JP6222803B2 - Dental post - Google Patents

Description

  The present invention relates to a dental post that fills the root canal of a tooth after pulpectomy (pulping).

Pulpitis occurs due to the progress of caries. The fundamental treatment is to remove (pulp) the infected pulp and fill it with root canal filling material.
As shown in FIG. 1, the outer shape of a tooth is formed by a hard tissue 20 such as enamel, dentin, cementum, and a root canal 31 that is a cavity inside the tooth has a pulp. There is a periapical hole 32 at the tip of the root canal, and this is a hole at the tip of the root of the tooth for nerves and blood vessels in the pulp to conduct outside the tooth. The periphery of the apical hole is constituted by apical periodontal tissue. In the conventional treatment of pulpitis, first, after the operator cuts and removes the affected crown 21, the infected pulp in the root canal is removed, and the root canal is enlarged to an appropriate size with a needle-shaped file. To do. The surgeon fills the enlarged root canal with root canal filler and closes the apical foramen. At that time, the sealer may be filled in a gap formed between the root canal filling material and the root canal wall. By the above process, the infection route from the oral cavity to the periapical periodontal tissue through the root canal is blocked. At the same time, the tissue fluid of the apical periodontal tissue is also prevented from entering the root canal.
The root canal filling material or sealer used in this treatment should have a filling material such that the root canal wall and apical hole are tightly closed to prevent saliva and tissue fluid from entering, and apical periodontal tissue. For example, there are no adverse effects, low antigenicity, and disinfection and sterilization are possible. For this reason, a gutta percha made of a rubber material and zinc has been widely used. The gutta-percha point is thermoplastic and is widely used in dentistry as a root canal filling material because it can well seal the root canal and apical hole.
Some gutta-percha can seal the root canal only with solid filling material, but as an adhesive to be fixed, an adhesive that exhibits high adhesiveness to the tooth, so-called sealer, is used for sealing. By increasing, the invasion of bacteria due to marginal leakage can be prevented and secondary infection itself can be suppressed. By using such a sealer, it has become possible to use various materials such as materials with excellent material mechanical properties other than gutta percha as posts. In view of this, attempts have been made to use various materials and structures that satisfy the performance not satisfied by the gutter percha.

For example, simply sealing it is not sufficient for functional recovery as a tooth, and it is necessary to support a prosthesis such as a coated crown provided for repairing a crown defect part to withstand occlusal stress. A strong abutment structure is desired. Such root canal posts or dental posts have been considered.
As a material of the dental post, a metal material is used as shown in Patent Document 1. Metals have the advantage of having a robust strength and a very distinct X-ray contrast.
However, since it is extremely difficult to develop chemical adhesiveness with the tooth material etc., there is a risk of detachment, and the metal material can improve the adhesion by devising the shape of the screw etc. It is illustrated.
In addition, it has been pointed out that the metal material has a material mechanical property such as elastic modulus that is too different from that of the tooth, which may cause the remaining tooth to break.

On the other hand, with the improvement of the strength of the structure and the improvement of the retainability to the tooth structure, new problems relating to the re-root canal treatment have also occurred. In other words, once the treatment has been completed, if the root canal is not sufficiently cleaned and sterilized, or if secondary infection occurs in a portion of the root canal due to marginal leakage, the support including the root post is included. The entire base structure must be removed from the abutment and re-treated. However, when a high-strength metal material is used as the post, if the mechanical joint between the post and the tooth is strong, it is rather impossible to remove the post rather than say it is very difficult. It may be. Therefore, there are cases where it is necessary to remove the tooth, and often the effort to restore the crown is completely neglected.
In order to solve such a problem, as shown in Patent Document 2, by selecting a dental post whose elastic modulus is similar to the elastic modulus of a tooth, particularly dentin, stress on the tooth It is a way to avoid concentration. A fiber reinforced resin has been proposed as a material for such a root post.
Furthermore, since the resin material is easier to bend than metal, there is also an advantage that even a narrowly bent root canal is easy to enter.

Needless to say, the shape of the root canal of the teeth is very different, and it is difficult to see, and even the dental post as described above has a considerable skill to reach the apex. Often required. During root canal treatment, root canal enlargement is performed along with removal of the affected area and sterilization, so the above-mentioned difficulty may not be improved to some extent. In addition to the momentum, it has been found that the remaining amount of tooth significantly affects the strength and durability of the tooth after treatment, and thus the root canal enlargement has been required to be minimal. . Therefore, it has been required to be able to be easily inserted into a root canal that is almost thinly bent and to be pressurized and filled.
Moreover, since the X-ray contrast property is unclear in the resin material, there is a problem that the material deterioration occurs when an X-ray contrast agent such as barium sulfate is added. In order to overcome the above-mentioned problems, mixing aid mixing, miniaturization of contrast agent filler, surface modification, etc. have been studied so that they are uniformly mixed, but there are also problems such as labor and cost. I have it.

JP-A-56-136542 JP 5-505316 gazette

  The present inventor has made practical use of a root canal filling material having better stability, workability, disinfection, and robust material mechanical strength as an abutment building post than conventionally used root canal filling materials. As a result of various studies to be completed, the present invention has been completed, and the object of the present invention is to be easily sterilized and sterilized, physicochemically stable, low antigenicity, hardness enough to fill a curved root canal and thin root canal An object of the present invention is to provide a dental post that can be placed in a living body for a long period of time by a material that does not have a harmful effect on elasticity and periapical periodontal tissue and does not deteriorate, and that easily imparts X-ray contrast properties.

The above objects and advantages of the present invention are as follows.
A dental post having a hollow extending from one end to the other;
Less than or equal to the diameter of the posts is 1.9 mm, and / or, the hollow diameter Ri der than 1.4mm or less 0.1 mm, the same one of the diameter also over the other end from the one end and of said post diameter Is achieved by a dental post characterized by being at least 0.1 mm larger than the hollow diameter .

The above objects and advantages of the present invention are secondly,
A dental post having a hollow extending from one end to the other;
Both the diameter of the post and the diameter of the hollow are the same from the one end to the other end, and an axis parallel to the direction from the one end to the other end is defined as a parallel axis and a direction perpendicular thereto. As a vertical axis
The length ratio of the dental post in the parallel axis / vertical axis and / or the length ratio in the major axis / minor axis is 4 or more, and
Length in parallel axis and / or length in long axis is 4-40mm
It is achieved by a dental post characterized by having a shape that is

  In the present invention, since the dental post has a hollow extending from one end to the other end, compared to a post having no hollow, it is easy to compress and bend and deform smoothly when inserted into the root canal. The apex is reachable. Once the insertion of the hollow post is completed, the hollow inner wall is relatively smooth unlike the endodontic root canal, so that the operability is good, and then the hollow inside is filled with a sealer. Then, it may be solidified, or a post or a plurality of points thinner than the hollow may be inserted, and if necessary, a sealer may be further filled and cured.

It is explanatory drawing which fills a root canal with the post | mailbox of this invention. It is a cross-sectional view of another aspect of the post of the present invention. It is a cross-sectional view of another aspect of the post of the present invention. It is a cross-sectional view of another aspect of the post of the present invention. It is a conceptual diagram of the longitudinal cross-section of another aspect of the post | mailbox of this invention. It is a conceptual diagram of the longitudinal section which fills a root canal with the post of the present invention. It is a conceptual diagram of the longitudinal section which fills a root canal with the post of the present invention.

As shown in FIG. 1, the present invention has the following first and second inventions so that a post can be easily inserted even if the root canal is curved and thin.
The first invention of the present application is
A dental post having a hollow extending from one end to the other;
A dental post having a diameter of the post of 1.9 mm or less and / or a diameter of the hollow of 1.4 mm or less.
In addition, when the hollow is not cylindrical, the diameter of a circle obtained by deforming a non-circular cross section into a circular equivalent area may be calculated, and when the cross-sectional area is not constant from one end to the other, What is necessary is just to calculate the diameter of the circle | round | yen which deform | transformed the said hollow volume into the cylinder which makes the other end length from equal volume, and should just apply to the said hollow diameter. The same applies to the diameter of the post.

In the first invention of the present application,
The diameter of the post is 1.9 mm or less, and / or the hollow diameter is 1.4 mm or less,
Preferably, the diameter of the post is 1.5 mm or less and / or the hollow diameter is 1 mm or less,
More preferably, the diameter of the post is 1.3 mm or less and / or the diameter of the hollow is 0.5 mm or less.
If the diameter of the post exceeds the upper limit of the numerical range, it is too thick and it becomes difficult to smoothly insert the post into the root canal. Further, if the hollow diameter exceeds the upper limit of the numerical range, the diameter of the post increases in a form pushed by it, and as described above, it becomes unpreferable, the wall thickness of the hollow post becomes thin, and the strength is reduced. There is a risk that it will be lowered, or it will be greatly deformed due to slip resistance during insertion, making it difficult to insert or maintaining the smoothness of the inner surface.

In the first invention of the present application,
Preferably, the diameter of the post is 0.7 mm or more and / or the hollow diameter is 0.1 mm or more.
More preferably, the diameter of the post is 0.8 mm or more and / or the hollow diameter is 0.2 mm or more,
More preferably, the diameter of the post is 0.9 mm or more and / or the hollow diameter is 0.3 mm or more.
If the diameter of the post is below the lower limit of the numerical range, the gap between the root canal inner wall and the outer surface of the post is too large, and it is necessary to use many sealers, which is not preferable because it causes large polymerization shrinkage, The post ratio is lower than that of the sealer, and there is a possibility that excellent material mechanical properties of the post are difficult to be exhibited. If the hollow diameter is below the lower limit of the above numerical range, it will be easy to compress and bend in appearance when inserting a root canal, and the characteristics of being able to reach the root apex smoothly will not be sufficiently exhibited. It is.

  In the first invention, preferably, the diameter of the post is 0.1 mm or more larger than the diameter of the hollow. More preferably, it is 0.2 mm or more larger, and still more preferably 0.3 mm or more. If the value falls below the lower limit of the numerical range, the wall thickness of the hollow post is reduced, resulting in a decrease in strength, a large deformation due to slip resistance during insertion, and difficulty in insertion, or smoothing of the inner surface. There is a risk that it may be difficult to maintain the sex.

  In the case of the first invention, the length of the post is adjusted to be approximately equal to the length when actually embedded in the root canal, and after the excess is cut during the treatment, the length is finely adjusted. In this mode, the length is adjusted to many times, and it corresponds appropriately to the mode in which the amount of use is divided and finely adjusted again after inserting the root canal.

The second invention
A dental post having a hollow extending from one end to the other;
An axis parallel to the direction from the one end to the other end is defined as a parallel axis, and a direction perpendicular thereto is defined as a vertical axis.
The length ratio of the dental post in the parallel axis / vertical axis and / or the length ratio in the major axis / minor axis is 4 or more, and
Length in parallel axis and / or length in long axis is 4-40mm
A dental post characterized by having a shape of

In the case of the second invention, the length of the post is approximately equal to the length when it is actually embedded in the root canal, preferably slightly longer. It corresponds appropriately to a mode in which the length is finely adjusted.
In the case of the second invention,
The ratio of the length in the parallel axis / vertical axis and / or the ratio of the length in the major axis / minor axis is 4 or more. Preferably, the ratio of length in parallel axis / vertical axis and / or the ratio of length in major axis / minor axis is 7 or more, more preferably the ratio of length in parallel axis / vertical axis, And / or the ratio of the length in the major axis / minor axis is 9 or more. If the lower limit of the numerical range is not reached, the shape of the root canal is not suitable. In the case of the second invention, it is preferable that the parallel axis and the long axis, and the vertical axis and the short axis respectively coincide. In addition, if the post is a hollow cylindrical shape having a parallel axis or a long axis as a rotation axis, the length of the corresponding vertical axis or short axis is uniquely determined, but the outer shape is non-cylindrical (the cross section is elliptical). Shape, a truncated cone that tapers in the long axis direction, etc.), the outer shape (assuming that it is hollow) is transformed into a cylinder with the same length as the parallel axis or the length of the long axis. In this case, the diameter of the cylinder is the length of the corresponding vertical axis or short axis.

  Moreover, in the case of 2nd invention, the length in a parallel axis and / or the length in a long axis are 4-40 mm. Preferably, the length on the parallel axis and / or the length on the long axis is 8-25 mm, more preferably the length on the parallel axis and / or the length on the long axis is 12-20 mm. is there. If the value falls below the lower limit of the numerical range, the length of the dental post may be inconvenient and may be inconvenient. If the value exceeds the upper limit, the length is substantially equal to the length when actually embedded in the root canal. In addition, the use form in which the length is finely adjusted by cutting off the excess during the treatment is problematic.

  In the case of the second invention, preferably, the ratio of the length in the parallel axis / vertical axis and / or the ratio of the length in the major axis / minor axis is 30 or less. More preferably, the ratio of the length in the parallel axis / vertical axis and / or the ratio of the length in the major axis / minor axis is 20 or less, more preferably the ratio of the length in the parallel axis / vertical axis And / or the ratio of the length in the major axis / minor axis is 13 or less. If the upper limit of the numerical range is exceeded, there is a fear that the shape of the root canal is not suitable.

The length of the post is approximately equal to the length when it is actually embedded in the root canal, preferably a little longer, and cut the excess during the treatment to fine-tune the length. in an embodiment, the posts Ru Oh substantially cylindrical shape.
This is later described from, unless otherwise stated, as a rule, is a common matter to the first invention and the second invention.

The angle of the post of the present invention that can be bent without breakage per 10 mm is preferably 10 degrees or more, more preferably 15 degrees or more, still more preferably 90 degrees or more, particularly preferably when the straight line state is 0 degree. It is 180 degrees or more. Below the lower limit of the numerical range, it becomes difficult to insert into a curved root canal.
However, if it is too easy to be deformed, it is still difficult to insert it into the root canal. Therefore, the pressure at which the post of the present invention is bent and deformed by 90 degrees or more is preferably 3 gf / more, More preferably, it is 15 gf / line or more, More preferably, it is 50 gf / line or more, Most preferably, it is 150 gf / line or more.

  In the hollow post of the present invention, it is preferable that the hollow portion is positioned substantially at the center of the post so that a local weak portion or the like cannot be formed, and the number of hollow portions is preferably one per post.

As shown in FIG. 2 in a range where the strength does not decrease or the sliding resistance at the time of insertion greatly deforms and it becomes difficult to insert and it is difficult to maintain the smoothness of the inner surface. As described above, a side hole or a side tube such as the inner / outer connecting tube hole 13a that communicates between the outside of the post side surface and the hollow may be provided. In order not to cause the above problem, the diameter of the side hole is preferably 200 μm or less, more preferably 10 μm or less, still more preferably 1 μm or less, and / or 50% or less, more preferably 10%, of the diameter of the hollow post. In the following, it is more preferably 2% or less, and the porosity of the post wall due to side holes or the like (excluding the central hollow portion) is preferably 50% or less, more preferably 10% or less, and further preferably 2%. It is as follows. The porosity can be measured by embedding or impregnating with a resin or the like and then observing the cross section with an optical microscope or an electron microscope, but under conditions close to the state when actually inserted into the root canal as much as possible. It is preferable to measure. For example, if the post is expanded and inserted into the root canal by applying pressure to the hollow portion, it is reasonable to measure the porosity in such a state. As shown in FIG. 2, in addition to the inner and outer communication tube holes, the blind wall holes 13b and 13b ′ having dead ends on the way to the inner wall surface of the hollow portion and / or the outer wall surface of the post, A branch pipe system 13d which is in the form of one of the outer wall of the post, return pipe holes 13c and 13c ', or an internal / external communication pipe hole, a blind pipe hole or a return pipe hole, and has a branch of the pipe inside, and further a branch pipe There may be a perforated tube system 13e having three or more holes.

As described above, a network structure having an excessively high porosity is not preferable, but even if the porosity is not high, the intersections of the networks are not substantially bonded, and the form of a slidable woven fabric is greatly deformed. It is easy and not preferable.
As the post form, not only a single-phase resin matrix, but also, for example, dispersed fibers, mesh fibers, entangled fibers, woven fabric fibers, nonwoven fabric fibers, etc. may be used as needed. It may be impregnated, but if the fiber is exposed on the outer surface and / or inner surface of the post, it is not preferable because it causes sliding friction with the inner wall of the root canal and the hollow filling, Therefore, the number of exposed fibers per post length is preferably 100 fibers / cm or less, more preferably 10 fibers / cm or less, still more preferably 3 fibers / cm or less, on the outer surface of the post (the inner surface of the hollow part is the same), and / or Alternatively, the diameter of the exposed fiber is preferably 500 μm or less, more preferably 100 μm or less, still more preferably 30 μm or less, and / or the exposure degree of the exposed fiber is the circumferential angle of the fiber Is preferably 180 degrees or less, more preferably 60 degrees or less, still more preferably 30 degrees or less, and / or the area in which the fibers occupy the hollow inner wall area is preferably 50% or less, more preferably 10% or less. More preferably, it is 3% or less.

  Alternatively, as shown in FIGS. 3 and 4, a cut is made between the outside of the post side surface and the hollow in the radial direction or in a diagonal direction with respect to the radial direction over substantially the entire length of the post or hollow. As long as there is no external force due to the elastic restoring force, the cut may have cut portions 14 and 14 ′ that are sealed. Further, the cut portion may be substantially balanced with respect to the hollow, may be oblique, or may be wound with a spiral. There is no problem with the cut portion even if the fiber is exposed beyond the above numerical range.

  In the post having a hollow according to the present invention, the hollow portion may be electrically connected from one end to the other end without any obstacle, but as shown in FIG. A plug 15 may be provided for the purpose of sealing the hole. If the plug is detachable, it is impossible to make a fine adjustment again after inserting the root canal after the post has been adjusted to a length many times longer than the length when it is actually embedded in the root canal. It is applicable. Further, a vent 16 for deaeration or liquid removal may be provided in the vicinity of the plug or the vicinity thereof. However, since the characteristic that it can be smoothly inserted into a curved thin root canal is reduced if the plug substantially lacking in the hollow is long, as the tip shape, the outer diameter is 90% or more of the post average outer diameter, In addition, it is not preferable that the length of the hollow portion or the portion where the inner diameter of the hole is 10% or less of the post average inner diameter is 5 mm or more. The lower limit of the outer diameter is more preferably 80%, still more preferably 70%. Further, the lower limit of the hollow inner diameter is more preferably 20%, and further preferably 30%. The lower limit of the length is more preferably 2 mm, and still more preferably 1 mm.

Although the usage example of the post | mailbox of this invention is illustrated below, it is not limited to this at all.
First, the tooth to be treated is extracted and the root canal is expanded with a reamer or the like. However, in order to maintain the strength of the tooth wall, root canal enlargement is kept to a minimum. Next, the formed root canal is sterilized with a hypochlorous acid-based disinfectant solution, washed with water, water is removed with an air gun or a paper point, and the adhesiveness is improved as necessary. The tooth surface is etched or primed. Further, before the hollow post is inserted, the root canal is applied or filled as necessary with an adhesive containing a polymerizable monomer as a sealer. When the preparation is completed, the post of the present invention is inserted into the root canal toward the apex. At this time, the hollow portion of the post may not be filled with anything, or may be filled with a polymerizable monomer having uncured fluidity or a solvent thereof. In consideration of later air venting, a filler other than gas may be included in advance. However, at this point, it is still better not to put a rigid body that substantially impairs the stretchability of the hollow portion of the hollow dental post. The rigid body does not substantially compressively deform even when an external force is applied. For example, the rigid body has a compressive deformability equal to or smaller than the material constituting the post. The rigid body that substantially hinders the stretchability by the hollow portion has a shape having a short diameter approximately equal to the inner diameter of the hollow portion and / or a long diameter approximately equal to the length of the post. Therefore, as a rigid body that does not substantially impair the stretchability due to the hollow portion, the minor axis is preferably 100% or less, more preferably 30% or less, still more preferably 10% or less, and / or the inner diameter of the hollow portion. The major axis is preferably 50% or less, more preferably 10% or less, and still more preferably 5% or less of the length of the post. If nothing is filled in the hollow part, after inserting a post having a hollow part into the root canal, the opening of the injection pipe having a smaller outer diameter than the hollow part is brought to the tip of the root canal, Sealers may be injected from there. After the injection, the pipe may be pulled out or embedded as it is.

  Thereafter, the already filled polymerizable monomer may be polymerized, and as shown in FIG. 6, a substantially cylindrical shape or a substantially conical shape (table ) A post having a substantially cylindrical cone (trapezoid) shape may be inserted, or a plurality of substantially conical point 40 (gutter percha point, accessory point, silver point) may be inserted. As a result, not only the apical hole is sealed, but also the function of supporting the occlusal force as the abutment structure is exhibited, and this function of the post of the present invention can be assisted. Therefore, if these auxiliary functions are sufficient, the post of the present invention may have no problem of having an occlusal force support function in some cases. Moreover, you may fill with a small diameter filler with a fluid filler. In any case, it is possible to work easily with less frictional resistance than directly inserting and filling the root canal without a hollow post.

Further, as shown in FIG. 7, a ring-shaped sleeve 41 having an inner diameter capable of tightly circumscribing the post is disposed in the vicinity of the outer periphery of the post, so that a substantially inverted truncated cone-shaped root canal It is possible to make up for the lack of post volume.
Furthermore, the radiopacity imparting agent may be contained in the dental post material of the present invention, but may be contained in a material inserted into or filled in the hollow portion. Inclusion of the imparting agent in the material of the dental post is necessary to solve the extremely difficult polymer material molding technical problem of uniformly mixing and molding materials having extremely different specific gravities. Even if it can be successfully molded, the material properties are often inferior compared to non-containing products. Therefore, it is preferable to fill the hollow portion of the dental post having a hollow of the present invention with a fluid filler containing the imparting agent.

  Radiopacifiers are known in the art such as, for example, calcium, barium, bismuth, magnesium, and rare earth metals of atomic number 58-71 or their oxides, carbonates, fluorides or nitrates. Things are included. These radiopacity imparting agents may be used alone or in combination.

Preferred radiopacifiers include, for example, barium, bismuth, lanthanum, hafnium, strontium, tantalum, ytterbium, yttrium, zirconium or zinc oxides, carbonates, nitrates or fluorides, more preferred X-rays. Impermeability imparting agents include barium, lanthanum, strontium, ytterbium or tantalum oxides, carbonates or fluorides.
More specifically, particularly preferable radiopaque imparting agents include, for example, BaO, (BiO) ₂ CO ₃ , La ₂ O ₃ , La ₂ (CO ₃ ) ₃ , SrO, SrCO ₃ , SrF ₂ , Ta _2. Examples thereof include O ₅ , TaF ₅ , Y ₂ O ₃ , YF ₃ , ZnO, ZrO, and ZrCO ₃ . Among these, particularly preferred radiopaque imparting agents include ytterbium fluoride and bismuth subcarbonate.

As the filler, for example, various inorganic, organic, or inorganic / organic composite fillers conventionally used can be used. Specific examples thereof include silicon dioxide (for example, quartz, quartz glass, silica gel) and alumina. Various glasses containing silicon as a main component and containing boron and / or aluminum together with various heavy metals, various ceramics, calcium fluoride, calcium phosphate, barium sulfate, zirconium dioxide, titanium dioxide, and the like can also be used. For the surface treatment of the filler, a commonly used silane coupling agent, for example, ω-methacryloxyalkyltrimethoxysilane (carbon number between methacryloxy group and silicon atom: 3 to 12), ω-methacryloxyalkyltrimethyl. Organosilicon compounds such as ethoxysilane (carbon number between methacryloxy group and silicon atom: 3 to 12), vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltriacetoxysilane are used. Furthermore, when manufacturing the dental post of the present invention, general additives such as an organic solvent, water, a stabilizer, and a pigment can be blended in the photopolymerization curable composition as necessary.
As these components, specifically, those described in JP-A-6-9327 and JP-A-7-97306 can be used, and the photocurable composition can also be used. it can.

The material constituting the post of the present invention is not particularly limited, and the following can be exemplified.
Polyamide, polyolefin (for example, polyethylene and polypropylene), polyester, polycarbonate, styrene, styrene acrylonitrile resin, ABS resin, polyimide, polyaryl ester, polysulfone, polyacetal, polyphenylene sulfide, epoxy resin, vinyl ester resin, polyurethane, unsaturated polyester , Melamine, silicone, phenol and the like.
In addition, a polymer obtained by curing a curable composition containing an organic matrix such as acrylic described later, that is, a polymerizable (meth) acrylic acid ester and a polymerization initiator can also be suitably used.
These polymers may be used alone or in combination.
Moreover, it is also preferable to make a reinforced fiber composite with said polymer. Reinforcing fibers include glass fibers (such as E glass and S glass), carbon fibers, ceramic fibers, alumina fibers, zirconia fibers, and other inorganic fibers, poly (meth) acrylic fibers, polyolefin fibers, polyester fibers, polyarylate fibers, and aromatics. Organic fibers such as group polyamide fibers. Of these reinforcing fibers, glass fibers are preferred in terms of mechanical strength. Of the alumina fibers, zirconia fibers, and glass fibers, barium glass fibers are particularly excellent in X-ray contrast.
These reinforcing fibers may be used alone or in combination.

  The fibers as described above are preferably used after pretreatment with a coupling agent such as γ-methacryloxypropyltriethoxysilane, for example. In the pretreatment using such a coupling agent, usually, the coupling agent is dissolved in an organic solvent, and after the fibers, the knitted fibers, and the assembled fibers are crushed therein, A method of lifting from the solution and drying is employed. Moreover, it is preferable to heat this fiber after being soaked and pulled up in the coupling agent.

  Moreover, as a sealer for sealing the gap between the post and the root canal tooth wall, an organic cement such as a conventional inorganic cement or a glass ionomer system may be used, but an organic matrix such as acrylic, that is, polymerizable (meth) acrylic acid A curable composition containing an ester and a polymerization initiator is preferred.

  The polymerizable (meth) acrylic acid ester used in the sealer includes a monofunctional polymerizable monomer and a polyfunctional polymerizable monomer. As the monofunctional polymerizable monomer, a (meth) acrylate monomer is preferable.

Examples of this (meth) acrylate monomer include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, lauryl Alkyl esters of (meth) acrylic acid such as (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2- Or 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 1,2 Or hydroxyalkyl esters of (meth) acrylic acid such as 1,3-dihydroxypropyl mono (meth) acrylate and erythritol mono (meth) acrylate; diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, polyethylene glycol mono Polyoxyalkylene mono (meth) acrylates such as (meth) acrylate and polypropylene glycol mono (meth) acrylate;
Ethylene glycol monomethyl ether (meth) acrylate, ethylene glycol monoethyl ether (meth) acrylate, diethylene glycol monomethyl ether (meth) acrylate, triethylene glycol monomethyl ether (meth) acrylate, polyethylene glycol monomethyl ether (meth) acrylate, polypropylene glycol monoalkyl (Poly) oxyalkylene monoalkyl ether (meth) acrylate such as ether (meth) acrylate; fluoroalkyl ester of (meth) acrylic acid such as perfluorooctyl (meth) acrylate and hexafluorobutyl (meth) acrylate;
Silane compounds having a (meth) acryloxyalkyl group such as γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltri (trimethylsiloxy) silane; and tetrahydrofurfuryl (meth) acrylate (Meth) acrylates having a heterocyclic ring of

  Moreover, as a polyfunctional polymerizable monomer, polymeric (meth) acrylic acid ester is preferable. Examples include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, hexylene glycol di (meth) acrylate, trimethylolpropane. Poly (meth) acrylates of alkane polyols such as tri (meth) acrylate and pentaerythritol tetra (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene Glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, dibutylene glycol di (meth) acrylate, dipentaeryth Toruhekisa (meth) polyoxyalkane polyol poly (meth) acrylates such as acrylates, aliphatic represented by each of the following formulas (1) to (3), alicyclic or aromatic (meth) acrylate;

(In the above formula, each R independently represents a hydrogen atom or a methyl group, m and n each represents 0 or a positive number, and R ¹ represents a divalent group described below);

An alicyclic or aromatic epoxy di (meth) acrylate represented by the following formula (2);

(In the above formula, each R independently represents a hydrogen atom or a methyl group, n represents 0 or a positive number, and each R ² independently represents — (CH ₂ ) ₂ —, — (CH ₂ ) ₄ —. Or the following divalent group):

  Furthermore, the polyfunctional (meth) acrylate etc. which have a urethane bond in the molecule | numerator represented by following formula (3) can be mentioned.

(In the above formula, each R independently represents a hydrogen atom or a methyl group, and R ³ represents — (CH ₂ ) ₂ —, — (CH ₂ ) ₄ —, — (CH ₂ ) ₆ —, or Group).

  Among the compounds exemplified above, monofunctional polymerizable (meth) acrylic acid esters include methyl (meth) acrylate, alkyl (meth) acrylates such as ethyl (meth) acrylate, and 2-hydroxyethyl (meth). Such as acrylate, hydroxyl group-containing (meth) acrylate such as 1,3-dihydroxypropyl mono (meth) acrylate, erythritol mono (meth) acrylate, triethylene glycol monomethyl ether (meth) acrylate, triethylene glycol mono (meth) acrylate Particularly preferred are (meth) acrylates having an ethylene glycol chain in the molecule.

  As the polyfunctional polymerizable (meth) acrylic acid ester, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,6-bis (methacryloxyethyloxycarbonylamino) -2, Di (meth) acrylate having an ethylene glycol chain in the molecule such as 2,4- (or-2,4,4-) trimethylhexane, the following formulas (3) -1 to (3) -3

(In the above formula, each R independently represents a hydrogen atom or a methyl group, and m + n is 2 to 20),

(In the above formula, each R independently represents a hydrogen atom or a methyl group),

(In the above formula, each R independently represents a hydrogen atom or a methyl group),
The compounds represented by each of these are particularly preferably used.

In the sealer, the acrylic organic matrix may contain a polymerizable monomer having an acidic group in the molecule. By using a polymerizable monomer having an acidic group in the molecule, the adhesion performance with reinforcing fibers, inorganic materials, and teeth is greatly improved. Specific examples of the polymerizable monomer having an acidic group in the molecule include (meth) acrylic acid and its anhydride, 1,4-di (meth) acryloxyethyl pyromellitic acid, and 6- (meth) acryloxyethyl. Naphthalene-1,2,6-tricarboxylic acid, N- (meth) acryloyl-p-aminobenzoic acid, N- (meth) acryloyl-o-aminobenzoic acid, N- (meth) acryloyl-m-aminobenzoic acid, N- (meth) acryloyl-5-aminosalicylic acid, N- (meth) acryloyl-4-aminosalicylic acid, 4- (meth) acryloxyethyl trimellitic acid and its anhydride, 4- (meth) acryloxybutyl trimellitic Acid and its anhydride, 4- (meth) acryloxyhexyl trimellitic acid and its anhydride, 4- (meth) acryloxydecyl Limellitic acid and its anhydride, 2- (meth) acryloyloxybenzoic acid, 3- (meth) acryloyloxybenzoic acid, 4- (meth) acryloyloxybenzoic acid, β- (meth) acryloyloxyethyl hydrogen succinate , Β- (meth) acryloyloxyethyl hydrogen maleate, β- (meth) acryloyloxyethyl hydrogen phthalate, 11- (meth) acryloyloxy-1,1-undecanedicarboxylic acid, p-vinylbenzoic acid, etc. Monomers containing acid groups or anhydrides thereof;
A monomer containing a phosphoric acid group such as (2- (meth) acryloxyethyl) phosphoric acid, (2- (meth) acryloxyethylphenyl) phosphoric acid, 10- (meth) acryloxydecylphosphoric acid; and p -Monomers containing sulfonic acid groups such as styrenesulfonic acid and 2-acrylamido-2-methylpropanesulfonic acid.

  Among these, a monomer containing a carboxylic acid group is preferable, and 4-methacryloxyethyl trimellitic acid and its anhydride are particularly preferable. The polymerizable monomer having an acidic group in the molecule is preferably 1 to 50% by weight, particularly preferably 3 to 30% by weight, based on the total amount of polymerizable components in the acrylic organic matrix. Used.

In the sealer, the acrylic organic matrix contains the polymerizable acrylic ester and, if necessary, a polymerizable monomer having an acidic group in the molecule, but these may be contained as monomers. In addition, these may be contained as a partial polymer.
Moreover, these can be used individually or in mixture of 2 or more types.

Among these polymerizable monomers, as the above component, from the viewpoint of enhancing the flexibility and removability of the cured product, the chain length is 17 or more, preferably 19 to 300, more preferably 25 to 200. It is more preferable to use a long-chain polymerizable monomer having a structure of 30 to 100 atoms. Such a long-chain structure is not limited to a specific chemical structure as long as the molecular chain is sufficiently long and flexible, but specific examples include four or more oxyalkylene repeating units. It is more preferable to use a polyalkylene glycol di (meth) acrylate having a structure (— (— (— CH ₂ —) _p —O—) _n —; p is 2 or more, n is 4 or more), propylene glycol and Polyethylene glycol di (meth) acrylate and / or polypropylene glycol di (meth) acrylate having 4 to 60, more preferably 9 to 40, and still more preferably 11 to 28 repeating units derived from ethylene glycol. More preferably, it is used. When the number is less than the lower limit of the numerical range of the number of atoms or the number of repeating units, the removability is lowered. On the other hand, when the upper limit is exceeded, the polymerization becomes insufficient, which is not preferable.

  The chain length of the long-chain polymerizable monomer is presumed to have a great influence on flexibility due to free rotation of bonds between atoms. Therefore, double bonds remaining after polymerization are considered undesirable. Therefore, when calculating the numerical values such as the number of atoms, it is preferable to employ a numerical value obtained by subtracting the double bond or the like. Specifically, an atomic group (> C = C <) bonded by a double bond on the target molecular chain path is counted as one atom. This is because a single-bonded atom on a molecular chain has two axes that can freely rotate, whereas two carbon atoms are double-bonded on the molecular chain path. This is because there are only two bond axes that can freely rotate by combining two atoms. An aromatic ring or its condensed ring or spiro ring should be counted as one atom. Three- and four-membered rings may be regarded as the same. Rings of 5 or more members have a degree of freedom of conformational transformation such as chair shape or boat shape, but there are limitations, so we decided to add 1/4 atomic counts, and eventually 1 + 1/4 in total It is reasonable to do. Every time a 5-membered or higher ring is added as a condensed ring or a spiro ring, it is appropriate to add ¼ atom. According to this, for example, in the case of a bicyclo fused ring system (for example, a naphthalene ring system fully saturated with hydrogen), 1 + 1/4 + 1/4. In addition, it is not necessary to consider in particular about the double bond which is not on the said molecular chain like carbonyl oxygen. In addition, it is preferable not to count the atom (hydrogen etc.) of the molecular chain terminal. Even if the molecular chain is slightly shortened, it is preferable to select and count the route so that the polymerizable double bond is at the end of the molecular chain.

  Furthermore, the long-chain polymerizable monomer is preferably at least bifunctional or more, and more preferably has a polymerizable double bond at both ends of the long-chain structure. Alternatively, it is considered important to have the long chain structure between at least two polymerizable double bonds. Perhaps, in a stable thermodynamic equilibrium state, the long chain structure is predominantly in a contracted form rather than an extended form, and the polymerizable double bonds at both ends thereof form a crosslink of the polymer molecule. It is thought that this is the situation. Then, when the polymerization is cured and enters the polymerization shrinkage process, it is presumed that the contracted form changes to the fully expanded form, thereby contributing to stress relaxation of the polymerization shrinkage. For example, those having 4 to 30 repeating units derived from polyethylene glycol and polypropylene glycol represented by the following formulas (3) -4 and (3) -5 are particularly preferably used.

(Here, Ra in Formula (3) -4 is each independently H or CH ₃ , and n is 4 to 30.)

(Here, Ra in formula (3) -5 is each independently H or CH ₃ , and n is 4 to 30).
When the total polymerizable monomer is 100 parts by weight, the long-chain polymerizable monomer is preferably 5 to 95 parts by weight, more preferably 9 to 70 parts by weight, still more preferably 15 to 50 parts by weight. Included. When the lower limit of the numerical range is not reached, the effect of flexibility is not sufficiently exhibited, and when the upper limit is exceeded, the long-chain polymerizable monomer is polymerized in the polymer formed when the upper limit is exceeded. There is a risk that the main chain of the polymer will be relatively weak and weak, such as being brittle. Especially when the component is composed of a long-chain oxyalkylene repeating unit, the compatibility with the hydrophobic monomer decreases during polymerization. Or the water resistance of the polymerized cured body may be lowered, which is not preferable.

  The acrylic organic matrix used in the sealer preferably contains a polymerization initiator. Examples of such polymerization initiators include organic peroxides, inorganic peroxides, boron-containing polymerization initiators, α-diketone compounds, organic amine compounds, organic sulfinic acids, organic sulfinates, inorganic sulfur compounds, organic phosphorus compounds and Mention may be made of barbituric acids. These can be used alone or in combination of two or more. For convenience, these polymerization initiators are classified into a room temperature chemical polymerization type, a photopolymerization type, or a combined dual type thereof. Examples of the peroxide used in the room temperature chemical polymerization type include diacetyl peroxide, dipropyl peroxide, dibutyl peroxide, dicapryl peroxide, dilauryl peroxide, benzoyl peroxide (BPO), p, p′-dichlorobenzoyl peroxide, p. , P'-dimethoxybenzoyl peroxide, p, p'-dimethylbenzoyl peroxide, organic peroxides such as p, p'-dinitrodibenzoyl peroxide and ammonium persulfate, potassium persulfate, potassium chlorate, potassium bromate and superphosphorus Mention may be made of inorganic peroxides such as potassium acid. These peroxides are preferably used in an amount in the range of 0.01% by weight to 5% by weight with respect to the polymerizable component in the acrylic organic matrix.

  Among the polymerization initiators, examples of the boron-containing polymerization initiator include an organic boron compound or a composition containing the same. Examples of the organic boron compound include triethyl boron, tripropyl boron, triisopropyl boron, tributyl boron, tri-sec-butyl boron, triisobutyl boron, tripentyl boron, trihexyl boron, trioctyl boron, tridecyl boron, and tridodecyl. Tri (cyclo) alkylboron such as boron, tricyclopentylboron, tricyclohexylboron; alkoxyalkylboron such as butoxydibutylboron; dialkylborane such as butyldicyclohexylborane, diisoamylborane, 9-borabicyclo [3.3.1] nonane And a compound in which a part of the above compound is partially oxidized. Furthermore, these compounds can be used in combination. Among these, tributyl boron or partially oxidized tributyl boron is preferably used. As the partially oxidized tributyl boron, for example, one obtained by adding 0.3 to 0.9 mol of oxygen to 1 mol of tributyl boron is preferably used. These organoboron compounds are preferably used in an amount within the range of 0.1% by weight to 50% by weight with respect to the polymerizable component contained in the acrylic organic matrix.

  Moreover, as a polymerization initiator used by a photopolymerization type, the polymerization initiator which can be photopolymerized, for example by irradiating an ultraviolet ray or visible light is used. The polymerization initiator that can be used in the photopolymerization is not particularly limited, and examples thereof include benzyl, 4,4′-dichlorobenzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzophenone, and 9,10-anthraquinone. And ultraviolet or visible light sensitizers such as diacetyl, d, l-camphorquinone (CQ), and trimethylbenzoyldiphenylphosphine oxide. The polymerization initiator that can be photopolymerized by irradiation with ultraviolet rays or visible rays is preferably within a range of 0.01% by weight to 5% by weight with respect to the polymerizable component in the acrylic organic matrix. Used in quantity.

When the acrylic organic matrix is polymerized by room temperature chemical polymerization or photopolymerization, a reducing compound can be used in combination. Examples of the organic reducing compound include N, N-dimethylaniline, N, N-dimethyl-p-toluidine (DMPT), N, N-diethyl-p-toluidine, N, N-diethanol-p-toluidine. (DEPT), N, N-dimethyl-p-tert-butylaniline, N, N-dimethylanisidine, N, N-dimethyl-p-chloroaniline, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, N, N-dimethylaminobenzoic acid and its alkyl ester, N, N-diethylaminobenzoic acid (DEABA) and its alkyl ester, N, N-dimethylaminobenzaldehyde (DMABAd), etc. Aromatic amines; N-phenylglycine (NPG), N-tolylglycine NTG), N, etc. N- (3--methacryloyloxy-2-hydroxypropyl) phenylglycine (NPG-GMA) may be used.
In particular, in order to reliably cure the acrylic organic matrix used in the sealer and further improve the adhesion to reinforcing fibers, inorganic materials, and teeth, an amine compound represented by the following formula (4) or the following It is preferable to contain at least one amine compound represented by the formula (5).

In the above formula (4), R ⁴ and R ⁵ are each independently a hydrogen atom or an alkyl group which may have a functional group or a substituent, and R ⁶ is a hydrogen atom or a metal atom. .

In the above formula (5), R ⁷ and R ⁸ are each independently a hydrogen atom or an alkyl group, and R ⁹ is a hydrogen atom, a functional group, an alkyl group which may have a functional group or a substituent, or Similar alkoxyl groups.
These amine compounds are preferably blended in the acrylic organic matrix in an amount within the range of 0.01% by weight to 5% by weight.

  Examples of the amine compound represented by the formula (4) include NPG, NTG, NPG-GMA, and the like. Of these, NPG is particularly preferably used.

  Examples of the amine compound represented by formula (5) include N, N-dimethylaminobenzoic acid and its alkyl ester, N, N-diethylaminobenzoic acid (DEABA) and its alkyl ester, Aliphatic alkylaminobenzoic acid and its alkyl ester represented by propylaminobenzoic acid and its alkyl ester, N-isopropylaminobenzoic acid and its alkyl ester, N-isopropyl-N-methylaminobenzoic acid and its alkyl ester, etc .; Aliphatic alkylaminobenzaldehyde represented by DMABAd, N, N-diethylaminobenzaldehyde, N, N-dipropylaminobenzaldehyde, N-isopropyl-N-methylaminobenzaldehyde, etc .; N, N-dimethylaminoacetyl N, N-diethylaminoacetylbenzene, N, N-dipropylaminoacetylbenzene, N-isopropylaminoacetylbenzene, N-isopropyl-N-methylaminoacetylbenzene and the like aliphatic alkylaminoacetylbenzene and fat Group alkylaminoacylbenzene. These amine compounds can be used alone or in combination.

Examples of reducing compounds that may be used in the sealer include benzenesulfinic acid, o-toluenesulfinic acid, p-toluenesulfinic acid, ethylbenzenesulfinic acid, decylbenzenesulfinic acid, dodecylbenzenesulfinic acid, and chloro. Aromatic sulfinic acids such as benzenesulfinic acid and naphthalene sulfinic acid or salts thereof can be used in combination. As the inorganic reducing compound, a reducing inorganic compound containing sulfur can be preferably used. As such a compound, a reducing inorganic compound used as a redox polymerization initiator when polymerizing a radically polymerizable monomer in a medium such as water or an aqueous solvent is preferable. For example, sulfurous acid, bisulfite, metasulfite, Bisulfite, pyrosulfite, thiosulfuric acid, 1 dithionic acid, 1,2 thionic acid, hyposulfite, hydrosulfurous acid and salts thereof may be mentioned. Of these, sulfites are preferably used, and sodium sulfite, potassium sulfite, sodium hydrogen sulfite, and potassium hydrogen sulfite are particularly preferable. These reducing inorganic compounds can be used alone or in combination. These reducing inorganic compounds are preferably used in an amount within the range of 0.01% by weight to 5% by weight with respect to the polymerizable component in the acrylic organic matrix.
As described above, a polymer cured or partially polymerized semi-cured material or prepolymer with these compositions may be used as a material constituting the dental post of the present invention.

Example 1
First, a fiber tube (glass fiber 200) braided with a glass fiber (ECG-150 manufactured by Central Glass Co., Ltd., fiber diameter 9 μm, twist number 3.6 times / 25 mm) with a polypropylene cylinder having an outer diameter of 0.435 mm as a core. 16 × 3 bundles, an inner diameter of 1.5 mm, an outer diameter of 1.9 mm, and a basis weight of 300 g / m ² ) were prepared.
Next, the cored fiber tube was immersed in a liquid of γ-methacryloxypropyltrimethoxysilane (TSL8370: manufactured by GE Toshiba Silicone Co., Ltd.) for 10 minutes, taken out from the liquid and left at room temperature for 30 minutes. The glass fiber surface was dried at 40 ° C. for 40 minutes and treated with silane.
After applying a tensile stress of 340 g in the major axis direction only to the surrounding glass fibers (the circumference became thinner, but substantial stretching was not recognized in the major axis direction), a cylindrical structure was obtained.
Furthermore, as a matrix for filling the fiber gap, 1 g of DRYBPO as a polymerization initiator is added as an external addition to 100 g of a mixture of acrylic organic art resin SH-500S (50 wt%) and NKESTER3G treated product (50 wt%), and polymerization is prohibited. 0.02 g of p-methoxyphenol as a material was added and a dissolved matrix was used.
That is, the cylindrical structure is dipped in the matrix mixed liquid for 10 minutes, the structure is taken out from the liquid, left at room temperature for 60 minutes, and then heated and polymerized at 125 ° C. for 50 minutes. The polypropylene column at the center was pulled out.
Also for the hollow inner wall, each treatment agent is sequentially injected into the hollow, and then the same cylinder as described above is inserted and withdrawn, the same treatment is performed, the silane treatment and the matrix treatment are performed, and the dental post having a hollow It was. The diameter was 1.31 mm. This was cut into a length of 20 mm. It was confirmed that there were substantially no exposed fibers on the outer surface of the post or the inner surface of the hollow.

25 parts by weight of triethylene glycol dimethacrylate 75 parts by weight of 1,6-bis (methacryloxyethyloxycarbonylamino) -2,2,4- (2,4,4) trimethylhexane, 0.3 part by weight of camphorquinone , N, N-dimethylaminobenzoic acid-2-butoxyethyl 0.3 part by weight, and barium glass (manufactured by SCHOTGLASVERKE, GM8235, average particle size 1 μm, 1 weight γ-methacryloxypropylmethoxy Silane-treated) 200 parts by weight were mixed to prepare a uniform filler paste.
In the X-ray image, the tooth to be treated is read with an angle between the axis of the root canal entrance and the axis of the apex near the apex of approximately 60 degrees (0 degrees if straight), and the apex is 0.5 mm thick The root canal was expanded and the root canal was further sterilized.
After the paste was applied to the root canal, the post filled with the paste in a hollow space was inserted. The operator's insertion feels smooth and tightly filled.
Insert a gutta-percha point further into the hollow of the post, cut off the extra length post and point, remove the excess paste, and then use a visible light irradiator (Morita Tokyo Seisakusho, Alphalite II). Visible light was irradiated for 60 seconds to cure the paste and complete the abutment construction.
When confirmed by X-ray observation later, a close X-ray image that closed the apical hole was confirmed, and it was confirmed that the post was also inserted to the vicinity of the tip of the root canal.

Example 2
Methyl methacrylate (MMA) 49.9 parts by weight, tricosaethylene glycol dimethacrylate (23G) 33.3 parts by weight, ethoxylated isocyanuric acid triacrylate (A-9300) 10.8 parts by weight, N-phenylglycine Instead of a matrix composed of 3.6 parts by weight of sodium (NPG-Na), 1.2 parts by weight of camphorquinone (CA) and 1.2 parts by weight of sodium p-toluenesulfinate (p-TSNa), the polymerization conditions were changed to 37 ° C. Similar results were obtained when carried out in the same manner as in Example 1 except that the time was 24 hours.

10: hollow post 11: post hollow portion 12: post wall 13a: inner and outer communication tube holes 13b, 13b ′: blind tube hole 13c, 13c ′: return tube hole 13d: branch tube system 13e: porous tube system 14: Cut section 14 ': Cut section 15 oblique to the radial direction 15: Tip plug 16: Hole 20: Dental hard tissue 21: Removed affected crown 30: Cavity 31: Root canal 32: Apical hole 40: Point 41: Sleeve

Claims (5)

A dental post having a hollow extending from one end to the other;
Less than or equal to the diameter of the posts is 1.9 mm, and / or, the hollow diameter Ri der than 1.4mm or less 0.1 mm, the same one of the diameter also over the other end from the one end and of said post diameter Is a dental post characterized by being 0.1 mm or more larger than the hollow diameter . The dental post according to claim 1, wherein the diameter of the post is 0.7 mm or more and / or the diameter of the hollow is 0.1 mm or more. A dental post having a hollow extending from one end to the other;
Both the diameter of the post and the diameter of the hollow are the same from the one end to the other end, and an axis parallel to the direction from the one end to the other end is defined as a parallel axis and a direction perpendicular thereto. As a vertical axis
The length ratio of the dental post in the parallel axis / vertical axis and / or the length ratio in the major axis / minor axis is 4 or more, and
Length in parallel axis and / or length in long axis is 4-40mm
A dental post having a shape of 4. The dental post according to claim 3 , wherein the ratio of the length in the parallel axis / vertical axis and / or the ratio of the length in the major axis / minor axis is 30 or less. A dental post having a hollow is inserted into the endodontic root canal without inserting a rigid body that substantially impairs the stretchability of the hollow part into the hollow part, and then used in a therapeutic procedure for filling the hollow with a filler. dental post according to claim 1 or 3, characterized in that a dental post having a hollow to be.