JPH0747086A - Die forming material for dental use - Google Patents

Abstract

PURPOSE:To mount an artificial tooth set stably and allow removing easily by performing the binding through overlapping of a low melting point resin on a molding of a shape memory resin. CONSTITUTION:An artificial tooth set 1 is equipped with artificial teeth 2 and an artificial tooth bed 3, wherein the part 7a near the chin bank undercut of the tooth bed 3 is made of a shape memory resin while the other part 7b is made of ordinary acrylic resin or the like. The two parts are bonded together by adhesion or fusion attachment. When the tooth set is to be put off, it is heated to over the glass transition point and softened, and separation takes place upon opening the part near the undercut. Mounting is made in the condition that the part near' the chin bank undercut is opened, followed by heating, deformation, and fitting, and then the temp. is sunk to under the glass transition point.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a casting material in the dental field.

[0002]

[Prior art and its problems]

(1) About dentures Partial dentures have a so-called clasp (a metal hook made by bending a wire or casting an alloy and generally called a spring) as a maintenance device for mounting the denture in the oral cavity. I use it a lot. This is because the metal part covers the buccal side and the lingual side of the residual tooth in a "striped" shape, and extends from the artificial tooth part or the denture base adjacent to one side of the residual tooth, and the tip is the other side of the residual tooth. The structure is located in the undercut on the side of, and the clamping force between the two blades of the residual tooth is used for the maintenance force of the denture.

Therefore, the clasps existing on both wings of the residual teeth are one of the causes of damaging the oral tissue such as impairing the aesthetics of the oral cavity, abrading the tooth substance, and causing the motion of the residual teeth.

Further, since it is made of metal, there is a problem of loss of clamping force for residual teeth due to metal fatigue or loss of maintenance function of denture due to damage to hook blades, etc. within a short period of time. Has become. In addition to these, there are attachments (metal connection tools), but most of them have a metal crown over the remaining teeth, and one of the attachments is fixed to it by means such as soldering, and the other is embedded and fixed in the denture. It mechanically connects the two, and has a structure to attach and detach them. There is also a telescope similar to the relationship between the tea canister and the lid. This consists of covering the inner teeth of a metal double crown over the remaining teeth and connecting the outer crown to the denture.
The frictional resistance of the outer crown is used for maintaining the denture.

When these attachments and telescopes are used, there is a problem in that a large amount of tooth substance is removed and technical difficulty is involved in the treatment, and it is expensive because of the use of precious metal precision parts and the necessity of high precision technology. It is a technology that is not universal because it requires various treatment costs.
In addition, it includes many problems such as breakage problems and maintenance difficulty because it is a precious metal precision part having insufficient hardness and strength.

(2) Denture base Generally, a denture is mounted in the oral cavity depending on its stability depending on its suction force and its maintenance force (resisting force against denture detachment) on its remaining teeth. In the case of full dentures with no residual teeth, the floor area is set as wide as possible and the denture base is extended to the undercut of the alveolar ridge to enhance the suction and maintenance power. In recent years, attempts have been made to improve the maintenance power of artificial teeth by artificially building an undercut by embedding ceramic granules under the mucous membrane of the ridge.

As described above, the conventional denture base designed to cover the undercut with the denture base resin is liable to damage the alveolar ridge during attachment / detachment, and often results in the removal of the denture base extended to the corner undercut portion. .

(3) Casting material One of the basic techniques of dental technology is the casting technique by the lost wax method, and wax is usually used as the casting material. However, the conventional casting wax has a high plasticity at room temperature and is liable to be deformed. Especially, the tip portion of the casting wax is widened when it is removed from the plaster model at the time of casting.Therefore, it is necessary to consider the correction. Was a cause of a decrease in accuracy.

(4) Basic Idea for Solving Problems Recently, a synthetic resin having a shape memory property has attracted attention, and a technique of using the shape memory resin in a special mode is being developed in various fields. This shape memory resin is
Utilizing a large change in elastic modulus before and after the glass transition point, by heating to a temperature above the glass transition point to soften it, deforming it into a desired shape, and holding this deformation and cooling to a temperature below the glass transition point, It is fixed to this deformed shape, and the fixed shape can be easily erased (recovered) by heating above the glass transition point.

The present invention has been made by paying attention to the properties of the above-mentioned shape memory resin, and intends to solve the above-mentioned problems of the denture, the denture base and the molding material by effectively utilizing the properties. .

[0011]

In order to solve the above-mentioned problems, the present invention provides the following denture, denture base and casting material.

1) A denture having a denture base made of a shape memory resin.

2) A denture base portion located at the undercut of the residual tooth is made of a shape memory resin.
tooth.

3) At least the portion of the denture base located under the ridge undercut is made of shape memory resin.
Denture base to be collected.

4) A molding material characterized in that a low-melting resin is superposed on and bonded to a shape memory resin molded product.

[0016]

[Action and effect]

(1) Denture The denture according to the present invention has the following effects. A denture whose denture base is made of a shape memory resin is made deformable by heating the denture base above the glass transition point when it is installed in the oral cavity, and fitting while deforming according to the shape of the oral cavity.
In that state, the temperature can be lowered to the temperature in the oral cavity, so that the wearer can wear it stably. At the time of detachment, the denture base can be easily removed by heating it to soften it so that it can be deformed.

Further, according to the denture in which the portion of the denture base located in the residual tooth undercut is made of shape memory resin, the residual tooth undercut portion made of shape memory resin is heated above the glass transition point when the denture is attached. The shape memory resin into a deformable rubber state, and while fitting it while deforming it along the narrowed part of the remaining tooth, the temperature is lowered to the body temperature below the glass transition point, so that the shape memory resin hardens to the glass state and the denture becomes It can be firmly fixed, and the denture can be prevented from falling off and a good maintenance state can be obtained. On the other hand, when the denture is removed, the undercut portion is softened and deformed by heating the undercut portion to a temperature equal to or higher than the glass transition point, so that the denture can be easily removed.

(2) Denture base Since the denture base according to the present invention is composed of shape memory resin at least in the portion located in the undercut of the alveolar ridge, it is softened by heating above the glass transition point when the denture is removed. By doing so, it is possible to open the part covered by the undercut of the alveolar ridge and remove the denture.Also, at the time of wearing, put on the part covered by the undercut of the alveolar ridge with the part open, then warm and deform the undercut of the alveolar ridge. By fitting it to the cut part, it can be worn stably, and by lowering the temperature to the body temperature as it is, the undercut can be covered without damaging the alveolar ridge.

(3) About Molding Material Since the molding material according to the present invention is formed by superposing a low melting point resin on a shape memory resin, the precision molding property of the low melting point resin and the shape memory property of the shape memory resin Has both.
Therefore, this is heated and the low melting point resin is applied to the mold to take the mold, and the temperature is lowered as it is to keep the shape memory resin in the glass state to maintain the mold taking state, and the high precision mold taking is performed. It can be carried out.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 5 relate to a partial denture,
In particular, FIGS. 3 to 5 show changes in the shape of the maintenance device when the denture is attached. In each drawing, (1) is a denture, and the artificial tooth (2) and the denture base (3) are integrally configured. (4) is a residual tooth and (5) is a gum. Note that FIG.
5 shows a partial denture having a large floor area applied to the case where the residual tooth is isolated, and FIGS. 6 and 7 show intermediate tooth defects with a small floor area when the residual tooth is located at both ends of the denture. Of the partial denture.

The denture base is wholly made of shape memory resin, or the base portion is made of acrylic resin or other resin and the undercut portion (3a) of the residual tooth (4) is made of shape memory resin, or For the remaining tooth undercut portion (3a) of the denture base, the shape memory resin maintenance portion (3
It is manufactured separately as b) and is manufactured by being embedded or adhered to the denture base.

The attachment / detachment of the denture in the case of using the denture maintenance part (3b) will be described below.

When the denture (1) is attached, the shape memory resin maintaining portion (3b) is heated to a temperature not lower than its glass transition point so as to be in a deformable rubber state. This heating may be performed on the entire denture including the maintenance portion (3b) by immersing the denture in warm water, or a portion including only the maintenance portion (3b) or its surroundings by blowing heated air or the like. May be done to. In this state, the void portion of the denture is fitted to the residual tooth (4) according to the order of FIGS. 3 to 5. At this time, the maintenance portion (3b) of the denture base is fitted while being deformed along the undercut portion of the residual tooth as shown in FIGS. 3 to 5, and the state shown in FIG. 5 is maintained.
By setting b) to be equal to or lower than the glass transition point, the maintenance portion (3b) is deformed and fixed in the glass state, so that the denture can be firmly held.

On the other hand, when removing the denture (1), after heating the maintaining portion (3b) to make it a deformable rubber state,
Since the maintenance portion (3b) is deformed when it is removed from the remaining teeth, the denture can be easily removed. Maintenance part (3
The heating of b) can be performed by, for example, containing hot water having a temperature of not less than the glass transition point in the oral cavity, for example, hot water of 60 ° C. to 65 ° C., and bringing the hot water into sufficient contact with the maintenance portion. It is also possible to spray hot water or hot air at an appropriate temperature on the maintenance part. The heating method for attaching / detaching the denture can be similarly used for the following denture bases.

Even when the entire denture base is made of shape memory resin instead of the above, or when the portion located at the residual tooth undercut is made of shape memory resin, it can be attached and detached in the same manner. That is, when the denture is attached or detached, the shape memory resin portion or the entire denture including the shape memory resin portion is heated to a temperature not lower than the glass transition point of the shape memory resin constituting the denture to make it rubbery elastic, and its deformability is utilized. In the oral wearing condition, the denture can be mounted by sandwiching the narrowed part of the remaining tooth from both adjacent surfaces of the denture base by curing at a temperature below the glass transition point, so the maintenance power is comparable to that of the clasp. It will be strengthened so that it does not become. as a result,
The area of the denture base can be sufficiently narrowed, the temperature and taste of food can be actually sensed, and it is easy to design and manufacture as a so-called palate-free denture with no pronunciation disorder, and the feeling of wearing the denture is improved.

Further, unlike the clasp, since the tooth surface is not rubbed when the denture is attached, the problem of tooth wear is eliminated,
Unlike the clasp, which can protect the dentin of the residual tooth and clamp the residual tooth on both sides of the survivor line, the occlusal stress of the denture is rarely transmitted to the residual tooth, and the residual portion causes the residual tooth to reach the residual tooth. It can prevent damage.

Furthermore, since it is a synthetic resin, it is extremely inexpensive, and there is almost no fear of damage or deformation like a metal clasp, and even if the function deteriorates or is damaged due to some cause after use, replacement is extremely easy. And there's no need to remove dentures for maintenance for days. By using a shape memory resin, these can be made to have the same color as the tooth color or gum color, so part of the tooth surface is not covered with a metal color like a metal clasp, and the natural feeling is not impaired. It is possible to improve the sex.

Next, an example of a denture having a denture base according to the present invention will be described with reference to FIGS.

The denture (1) is provided with an artificial tooth (2) and a denture base (3), the part (7a) near the undercut of the alveolar ridge of the denture base (3) is made of shape memory resin, and the other part ( 7
b) is composed of a usual acrylic resin or the like. Both parts (7) and (8) are firmly bonded by adhesion or fusion.

As described above, by forming the part near the undercut of the alveolar ridge with the shape memory resin, when the denture leaves the oral cavity, the part above the undercut is heated by softening by heating above the glass transition point. Can be opened and removed. On the other hand, at the time of mounting, after mounting the part near the undercut of the alveolar ridge, it is heated and deformed so that it fits the alveolar ridge, and then the temperature is lowered below the glass transition point. The denture can be stably attached by covering the undercut portion of the. Therefore, even if the denture base is extended to the undercut portion of the alveolar ridge, there is no risk of damaging the alveolar ridge during attachment / detachment. Moreover, since the floor area of the denture base can be increased, it is possible to improve the maintenance force when mounting the denture.

In the above embodiment, the example in which only the portion near the undercut of the alveolar ridge is made of the shape memory resin has been described, but the same applies when the entire denture base is made of the shape memory resin.

10 to 13 show an embodiment of a casting material according to the present invention. The molding material (8) is formed by stacking the shape memory resin (9) and the low melting point resin (10) having a melting point of about 60 ° C.
Both are bonded or fused. The casting material (8) is used for making a casting model of the metal fitting (12) for maintaining the artificial tooth (11) as shown in FIG. 11, and is used as follows. First, as shown in FIG. 12, a portion (15) corresponding to the maintenance fitting (12) is cast from the plaster model (3) using the casting material (8). At this time, the molding material (8) is heated to a temperature equal to or higher than the melting point of the low-melting resin, and the low-melting resin (10) side is pressed against the tooth surface to mold. In this case, the shape memory resin (9) is also heated above the glass transition point and softened, so that it is easily deformed. After taking the mold in this way, the temperature is lowered and the shape of the shape memory resin (9) is fixed. In this state, the sprue (14) is planted in the portion (15), and the sprue is held and pulled out from the model (13). The casting model thus obtained is buried in foundry sand and used for casting in a usual manner. According to this casting material (8),
Precise molding can be performed by the good molding material of the low melting point resin and the easiness of deformation of the shape memory resin during heating.

Further, according to the present molding material, even a complicated shape as shown in FIG. 13 can be directly molded from the plaster tooth mold.
The manufacturing process of the cast body can be shortened. In addition,
Shape memory resins that can be used in the above-described denture maintenance device, denture base, and molding material include urethane-based, styrene-butadiene-based, crystalline diene-based, norbornene-based polymers and the like.

Among them, polyurethane is preferable, and more specifically, a bifunctional diisocyanate, a bifunctional polyol, and a bifunctional chain extender containing an active hydrogen group are used in a molar ratio of diisocyanate: polyol: chain extender. Agent = 2.0
To 1.10: 1.00: 1.00 to 0.10. It was compounded and polymerized by a prepolymer method. It contained NCO groups and OH groups at the ends in approximately equal amounts and had a glass transition point of −.
Those having a crystallinity of 3 to 50% by weight at 50 to 60 ° C. are preferably used.

Since this polyurethane does not have an excessive NCO group at the end of the molecule, the crosslinking reaction does not proceed and it is a chain molecule. In addition, since it has the above-mentioned crystallinity, deformation, Molding can be performed easily and satisfactorily.

It should be noted that 2 which is a raw material of the above polyurethane
The functional isocyanates of the general formula is represented by OCN-R-NCO, R is - (CH ₂₎ - means an _n group one or two phenylene groups. Specifically, 2,4-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, carbodiimide-modified 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate and the like can be used.

Further, as the bifunctional polyol, general formula is represented by OH-R'-OH, R 'is - (CH ₂₎ - means an _n group one or two phenylene groups. Further, a reaction product of a bifunctional polyol and a bifunctional carboxylic acid or a cyclic ether can be used. Specifically, polypropylene glycol, 1,4-butane glycol adipate, polytetramethylene glycol, polyethylene glycol, a reaction product of bisphenol A and propylene oxide, or the like can be used.

As the bifunctional chain extender containing an active hydrogen group, the general formula is represented by OH-R "-OH, and R" means-(CH ₂ ) _-n group or 1 or 2 phenylene groups. Further, there are reaction products of the chain extender and a bifunctional carboxylic acid or a cyclic ether, and specific examples thereof include ethylene glycol, 1,4-butane glycol, bis (2-hydroxyethyl) hydroquinone and bisphenol. A reaction product of ethylene oxide, a reaction product of bisphenol A and propion oxide, and the like can be used.

The polyurethane of the present invention synthesized from these raw materials can be represented by the following general formula.

HOR "OCONH (RNHCOOR'OCONH) nRNHCOO-R" OCONH (RNHCOOR'OCONH) mRNHCOOR "OH m = 1 to 16 n = 0 to 16 Table 1 shows adjustment examples of the above shape memory polyurethane elastomer. For example, if No. 40 in Table 1 is used, a glass transition point of 48 ° C. can be produced,
This glass transition point can be freely set by changing the types, compounding ratios and the like of the above-mentioned isocyanate, polyol and chain extender.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Table 3]

[0044]

[Table 4]

[Brief description of drawings]

FIG. 1 is a rear view of an embodiment of a denture according to the present invention viewed from the lingual side.

FIG. 2 is a plan view of an embodiment of a denture according to the present invention viewed from the lingual side.

FIG. 3 is a rear view showing a process of mounting a denture.

FIG. 4 is a rear view showing the process of mounting a denture in order.

FIG. 5 is a rear view showing a process of mounting a denture.

FIG. 6 is a rear view showing an embodiment of a denture in the case of a missing intermediate tooth.

FIG. 7 is a rear view showing a mounted state of the artificial tooth of FIG.

FIG. 8 is a plan view of a denture provided with a denture base according to the present invention.

9 is a vertical sectional front view of the denture base of FIG. 8. FIG.

FIG. 10 is a perspective view of a clasp casting casting material according to the present invention.

FIG. 11 is a plan view of a denture manufactured using the casting material of FIG.

FIG. 12 is a front view showing a state of making a mold with the mold material of FIG.

13 is a perspective view of the casting material after casting according to FIG.

[Explanation of symbols]

 (1) ...... Denture (2) …… Artificial tooth (3) …… Denture base (3a) …… Undercut part (3b) …… Maintenance part (4) …… Remaining tooth (5) …… Gum (6) ) …… Ridge (7) …… Undercut

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication location A61K 6/10 7019-4C (72) Inventor Isao Fukumoto 359-8 Ishiharada-cho, Kashihara-shi (72) Invention Person Isao Nagata 12-15, Suikoen, Hirakata

Claims (1)

[Claims] 1. A dental casting material comprising a shape memory resin molded article and a low melting point resin which are superposed and bonded to each other.