WO2003045141A1

WO2003045141A1 - Clear tooth sample and process for producing the same

Info

Publication number: WO2003045141A1
Application number: PCT/JP2001/010360
Authority: WO
Inventors: Tsuneyuki Yamamoto
Original assignee: Hokkaido Technology Licensing Office Co., Ltd.
Priority date: 2001-11-28
Filing date: 2001-11-28
Publication date: 2003-06-05
Also published as: AU2002222554A1; JPWO2003045141A1

Abstract

A process for producing a clear sample of an animal tooth characterized by involving: (a) the step of taking an impression of the crown of the tooth; (b) the step of eliminating inorganic matters from the tooth; (c) the step of eliminating the pulp from the tooth and coloring the pulp chamber and the pulp canal; (d) the step of clearing the tooth, from which the inorganic matters have been eliminated, with the use of a clearing agent; (e) the step of penetrating an energy-hardening composition into the cleared tooth; (f) the step of hardening the energy-hardening composition by applying definite energy thereto; and (g) the step of forming a detachable layer having the same shape as the original tooth enamel on the above-described tooth, from which the enamel has been eliminated, by using the crown pattern as described above.

Description

Specification

FIELD OF THE INVENTION

The present invention relates to a transparent sample of teeth made from animal (eg, human) teeth and a method for producing the same. Background art

In 1991, Moral, Germany, first conceived a transparent tooth specimen with black ink injected into the pulp cavity. The method of manufacturing this transparent specimen includes (1) a step of perforating the pulp chamber and dissolving the pulp tissue with hydrogen peroxide water, (2) a step of injecting ink into the root canal, and (3) a high humidity with the crown facing upward. (4) denitrating the teeth using nitric acid, and (5) immersing in phenol to make it transparent. Thereafter, the improved method provided by Ono included (1) a step of perforating the pulp chamber and dissolving the pulp tissue with dental antiformin, (2) a step of immersing the teeth in acetone, and (3) a step of immersing the teeth in 60. (4) denitrating the teeth using nitric acid, and (5) phenol or salicylic acid. It consists of a step of immersing in methyl to make it transparent.

The transparent tooth specimen infused with black ink produced by these methods is excellent in that it can observe the root canal that has been dyed black through the dentin without destroying the root, and is most suitable for studying the root canal morphology. It has been used frequently.

However, transparent agents such as methyl phenol disalicylate used in these production methods have a strong pungent odor and are harmful to skin and mucous membranes. Therefore, the specimen must be observed while immersed in a transparent agent in a sealed glass bottle, and the specimen cannot be freely touched with bare hands. This is a significant obstacle for observation and photography. Furthermore, the enamel disappears with the removal of minerals by decalcification, so that the original crown shape cannot be maintained. Disclosure of the invention The present invention relates to a method for producing a transparent specimen of an animal tooth,

(a) taking the crown of the tooth;

(b) removing minerals from the teeth;

(c) removing the pulp from the tooth and coloring the pulp chamber and the root canal;

(d) a step of making the tooth from which minerals have been removed transparent with a clarifying agent;

(e) a step of penetrating the energy-curable composition into the transparentized teeth; (f) a step of curing the energy-curable composition by heating or light irradiation; and

(g) using the mold of the crown, a step of detachably forming a layer having the same shape as the enamel of the original tooth on the tooth where the enamel has disappeared due to the removal of the inorganic substance. It is a method characterized by the following. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic diagram of a photograph showing a mold of a crown before decalcification taken with a silicone impression material. Fig. 2 is a schematic view of a photograph showing the infusion of black ink using a syringe into the pulp chamber (right) and the root canal (left) after decalcification and division. Fig. 3 shows that after dehydration, the specimen clarified with methyl salicylate was immersed in a mixture of styrene monomer, styrene monomer and rigorac in a ratio of 1: 1, 1: 2, and 1: 3, and finally immersed in pure rigorac. And Fig. 4 is a schematic diagram of a photograph showing that a rigorac is infiltrated into a specimen. FIG. 4 is a schematic view of a photograph showing that excess rigorac is being wiped from the specimen surface immediately before polymerization. FIG. 5 is a schematic view of a photograph showing the re-joining of the pulp chamber (crown) and the root canal. FIG. 6 is a schematic view of a photograph showing the re-joined specimen being put into an ultraviolet polymerization vessel. FIG. 7 is a schematic view of a photograph showing a resin mold containing a hardening agent being poured into a mold for a crown already taken. FIG. 8 is a schematic view of a photograph showing a state where a transparent sample is inserted and the urethane resin is waiting for curing. FIG. 9 is a schematic view of a photograph showing a state where a transparent sample was taken out after the urethane resin was cured. FIG. 10 is a schematic view of a photograph showing a crown and a transparent specimen reconstructed with urethane resin. FIG. 11 is a schematic view of a photograph showing transparent specimens of various tooth types in which the crown has been reconstructed. BEST MODE FOR CARRYING OUT THE INVENTION

First, definitions of terms used in the present specification will be described below.

"Animal" refers to any animal that has teeth. Examples include mammals such as humans, dogs and cats. This kind of transparent specimen is used for humans, for example, in lectures at dentistry courses at universities, etc., and for explanations to patients at dental clinics. For animals other than humans, for example, veterinary medicine at universities, etc. It is used for lectures and explanations to owners at animal hospitals.

“Transparent” means that the colored pulp chamber and root canal are observable to the naked eye from the outside, and includes not only colorless and transparent but also colored transparent.

“Coloring” is not particularly limited as long as the pulp chamber and the root canal can be distinguished when the transparent specimen is viewed from the outside with the naked eye. Preferably, black is used.

The “transparent agent” is not particularly limited as long as it is a substance that makes the tooth from which enamel has been removed transparent. For example, methyl salicylate and phenol are exemplified, and methyl salicylate is preferred.

The “energy-curable composition” is not particularly limited as long as it is a composition that is cured by applying energy such as heat or light and does not lose the transparency of teeth after curing. For example, Rigolac ™ (manufactured by Showa Polymer Co., Ltd.), whose curing component is an ultraviolet-curable unsaturated polyester resin, may be mentioned.

Next, the steps (a) to (g) will be described in order.

First, in the step (a), as a method of taking a mold of a tooth crown, for example, a method using a dental impression material can be mentioned. Before taking the mold, it is preferable to brush the tooth surface using a dental scaler and a strong alkaline aqueous solution such as K〇H or NaOH.

Next, in the step (b), as a method for removing the minerals of the teeth, there is a method using an acid chelating agent. For example, according to a conventional method, a method of immersing a tooth in a formic acid solution for several weeks can be mentioned.

Further, as a method of removing pulp from the teeth in the step (c), there is a method of cutting the teeth, dividing the pulp into a pulp chamber and a root canal, and removing the pulp from each. 10 Summary The method for producing a transparent specimen of an animal tooth, comprising: (a) removing the crown of the tooth; (b) removing minerals from the tooth; (c) removing pulp from the tooth. Removing and coloring the pulp chamber and the root canal; (d) translucent the tooth from which minerals have been removed with a translucent agent; (e) applying an energy-curable composition to the transparentized tooth. (F) applying the predetermined energy to cure the energy-curable composition; and (g) using the mold of the crown to remove the enamel from the tooth. Further comprising the step of removably forming a layer having the same shape as the enamel of the original tooth.

It is. In the past, the technique of perforating the pulp chamber was used, and the resulting specimen was an imperfect one in which the pulp chamber was destroyed. However, according to this method, the pulp chamber remains in its original shape. A suitable sample can be obtained. Note that, for example, a razor is used for the division, and for example, tweezers are used for removing the pulp. In this process, demineralization precedes pulp removal, so if it is used for teeth where only organic matter remains, the chemical removal of the conventional method, which dissolves the entire tooth, is not suitable.

Further, as a method of coloring the pulp cavity and the root canal in the step (c), for example, a method of depositing a coloring agent on the exposed pulp chamber wall and the root canal wall after removing the pulp can be mentioned. . The coloring agent is not particularly limited as long as it is easily deposited on these walls and hardly eluted in the subsequent processing, and examples thereof include black ink. Further, as another coloring method, a method of penetrating and attaching a coloring agent to the pulp chamber and the root canal by the suction means from the apical hole at the root of the tooth is mentioned. According to this method, a tooth cutting step is not required, which is preferable in manufacturing.

Next, in step (d), the teeth from which the inorganic material has been removed are immersed in a transparent agent. The immersion time depends on the size of the teeth and the type of clarifying agent used. For example, when methyl salicylate is used as the clarifying agent, any tooth can be clarified in 24 to 48 hours. It is preferred that the teeth be dehydrated with a dehydrating agent such as ethanol prior to this step.

In addition, in 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 the steps are performed in the immersion liquid having a low concentration of the energy-curable composition and a high concentration. It is preferred to immerse the transparentized teeth. By gradually increasing the concentration in this way, the transparent agent that has permeated into the teeth can be reliably replaced with the energy-curing 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 last immersion liquid. Here, the solvent is not particularly limited as long as it is a substance that is compatible with the clarifying agent and the energy-curable composition.For example, when methyl salicylate is selected as the clarifying agent, a styrene monomer may be used. It is suitable.

In the step (f), energy corresponding to the energy-curable composition to be used is applied to cure the composition. For example, when using a thermosetting composition, In addition, when a photocurable composition is used, light of an appropriate wavelength is irradiated. Once the energy-curable composition is polymerized and hardened, the divided pulp chamber and root canal rejoin, and the specimen can be handled with bare hands without losing transparency. Becomes

In the step (g), for example, first, an appropriate anti-adhesion sheet (for example, manufactured by Parafilm Sanko Junyaku Co., Ltd.) is coated on the sample cured in the step (f), and then the appropriate curing is performed. The acidic composition is poured into the mold obtained in step (a), and after at least the crown portion of the sample is inserted, the composition is cured. Then, after hardening, it is pulled out from the specimen, the shape is adjusted, and an enamel layer model is created. The curable composition used here is: 1) cured even when the air force is shut off, 2) the cured model has elasticity for easy attachment and detachment, and 3) the cured product obtained in step (f) It is preferable that it has the property of not adhering to the substrate. A white urethane resin having these properties and having the highest durability is particularly suitable.

The transparent specimen thus obtained can be handled freely with bare hands by embedding it in the resin, making observation and photography much easier than with conventional ones. In addition, since the coloring agent (black ink) is injected without destroying the pulp, the original pulp morphology can be observed. Furthermore, by reconstructing the enamel layer, the specimen can be given a natural shape as a tooth. Also, by removing the enamel layer, the morphology of the coronal dentin and the medulla can be observed. Example

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS. 1 to 11. First, for the preparation of a transparent specimen, a set of 28 teeth, excluding the third molar, collected from humans was prepared, and these were combined with a dental scaler at 30% (5.35 N) K〇. H tooth solution was used to brush the tooth surface. Next, as shown in Fig. 1, a dental impression mold for dental use (trade name: JM Silicone, manufacturer: Nissin Co., Ltd.) was used to mold the crown of these teeth. These teeth were immersed in 5% formic acid for 2 weeks to completely remove the minerals from the teeth. Next, as shown in Fig. 2, the tooth was cut with a force razor to divide it into a crown and a root, and the pulp was extracted from the exposed pulp chamber and root canal. And removed it. Then, black ink was injected with a syringe into the pulp chamber from which the pulp was extracted and the root canal. Next, after removing excess ink, the teeth were immersed in 70%, 80%, 90%, and 100% ethanol, respectively, for 24 hours to dehydrate. Then, as shown in FIG. 3, the teeth after dehydration were immersed in methyl salicylate for 48 hours. As a result, a tooth was obtained in which the pulp chamber and the root canal, which were colored black with black ink, were transparent to the extent that they could be visually observed from the outside. Next, as shown in FIG. 3, the clarified teeth were placed in a styrene monomer for 24 hours and in a mixture of styrene monomer and Rigolac® {1: 1 (volume ratio)} for 24 hours in styrene. 24 hours in a mixture of monomer and Rigolac ® {1: 2 (volume ratio)}, 24 hours in a mixture of styrene monomer and Rigolac ® {1: 3 (volume ratio)}, curing agent (product name) : QCU-3 Manufacturer: Nisshin EM Co., Ltd.) was immersed in Rigolac® (only) containing 0.3% (by weight) for 120 hours, in order to cure the methyl salicylate in the teeth. Almost completely replaced with resin (Rigolac®). Then, as shown in Fig. 4 and Fig. 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. Photocurable resin was polymerized with ULTRAVIOLET POLYMERIZER MODEL TUV-100) (wavelength

360 nm, 24 hours). Next, Parafilm® is wrapped very thinly around the crown portion of the reassembled tooth, and, as shown in FIG. 7, on the other hand, as shown in FIG. The base material Takenate, curing agent: Evening Kerac (Manufacturer: Takeda Mitsui Chemicals, Inc.) was poured, and the crown was inserted into the urethane resin as shown in FIG. Then, it was left for 48 hours in this state to be cured. Next, as shown in Fig. 9, the transparent sample and the cured urethane resin were separated from the mold, and the excess urethane resin was cut along the cervical line. After that, unnecessary Parafilm® was peeled off from the sample. Finally, the shaped urethane resin was placed in a high-temperature bath at 60 days and nights to be completely cured. The specimens produced in this way are shown in FIGS. 10 and 11. In the obtained specimen, the enamel layer made of urethane resin was removable, and the specimen had a light amber color, so that the black color of the pulp chamber and the root canal wall could be clearly confirmed. Industrial applicability As described above, the transparent specimen of the tooth according to the present invention can be handled freely with bare hands, which is useful for observation and photography, and since the pulp chamber is not destroyed, it is suitable for observation of the original pulp morphology. It is useful, and moreover, because the enamel layer is detachable, it is also useful for observing the morphology of the coronary dentin and the medulla.

Claims

The scope of the claims

1. a method for producing a transparent specimen of animal teeth,

(a) taking the crown of the tooth;

(b) removing minerals from the teeth;

(d) clarifying the tooth from which enamel has been removed with a clarifying agent;

(e) penetrating the energy-curable composition into the transparentized teeth;

(f) curing the energy-curable composition by applying a predetermined energy; and

(g) utilizing the mold of the crown to form a layer of the same shape as the original tooth enamel on the tooth from which the enamel has been removed along with the removal of the inorganic matter, in a removable manner. A method characterized by the following.

2. The method according to claim 1, wherein the animal is a human.

3. Process (c) Force The teeth are cut and divided into a pulp chamber and a root canal. After removing the pulp from each, a coloring agent is applied to the exposed walls of the pulp chamber and the root canal. The method according to claim 1 or 2, comprising:

4. The method according to claim 1, wherein the step (c) includes permeating and attaching a coloring agent to the pulp chamber and the root canal by suction means from the apical hole at the root of the tooth. the method of.

5. The method according to any one of claims 1 to 4, wherein the coloring agent is ink.

6. The method according to any one of claims 1 to 4, wherein the clarifying agent in step (d) is methyl salicylate.

7. The method according to any one of claims 1 to 6, wherein the energy-curable composition in step (e) is an ultraviolet-curable unsaturated polyester resin.

8. In step (e), a plurality of immersion liquids having different concentrations of the energy-curable composition are used, and the teeth, which have been clarified stepwise from an immersion liquid having a low concentration of the energy-curable composition to a high immersion liquid, The method according to any one of claims 1 to 7, wherein the method is immersed.

9. The method according to claim 8, wherein the solvent of the energy curing composition in the immersion liquid is a styrene monomer.

10. In step (g), urethane resin is poured into the mold obtained in step (a), and the hardened tooth obtained in step (f) is inserted. The method according to any one of claims 1 to 9, wherein the layer is formed by curing a resin.

11. A transparent sample of a tooth manufactured by the method according to any one of claims 1 to 10.