JP6506924B2 - Paint containing conductive diamond powder, electrode and dental treatment tool for electrode formation - Google Patents

Description

  The present invention relates to a conductive diamond powder-containing paint for forming an electrode, an electrode and a dental treatment tool.

  It is known to electrolyze water or an aqueous solution to produce ozone or peroxide and use it for sterilization and the like. For example, Patent Document 1 and Non-patent Document 1 describe that electrolytic water containing ozone or peroxide generated by electrolyzing raw material water in an electrolytic unit having an anode formed of conductive diamond is used for sterilization. It is done. When a saline solution is used as the raw material water, chlorine is generated, and an aqueous solution containing hypochlorite ion may be obtained. The anode formed of conductive diamond is obtained by forming a conductive diamond (BDD) thin film on the surface of a substrate by a chemical vapor deposition (CVD) method.

  Sterilization is used in every aspect of life. In particular, it is an important technology in the medical field. For example, as a field requiring sterilization, there is a field of dental treatment where inflammation in the oral cavity needs to be suppressed. Among the treatment of diseases in the oral region, the main treatments for diseases involving bacteria are caries treatment, periodontal treatment and root canal treatment.

  Caries is known to occur in Streptococcus mutans bacteria etc. If S. mutans bacteria is sterilized at the caries site and simply filled with filling material, it is usually used for dental treatment. It is possible to fill without cavity formation to remove the infected tooth quality that is being performed, and not only relieve the pain of the patient but also greatly reduce the burden on the dentist. Moreover, since it is not necessary to cut the tooth quality, it is good news from the viewpoint of preservation of the tooth quality. In some cases, since filling can be performed without extracting the dental pulp, there is also an advantage that the teeth can be kept alive.

  On the other hand, soft tissue in the periodontal region around dentin exfoliates deeply from the tooth and forms a deep groove called pocket, and periodontitis bacteria such as Porphyromonas gingivalis, which is an anaerobic bacterium, there. It is periodontal disease that proliferates, activates osteoclasts and causes bone resorption. For this purpose, it is necessary to sterilize periodontitis bacteria in the pocket, but an antibacterial agent is prescribed, and treatments for removing tartar and the like are widely used. In this case as well, if sterilization and sterilization can be performed without resorting to antibiotics, topical antibiotics for antibiotics may not be used, which is also good news for patients.

  In root canal treatment, usually, the root canal is enlarged to a suitable size, or mechanical removal of contaminated tooth substance with a metal file or the like is performed, and then the sodium canal is treated with an aqueous solution of sodium hypochlorite or hydrogen peroxide solution. After sterilizing the inside and washing with EDTA etc., it is performed by the root canal filling method using gutta percha point and sealer for root canal. As a result, it is ideal that the root canal be filled using a root canal sealer to make the root canal sterile. However, the inner diameter of the root canal of human teeth is usually about 0.4 mm-0.5 mm even when the root canal is enlarged, and the root canal is developed complicatedly called side branch, and Enterococcus faecalis (Enterococcus faecalis) etc. It is difficult to sterilize the whole of the infected canals. It is not easy to fill the root canal sealer without any gap for the same reason. Moreover, in the sterilization method using a drug, the side effect of the drug is a problem that must always be considered. Therefore, in the conventional root canal treatment currently performed, bacteria may remain in the root canal and cause inflammation etc. It is impossible to sterilize the root canal by filling the root canal once It was not easy.

JP, 2006-346203, A JP, 2013-76130, A

Electrochemistry, 81 (8), 627-633 (2013)

  The present inventors planned and examined performing sterilization in dental treatment such as the above-mentioned caries, periodontal disease, and root canal treatment using electrolytic method. Specifically, the needle-like or plate-like base material includes an anode in which a conductive diamond (BDD) thin film is coated by CVD and has dimensions and a structure which can be inserted into a root canal which is a capillary particularly among dental treatments. The electrolysis unit which it has is produced, It electrolyzes using this electrolysis unit, The electrolyzed water which has bactericidal power was produced | generated, and the method to disinfect was examined. As a result, it was possible to generate electrolytic water, but it was also found that the adhesion strength of the BDD thin film to the base material was weak, and part of it peeled off from the base material when producing the electrolytic unit. The needle-like substrate was a flexible needle having a diameter of about 0.5 mm, and the BDD thin film easily peeled off when the substrate was bent. Further, peeling of the BDD thin film was also observed when gas such as oxygen was generated by electrolysis and gas was generated at the interface between the base and the BDD thin film. Even the enlarged root canal for the treatment of the root canal has an inner diameter of about 0.4 mm, and it was necessary to make an even thinner electrode.

  Further, Patent Document 2 describes an electrode using a film made of a mixture of BDD powder and a resin binder. The electrode described in Patent Document 2 is an electrode in which a BDD ink containing a BDD powder and an insulating binder is deposited on a carbon paste. The conductive diamond electrode described in the example of Patent Document 2 is produced using a BDD ink in which the BDD powder and polyester resin are varied between 18 and 89% of the volume ratio of BDD powder to the volume of polyester resin. It is The present inventors made a BDD ink based on the description of this example, and produced an electrode having a coating consisting of BDD powder and a polyester resin on a needle-like base material, and using this electrode, the root canal Electrolyzed water was generated to study sterilization in the root canal. As a result, in the case of a coating with a high BDD powder content, it was possible to generate electrolyzed water in the root canal. However, gas such as oxygen was generated by the electrolysis, and peeling of the BDD powder-containing thin film was observed by the impact and load.

  Therefore, the present invention has high adhesion strength to the surface of the substrate, and covers the surface of the substrate conforming to the flexible needle or the flexible needle, and when the substrate is bent or by electrolysis etc. It is an object of the present invention to provide a conductive paint for electrode formation which can provide a thin film which is not easily peeled off even when the gas is generated, and to provide an electrode having a conductive thin film which is hardly peeled using this paint. I assume. Another object of the present invention is to provide an electrolysis unit using the above electrode and a dental treatment instrument using the electrolysis unit.

  The present inventors examined development of a material using BDD powder and having high adhesion strength with the surface of the substrate and having conductivity that can be used as an electrode material, particularly an electrode material for electrolysis. As a result, a film formed on the surface of a substrate using a composition containing a predetermined ratio of BDD powder and ion exchange resin or a composition containing a predetermined ratio of BDD powder and an insulating binder and silicone rubber is used. The present invention has been accomplished by finding that it has good adhesive strength with the surface of a substrate and that electrolytic water can be generated by electrolysis.

The present invention is as follows.
[1]
A conductive paint for electrode formation, comprising conductive diamond powder (BD-DP) and an ion exchange resin dispersion.
[2]
A conductive paint for electrode formation, comprising conductive diamond powder (BDDP), an insulating binder and silicone rubber.
[3]
An electrode substrate and an electrode having a conductive film provided on the surface of at least a part of the substrate, wherein the conductive film comprises a conductive diamond powder (BDDP) and an ion exchange property. The above electrode containing a resin or containing BDDP and an insulating binder and silicone rubber.
[4]
The electrode according to [3], wherein the electrode substrate is a needle-like or plate-like substrate.
[5]
The electrolysis unit containing the electrode as described in [3] or [4], and a counter electrode.
[6]
The electrolysis unit containing the electrode as described in [3] or [4], a separator, and a counter electrode.
[7]
An electrode unit according to [3] or [4], wherein the electrode substrate is acicular, and an electrolytic unit formed by winding a tape-like counter electrode on the electrode with an ion exchange membrane interposed between the electrode and the counter electrode.
[8]
The electrolysis unit according to any one of [5] to [7], which is for dental treatment.
[9]
The electrolytic unit according to any one of [5] to [7], which is for caries, periodontal disease, or root canal treatment.
[10]
The dental treatment instrument containing the electrolysis unit of any one of [5]-[7].
[11]
The dental treatment instrument according to [10], wherein the dental treatment instrument is a caries, periodontal disease, or root canal treatment instrument.

  According to the present invention, the substrate surface is coated with a high adhesive strength with flexibility and is flexible, and the substrate peels even when the substrate is bent or when a gas such as oxygen is generated by electrolysis. It is possible to provide a conductive diamond powder-containing paint for electrode formation which can provide a difficult thin film, and an electrode having a conductive thin film which is formed using this paint and which is not easily peeled off. Furthermore, according to the present invention, it is also possible to provide an electrolysis unit using the above-mentioned electrode and a dental treatment instrument using the electrolysis unit, in particular a root canal treatment instrument.

The figure of the electrolysis unit of the present invention is shown (the left: close-up view near the interface, the right: an overall image of the central part). The electron microscope image in a root canal is shown. (A) Periodontitis bacteria P. gingivalis (P. gingivalis) cultured on the intratubular surface. (B) The surface of the root canal after energization with a BDD electrode at 7.5 V for 30 seconds. (C) Sodium hypochlorite treatment for 30 seconds. (D) PBS wash for 30 seconds only.

[Conductive paint for electrode formation]
The conductive paint for electrode formation of the present invention comprises a paint containing conductive diamond powder (boron-doped diamond powder, hereinafter abbreviated as BDDP) and an ion exchange resin dispersion (hereinafter, called paint A), and BDDP A paint containing an insulating binder and silicone rubber (hereinafter referred to as paint B).

  As the conductive diamond powder, for example, conductive diamond particles using diamond particles (DP: Diamond Powder) as a base material and forming a boron-doped diamond (BDD: Boron Doped Diamond) layer on the surface of the diamond particles What consists of

  The diamond particles may be natural diamond powder or artificially produced diamond powder, such as insulating diamond powder commercially available as an abrasive. The artificial diamond powder can be produced by thermal CVD, a CVD method such as RF plasma, a thermal filament CVD method, a PVD method such as an ion beam method or an ionized deposition method, a high temperature high pressure method, or the like. The particle diameter (average particle diameter) and the shape of the diamond particles are not particularly limited, but taking into consideration the workability of the BDDP-containing paint and the thickness of the BDDP-containing layer after drying the BDDP-containing paint, etc. It is set. For example, when the particle diameter of the diamond particles is 5 nm to 100 μm, more preferably 50 nm to 10 μm, sufficient workability can be ensured for producing an electrode having a BDDP containing layer by printing a BDDP containing paint. It becomes easy to ensure that the BDDP and the electrode substrate are electrically connected to each other.

When forming a BDD layer on the surface of the diamond particles, the amount of boron to be doped to the diamond is at least 10 ppm, more preferably 1000 ppm or more, and still more preferably 10000 ppm or more of boron relative to the carbon constituting the diamond. (In other words, the boron concentration ratio in the crystal is 10 ²⁰ to 10 ²² cm ^-3 ) BDDP particles having sufficient conductivity can be obtained.

<Paint A>
The paint A contains BDDP and an ion exchange resin dispersion. The ion exchange resin dispersion is a dispersion of a resin having ion exchangeability in a dispersion medium, and the resin having ion exchangeability is appropriately selected from so-called ion exchange resins, and preferably has excellent durability. It can be a fluororesin-based ion exchange resin. As a fluororesin-based ion exchange resin, a perfluoro ion exchange resin can be mentioned, and as a dispersion of a perfluoro ion exchange resin, for example, Nafion (registered trademark, the same applies hereinafter) dispersion, perfluoro ion exchange resin solution (Asaplex (registered trademark) -Asiplex (registered trademark) -SS-1000: trade name, resin concentration 5%) and the like can be mentioned. However, it is not the intention limited to these.

Nafion is a perfluorocarbon material composed of a carbon-fluorine hydrophobic Teflon (R) backbone and a perfluoro side chain having a sulfonic acid group, and is typically tetrafluoroethylene and perfluoro [2- ( [1] A copolymer of fluorosulfonylethoxy) propyl vinyl ether], which is a non-crosslinkable polymer, generally having the following structure.

  Nafion is not completely dissolved in the solvent and exists as a colloidal solution (dispersion). In general, it is considered that they are aggregated in a relatively large colloid having a diameter of about 10 nm in a solvent. Therefore, the measurement of molecular weight is difficult, and it is estimated to be about 10,000 to 1,000,000. As the Nafion dispersion which is an ion exchange resin dispersion, for example, Nafion (registered trademark) 5 wt% dispersion, Nafion (registered trademark) 10 wt% dispersion, and Nafion (registered trademark) 20 wt% dispersion are commercially available. . Each is a liquid in which 5 wt%, 10 wt% or 20 wt% of Nafion (ion exchange resin) is dispersed in a mixed solvent of 1-propanol and 2-propanol.

  The content ratio (mass ratio) of BDDP to the ion exchange resin dispersion in the ion exchange resin dispersion in the paint A is that the film formed on the surface of the substrate for the electrode functions as an electrode for electrolysis (ie, BDDP mass, considering that it has good conductivity) and adhesion strength between the coating formed on the substrate surface and the substrate is good (that is, it does not peel off or is difficult to peel off in handling and electrolysis) The ion exchange resin mass is suitably in the range of 10 to 200, preferably in the range of 20 to 150, more preferably in the range of 30 to 100, and still more preferably in the range of 40 to 70, where . As a general tendency, as the BDDP mass increases, the conductivity increases, and as the ion exchange resin mass increases, the adhesion strength to the substrate increases.

  The paint A can contain an organic solvent in addition to the BDDP and the ion exchange resin dispersion. As described above, when the ion exchange resin dispersion is Nafion (R) 20 wt% dispersion or the like, propanol is contained in the Nafion (R) 20 wt% dispersion, but in addition to this, It can also contain an organic solvent. Paints can also be made without the use of additional organic solvents. The additional organic solvent is suitably one capable of well dispersing BDDP and ion exchange resin, and, for example, alcohols used in Nafion (registered trademark) 20 wt% dispersion etc. (eg ethanol) , 1-propanol, 2-propanol) can be mentioned. However, it is not the intention limited to this organic solvent. The amount of the organic solvent used can be appropriately determined in consideration of the viscosity, coating performance, etc. required of the paint.

<Paint B>
The paint B is a paint containing BDDP, an insulating binder and silicone rubber. As an insulating binder, the polyester resin which is a condensation polymer of polyhydric carboxylic acid (dicarboxylic acid) and polyalcohol (diol) can be mentioned, for example. Furthermore, as the insulating binder, in addition to polyester resin, for example, various modified polyester resins such as urethane modified polyester resin, epoxy modified polyester resin, acrylic modified polyester, polyether urethane resin, polycarbonate urethane resin, polyethylene, polypropylene, ethylene Vinyl acetate polymer, polyolefin resin such as maleated polyolefin, vinyl chloride / vinyl acetate polymer, epoxy resin, phenol resin, polyamide imide, nitrocellulose, cellulose acetate butyrate (CAB), cellulose acetate propionate (CAP) And modified celluloses can also be used.

  The silicone rubber can be an uncured silicone rubber raw material composition, and can be, for example, a one-component heat-curable silicone resin. The one-component heat-curable silicone resin is not particularly limited, and examples thereof include a one-component heat-curable silicone adhesive manufactured by Shin-Etsu Silicone Co., Ltd., such as KE-1830.

  The content ratio (mass ratio) of BDDP to the insulating binder and silicone rubber in the coating material B is that the film formed by applying on the surface of the substrate for the electrode functions as an electrode for electrolysis, that is, good conductivity And the adhesive strength between the coating formed on the surface of the substrate and the substrate (that is, not peeling or difficult to peel in handling and electrolysis), the BDDP mass is 100 When the total content of the insulating binder and the silicone rubber is in the range of 10 to 200, preferably in the range of 15 to 150, more preferably in the range of 20 to 100, still more preferably in the range of 25 to 45 is there. As a general tendency, as the BDDP mass increases, the conductivity increases, and as the total content of the insulating binder and the silicone rubber increases, the adhesive strength increases.

  The content ratio (mass ratio) of the insulating binder to the silicone rubber is the mass of the insulating binder in consideration of the adhesion strength between the film coated on the surface of the substrate and the substrate and the application of the strength to the film. It is appropriate that the content weight of the silicone rubber is in the range of 1 to 50, preferably in the range of 3 to 30, more preferably in the range of 5 to 25, and still more preferably in the range of 5 to 15. . As a general tendency, the higher the content of silicone rubber, the higher the adhesive strength and the film strength. However, the present invention is not intended to be limited to the above range, and all are intended for illustration.

  The paint B can contain an organic solvent in addition to the BDDP, the insulating binder and the silicone rubber. The organic solvent can be one capable of dissolving the insulating binder and the silicone rubber, and examples thereof include methyl ethyl ketone (MEK) and isophorone. However, it is not the intention limited to this organic solvent. The amount of the organic solvent used can be appropriately determined in consideration of the viscosity, coating performance, etc. required of the paint.

[electrode]
The electrode of the present invention is an electrode having an electrode substrate and a conductive film provided on the surface of at least a part of the substrate. Furthermore, the conductive film contains BDDP and an ion exchange resin, or contains BDDP, an insulating binder and a silicone rubber (cured product). The content of BDDP in the conductive film is selected from the viewpoint that the conductive film exhibits good conductivity (current conductivity) even in electrolysis which requires a relatively large amount of current, for example, 10% by mass or more Is preferably 20% by mass or more, more preferably 30% by mass or more, still more preferably 40% by mass or more, and still more preferably 50% by mass or more. The content of BDDP in the conductive film is 60% by mass or more, more preferably 70% by mass or more, from the viewpoint of having better conductivity (electrical conductivity). By increasing the BDDP content, the conductivity is improved, but on the other hand, the content of the ion exchange resin or the insulating binder and the silicone rubber (cured product) decreases, so the adhesive strength of the conductive film is increased. Tend to decrease. When this point is taken into consideration, the upper limit of the BDDP content is practical although it depends on the type of ion exchange resin or insulating binder and silicone rubber (cured product), the type of BDDP (eg, particle diameter etc.), etc. To about 80% by mass. However, this upper limit is merely a guide and is not intended to be limiting.

  The conductive film containing BDDP and ion exchange resin can be formed by applying the paint A and removing (evaporating) the organic solvent contained in the paint. A conductive film containing BDDP, an insulating binder and silicone rubber is formed by applying the paint B, removing (evaporating) the organic solvent contained in the paint, and curing the uncured silicone rubber. Can. A known method can be appropriately used for the method of applying the paint to the substrate, the method of removing (evaporating) the organic solvent, the method of curing the uncured silicone rubber, and the like.

  The shape and size of the electrode substrate are not particularly limited. It can determine suitably in consideration of the use of the electrode of the present invention. The electrode substrate can be, for example, a needle-like or plate-like substrate. When the electrode of the present invention is used for dental treatment, particularly for root canal treatment, the electrode substrate is suitably a needle-like member having a diameter of about 0.05 to 0.5 mm. However, the electrode substrate is not intended to be limited to a needle-like substrate, and various electrode substrates can be adopted according to the use of the electrode. Further, the material of the electrode base material is preferably a material having resistance to oxidation when the electrode is used as an anode. Examples thereof include noble metals such as platinum and metal materials such as titanium. Alternatively, a noble metal such as platinum may be plated on the electrode substrate to impart resistance. However, it is not the intention limited to this. The electrode base material other than needle-like may be in various forms such as plate-like and mesh-like.

  The electrode of the present invention can be produced by applying the paint A or B on the surface of the electrode substrate, and then drying and if necessary heat curing. The thickness of the conductive film is not particularly limited, but can be, for example, in the range of 1 μm to 1 mm. In the case of an electrode for treatment of the root canal, for example, it can be in the range of 1 μm to 200 μm, preferably in the range of 5 μm to 100 μm.

[Electrolysis unit]
The electrolysis unit of the present invention comprises the electrode of the present invention and the counter electrode. Furthermore, as an aspect of the electrolysis unit of the present invention, one including the electrode, the separator and the counter electrode of the present invention can also be mentioned. The separator may be any member capable of providing electrical isolation without short-circuiting the electrode of the present invention and the counter electrode. As the separator, for example, a solid electrolyte such as a conductive resin can be used, and for example, a Nafion (registered trademark) film or an Aciplex (registered trademark) film can be used. Alternatively, the ion exchange resin dispersion used as the material of the paint A may be applied to the counter electrode to integrate the counter electrode with the separator. The film thickness of the separator can be appropriately selected in consideration of the structure and dimensions of the electrolytic unit, and further the electrolytic conditions. The counter electrode is not particularly limited as long as the electrolysis unit can function as an electrolysis system. When the electrolysis unit of the present invention is used for electrolysis of water or an aqueous solution, hydrogen is generated because the counter electrode is a cathode. Therefore, for example, a material having a low hydrogen generation overvoltage is appropriate. The electrolysis which consists of noble metal materials, such as platinum, can be illustrated.

  As an example, mention may be made of an electrode according to the present invention in which the electrode substrate is needle-like, and an electrolysis unit in which a tape-like counter electrode is wound on the electrode with an ion exchange membrane interposed between the electrode and the counter electrode. it can. The tape-like counter electrode can be spirally wound around the electrode. Specifically, as shown in FIG. 1, for example, an ion exchange membrane, for example, a Nafion (registered trademark) membrane 20, is interposed between an electrode 10 provided with a conductive coating on a needle-like substrate, for example, a metal (platinum ) The tape 30 can be wound. The thickness of the metal (platinum) tape 30 is suitably in the range of 10 to 100 μm so that the diameter of the electrolytic unit is smaller than the inner diameter of the root canal, and the thickness of the ion exchange membrane is also in the range of 10 to 100 μm Is appropriate.

  The electrolytic unit of the present invention can be for dental treatment, for example, for caries, periodontal disease, or root canal treatment. The electrolysis unit shown in FIG. 1 is particularly useful for root canal treatment. However, the electrolysis unit of the present invention is not intended to be limited to dental treatment, and can also be used as a device for preparing other electrolyzed electrolyzed water. The size, shape, and structure of the electrolytic unit can be appropriately selected according to the desired amount of electrolytic water and the like. For example, the electrolysis unit containing the electrolysis of the present invention and the counter electrode (not including the separator) can be used as a substitute for the electrolysis unit of the electrolyzed water spray device described in Patent Document 1 and Non-Patent Document 1.

  The electrolytic unit of the present invention can also include, in addition to the electrode of the present invention (separator) and the counter electrode, a lead wire, a switch and a power source for connecting the electrode and the counter electrode of the present invention to the power source. The power source is not particularly limited, but may be, for example, a direct current power source, specifically a battery. In particular, in the case of dental treatment or root canal treatment, the electrolytic unit is small in size, and in consideration of operability, a small power source (for example, dry cell or button battery) integrated with the electrolytic unit and switch. It can also be. The voltage used for the electrolysis can be, for example, in the range of 2.5 to 12 V, and the fact that it is in the range of 3 to 10 V means that the electrolysis of water is easily performed to easily generate an oxidant such as ozone. It is preferable from the viewpoint. Further, the solution used for electrolysis may be water or an aqueous solution obtained by adding a suitable solute to water, and when using a solute, it can be appropriately selected according to the application. If a chloride such as sodium chloride (NaCl) is used as a solute, chlorine and / or hypochlorous acid can be produced by electrolysis. The solution used for the electrolysis can also be, for example, saline or phosphate buffered saline.

[Dental treatment equipment]
The present invention includes a dental treatment apparatus including the electrolysis unit of the present invention. The dental treatment instrument can be a root canal treatment instrument. The dental treatment apparatus of the present invention can easily produce a sterilizing aqueous solution, and in particular, can produce a sterilizing aqueous solution at a treatment site.

  Hereinafter, the present invention will be described in more detail based on examples. However, the examples are illustrative of the present invention, and the present invention is not intended to be limited to the examples.

Example 1
3 g of a polyester resin is dissolved at 35 ° C. in a mixed solvent of 6.3 g of methyl ethyl ketone and 7.8 g of isophorone. Add 0.3 g of silicone resin (Shin-Etsu Silicone, KE-1830) and stir well (solution A). BDDP and solution A are mixed in a weight ratio of 1: 3 to obtain a BDD paste. This BDD paste is applied to a dental file with a maximum diameter of 0.3 mm used for root canal expansion, heated to 60 ° C. for 1 hour or more, and further heated to 120 ° C. for 10 minutes or more to produce a BDD electrode. On the other hand, in order to attach an ion exchange membrane to an Al electrode, an aqueous solution of 12.5 wt% Nafion is applied to an Al foil, heated at 60 ° C. for 1 hour or more, and further heated at 120 ° C. for 10 minutes. An ion exchange membrane is formed on the Al electrode. The Al electrode is cut to a width of about 1 mm, and the Al electrode is spirally wound around the BDD electrode so that a portion of the ion exchange membrane is in contact with the surface of the BDD electrode to produce an electrolytic unit.

  The electrolytic unit produced by the above method does not break even when it is applied to a bent root canal, and when a voltage of 7.5 V is further applied in 1.5 ml of distilled water, 0.7 mg / l of ozone is generated. It confirmed, and it turned out that it can be used by dental treatment etc. In addition, the ozone concentration measurement in this-application Example was performed using the multipurpose water quality meter digital pack test * multi and pack test * ozone (both Kyoritsu Chemical-Chemical laboratory). 1.5 mL of the sample solution was subjected to color test by 4-aminoantipyrine enzymatic method using Pack test ozone, and its absorbance was measured by Digital Pack Test Multi to calculate the concentration.

  As a result of culturing P. gingivalis (P. gingivalis) in the root canal of the bovine tooth and applying a voltage of 7.5 V for 30 seconds using this electrolytic unit, the bacteria disappeared from the surface of the root canal. The observation photograph by the electron microscope is shown in FIG. It was confirmed from this SEM observation that this electrolytic unit is also effective for sterilization. (FIG. 2) (A) Periodontitis bacteria P. gingivalis (P. gingivalis) cultured on the intratubular surface. (B) The surface of the root canal after energization with a BDD electrode at 7.5 V for 30 seconds. I do not recognize bacteria. (C) Sodium hypochlorite treatment for 30 seconds. I do not recognize bacteria. (D) PBS wash for 30 seconds only. Many bacteria were recognized.

  Examples 2 to 4 conformed to Example 1 to produce BDD electrodes. The main differences are summarized in the table. Details will be described later.

Example 2
A BDDP and Nafion dispersion (20% Nafion® Dispersion Solution DE 2021 CS type), which is an ion exchange resin dispersion, were weighed to a weight ratio of 10: 5 and mixed to obtain a BDD paste. The BDD paste was applied to a root canal enlargement file (Manny K file 28 mm / # 30) having a maximum diameter of 0.3 mm, and heated at 60 ° C. for 1 hour and at 120 ° C. for 10 minutes to obtain a BDD coated file. The above Nafion dispersion is applied on one side of a platinum foil (99.98%, 0.02 mm thickness, Nyako, PT-353212), and it is finely cut after heating at 60 ° C. for 1 hour and at 120 ° C. for 10 minutes. I got a gold foil ribbon.

  This was wrapped around a BDD coated file so that the Nafion side was in contact, and silicone resin KE-1830 (Shin-Etsu Silicone) was applied to the tip and fixed by heating at 60 ° C. for 1 hour and 120 ° C. for 10 minutes.

Example 3
A BDDP and Nafion dispersion (20% Nafion (registered trademark) Dispersion Solution DE 2021 CS type), which is an ion exchange resin dispersion, were weighed to a weight ratio of 10: 5 and mixed to obtain a BDD paste. Platinum plating was applied to a root canal enlargement file (Manny K file 28 mm / # 08) with a maximum diameter of 0.08 mm.

  A file and a platinum wire were immersed therein, and the file was used as a cathode and a platinum wire as an anode, electrolyzed for 30 minutes under the conditions of 2.5 V DC, 30 mA and washed with water to obtain a platinum plated file. The above-mentioned BDD paste was applied to this, and heated at 60 ° C. for 1 hour and at 120 ° C. for 10 minutes to obtain a BDD-coated platinum plated file. The above Nafion dispersion is applied on one side of a platinum foil (99.98%, 0.02 mm thickness, Nyako, PT-353212), and it is finely cut after heating at 60 ° C. for 1 hour and at 120 ° C. for 10 minutes. I got a gold foil ribbon.

  This was wrapped around a BDD-coated platinum-plated file so that the Nafion side was in contact, and silicone resin KE-1830 (Shin-Etsu Silicone) was applied to the tip and fixed by heating at 60 ° C. for 1 hour and 120 ° C. for 10 minutes.

  The prepared electrolytic unit was adapted to a bent root canal without breaking, and when a voltage of 7.5 V was further applied in 1.5 ml of distilled water, it was confirmed that 0.41 mg / l of ozone was generated. It turned out that it can be used by dental treatment etc.

Example 4
3 g of a polyester resin is dissolved at 35 ° C. in a mixed solvent of 6.3 g of methyl ethyl ketone and 7.8 g of isophorone. Add 0.3 g of silicone resin (Shin-Etsu Silicone, KE-1830) and stir well (solution A). BDDP and solution A are mixed in a weight ratio of 2: 3 to obtain a BDD paste. This BDD paste is applied to a dental file with a maximum diameter of 0.08 mm used for platinum-rooted root canal expansion similar to Example 3, heated to 60 ° C. for 1 hour or more, and further heated to 120 ° C. for 10 minutes or more, BDD Make an electrode. On the other hand, in order to attach an ion exchange membrane to an Al electrode, an aqueous solution of 12.5 wt% Nafion is applied to an Al foil, heated at 60 ° C. for 1 hour or more, and further heated at 120 ° C. for 10 minutes. An ion exchange membrane is formed on the Al electrode. The Al electrode is cut to a width of about 1 mm, and the Al electrode is spirally wound around the BDD electrode so that a portion of the ion exchange membrane is in contact with the surface of the BDD electrode to produce an electrolytic unit.

  The electrolytic unit produced by the above method did not break even when it was applied to a bent root canal. Further, when a voltage of 7.5 V was applied in 1.5 ml of distilled water, it was confirmed that 1.36 mg / l of ozone was generated. It has been found that this electrolysis unit can be used in dental treatment and the like.

Comparative Example 1
3 g of a polyester resin is dissolved at 35 ° C. in a mixed solvent of 6.3 g of methyl ethyl ketone and 7.8 g of isophorone (solution A). BDDP and solution A are mixed in a weight ratio of 3: 5 to obtain a BDD paste. This BDD paste is applied to a dental file with a maximum diameter of 0.3 mm used for root canal expansion, heated to 60 ° C. for 1 hour or more, and further heated to 120 ° C. for 10 minutes or more to produce a BDD electrode. On the other hand, in order to attach an ion exchange membrane to an Al electrode, an aqueous solution of 12.5 wt% Nafion is applied to an Al foil, heated at 60 ° C. for 1 hour or more, and further heated at 120 ° C. for 10 minutes. An ion exchange membrane is formed on the Al electrode. The Al electrode is cut to a width of about 1 mm, and the Al electrode is spirally wound around the BDD electrode so that a portion of the ion exchange membrane is in contact with the surface of the BDD electrode to produce an electrolytic unit.

  The electrolytic unit produced by the above method was broken without adapting to the bending of the bent root canal and could not be used as an electrode.

Example 5
The hydroxyapatite plate (diameter 5 mm, thickness 1 mm) sterilized by autoclaving at 121 ° C. for 15 minutes was immersed in 2 ml of BHI liquid medium, and E. faecalis (E. faecalis) was anaerobically cultured overnight. A film of E. faecalis (E. faecalis) was formed on the HA plate. The BHI liquid medium was discarded, 2 ml of a normal PBS buffer solution was added, and the BDD electrolysis unit prepared in Example 4 was energized at 7.5 V for 15 seconds. Thereafter, 20 μl of sodium thiosulfate was added to completely remove the remaining active oxygen. The concentration of viable bacteria was compared by the fluorescence intensity by alamar blue. That is, the fluorescence intensity was compared after 15 seconds of energization and when immersed in a PBS solution for 15 seconds without energization. As a result, when the BDD electrolytic unit was operated at 7.5 V for 15 seconds, the fluorescence intensity decreased by 53%, and the bactericidal effect was clearly recognized.

Example 6
The hydroxyapatite plate (diameter 5 mm, thickness 1 mm) sterilized by autoclaving at 121 ° C. for 15 minutes was immersed in 2 ml of BHI liquid medium, and S. mutans (S. mutans) was anaerobically cultured overnight. A film of S. mutans (S. mutans) was formed on the HA plate. The BHI liquid medium was discarded, 2 ml of a normal PBS buffer solution was added, and the BDD electrolysis unit prepared in Example 4 was energized at 7.5 V for 15 seconds. Thereafter, 20 μl of sodium thiosulfate was added to completely remove the remaining active oxygen. The concentration of viable bacteria was compared by the fluorescence intensity by alamar blue. That is, the fluorescence intensity was compared after 15 seconds of energization and when immersed in a PBS solution for 15 seconds without energization. As a result, when the BDD electrolysis unit was operated at 7.5 V for 15 seconds, the fluorescence intensity decreased by 55%, and the bactericidal effect was clearly recognized.

Comparative example 2
The hydroxyapatite plate (diameter 5 mm, thickness 1 mm) sterilized by autoclaving at 121 ° C. for 15 minutes was immersed in 2 ml of BHI liquid medium, and S. mutans (S. mutans) was anaerobically cultured overnight. A film of S. mutans (S. mutans) was formed on the HA plate. The BHI liquid medium was discarded, 2 ml of a normal PBS buffer was added, and 100 ppm aqueous sodium hypochlorite solution was allowed to act for 15 seconds. The concentration of viable bacteria was compared by the fluorescence intensity by alamar blue. That is, the difference in fluorescence intensity was measured when immersed in a PBS solution containing sodium hypochlorite for 15 seconds and in a PBS solution not containing sodium hypochlorite. From this result, when 100 ppm sodium hypochlorite was contained, the fluorescence intensity decreased by 35%, and a bactericidal effect was observed. It is assumed that the performance of the BDD electrolytic unit is superior and practical and effective, considering that the sterilizing ability of sodium hypochlorite is generally known.

Example 7
Human extraction teeth were prepared. When the inner diameter of the root canal was less than 0.4 mm, it was enlarged with a root canal reamer to 0.4 mm. The root canal was thoroughly washed with a PBS solution and sterilized at 121 ° C. for 15 minutes to obtain a sample. This sample was immersed in 2 ml of BHI liquid medium, and P. gingivalis was further added, and cultured overnight, and the root canal was filled with bacteria. On the other hand, according to the method of Example 4, a BDD electrolytic unit with an outermost diameter of 0.25 mm to 0.3 mm was produced. Bacterial fluid was removed from the root canal containing the cultured bacteria overnight and replaced with PBS buffer. Using this BDD electrolysis unit, a sterilization condition was investigated by applying a voltage of 7.5 V for 60 seconds. After energization, the bacteria in the root canal were scraped with a # 50 k-file and suspended in 1 ml of PBS solution. 0.6 ml of this suspension was taken and cultured on blood agar medium. Bacterial colonies were not cultured in those which were energized. On the other hand, many colonies of bacteria were observed on the medium in the case of non-energized cells. The results of culture on this blood agar medium also revealed that the BDD electrolyzing unit has a bactericidal effect.

Examples 8 and 9
The culture was performed in exactly the same manner as in Example 7. The bacteria were just investigated for S. mutans (S. mutans) and E. faecalis (E. faecallis). The cells were not cultured when the cells were energized at 7.5 V for 60 seconds.

Example 10
The extracted bovine root canal was prepared. The diameter of the root canal was adjusted to 1 mm or more. Sterilized in an autoclave at 121 ° C. for 15 minutes. On the other hand, a BDD electrolysis unit was prepared according to the preparation method in Example 2. P. gingivalis (P. gingivalis) was cultured overnight to propagate the bacteria in the canal root canal. The root canal was replaced with a PBS buffer solution, a BDD electrolysis unit was inserted, a voltage of 7.5 V was applied, and current was applied for 30 seconds. The decrease in bacterial concentration was measured by fluorescence spectroscopy using alamar blue before and after current application. The fluorescence intensity before and after energization decreased 99%, and the bactericidal effect of the BDD electrolysis unit was confirmed.

Examples 11 and 12
According to the method of Example 10, the effect of the BDD electrolyzing unit was measured by changing the bacterial species. The cells used and the results are summarized in the table. The size of the bovine canal and the electrification conditions are the same as in Example 10.

The effect of the BDD electrolysis unit was confirmed in any of Examples 11 and 12.
It turned out that each example has a very excellent bactericidal effect after energization.

Comparative example 3
According to Example 10, the extracted bovine tooth root canal was prepared. The diameter of the root canal was adjusted to 1 mm or more. P. gingivalis (P. gingivalis) was cultured overnight to propagate the bacteria in the canal root canal. The root canal was washed with physiological saline (PBS solution) for 30 seconds. The decrease in bacterial concentration was measured by fluorescence spectroscopy using alamar blue before and after washing. The reduction rate before and after washing was almost unchanged at 2%.

Example 13
0.05 g of the coating solution A prepared in Example 1 was applied to a Pt plate and an Al foil (1 cm ² ), respectively, and was cured by heat treatment in the same manner as in Example 1. The obtained film had sufficient flexibility and conductivity. The prepared electrode was used as an anode and a Pt wire was used as a cathode, both were immersed in PBS, and a voltage of 7.5 V was applied to carry out electrolysis. Both electrodes were electrolyzable without peeling even in PBS.

  The present invention is useful in the fields related to electrode manufacturing technology and electrolytic water manufacturing technology.

Claims (12)

Conductive diamond powder (boron-doped diamond powder, BDDP ) and containing ion exchange resin dispersion, and the gas generating ion exchange resin mass area by der of 30 to 200 when the BDDP mass and 100 Conductive paint for electrode formation used . A conductive paint for electrode formation, comprising conductive diamond powder (BDDP), an insulating binder and silicone rubber. An electrode used for gas generation, comprising: an electrode substrate and a conductive film provided on the surface of at least a part of the substrate, wherein the conductive film is a conductive diamond powder (BD) ) and containing ion exchange resin, and the ion-exchange resin mass area by der of 30 to 200 when the BDDP mass and 100, the electrode. An electrode substrate and an electrode having a conductive film provided on the surface of at least a part of the substrate, wherein the conductive film comprises a conductive diamond powder (BDDP) and an insulating binder And the electrode containing silicone rubber. The electrode according to claim 3 or 4 , wherein the electrode substrate is a needle-like or plate-like substrate. The electrolysis unit containing the electrode in any one of Claims 3-5 , and a counter electrode. The electrolysis unit containing the electrode in any one of Claims 3-5 , a separator, and a counter electrode. An electrode substrate having a needle shape and an electrode having a conductive film provided on the surface of at least a part of the substrate, wherein the conductive film is a conductive diamond powder (BDDP) And an electrode containing an ion exchange resin, or an electrode containing BDDP and an insulating binder and a silicone rubber , wherein the electrode is wound with a tape-like counter electrode by interposing an ion exchange membrane between the electrode and the counter electrode. , Electrolysis unit. An electrode substrate and an electrode having a conductive film provided on the surface of at least a part of the substrate, wherein the conductive film comprises a conductive diamond powder (BDDP) and an ion exchange property. or containing a resin, or BDDP the electrodes and the electrolytic unit comprises a counter electrode comprising an insulating binder and silicone rubber, or the electrode, a electrolytic unit comprising a separator and a counter electrode, dental der Ru electrolytic unit . An electrode substrate and an electrode having a conductive film provided on the surface of at least a part of the substrate, wherein the conductive film comprises a conductive diamond powder (BDDP) and an ion exchange property. An electrolytic unit comprising a resin, or an electrode and a counter electrode containing BDDP and an insulating binder and a silicone rubber, or an electrolytic unit comprising the electrode, a separator and a counter electrode, wherein the dental caries, periodontal disease, or root canal therapeutic der Ru electrolytic unit. The dental treatment instrument containing the electrolysis unit of any one of Claims 6-8 . The dental treatment instrument according to claim 11 , wherein the dental treatment instrument is a caries, periodontal disease or root canal treatment instrument.