JP5110953B2 - Implant - Google Patents

Description

  The present invention relates to an implant for fixing an object to be fixed to a bone, and more particularly to a dental implant for fixing an artificial tooth to an alveolar bone.

  The implant (artificial tooth root) method currently used in dentistry is a treatment method in which an artificial tooth root (implant) is embedded in the alveolar bone of the jawbone and the artificial tooth is attached thereto as shown in FIG. As the implant material, titanium having excellent biocompatibility is applied. Titanium implants are directly treated with the jawbone, so there is no worries about wobbling or detachment like dentures, and this is an increasingly expected treatment in an aging society.

  However, titanium implant materials can provide a strong bond with the jawbone, but the impact force at the time of occlusion is directly transmitted to the implant-bone interface, and it is poor in mobility. It tends to cause stress concentration. Furthermore, even if the load is less than the fracture strength of the bone in a single shot, if it is repeatedly applied for a long time, an abnormal load may be applied to the jawbone beyond the physiological load capacity of the bone.

  On the other hand, in the case of natural teeth, even if a large external force is momentarily applied at the time of occlusion, the impact force is relaxed to the biologically acceptable range of the alveolar bone by the periodontal ligament fibers having a unique structure and arrangement (Fig. 7). This allows the alveolar bone to withstand frequent occlusal impacts. In addition, periodontal ligament fibers always secrete factors that regulate cell growth and differentiation in response to mechanical external forces, and maintain their own structure and physiological homeostasis while leading to bone remodeling.

  Furthermore, natural teeth have various sensory receptors in the periodontal ligament fibers, and it is considered that the occlusal force and mastication rhythm are controlled through this. However, since implants without periodontal ligaments have little sensation, they not only lack chewing texture and texture, but may damage alveolar bone due to excessive biting force. In addition, since titanium implants are directly bonded to the alveolar bone, they have the disadvantage that the periodontal ligament cannot be formed.

  That is, it is impossible to achieve the function of adjusting the masticatory force and the function of sensing it with a conventional implant that cannot form a periodontal ligament. Therefore, the implant has not only a lack of chewing response and texture, but also has problems such as serious damage to the alveolar bone caused by excessive biting force acting on the implant.

  In addition, as an implant provided with the buffer function, the thing of patent document 1 is known, for example. The implant described in Patent Document 1 is provided with a cap-like cushioning material made of polyoxymethylene having viscoelasticity between an artificial tooth and an implant body. A buffer function is realized.

JP 2002-625 A

  However, although the implant described in Patent Document 1 can realize a buffer function, it cannot sense the masticatory force as described above. Therefore, there is a possibility that an excessive occlusal force exceeding the buffering capacity of the implant is applied.

  In view of this, an object of the present invention is to provide an implant that provides a sense of natural teeth and is highly safe.

  The implant of the present invention is an implant for fixing an object to be fixed such as an artificial tooth, a joint, or a bone to a bone, and includes a piezoelectric sensor that generates a weak current when pressed. According to the implant of the present invention, when the object to be fixed is pressurized, the piezoelectric sensor generates a weak current corresponding to the pressure, and the generated weak current stimulates a nerve near the implant. The pressurization of the fixed object can be perceived. Further, since the piezoelectric sensor itself is deformed when pressurized, a buffer function can be realized.

  Here, the piezoelectric sensor is desirably formed of a piezoelectric material. Piezoelectric materials generate voltage when force is applied, and generate force when voltage is applied, and can generate a weak current according to pressure, and can detect pressurization with a simple structure. An implant is obtained.

Examples of the piezoelectric substance include a piezoelectric polymer material such as polyvinylidene fluoride (PVDF), quartz (SiO ₂ ), zinc oxide (ZnO), Rochelle salt (potassium sodium tartrate: KNaC ₄ H ₄ O ₆ ), titanium. Lead zirconate (PZT: Pb (Zr, Ti) O ₃ ), lithium niobate (LiNbO ₃ ), lithium tantalate (LiTaO ₃ ), lithium tetraborate (Li ₂ B ₄ O ₇ ), langasite (La ₃₎ Ceramic piezoelectric materials such as Ga ₅ SiO ₁₄ ), aluminum nitride, tourmaline, laminated materials or composites of these polymer piezoelectric materials and ceramic piezoelectric materials, conductive polymers such as rear acetylene and polythiophenes, etc. Can be used. In particular, if a polymer piezoelectric material that is flexible and easily deformed, such as PVDF, is easily inserted into the implant. Further, in the case of a hard material such as a ceramic piezoelectric material, handling is facilitated if a composite material with a polymeric piezoelectric material is used. In addition, as another pressure sensor, a sensor that generates a weak current corresponding to pressurization using a power source such as a battery can be used.

  Further, the implant of the present invention has a root portion formed of a conductive material and fixed to the bone, and an abutment portion formed of the conductive material, to which an object to be fixed is fixed and attached to the root portion, The piezoelectric sensor is desirably provided between the root portion and the abutment portion in a state of being insulated from either the root portion or the abutment portion. As a result, an electric circuit is formed by the piezoelectric sensor, one of the root portion or the abutment portion, and the bone, and the weak current generated by the piezoelectric sensor is transmitted to the bone through either the root portion or the abutment portion.

(1) By providing a piezoelectric sensor that generates a weak current when pressurized, a weak current corresponding to the pressure is generated when the object to be fixed is pressed, and the generated weak current is present near the implant. By stimulating the nerve to perform, an implant capable of perceiving the pressurization of the object to be fixed is obtained. In addition, the piezoelectric sensor itself can be deformed during pressurization, so that a buffering function can be realized. In addition to the perception function of pressurization, it is possible to prevent an excessive impact from being applied, and a highly safe implant is realized. it can.

(2) If the piezoelectric sensor is formed of a piezoelectric substance, it is possible to generate a weak current according to pressure with a simple structure, and an implant capable of perceiving pressurization is obtained.

(3) Since it is made of a flexible and easily deformable piezoelectric material such as PVDF, a low-cost implant that can be inserted into the implant and perceives pressurization with a simple structure can be obtained.

  1 is a cross-sectional view showing a state in which an implant according to an embodiment of the present invention is applied, FIG. 2 is a cross-sectional view showing a state of weak current generation in the implant of FIG. 1, and FIG. 3 is an exploded cross-sectional view of the implant of FIG. It is.

  In FIG. 1, an implant 1 according to an embodiment of the present invention is a dental implant for fixing an artificial tooth 2 as an object to be fixed to an alveolar bone 3 of a jawbone as a bone, and an artificial tooth root portion fixed to the alveolar bone 3. 4, an abutment portion 5 to which the artificial tooth 2 is fixed and attached to the artificial tooth root portion 4, and a piezoelectric sensor 6 provided between the upper abutment portion 5 a and the lower abutment portion 5 b of the abutment portion 5. It consists of.

  As shown in FIG. 3, the artificial tooth root portion 4 is formed in a cylindrical shape from titanium as a conductive material. A male screw portion 4a for screwing and fixing to the alveolar bone 3 is formed on the outside of the artificial tooth root portion 4, but the male screw portion 4a can be omitted. In short, the outer peripheral portion of the artificial root portion 4 may have the same configuration as that of a conventional implant, and it is sufficient if it can be firmly fixed to the alveolar bone 3. Inside the artificial tooth root portion 4, a hollow portion 4 b in which a columnar portion 5 c of the abutment portion 5 described later is accommodated, and a female screw portion into which a male screw portion 7 b formed in the lower abutment portion 5 b of the abutment portion 5 is screwed. 4c is formed. The wall surface of the hollow portion 4b is covered with an insulator 4d.

  The abutment portion 5 is formed in a substantially columnar shape from titanium as a conductive material. The upper abutment portion 5 a of the abutment portion 5 is formed with a male screw portion 7 a for screwing and fixing to the artificial tooth 2, but this male screw portion 7 a is omitted in the same manner as the male screw portion 4 a of the artificial tooth root portion 4. Is possible. In short, the upper outer peripheral portion of the upper abutment portion 5a may have the same configuration as that of a conventional implant, as long as it can be firmly fixed to the artificial tooth 2. The columnar part 5 c of the abutment part 5 is formed in a columnar shape and is movable in the hollow part 4 b of the artificial tooth root part 4. The columnar portion 5c can also be formed in a polygonal column shape.

  The piezoelectric sensor 6 is made of a polymer piezoelectric material such as polyvinylidene fluoride (PVDF) that generates a weak current when pressed. Polyvinylidene fluoride is a piezoelectric material that is flexible and easily deformed. The piezoelectric sensor 6 is bonded in a state of being sandwiched between the upper support part 5a and the lower support part 5b. As shown in FIG. 2, the piezoelectric sensor 6 includes the artificial tooth root 4, the upper abutment portion 5 a and the lower abutment portion 5 b of the abutment portion 5 in a state where the abutment portion 5 is fixed to the artificial tooth root portion 4. Between the artificial tooth root 4 and the insulator 4d. Note that the piezoelectric sensor 6 and the artificial tooth root 4 are electrically connected through the lower abutment 5b. In addition, the piezoelectric sensor 6 and the artificial tooth root 4 are electrically connected through the gum G as shown in FIG.

  In the implant 1 having the above-described configuration, when the artificial tooth 2 is pressurized by occlusion, the applied pressure is transmitted to the piezoelectric sensor 6 through the upper abutment 5a, and the piezoelectric sensor 6 is compressed. The piezoelectric sensor 6 generates a weak current C corresponding to the applied pressure, and the generated weak current C stimulates a nerve existing near the implant 1. Thereby, the person can perceive the pressurization of the artificial tooth 2. At this time, the piezoelectric sensor 6 itself is deformed to exhibit a buffer function. Therefore, in this implant 1, it is possible to prevent an excessive impact from being applied together with the pressure perception function, and the safety is high.

  In the implant 1 according to the present embodiment, since the piezoelectric sensor 6 is formed of a flexible and easily deformable piezoelectric material, the implant 1 is easily sandwiched between the upper abutment portion 5a and the lower abutment portion 5b. It is possible to insert into the implant 1 by a simple structure. Therefore, the implant 1 in the present embodiment can be manufactured at a low cost, and a low-cost implant 1 that can perceive pressurization can be provided.

  FIG. 4 is a cross-sectional view showing a modification of the implant 1 in the present embodiment. As shown in FIG. 4, in this implant 1a, the insulator 40d on the contact surface between the upper abutment portion 50a and the hollow portion 40b of the artificial tooth root portion 40 is omitted, and the male screw portion 70b of the lower abutment portion 50b and the artificial thread portion 70b A contact surface of the root portion 40 with the female screw portion 40c is covered with an insulator 40d. Thereby, the piezoelectric sensor 6 is electrically connected to the alveolar bone 3 at the lower end surface of the lower abutment portion 50b, and is electrically connected to the artificial tooth root portion 40 through the upper abutment portion 50a.

  In the example shown in FIGS. 1 and 2, the weak current C generated by the piezoelectric sensor 6 flows in a shallow position of the alveolar bone 3, i.e., a position close to the gingiva G, so that nerves in the gingival G are mainly stimulated. On the other hand, in the example shown in FIG. 4, the weak current C generated by the piezoelectric sensor 6 flows deep in the alveolar bone 3 and mainly stimulates nerves in the alveolar bone 3. Thus, the position of the nerve stimulated by the weak current C can be controlled by changing the position of insulation by the insulators 4d and 40d.

  FIG. 5 is a cross-sectional view of an implant 1b showing still another embodiment of the present invention. In the example shown in FIG. 5, a moving shaft 8 as an abutment portion having a tip (lower end) having a conical shape is fixed to the artificial tooth 2, and a hollow portion 10 having a lower end having a conical shape is formed in the artificial tooth root portion 9. ing. The wall surface of the hollow portion 10 is covered with an insulator 11 except for a conical portion. Further, the piezoelectric sensor 12 is disposed on the conical wall surface of the hollow portion 10 leaving the lower end portion.

  In this configuration, when the artificial tooth 2 is pressurized by occlusion, the moving shaft 8 moves downward and compresses the piezoelectric sensor 12. The piezoelectric sensor 12 generates a weak current C corresponding to the applied pressure of the moving shaft 8, and the generated weak current C stimulates a nerve existing near the implant 1b. Thus, even if it is the structure of the implant 1b shown in FIG. 5, the person can perceive the pressurization of the artificial tooth 2. FIG.

  In the present embodiment, the dental implant for fixing the artificial tooth 2 to the alveolar bone 3 has been described. However, the present invention can also be applied to an implant for fixing other objects to be fixed to bones such as joints of a human body. It is.

  The implant of the present invention is useful as an implant for fixing an object to be fixed to a bone, and in particular, a dentist for fixing a safe artificial tooth to an alveolar bone with a natural tooth-like sensation. Suitable as an implant.

It is sectional drawing which shows the state which performed the implant in embodiment of this invention. It is sectional drawing which shows the mode of the weak electric current generation | occurrence | production of the implant of FIG. It is sectional drawing which decomposed | disassembled the implant of FIG. FIG. 6 is a cross-sectional view of an implant showing another embodiment of the present invention. FIG. 6 is a cross-sectional view of an implant showing yet another embodiment of the present invention. It is sectional drawing which shows the example of the conventional implant. It is sectional drawing of a natural tooth.

Explanation of symbols

1, 1a, 1b Implant 2 Artificial tooth 3 Alveolar bone 4,40 Artificial root 4a, 40a Male thread 4b, 40b Hollow 4c, 40c Female thread 4d, 40d Insulator 5 Abutment 5a, 50a Upper abutment 5b , 50b Lower abutment part 6 Piezoelectric sensor 7a, 7b, 70b Male thread part 8 Moving shaft 9 Artificial root part 10 Hollow part 11 Insulator 12 Piezoelectric sensor G Gingival C Weak current

Claims (4)

An implant for fixing an object to be fixed to bone,
A root formed of a conductive material and secured to the bone;
An abutment part formed of a conductive material, to which an object to be fixed is fixed and attached to the root part,
Between the root portion and the abutment portion, provided in a state of being insulated against one of the root portion or abutment portion, <br/> a piezoelectric sensor that generates a weak current by pressurized Implant with   The implant according to claim 1, wherein the piezoelectric sensor is made of a piezoelectric material. The abutment is movably attached to the root,
The implant according to claim 1 or 2 , wherein the piezoelectric sensor is pressurized by an operation of the abutment portion. The implant according to any one of claims 1 to 3 , wherein the object to be fixed is an artificial tooth, the bone is an alveolar bone, and the root is an artificial tooth root.

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