JPWO2003045141A1 - Teeth transparent specimen and method for producing the same - Google Patents

Abstract

In a method for producing a transparent specimen of an animal tooth, (a) a step of taking a crown of the tooth; (b) a step of removing minerals of the tooth; (c) a pulp from the tooth to remove the pulp And a step of coloring the root canal; (d) a step of clarifying the tooth from which the inorganic material has been removed by a clearing agent; (e) a step of allowing the energy curable composition to penetrate into the transparentized tooth; f) curing the energy curable composition by applying predetermined energy; and (g) using the crown mold on the tooth from which the enamel has been removed, And a step of detachably forming a layer having the same shape as the enamel.

Description

TECHNICAL FIELD The present invention relates to a transparent tooth specimen prepared from animal (for example, human) teeth and a method for producing the same.
Background Art In 1914, Moral, Germany, first devised a transparent specimen of a tooth in which ink was injected into the pulp cavity. The method for producing this transparent specimen is as follows: (1) perforating the pulp chamber and dissolving the pulp tissue with hydrogen peroxide, (2) injecting ink into the root canal, and (3) high humidity with the crown facing up And (4) a step of demineralizing the teeth using nitric acid, and (5) a step of immersing in phenol to make it transparent.
Thereafter, the improved method provided by Ono consists of (1) perforating the pulp chamber and dissolving the pulp tissue with dental antiformin, (2) immersing the teeth in acetone, (3) placing the teeth at 60 ° C. A step of volatilizing acetone immersed in the ink and penetrating into the root canal, instead of penetrating the ink into the root canal, (4) a step of demineralizing the teeth using nitric acid, and (5) phenol or methyl salicylate It consists of the process of making it transparent by soaking.
The transparent tooth preparation prepared by these methods, infused with ink, is excellent in that it can observe the root canal stained black through the tooth structure without destroying the root, and is the most suitable for the study of root canal morphology. Has been used frequently.
However, clearing agents such as phenol and methyl salicylate used in these production methods have a strong irritating odor and are harmful to the skin and mucous membranes. Therefore, the specimen must be observed while immersed in a clearing agent in a sealed glass bottle, and the specimen cannot be touched freely with bare hands. This is an extremely hindrance for observation and photography. Furthermore, since the enamel disappears with the removal of minerals by decalcification, the original crown shape cannot be maintained.
DISCLOSURE OF THE INVENTION The present invention relates to a method for producing a transparent specimen of animal teeth,
(A) taking the crown of the tooth;
(B) removing the mineral of the teeth;
(C) removing the pulp from the teeth and coloring the pulp chamber and root canal;
(D) a step of transparentizing the tooth from which the inorganic material has been removed with a transparent agent;
(E) a step of allowing the energy curable composition to penetrate into the transparent tooth;
(F) a step of curing the energy curable composition by heating or light irradiation; and (g) using the crown mold, on the tooth from which the enamel has disappeared due to the removal of minerals. The method includes a step of detachably forming a layer having the same shape as the tooth enamel.
BEST MODE FOR CARRYING OUT THE INVENTION First, definitions of terms used in the present specification will be described below.
“Animal” refers to all animals having teeth. Examples include mammals such as humans, dogs and cats. This type of transparent specimen is used for humans, for example, in lectures at dental courses at universities, etc., and for explaining to patients at dental clinics. For non-human animals, for example, veterinary medicine at universities, etc. Used for lectures and explanations to owners in animal hospitals.
“Transparent” means that the colored pulp and root canal can be observed with the naked eye from the outside, and includes not only colorless and transparent but also colored and transparent.
The “coloring” is not particularly limited as long as it is a color that can distinguish the medullary chamber and the root canal when the transparent specimen is viewed from the outside with the naked eye. A preferred example is black.
The “transparent” is not particularly limited as long as it is a substance that makes the tooth from which enamel has been removed transparent. Examples thereof include methyl salicylate and phenol, and methyl salicylate is preferable.
The “energy curable composition” is not particularly limited as long as it is a composition which is cured by applying energy such as heat and light and does not lose the transparency of the teeth after curing. For example, Rigolac registered trademark (manufactured by Showa Polymer Co., Ltd.) whose curing component is an ultraviolet curable unsaturated polyester resin can be mentioned.
Next, step (a) to step (g) will be described in order.
First, in the step (a), examples of a method of taking a dental crown mold include a method using a dental impression material. Before taking the mold, it is preferable to use a dental scaler and a strong alkaline aqueous solution such as KOH or NaOH to clean the tooth surface.
Next, in the step (b), there is a method of using an acid or a chelating agent as a method for removing the mineral of teeth. For example, according to a conventional method, a method of immersing teeth in a formic acid solution for several weeks can be mentioned.
In addition, as a method for removing the pulp from the tooth in the step (c), there is a method in which the tooth is cut and divided into a pulp chamber portion and a root canal portion, and the pulp is removed for each. Previously, a method of perforating the medullary chamber was used, and the resulting specimen was incomplete with the medullary chamber destroyed, but according to this method, the medullary chamber remains in its original shape. A suitable specimen can be obtained. For the division, for example, a razor is used, and for removing the dental pulp, for example, tweezers are used. In this step, since decalcification precedes removal of the pulp, if it is used on a tooth where only organic matter remains, the conventional chemical removal that dissolves the entire tooth is not suitable.
Examples of the method for coloring the pulp cavity and the root canal in the step (c) include a method of depositing a coloring agent on the pulp chamber wall and the root canal wall that are exposed after removing the pulp. The colorant is not particularly limited as long as it easily deposits on these walls and does not easily dissolve during the subsequent processing, and examples thereof include ink. Furthermore, as another coloring method, there is a method in which a coloring agent penetrates and adheres to the medullary canal and the root canal by suction means from the apical hole at the root of the tooth. According to this method, a tooth cutting step is not necessary, which is preferable in manufacturing.
Next, in the step (d), the tooth from which the inorganic material has been removed is immersed in a transparent agent. The immersion time depends on the size of the teeth and the type of clearing agent used. For example, when methyl salicylate is used as the clearing agent, any tooth becomes transparent in 24 to 48 hours. Prior to this step, it is preferable to dehydrate the teeth with a dehydrating agent such as ethanol.
In addition, with respect to the step (e), a plurality of immersion liquids in which the concentration of the energy curable composition is changed with an appropriate solvent are used, and stepwise from an immersion liquid having a low concentration of the energy curable composition to a high immersion liquid. It is preferable to immerse the transparent teeth. By increasing the concentration stepwise in this way, it is possible to reliably replace the transparent agent that has penetrated into the teeth with the energy curable composition. Note that only the solvent may be used as the first immersion liquid, and only the energy curable composition may be used as the final immersion liquid. Here, the solvent is not particularly limited as long as it is a substance compatible with the clearing agent and the energy curable composition. For example, when methyl salicylate is selected as the clearing agent, a styrene monomer may be used. Is preferred.
At a process (f), the energy according to the energy curable composition to be used is provided, and the said composition is hardened. For example, when a thermosetting composition is used, heat is applied, and when a photocurable composition is used, light having an appropriate wavelength is irradiated. Once the energy curable composition is polymerized and solidified in this way, the divided pulp chamber and root canal can be rejoined and the specimen can be handled freely with bare hands without losing transparency. It becomes.
In the step (g), for example, first, an appropriate adhesion preventing sheet (for example, Parafilm registered trademark, manufactured by Sanko Junyaku Co., Ltd.) is coated on the specimen after curing in the step (f), A curable composition is poured into the mold obtained in step (a), and after inserting at least the crown portion of the specimen, the composition is cured. And after hardening, it draws out from a sample, arranges a shape, and creates an enamel layer model. The curable composition used here is (1) cured even when air is shut off, (2) the cured model is elastic for easy attachment and detachment, and (3) in step (f). It is preferable that the obtained cured product has a property of not adhering. A white urethane resin having these properties and having the strongest durability is particularly suitable.
The transparent specimen thus obtained can be handled freely with bare hands by embedding the resin, and observation and photography are much easier than conventional ones. In addition, since the coloring agent (ink ink) is injected without destroying the medullary chamber, the original medullary chamber morphology can be observed. Further, by reconstructing the enamel layer, the specimen can be given a natural shape as a tooth. Moreover, by removing the enamel layer, it is possible to observe the morphology of the coronal dentin and the shape of the medullary chamber.
Embodiments Hereinafter, embodiments according to the present invention will be described with reference to FIGS. First, for the preparation of transparent specimens, a set of 28 teeth, excluding the third molar, collected from humans was prepared, and these were used with a dental scaler and 30% (5.35N) KOH aqueous solution. The surface was wiped out. Next, as shown in FIG. 1, a dental silicone impression material (trade name: JM Silicon, manufacturer: Nissin Co., Ltd.) was used, and the crowns of these teeth were taken. These teeth were immersed in 5% formic acid for 2 weeks to completely remove the minerals of the teeth. Next, as shown in FIG. 2, the teeth were cut with a razor to separate them into a crown portion and a root portion, and the pulp was extracted with tweezers from the exposed pulp chamber and root canal. Ink was then injected into the pulp chamber and the root canal from which the pulp was extracted with a syringe. Next, after removing excess ink, the teeth were dipped in 70, 80, 90, and 100% ethanol for 24 hours, and dehydrated. Then, as shown in FIG. 3, the dehydrated teeth were immersed in methyl salicylate for 48 hours. As a result, it was possible to obtain a tooth in which the pulp chamber and root canal, colored black with ink, were transparent to the extent that they can be observed with the naked eye from the outside. Then, as shown in FIG. 3, the clarified teeth were mixed with the styrene monomer for 24 hours in the styrene monomer and for 24 hours in the mixture {1: 1 (volume ratio)} of the styrene monomer and Rigolac®. Curing agent (trade name: QCU) for 24 hours in the mixture {1: 2 (volume ratio)} of Rigolac® and 24 hours in the mixture {1: 3 (volume ratio)} of styrene monomer and Rigolac® -3 manufacturer: Nisshin EM Co., Ltd.) was immersed in Rigolac registered trademark (only) with 0.3% (weight ratio) for 120 hours in order, and methyl salicylate in the teeth was photocurable resin (Rigolac) (Registered trademark) was almost completely replaced. Then, as shown in FIGS. 4 and 5, the cut teeth are rejoined as in the state before cutting, and as shown in FIG. 6, an ultraviolet polymerization device (DOSAKA EM CO., LTD. ULTRAVIOLET The photocurable resin was polymerized by POLYMERIZER MODEL TUV-100 (wavelength 360 nm, 24 hours). Next, the Parafilm registered trademark was wrapped very thinly around the crown portion of the tooth thus recombined, and on the other hand, as shown in FIG. 7, urethane resin (trade name: main agent Takenate) was placed in the mold. , Hardener: Takelac manufacturer: Mitsui Takeda Chemical Co., Ltd.), and the crown portion was inserted into the urethane resin as shown in FIG. And in this state, it was left to cure for 48 hours. Next, as shown in FIG. 9, it was removed from the mold, the transparent specimen and the cured urethane resin were separated, and the excess urethane resin was cut along the tooth neck line. Thereafter, unnecessary Parafilm registered trademark was peeled off from the specimen. Finally, the shaped urethane resin was placed in a high temperature bath at 60 ° C. for a whole day and cured completely. The specimens thus produced are shown in FIGS. 10 and 11. The obtained specimen had a urethane resin enamel layer removable, and had a thin amber color, so that the black color of the pulp chamber and root canal wall could be clearly confirmed.
Industrial Applicability As described above, the transparent specimen of teeth according to the present invention can be handled freely with bare hands, so it is useful for observation and photography, and since the spinal cord is not destroyed, It is useful for observing the shape of the medullary chamber, and furthermore, since the enamel layer is removable, it is also useful for observing the shape of the coronal dentin and the shape of the medullary chamber.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a photograph showing a crown shape before decalcification taken with a silicone impression material. FIG. 2 is a schematic diagram of a photograph showing that the demineralization and division are finished and the ink is injected into the medullary chamber (right) and the root canal (left) using a syringe. Fig. 3 shows a sample made transparent by methyl salicylate after dehydration, and immersed in a 1: 1, 1: 2, 1: 3 mixture of styrene monomer, styrene monomer and ligolac, and finally immersed in pure rigorac. It is a schematic diagram of the photograph which shows the place which is making the rigorak permeate into. FIG. 4 is a schematic view of a photograph showing that the excess rigorac is wiped off from the specimen surface immediately before polymerization. FIG. 5 is a schematic view of a photograph showing a rejoined portion of the medullary chamber (crown) and root canal. FIG. 6 is a schematic view of a photograph showing a place where the rejoined specimen is put into an ultraviolet polymerization device. FIG. 7 is a schematic view of a photograph showing a urethane resin added with a curing agent poured into a dental crown mold that has already been taken. FIG. 8 is a schematic view of a photograph showing a state where a transparent specimen is inserted and the urethane resin is waiting to be cured. FIG. 9 is a schematic view of a photograph showing a transparent specimen taken out after the urethane resin is cured. FIG. 10 is a schematic diagram of a photograph showing a crown and a transparent specimen reconstructed with urethane resin. FIG. 11 is a schematic diagram of photographs showing transparent specimens of various tooth types in which the crown is reconstructed.

Claims (11)

In the method for producing a transparent specimen of animal teeth,
(A) taking the crown of the tooth;
(B) removing the mineral of the teeth;
(C) removing the pulp from the teeth and coloring the pulp chamber and root canal;
(D) a step of clarifying the tooth from which enamel has been removed with a clearing agent;
(E) a step of allowing the energy curable composition to penetrate into the transparent tooth;
(F) a step of curing the energy curable composition by applying predetermined energy; and (g) using the crown mold on the tooth from which the enamel has been removed along with the removal of minerals. And detachably forming a layer having the same shape as the original tooth enamel. The method of claim 1, wherein the animal is a human. Step (c) is to cut the teeth and divide the pulp into a pulp chamber and a root canal, remove the pulp for each, and then attach a coloring agent to the exposed pulp wall and root canal wall. A method according to claim 1 or claim 2 comprising. The method according to claim 1 or 2, wherein step (c) comprises infiltrating and attaching a coloring agent from the apical hole at the root of the tooth to the medullary chamber and root canal by suction means. . The method according to any one of claims 1 to 4, wherein the colorant is ink. The method according to any one of claims 1 to 4, wherein the clearing agent in the step (d) is methyl salicylate. The method according to any one of claims 1 to 6, wherein the energy curable composition in the step (e) is an ultraviolet curable unsaturated polyester resin. In the step (e), a plurality of immersion liquids having different energy curable composition concentrations are used, and the teeth that have been made transparent in stages are immersed in an immersion liquid having a low energy curable composition concentration from a low immersion liquid. The method according to any one of claims 1 to 7. The method according to claim 8, wherein the solvent of the energy curable composition in the immersion liquid is a styrene monomer. In the step (g), the urethane resin is poured into the mold obtained in the step (a), and after the teeth subjected to the curing treatment obtained in the step (f) are inserted, the urethane resin is cured. 10. The method according to any one of claims 1 to 9, wherein the layer is formed by: A transparent tooth specimen prepared by the method according to any one of claims 1 to 10.

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