implant body 900 according to the present invention is primarily intended to be a two-piece type, but is not limited to this form and can also be applied to a one-piece type implant.

[0035] That is, if there is any abnormality in the condition of the dental pulp in the cell retention chamber 140, it is checked, and after checking, the closing member 200 is inserted and fixed in the insertion hole 130, and then a superstructure is placed over the top of the one-piece type implant body 100. In such a case, it is possible to fill the fixing hole 120 with, for example, a biocompatible resin to fill the space.

[0036] (Embodiment 2) 5 is a diagram illustrating an implant body 900 according to embodiment 2 of the present invention. In the above-described embodiment 1, the closing member 200 is attached to the insertion hole 130 by frictional force when it is pushed into the insertion hole 130, and when removing the closing member 200, the closing member 200 is removed from the insertion hole 130 by pulling the upper part of the closing member 200 with a physical force that exceeds the frictional force.

[0037] In the second embodiment, the closing member 200 is detachable by a screw-in closing mechanism using a screw thread and a screw groove. That is, in the second embodiment, the closing member 200 is configured as a screw member having a screw head 230 at the top and a screw thread portion 240 at the bottom. That is, the screw thread portion 240 is formed in a spiral shape at the bottom of the outer periphery of the closing member 200. The cell retention chamber 140 is generally cylindrical. The screw head 230 of the closing member 200 is generally cylindrical with a diameter larger than the outer diameter of the cell retention chamber 140. The lower part of the closing member 200, where the screw thread portion 240 is formed in a spiral shape, is generally cylindrical. The insertion hole 130 is, for example, generally cylindrical. The insertion hole 130 constitutes a part of the cell retention chamber 140. The inner diameter of the insertion hole 130 is larger than the outer diameter of the lower part of the closing member 200. A screw groove portion 131 having a spiral screw groove that engages with the screw thread portion 240 is formed on the upper side of the cell retention chamber 140 and on the inner wall of the through-hole 160 (the inner wall of the insertion hole 130).

[0038] The lower outer periphery of the closure member 200, where the threaded portion 240 is formed, can be tapered in the longitudinal direction of the cylindrical shape to better fit into the insertion hole 130, and the taper angle can be, for example, 8 degrees or less, preferably 4 degrees or less.

[0039] FIG. 6 is a diagram illustrating the state in which the closing member 200 is attached to the implant body 900 according to the second embodiment of the present invention. As shown in FIG. 6 , in the second embodiment, after human stem cells are injected into the cell-retention chamber 140, the upper end of the cell-retention chamber 140 is closed by the closing member 200 by rotating the closing member 200, for example, clockwise, thereby threading the threaded portion 240 of the closing member 200 into the threaded groove portion 131. If it is necessary to wait several months in this state and check the condition of the dental pulp in the cell-retention chamber 140, the closing member 200 can be removed from the insertion hole 130 by rotating the closing member 200, for example, counterclockwise, thereby releasing the threaded portion 240 of the closing member 200 from the threaded groove portion 131. This allows the condition of the dental pulp growth in the cell-retention chamber 140 to be periodically observed.

[0040] The base materials constituting the implant body 100 and the closing member 200 are the same as those in the first embodiment. Therefore, for example, it is possible to configure the closing member 200 as a screw member made of a transparent or translucent ceramic material. The explanation of the human stem cells held in the cell holding chamber 140 is also the same as in the first embodiment. In the second embodiment, the implant body 900 according to the present invention is primarily assumed to be a two-piece type, but is not limited to this form and can also be applied to a one-piece type implant.

[0041] (Embodiment 3) 7 is a diagram illustrating an implant body 900 according to a third embodiment of the present invention. In the first embodiment described above, the closing member 200 is attached to the insertion hole 130 by frictional force when it is pushed into the insertion hole 130, and when the closing member 200 is to be removed, the closing member 200 is removed from the insertion hole 130 by pulling the upper part of the closing member 200 with a physical force that exceeds the frictional force.

[0042] In the third embodiment, the closing member 200 is detachable by an O-ring closing mechanism using an O-ring 250 attached to the closing member 200. That is, in the third embodiment, the closing member 200 is substantially cylindrical, and an annular groove 251 is provided on the lower outer periphery of the closing member 200, and the O-ring 250 is attached to the annular groove 251. The insertion hole 130 is, for example, substantially cylindrical. The inner diameter of the insertion hole 130 is approximately the same as the outer diameter of the O-ring 250 attached to the annular groove 251 or is slightly larger than the outer diameter of the O-ring 250.

[0043] 8 is a diagram illustrating the state in which the closing member 200 is attached to the implant body 900 according to the third embodiment of the present invention. As shown in FIG. 8, in the third embodiment, after human dental pulp stem cells are injected into the cell-retention chamber 140, the closing member 200 is pushed into the insertion hole 130, and the elastic force of the O-ring 250 causes the closing member 200 to be attached in close contact with the insertion hole 130. In the attached state, the upper part of the closing member 200 is exposed from the insertion hole 130. In this state, if it is desired to wait for several months to pass and then check the state of the dental pulp inside the cell-retention chamber 140, the closing member 200 can be removed from the insertion hole 130 by pulling the upper part of the closing member 200 with a physical force that exceeds the elastic force.

[0044] The O-ring 250 is preferably made of a biocompatible resin composition, such as silicone rubber, although there is no particular limitation on such a resin composition.

[0045] (Use of the implant body of the present invention) 9 is a diagram illustrating a usage mode of the implant body 900 according to the present invention. Here, the explanation will be divided into four steps using the implant body 900 of Embodiment 1, but the procedure is basically the same for the implant body 900 of Embodiment 2 and the implant body 900 of Embodiment 3.

[0046] In the first step, a hole for implanting the implant body 900 is drilled in the alveolar bone. The implant body 900 of the present invention is inserted into the hole drilled in the alveolar bone. Then, a solution containing human dental pulp stem cells is injected into the cell-retention chamber 140 from the upper opening 110 using a syringe. The injected solution containing human dental pulp stem cells fills the cell-retention chamber 140, and some of it overflows from the upper opening 110 and adheres to the outer periphery of the implant body 900. In addition, by injecting the stem cells through the through-hole 160 under pressure, the stem cells are forced to fill the area around the implant body 100 from the lower opening 150, which is expected to promote regeneration of the periodontal tissues around the implant body 100, including the periodontal ligament.

[0047] In the second step, the closing member 200 is inserted by pushing it into the insertion hole 130 to close the cell holding chamber 140. The gums are then temporarily sutured to close the wound where the implant was inserted. After a certain period of time, the sutures are removed from the temporarily sutured gums, the closing member 200 is removed from the insertion hole 130, and the state of growth of the dental pulp within the cell holding chamber 140 is observed. Note that the differentiation fate of dental pulp stem cells is dictated by the hardness of the matrix they contact, so periodontal ligament tissue is regenerated around the periphery of the implant body 900.

[0048] In the third step, after sufficient regeneration of the dental pulp in the cell holding chamber 140 has been confirmed, the abutment 300 is inserted and fixed.

[0049] In the fourth step, after it is confirmed that the implant body 900 has taken root in the alveolar bone, the artificial tooth 400 is attached to the abutment 300. This completes the treatment.

[0050] As described above, this embodiment provides an implant body that allows periodic and accurate observation of the state of dental pulp regeneration inside the implant body. Such an effect also contributes to the achievement of, for example, Goal 3 of the Sustainable Development Goals (SDGs) advocated by the United Nations, "Ensure good health and well-being for all." [Industrial Applicability]

[0051] It can be used for implant treatment. [Explanation of symbols]

[0052] 100: Implant body 110: Top of opening 120: Fixed hole 130: Insertion hole 131: Thread groove 140: Cell holding chamber 150: Lower opening 160:Through hole 200: Closing member 230: Screw head 240:Threaded part 250: O-ring 251: Annular groove 300: Abutment 400: Artificial teeth 900: Implant body

Claims

1. An implant body for generating dental pulp and periodontal ligament, The implant body has a through-hole formed therethrough, a cell holding chamber located below the through-hole for holding cells; an upper opening located at the upper end of the through-hole for injecting human stem cells into the cell holding chamber; an opening lower portion located at a lower end of the through hole; a closing member that is inserted from the top of the opening and closes the upper end of the cell retention chamber, The implant body, wherein the closing member is detachable.

2. 2. The implant body according to claim 1, wherein the closing member is a transparent member, allowing observation of the state of the cell holding chamber.

3. The cell holding chamber has a substantially cylindrical shape, the closing member has a generally cylindrical shape with a diameter larger than the outer diameter of the cell retention chamber, The closing member has a spiral thread formed on the lower outer periphery, a screw groove portion having a spiral screw groove that engages with the screw thread is formed on the upper side of the cell retention chamber and on the inner wall of the through-hole; The implant body according to claim 1, characterized in that it has a screw-in closure mechanism in which the upper end of the cell retention chamber is closed by the closure member by threading the threads of the closure member into the thread groove of the screw groove portion as the closure member rotates.

4. The cell holding chamber has a substantially cylindrical shape, the closing member has a generally cylindrical shape with a diameter larger than the outer diameter of the cell retention chamber, The closing member has an annular groove formed on the lower outer periphery, and an O-ring is fitted in the annular groove. a fitting portion into which a lower outer periphery of the closing member is fitted is formed on an upper side of the cell retention chamber and on an inner wall of the through-hole; The implant body according to claim 1, characterized in that it has an O-ring closing mechanism in which the upper end of the cell retention chamber is closed by the closing member when the lower outer periphery of the closing member is fitted into the fitting portion, causing the O-ring and the fitting portion to abut against each other.

5. A two-piece type implant body, 2. The implant body according to claim 1, wherein an abutment is inserted from the upper opening and fixed in a through hole extending from the upper end of the closing member to the upper opening.

6. 2. The implant body according to claim 1, wherein the human stem cells are human dental pulp stem cells.

7. 2. The implant body according to claim 1, wherein the outer surface of the implant body has a side surface shape of an ellipsoid of revolution with a ratio of 6 to 7:1.

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