JP2019058323A - Dental fiber post - Google Patents

Abstract

To provide a dental fiber post that can improve flexural strength while improving the amount of transmission of light.SOLUTION: A fiber post 1 has a plurality of light transmission fibers 2 extending in predetermined direction. The plurality of light transmission fibers 2 each have an outer diameter of 25 μm or more and 100 μm or less. When the plurality of light transmission fibers are each cut in a direction orthogonal to the predetermined direction, the cut areas total 0.10 mmor more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to dental fiber posts.

  It is known to construct an abutment on a tooth root and allow the abutment to support a crown prosthesis, when the dental crown collapses due to the progression of caries (carious tooth) and only the tooth root remains. In such an abutment construction, after the root canal is filled with a photocurable resin agent, the post is inserted into the root canal of the tooth root, and then the light curable resin agent is cured by irradiating light to make the post Fix to the root.

  However, there is a case where the irradiation light does not reach the deep part of the root, the photo-curable resin agent can not be sufficiently cured, and the post can not be sufficiently fixed to the root. Therefore, in such construction of a support, various studies have been made to sufficiently cure the photocurable resin agent.

  For example, a dental fiber post provided with one optical fiber with an outer diameter of 0.5 mm has been proposed (see, for example, Patent Document 1).

  Such dental fiber posts can transmit light in the direction in which the fiber posts extend by means of optical fibers. Therefore, in the abutment construction, light incident on the optical fiber is transmitted by the optical fiber and emitted from the optical fiber at the deep part of the tooth root. As a result, light can be irradiated to the photocurable resin agent located in the deep part of the tooth root.

Unexamined-Japanese-Patent No. 2010-42152

  However, with the dental fiber post described in Patent Document 1, the transmission amount (emission amount) of light is insufficient, and the photocurable resin agent located in the deep part of the tooth root can not be sufficiently cured. Then, although increasing the number of the optical fibers with which a dental fiber post is equipped is examined, when increasing the number of optical fibers, there exists a malfunction that bending strength falls.

  Therefore, the present invention provides a dental fiber post that can improve bending strength while improving transmission of light.

The present invention [1] comprises a plurality of light transmitting fibers extending in a predetermined direction, and the outer diameter of each of the plurality of light transmitting fibers is 25 μm or more and 100 μm or less, and each of the plurality of light transmitting fibers And a dental fiber post including a total of cross-sectional areas obtained by cutting in a direction orthogonal to the predetermined direction, 0.10 mm ² or more.

  The present invention [2] includes the dental fiber post according to the above-mentioned [1], wherein the material of each of the plurality of light transmitting fibers comprises glass.

  The present invention [3] includes the dental fiber post according to the above-mentioned [2], wherein the plurality of light transmitting fibers include an optical fiber including a core layer and a cladding layer covering the core layer.

  The present invention [4] is any of the above-mentioned [1] to [3], wherein the material of the light transmitting fiber contains a contrast component containing an element of the fifth period of the periodic table or the sixth period of the periodic table Contains the described dental fiber post.

  The present invention [5] includes a light transmitting fiber bundle in which all of the plurality of light transmitting fibers are bundled, and the light transmitting fiber bundle is formed by cutting the dental fiber post in the orthogonal direction. The dental fiber post according to any one of the above [1] to [4], which is located in a substantially central portion in cross section, is included.

  According to the dental fiber post of the present invention, the outer diameter of the light transmitting fiber is within the above range, and the total cross sectional area of the plurality of light transmitting fibers is equal to or more than the above lower limit. The bending strength can be improved while the amount can be improved.

FIG. 1A shows a perspective view of a fiber post as a first embodiment of a dental fiber post of the present invention. FIG. 1B shows a cross-sectional view of the fiber post shown in FIG. 1A. FIG. 2A shows a perspective view of the plurality of light transmissive fibers shown in FIG. FIG. 2B shows a cross-sectional view of the light transmitting fiber shown in FIG. 2A. FIG. 3 is an explanatory view for explaining a use mode of the fiber post shown in FIG. 1A. FIG. 4A shows a perspective view of a fiber post according to a second embodiment of the present invention. FIG. 4B shows a cross-sectional view of the fiber post shown in FIG. 4A. FIG. 5A shows a perspective view of a fiber post according to a third embodiment of the present invention. FIG. 5B shows a cross-sectional view of the fiber post shown in FIG. 5A. It is explanatory drawing for demonstrating the light transmittance test of the fiber post obtained by each Example and each comparative example.

First Embodiment
A fiber post 1 as an embodiment of the dental fiber post of the present invention will be described with reference to FIGS. 1A to 3.

  As shown in FIG. 1A, the fiber post 1 includes a plurality of light transmitting fibers 2 and a covering portion 3. The fiber post 1 has a substantially cylindrical shape extending in a predetermined direction. The fiber post 1 includes an incident end face 1A which is an end face in a predetermined direction, an outgoing end face 1B which is the other end face in a predetermined direction, and a circumferential surface 1C located between the incident end face 1A and the outgoing end face 1B. The dimensions of the fiber post 1 in the predetermined direction (longitudinal direction) are, for example, 10 mm or more and 30 mm or less. The outer diameter of the fiber post 1 is, for example, 0.5 mm or more and 3.0 mm or less.

(1) Light Transmissible Fiber As shown in FIGS. 2A and 2B, the light transmissive fiber 2 has a substantially cylindrical shape extending in a predetermined direction. The light transmitting fiber 2 is configured to be able to transmit light in a predetermined direction. The material of the light transmitting fiber 2 is a material capable of transmitting light, and examples thereof include glass and a transparent resin material. The material of the light transmitting fiber 2 can be used alone or in combination of two or more.

  Examples of the glass include single component glass, multicomponent glass and the like.

As a single component glass, quartz glass etc. are mentioned, for example. As multicomponent glass, for example, soda lime silica glass (for example, SiO ₂ -Al ₂ O ₃ -CaO-Na ₂ O), borosilicate glass (for example, SiO ₂ -B ₂ O ₃ -Al ₂ O ₃ -Na) _{2 O, SiO 2 -B 2 O} 3 -Al 2 O 3 -CaO, E glass, C glass), barium glass _{(e.g., SiO 2 -B 2 O 3 -BaO} -Al 2 O 3, SiO 2 -B ₂ O ₃ -BaO-ZnO, etc., lanthanum glass (eg, SiO ₂ -Al ₂ O ₃ -ZrO ₂ -P ₂ O ₅ -La ₂ O ₃ -Li ₂ O-K ₂ O), zirconium glass (eg, and _{SiO 2 -ZnO-La 2 O 3} -Al 2 O 3 -BaO-B 2 O 3 -Li 2 O-K 2 O-ZrO 2 -CaO), strontium glass (eg _If, like _{SiO 2 -B 2 O 3 -Al 2} O 3 -SrO), fluoroaluminosilicate glass _{(e.g., SiO 2 -Al 2 O 3 -F-} CaO-P 2 O 5 -Na 2 O), alumino Silicate glass etc. are mentioned. Glass can be used alone or in combination of two or more.

  As a transparent resin material, polyolefin, a polycarbonate, an acrylic resin, polyamide (for example, nylon etc.) etc. are mentioned, for example. Such transparent resin materials can be used alone or in combination of two or more.

  The material of such a light transmitting fiber 2 preferably contains a contrast component containing an element of the 5th period of the periodic table or the 6th period of the periodic table. The periodic table conforms to the IUPAC Periodic Table of the Elements (version dated 28 November 2016). The contrast component is, for example, an oxide of an element of the fifth period of the periodic table or the sixth period of the periodic table.

  If the material of the light transmitting fiber 2 contains a contrast component, it is possible to improve the radiopaque properties of the light transmitting fiber 2.

  As an element which an imaging | photography component contains, Preferably, Ba, La, and Zr are mentioned, More preferably, Ba is mentioned.

  The content ratio of the contrast component is, for example, 0.5% by mass or more, preferably 10% by mass or more, for example, 60% by mass or less, based on the total amount of the light transmitting fiber 2.

  Among such light transmitting fiber 2 materials, preferably, glass is mentioned, more preferably, multicomponent glass is mentioned, and particularly preferably, multicomponent glass containing the above-mentioned contrast component (specifically, Are barium glass, lanthanum glass, zirconium glass, strontium glass).

  When the material of the light transmitting fiber 2 contains glass, the bending strength of the fiber post 1 can be surely improved while the improvement of the transmission amount of light by the fiber post 1 can be surely achieved.

  Such a light transmitting fiber 2 may be composed of a single layer or a plurality of layers, but is preferably composed of a plurality of layers.

  In the first embodiment, the material of the light transmitting fiber 2 is the optical fiber including the above glass, more specifically, the light transmitting fiber 2 includes the core layer 2A and the cladding layer 2B covering the core layer 2A. .

  The core layer 2A has a refractive index larger than that of the cladding layer 2B. Core layer 2A preferably contains the above-described contrast component. As a material of the core layer 2A, for example, multicomponent glass (specifically, barium glass, lanthanum glass, zirconium glass, strontium glass) containing the above-mentioned contrast component is mentioned, and preferably, barium glass is mentioned.

When the material of the core layer 2A is a multicomponent glass containing the above contrast component, the content ratio of SiO _{2 in} the multicomponent glass is, for example, 10% by mass or more, preferably 20% by mass or more, for example, 80% % Or less, preferably 70% by mass or less, and the content ratio of the contrast component in the multicomponent glass is, for example, 5% by mass or more, preferably 20% by mass or more, for example, 60% by mass or less, preferably It is 50 mass% or less.

  The cladding layer 2B may contain the above-mentioned contrast component, but preferably does not contain the above-mentioned contrast component. As a material of cladding layer 2B, the above-mentioned multicomponent glass is mentioned, for example, Preferably, borosilicate glass is mentioned.

When the material of the cladding layer 2B is the above multicomponent glass, the content ratio of SiO _{2 in} the multicomponent glass is, for example, 20% by mass or more, preferably 30% by mass or more, for example, 80% by mass or less, preferably Is 75 mass% or less.

  Also, the dimension of the light transmitting fiber 2 in the predetermined direction (longitudinal direction) is, for example, the dimension in the longitudinal direction of the fiber post 1 or more, and preferably, the dimension in the longitudinal direction of the fiber post 1 However, one end face of the light transmitting fiber 2 shorter than the dimension in the longitudinal direction of the fiber post 1 may be exposed from the circumferential surface 1C of the fiber post 1. Specifically, the dimension of the light transmitting fiber 2 in the longitudinal direction is, for example, 1 mm or more and 30 mm or less.

  In the first embodiment, as shown in FIGS. 1A and 1B, one end surface of the light transmitting fiber 2 is exposed from the incident end surface 1A of the fiber post 1. The other end face of the light transmitting fiber 2 is exposed from the emitting end face 1 B of the fiber post 1.

  The outer diameter of the light transmitting fiber 2 (each of the plurality of light transmitting fibers 2) is 25 μm or more, preferably 30 μm or more and 100 μm or less, preferably 90 μm or less, more preferably 80 μm or less, particularly preferably It is 70 μm or less, particularly preferably 50 μm or less.

  If the outer diameter of the light transmitting fiber 2 is equal to or more than the above lower limit, the transmission amount of light in the fiber post 1 can be improved. If the outer diameter of the light transmitting fiber 2 is equal to or less than the above upper limit, the bending strength of the fiber post 1 can be improved.

  In addition, the light transmitting fiber 2 may be surface-treated with a known silane coupling agent, if necessary, and a polymerizable monomer having an acidic group (for example, a carboxy group, a phosphoric acid group, a sulfo group, etc.) It may be surface-treated.

A plurality of such light transmitting fibers 2 are provided in the fiber post 1. The sum of the cross-sectional areas of a cutaway of the each of the plurality of light transmitting fiber 2 in a direction perpendicular to the predetermined direction (the length direction of the fiber post 1), 0.10 mm ² or more, preferably, 0.12 mm ² or more More preferably, it is 0.13 mm ² or more, for example, 0.30 mm ² or less, preferably 0.25 mm ² or less.

  Sum of cross-sectional areas when cutting each of the plurality of light transmitting fibers 2 in a direction (hereinafter, referred to as radial direction) orthogonal to the predetermined direction (hereinafter, total of cross-sectional areas of the plurality of light transmitting fibers 2 If the above lower limit is exceeded, it is possible to improve the bending strength of the fiber post 1 while improving the transmission of light by the fiber post 1.

  The ratio of the sum of the cross-sectional areas of the plurality of light transmitting fibers 2 is, for example, 5% or more, preferably, when the area of the cut surface when the fiber post 1 is cut in the radial direction is 100%. 10% or more, for example, 40% or less, preferably 30% or less.

  The number of the plurality of light transmitting fibers 2 is, for example, 5 or more, preferably 10 or more, more preferably 20 or more, particularly preferably 100 or more, particularly preferably 150 or more, for example, The number is 500 or less, preferably 300 or less.

  In the first embodiment, all of the plurality of light transmitting fibers 2 are bundled to form a light transmitting fiber bundle 14. That is, the fiber post 1 includes the light transmitting fiber bundle 14 in which all of the plurality of light transmitting fibers 2 are bundled. In the light transmitting fiber bundle 14, the plurality of light transmitting fibers 2 may be twisted together, may not be twisted together, or may be only partially twisted.

  When the fiber post 1 includes the light transmitting fiber bundle 14, the bending strength of the fiber post 1 can be reliably improved.

  The light transmitting fiber bundle 14 is disposed so as not to be exposed from the circumferential surface 1C of the fiber post 1. The light transmitting fiber bundle 14 is preferably located at a substantially central portion in a cross section of the fiber post 1 cut in the radial direction. More specifically, the light transmitting fiber bundle 14 is arranged to overlap the central axis of the fiber post 1.

(2) Covering part The covering part 3 is all or at least a part of the circumferential surface of each of the plurality of light transmitting fibers 2 such that one end surface and the other end surface of each of the plurality of light transmitting fibers 2 are exposed. Cover. In the first embodiment, the covering portion 3 covers the entire peripheral surface of the light transmitting fiber bundle 14 such that one end surface and the other end surface of the light transmitting fiber bundle 14 are exposed. The thickness of the covering portion 3 (dimension between the light transmitting fiber bundle 14 and the circumferential surface of the covering portion 3 in the radial direction) is, for example, 100 μm or more, preferably 150 μm or more, for example, 700 μm or less, preferably 650 μm It is below. Moreover, the coating | coated part 3 is equipped with several fibers and an organic matrix.

(2-1) Fiber A plurality of fibers are wound around the light transmitting fiber bundle 14. Preferably, the plurality of fibers are braided and wound around the light transmitting fiber bundle 14. Examples of fibers include organic fibers and inorganic fibers. The fibers can be used alone or in combination of two or more.

  Examples of organic fibers include acrylic fibers, acetate fibers, copper ammonia fibers, polyamide fibers, polyamideimide fibers, polyimide fibers, cellulose fibers, polyvinylidene fibers, vinylon fibers, fluorocarbon resin fibers, polyacetal fibers, polyurethane fibers, polyolefin fibers, poly A vinyl chloride fiber etc. are mentioned. The organic fibers can be used alone or in combination of two or more.

  As an inorganic fiber, carbon fiber, ceramic fiber, glass fiber etc. are mentioned, for example. The inorganic fibers can be used alone or in combination of two or more.

  Among such fibers, preferably, inorganic fibers are mentioned, and more preferably, glass fibers are mentioned. As a material of glass fiber, the above-mentioned glass is mentioned, for example, Preferably, borosilicate glass is mentioned, More preferably, E glass is mentioned.

  The outer diameter of such a fiber is, for example, 1 μm or more, preferably 3 μm or more, for example, 30 μm or less, preferably 15 μm or less.

(2-2) Organic Matrix The organic matrix is impregnated with a plurality of fibers. The organic matrix is in contact with at least a portion of the circumference of each of the plurality of light transmitting fibers 2. The organic matrix is a polymer of polymerizable monomers.

  As a polymerizable monomer, the polymerizable monomer which has an ethylenically unsaturated double bond is mentioned, for example, Preferably, (meth) acrylate is mentioned. In addition, (meth) acrylate contains a methacrylate and / or an acrylate.

  As (meth) acrylates, for example, monofunctional (meth) acrylate having one (meth) acryloyl group, bifunctional (meth) acrylate having two (meth) acryloyl groups, three having three (meth) acryloyl groups Functional (meth) acrylates and the like can be mentioned. The (meth) acrylates can be used alone or in combination of two or more.

  Examples of monofunctional (meth) acrylates include alkyl mono (meth) acrylates (eg methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate etc.), hydroxyl group containing mono (meth) acrylates (eg 2) -Hydroxyethyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, dihydroxypropyl mono (meth) acrylate etc., polyoxyalkylene mono (meth) acrylate (eg polyethylene glycol mono (meth) acrylate, polypropylene glycol mono ( (Meth) acrylate etc.), aryl mono (meth) acrylates (eg benzyl (meth) acrylate etc), carboxy group-containing mono (meth) acrylates (eg 11- (methacryloyl) C) Undecane-1,1-dicarboxylic acid, 4-[[2- (methacryloyloxy) ethoxy] carbonyl] phthalic acid, etc., phosphoric acid group-containing mono (meth) acrylate (eg, 10-methacryloyloxydecyl dihydrogen) A phosphate, phosphoric acid (2-methacryloyl oxyethyl) phenyl etc., etc. are mentioned. Monofunctional (meth) acrylates can be used alone or in combination of two or more.

  Examples of difunctional (meth) acrylates include alkylene di (meth) acrylates (eg, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, butanediol di (meth) acrylate, etc.), hydroxyl group-containing di (meth) acrylate, etc. ) Acrylate (eg, 1,2-bis [3- (meth) acryloyloxy-2-hydroxypropoxy] ethane, pentaerythritol di (meth) acrylate, etc.), urethane di (meth) acrylate having a urethane bond (eg, [2 , 2,4-trimethylhexamethylene bis (2-carbamoyloxyethyl)] dimethacrylate etc., oxyalkylene di (meth) acrylates (eg ethylene glycol di (meth) acrylate etc), aromatic ring-containing di (meth) acrylates Rate (e.g., ethoxylated bisphenol A di (meth) acrylate, bisphenol A diglycidyl (meth) acrylate), and the like. The bifunctional (meth) acrylates can be used alone or in combination of two or more.

  Examples of trifunctional (meth) acrylates include isocyanurate tri (meth) acrylates having an isocyanurate ring, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate and the like. The trifunctional (meth) acrylates can be used alone or in combination of two or more.

  Among (meth) acrylates, preferably, difunctional (meth) acrylates are mentioned, and more preferably, urethane dimethacrylates are mentioned.

  The content ratio of the organic matrix is, for example, 10 parts by mass or more, preferably 15 parts by mass or more, for example, 50 parts by mass or less, preferably 40 parts by mass or less with respect to 100 parts by mass of the fibers.

(3) Method of Manufacturing Fiber Post In order to manufacture such a fiber post 1, first, a plurality of light transmitting fibers 2 are prepared. Then, the plurality of light transmitting fibers 2 are bundled, and if necessary, are twisted to prepare the light transmitting fiber bundle 14.

  Then, the above-mentioned fibers are wound around the light transmitting fiber bundle 14. Thereafter, the polymerizable monomer described above is impregnated into the fiber wound around the light transmitting fiber bundle 14. Then, the polymerizable monomer impregnated in the fiber is cured by a known method (such as heat curing or ultraviolet curing) to prepare an organic matrix.

  Thus, the fiber post 1 is manufactured.

  The fiber post 1 has excellent light transmission and rigidity.

  The flexural modulus of the fiber post 1 is, for example, 10 GPa or more, preferably 15 GPa or more, for example 50 GPa or less, preferably 40 GPa or less. The flexural modulus can be measured by a two-point bending test or a three-point bending test.

  The bending strength of the fiber post 1 is, for example, 300 MPa or more, preferably 400 MPa or more, more preferably 500 MPa or more, for example, 2000 MPa or less, preferably 1500 MPa or less. The bending strength can be measured according to the method described in the examples.

(4) Use mode of fiber post Such a fiber post 1 can be suitably used for construction of an abutment in dental treatment. Hereinafter, with reference to FIG. 3, the construction of the abutment using the fiber post 1 will be described.

  In the construction of the abutment, first, the root canal 11 is ground so that the post-myelination root canal 11 allows the insertion of the fiber post 1. Thereafter, the root canal 11 is filled with the photocurable resin agent 12 before curing.

  Next, the fiber post 1 is inserted into the root canal 11 so that the incident end face 1A of the fiber post 1 is located above the tooth 10 and the exit end face 1B of the fiber post 1 is located at the deep portion of the root canal 11. Then, light is irradiated from the upper side to the incident end face 1A by a known light irradiator. At this time, light is incident from the incident end face 1A, transmitted by the light transmitting fiber 2 of the fiber post 1, and then emitted from the emission end face 1B.

  Thereby, light is irradiated to the photocurable resin agent 12 located in the deep part of the root canal 11, and the photocurable resin agent 12 is hardened. Therefore, the fiber post 1 is fixed to the tooth 10. After that, around the fiber post 1 located above the tooth 10, the abutment 15 is built with the core resin 13.

(5) Effects and Effects As shown in FIGS. 1A and 1B, the fiber post 1 includes a plurality of light transmitting fibers 2. The outer diameter of each of the plurality of light transmitting fibers 2 is in the above range, and the sum of the cross sectional areas of the plurality of light transmitting fibers 2 is equal to or more than the above lower limit.

  However, when the outer diameter of each light transmitting fiber 2 is less than the above lower limit, there is a limit to improve the transmission amount of light, and when the outer diameter of each light transmitting fiber 2 exceeds the above upper limit, It is difficult to achieve both excellent light transmission and bending strength. In addition, even when the outer diameter of each light transmitting fiber 2 is in the above range, it may not be possible to achieve both excellent light transmission amount and bending strength.

  On the other hand, in the fiber post 1, the outer diameter of each light transmitting fiber 2 is in the above range, and the sum of the cross sectional areas of the plurality of light transmitting fibers 2 is not less than the above lower limit. Bending strength can be improved while improvement can be made.

Second Embodiment
Next, a fiber post 20 according to a second embodiment of the present invention will be described with reference to FIGS. 4A and 4B. In the second embodiment, the same members as those in the first embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted.

  In the first embodiment, as shown in FIG. 1A, the covering 3 comprises fibers and an organic matrix, but the covering 3 is not limited thereto.

  In the second embodiment, as shown in FIGS. 4A and 4B, the covering portion 21 does not include fibers, and is made of an organic matrix.

  According to the second embodiment, the same function and effect as those of the first embodiment can be obtained.

Third Embodiment
Next, a fiber post 22 according to a third embodiment of the present invention will be described with reference to FIGS. 5A and 5B. In the third embodiment, the same members as those in the first embodiment and the second embodiment described above are denoted by the same reference numerals, and the description thereof will be omitted.

  In the first embodiment and the second embodiment, as shown in FIG. 2A, the plurality of light transmitting fibers 2 are configured as the light transmitting fiber bundle 14, but the plurality of light transmitting fibers 2 is limited thereto. I will not.

  In the third embodiment, as shown in FIGS. 5A and 5B, the plurality of light transmitting fibers 2 are spaced apart from one another. The plurality of light transmitting fibers 2 are disposed so as not to be exposed from the circumferential surface 22C of the fiber post 1. The plurality of light transmitting fibers 2 are preferably distributed in a generally uniform manner in the cross section of the fiber post 22 cut in the radial direction.

In this third embodiment, the sum of the cross-sectional areas of the plurality of light transmitting fibers 2, 0.10 mm ² or more, preferably, 0.50 mm ² or more, for example, 1.5 mm ² or less, preferably, 1 .0 mm ² or less.

  The ratio of the sum of the cross-sectional areas of the plurality of light transmitting fibers 2 is, for example, 5% or more, preferably, when the area of the cut surface when the fiber post 22 is cut in the radial direction is 100%. 50% or more, for example, 90% or less, preferably 75% or less.

  Further, the number of the plurality of light transmitting fibers 2 is, for example, 5 or more, preferably 500 or more, for example, 3000 or less, preferably 2000 or less.

  According to such a third embodiment, it is possible to further improve the light transmission amount. Also in the third embodiment, the same function and effect as the first embodiment can be obtained.

<Modification>
In the first embodiment, the light transmitting fiber bundle 14 is disposed to overlap with the central axis of the fiber post 1, but the arrangement of the light transmitting fiber bundle 14 is not limited thereto. The light transmitting fiber bundle 14 may not overlap with the central axis of the fiber post 1 if it is not exposed from the circumferential surface 1C of the fiber post 1.

  In the first embodiment, all of the plurality of light transmitting fibers 2 are bundled to form the light transmitting fiber bundle 14, but the arrangement of the plurality of light transmitting fibers 2 is not limited thereto. A part of the plurality of light transmitting fibers 2 is bundled to form a light transmitting fiber bundle 14, and the other part of the plurality of light transmitting fibers 2 is disposed at a distance from the light transmitting fiber bundle 14 It may be done. Also, a plurality of light transmissive fiber bundles 14 may be spaced apart from one another.

  In the first embodiment, all of the plurality of light transmitting fibers 2 are optical fibers including the core layer 2A and the cladding layer 2B, but the type of the plurality of light transmitting fibers 2 is not limited thereto. A part of the plurality of light transmitting fibers 2 may be an optical fiber, and another part of the plurality of light transmitting fibers 2 may be a light transmitting fiber other than the optical fiber. Examples of light transmitting fibers other than optical fibers include organic fibers (light transmitting fibers 2 whose material is the above transparent resin material), inorganic fibers (the material is the above glass, and are composed of a single layer). Permeable fibers 2) can be mentioned.

  Each of the first embodiment, the second embodiment and the modification can be combined as appropriate.

Although an example is shown below and the present invention is explained still more concretely, the present invention is not limited to them. Specific numerical values such as blending ratios (content ratios), physical property values, parameters, etc. used in the following description are the blending ratios (content ratios) corresponding to those described in the above-mentioned "embodiments for carrying out the invention" ), Physical property values, parameters, etc. may be substituted for the upper limit (numerical values defined as “below”, “less than”) or lower limit (numerical values defined as “above”, “exceed”), etc. it can.
(Examples 1 and 2)
The number of optical fibers having the outer diameter (light transmitting fiber outer diameter) shown in Table 1 was prepared as shown in Table 1. The optical fiber comprises a core layer and a cladding layer, and the material of the core layer is barium glass (SiO ₂ -B ₂ O ₃ -BaO-ZnO), and the material of the cladding layer is borosilicate glass (SiO _2- it is a _{B 2 O 3 -Al 2 O 3} -CaO).

  Then, a plurality of optical fibers were bundled to prepare an optical fiber bundle. A plurality of glass fibers were then braided and wound around the optical fiber bundle. The glass fiber material is borosilicate glass (E glass).

  Then, a polymerizable monomer containing urethane dimethacrylate was impregnated into the glass fiber wound around the optical fiber bundle. Thereafter, the polymerizable monomers were thermally cured to prepare an organic matrix. This formed a coating comprising a plurality of glass fibers and an organic matrix.

The fiber post was obtained by the above. The outer diameter of the fiber post was 1.3 mm. The sum of the cross-sectional areas (total cross-sectional area of light transmitting fibers) when the plurality of optical fibers are cut in the radial direction is shown in Table 1.
(Example 3)
A fiber post is obtained in the same manner as in Example 1 except that the optical fiber is changed to the organic fiber having the outer diameter shown in Table 1 and the number of the organic fiber is changed to the number shown in Table 1. The The organic fiber was formed from a single layer, and the material of the organic fiber was polyamide (nylon).
(Example 4)
The covering portion is formed from an organic matrix (polymer of a polymerizable monomer containing urethane dimethacrylate) without using glass fiber, and a plurality of optical fibers are substantially uniform in cross section when the fiber post is cut in the radial direction. A fiber post was obtained in the same manner as in Example 1 except that the distribution was made overall to be (see FIGS. 5A and 5B).
(Comparative Examples 1 and 2)
A fiber post is prepared in the same manner as in Example 3, except that the organic fiber is changed to an organic fiber having an outer diameter shown in Table 2 and the number of organic fibers is changed to the number shown in Table 2. I got The total of the cross-sectional areas (total fiber cross-sectional area) when the plurality of optical fibers are cut in the radial direction is shown in Table 2.
(Comparative example 3)
A fiber post was obtained in the same manner as Example 3, except that the optical fiber was changed to an inorganic fiber having an outer diameter shown in Table 2. The inorganic fiber was formed from a single layer, and the material of the inorganic fiber was aluminosilicate glass.
(Comparative example 4)
A fiber post was obtained in the same manner as in Example 1, except that the optical fiber was changed to an optical fiber having an outer diameter shown in Table 2 and that the number of optical fibers was changed to the number shown in Table 2.
<Evaluation>
(Light transmission test)
The fiber post obtained in each Example and each Comparative Example was cut into a length of 18 mm and set in the test container 30 shown in FIG.

  Specifically, the test container 30 includes a container body 31 and a lid 32. The container body 31 has a substantially box shape opened upward. The container body 31 is filled with a photocurable resin (trade name: i-TFC Post Resin, manufactured by Sun Medical Co., Ltd.). The lid 32 closes the upper end of the container body 31. The lid 32 has an opening 33. The inner diameter of the opening 33 is substantially the same as the outer diameter of the fiber post.

  Then, the fiber post was inserted into the opening 33 of the lid 32 so that the incident end face of the fiber post was flush with the upper surface of the lid 32. The fiber post was disposed along the vertical direction.

  Then, light was irradiated for 20 seconds from the upper side with respect to the incident end face by a light irradiator 34 (trade name: Pencure 2000, manufactured by Morita Co., Ltd.).

And based on the length of the photocurable resin agent hardened | cured from the output end surface of a fiber post to the downward side in the orthogonal | vertical direction, the light transmittance of the fiber post was evaluated as follows. The results are shown in Tables 1 and 2.
A: 3 mm or more.
B: 2 mm or more and less than 3 mm.
C: 1 mm or more and less than 2 mm.
D: less than 1 mm.

(Bending strength measurement)
The fiber post of each example and each comparative example was subjected to a precision universal testing machine (trade name: Autograph AG-IS, manufactured by Shimadzu Corporation), and 3 at a distance between supporting points of 10 mm and a crosshead speed of 1.0 mm / min. The point bending test was implemented 5 times, and the average value was calculated. The results are shown in Tables 1 and 2.

In addition, it is desired that the dental fiber post has excellent bending strength against external stress, and if the bending strength is 500 MPa or more, it is suitable as a dental fiber post.
(X-ray contrast evaluation)
The X-ray contrast property of the fiber post of each Example and each Comparative Example was measured using a tabletop X-ray examination apparatus (trade name: μB1300-LFT60, manufactured by Matsuda Precision Co., Ltd.) under the conditions of a tube voltage 55 kV and a tube current 180 μA. It was measured. Using a photographed image of an aluminum step having a thickness dimension of 1 to 10 mm, a calibration curve was created with shading that reflected the X-ray transmittance by each thickness dimension. Similarly, using the photographed image of the fiber post of each example and each comparative example, the density of the radial center position in the fiber post was compared with the density of the aluminum step having each thickness. And the radiography contrast property of the fiber post of each Example and each comparative example was evaluated by each thickness equivalent of an aluminum step. The results are shown in Tables 1 and 2.

1 fiber post 2 light transmitting fiber 2A core layer 2B clad layer 14 light transmitting fiber bundle 20 fiber post 22 fiber post

Claims (5)

A plurality of light transmitting fibers extending in a predetermined direction;
The outer diameter of each of the plurality of light transmitting fibers is 25 μm or more and 100 μm or less,
A dental fiber post, characterized in that a total cross-sectional area when each of the plurality of light transmitting fibers is cut in a direction orthogonal to the predetermined direction is 0.10 mm ² or more.   The dental fiber post according to claim 1, wherein the material of each of the plurality of light transmitting fibers comprises glass.   The dental fiber post according to claim 2, wherein the plurality of light transmitting fibers include an optical fiber including a core layer and a cladding layer covering the core layer.   The dental fiber according to any one of claims 1 to 3, wherein the material of the light transmitting fiber includes a contrast component containing an element of the fifth period of the periodic table or the sixth period of the periodic table. post. A light transmissive fiber bundle in which all of the plurality of light transmissive fibers are bundled;
The said light transmissive fiber bundle is located in a substantially center part in the cross section when the said dental fiber post is cut | disconnected in the said orthogonal direction, It is characterized by the above-mentioned. Dental fiber post.

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