JPH0643290B2 - Dental polymerizable thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The dental polymerizable thermoplastic resin composition of the present invention is useful as a tray material and a base plate material. The resin composition of the present invention exhibits plasticity at room temperature and is easily plate-shaped,
The resin can be formed into a tray, and the resin obtained by polymerizing the resin softens at 30 to 100 ° C. Therefore, the plate or the tray can be softened by heating with hot water or hot air to facilitate repair or removal.

[Prior art]

To obtain an accurate oral impression of a patient in dentistry, a tray that fits into the patient's oral cavity is required.

As a material suitable for this tray, a powder component which is usually called a tray resin, which is mainly composed of a powdery acrylic resin containing a polymerization catalyst such as benzoyl peroxide, and a promoter such as NN ′ dimethylparatoluidine are mainly contained in a methyl methacrylate monomer. There is a so-called instant polymerization resin consisting of liquid components included,
The operator mixes the powder and the powder components in a ratio of about 2 to 1 (weight ratio) to form a plastic dough-like material, which is then stretched into a sheet or directly pressed or pressed onto a working model prepared in advance. After rolling for a certain period of time, the tray is completed by waiting for the polymerization by the polymerization reaction.

In the tray, an impression material having a high fidelity such as alginate, silicone, polysulfide, etc., which has a high fidelity that can be cured, is placed and inserted into the oral cavity of a patient to cure the impression material. Gypsum is poured into the sampled impression of the tooth mold, the plaster is cured to form a plaster tooth mold, and then the tray together with the impression material is removed from the plaster tooth mold to manufacture a plaster model.

JP-B-51-35071, JP-A-53-85990
Nos. 53-103691 and 53-110294 disclose such dental tray resins.

Although these publications describe a method of manufacturing a tray, this tray is rich in self-supporting property and excellent in strength in order to improve dimensional accuracy.

Therefore, when peeling the plaster tooth mold together with the impression material from the tray, a large amount of stress acts on the plaster tooth mold, which may damage the tooth mold.In this case, the impression is taken again from the patient,
It was necessary to manufacture a plaster mold.

In the process of making dentures, ant prostheses are also made in the process to make trial adaptations to patients and to correct and confirm their suitability.However, since dentures are usually made of dental paraffin wax, there are strength weaknesses. In order to make up for it, a means of reinforcing it with a base plate or the like containing shellac as a main component is taken, but it is also necessary to use one that exactly fits into the oral cavity of the patient.

Shellac can be removed by heating and softening it when removing the base plate, but it is often too soft when the base plate is made, and it is often difficult to mold the plate, and wrinkles and deformations often remain on the plate. Workability is difficult.

[Specific means for solving problems]

In the present invention, a liquid and a powder can be mixed to form a plate, tray, etc. at room temperature before polymerization, and a cured product obtained by polymerization is 5.0 × 10 ⁴ Newton / cm ² at 40 ° C.
The flexural modulus above is 2.0 × 10 ⁴ Newton / cm ² at 70 ℃
Since the dental polymerizable thermoplastic resin composition that gives a cured product having the following flexural modulus is used, it facilitates repair or removal of the cured plate or tray.

For example, using a resin composition that gives a polymer resin having a vicat softening point of 30 to 100 ° C. as a tray resin, a resin tray is prepared, an impression is taken, and then the tray is placed in hot water together with a plaster tooth mold. It is possible to prevent the plaster tooth mold from being damaged by dipping it or by pouring hot water or steam on the tray to soften the tray and peeling the softened tray together with the impression material from the plaster tooth model.

Since the tray obtained from the resin composition of the present invention does not take reuse into consideration, there is no problem even if the tray is deformed when it is detached from the dental mold.

That is, the present invention includes: (A) component: a monomer liquid containing methyl methacrylate as a main component (B) component: (meth) acrylic resin that dissolves or swells in the above monomer liquid (C) component: dibasic acid and carbon number Component (D) Component Comprising 1 to 18 Lower Alcohol: Polymerization Initiator To provide a dental polymerizable thermoplastic resin composition in which the components (A) to (D) are blended in a specific ratio. The polymer resin obtained by polymerizing the resin composition has a Vicat softening point of 30 to 100 ° C. and a flexural modulus of 5 measured at 40 ° C. according to JIS K-7203. × 10 ⁴ Newton / cm ² or more, 70
It gives a polymerized resin having a flexural modulus of 2 × 10 ⁴ Newton / cm ² or less measured at ° C.

(Resin Composition) The dental polymerizable thermoplastic resin composition of the present invention gives a resin having high rigidity (self-supporting property) at 20 ° C. to 35 ° C. by polymerization, and preferably 50 to 100 ° C. Gives a polymer resin that can be easily and quickly softened at 60 to 90 ° C.

These components of this resin composition are JIS K-72
The Vicat softening point measured at 06 is selected to give a polymerized resin of 30-100 ° C.

That is, for 100 parts by weight of the component (A), the component (B) is 15 to 4 parts by weight.
20 parts by weight, 0.5 to 60 parts by weight of component (C), 0.2 parts of component (D)
The amount of the component (B) is 10 to 400 parts by weight with respect to 100 parts by weight of the sum of the components (A) and (C).

As the component (A), methyl methacrylate alone may be used, or a part (50% by weight or less) thereof may be replaced with another vinyl monomer such as ethyl methacrylate, butyl acrylate or styrene.

As the (meth) acrylic resin as the component (B), a homopolymer or copolymer resin of a (meth) acrylic monomer such as polymethylmethacrylate, a methylmethacrylate / ethylmethacrylate copolymer, or a methylmethacrylate / butylacrylate copolymer can be used. can give.

The diester compound consisting of the dibasic acid of the component (C) and the lower alcohol having 1 to 18 carbon atoms is used for adjusting the softening point and in the room temperature polymerization of the resin powder (B) and the monomer liquid (A)
Formulated to maintain the plasticized dough-like state from mixing until just before curing for a longer time.

Such diester compounds include dibutyl phthalate, dioctyl phthalate, dioctyl adipate, dibutyl adipate, di-2-ethylhexyl maleate,
Examples thereof include diesters of dibasic acids such as dibutyl maleate and dioctyl fumarate with lower alcohols having 1 to 18 carbon atoms.

However, esters having carcinogenicity such as dibutyl phthalate and dioctyl phthalate are not preferable in terms of hygiene.

Examples of the polymerization initiator of the component (D) include the following (1) to (3).

(1) A redox catalyst composed of an organic peroxide and an amine, for example, a metal desiccant such as methyl ethyl ketone peroxide and dimethylaniline and, if necessary, cobalt naphthenate.

(2) Thermal polymerization initiators and accelerators such as organic peroxides and azoisobutyronitrile.

(3) Photosensitizer.

Examples of the organic peroxide include benzoyl peroxide, t-butylperoxybenzoate, dicumyl peroxide, dilauroyl peroxide, and the like. As photosensitizers, benzoin, benzoin methyl ether, P,
Examples thereof include P'-bis (dimethylamino) benzophenone and 2-ethylanthraquinone.

As the accelerator, N, N-dimethylparatoluidine,
Examples include tertiary amines such as N, N-diethanol paratoluidine, dimethylaniline, and triethanolamine.

In addition, pigments such as titanium white, red iron oxide, ultramarine blue, toluidine red, benzidine yellow, etc., if necessary in the above components (A) to (D); calcium carbonate, magnesium carbonate, diatomaceous earth,
Inorganic fine powders such as silica gel and magnesium silicate; silane coupling agents, titanium coupling agents; cross-linking agents such as polyfunctional acrylates; polymerization inhibitors such as hydroquinone; resin powders such as polypropylene and polyethylene may be added.

It should be noted that adding a small amount of paraffin, silicone oil, or silicone resin polyols for the purpose of improving the curability of the surface of the composition, preventing stickiness, etc. does not pose any problem, but adding a large amount causes the liquid to separate and preservability is improved. After being damaged or cured, it is not preferable because it may stick out on the surface of the cured product and cause stickiness or poor adhesion.

(Base Pellet or Tray) A base plate or tray is prepared by mixing a predetermined amount of a polymerization initiator, a monomer liquid in which an accelerator is dissolved, a diester compound, and a (meth) acryl-based resin powder to prepare a composition, which is then placed on the patient's mouth. When this resin composition was pressed onto a similar work model and cured at room temperature, the flexural modulus at 40 ° C. was 5 × 10 ⁴ Newton / cm ² or more, and the flexural modulus at 70 ° C. was 2 × 10 4. A base plate or tray of ⁴ Newton / cm ² or less is obtained.

This hardened base plate or tray has a high rigidity that is self-supporting at room temperature and does not deform at the oral temperature of the patient (about 32 to 38 ° C). The cured tray is also thermoplastic and has a Vicat softening point of 3
It is 0 to 100 ° C, preferably 40 to 90 ° C.

(Manufacturing method of plaster tooth mold) Impression materials such as alginate, silicone, and polysulfide are kneaded into this tray, the tray is placed in the patient's mouth, and the impression material is cured for 3 to 10 minutes to take the patient's tooth mold. After obtaining it, pour plaster into the cured impression material,
The plaster is hardened to obtain a plaster mold.

When pulling out the tray directly from this plaster tooth mold, the tooth mold may be damaged, and it is very difficult to take out the undercut without damaging it. After the mold is placed in hot water of 70 to 100 ° C. for 1 to 5 minutes to soften the tray, the tray is taken out of the hot water and removed from the plaster tooth mold while the tray is softened.

Instead of immersing the tray in hot water, boiling water may be applied to the tray, or the tray may be heated and softened by steam or hot air.

(Manufacture of Denture) After forming a wax pattern and arranging artificial teeth on a hardened base plate, this is embedded in gypsum in a flask to make a gypsum mold. After the plaster is hardened, the plaster mold made in hot water is dipped or hot water is applied to the plaster mold to wax the wax, and at the same time, the base plate is softened and removed. For removing the base plate, it may be heated and softened with steam or hot air.

A preliminarily prepared floor resin is embedded in the gypsum mold thus obtained, and after curing by heating, a denture in which artificial teeth are arranged is taken out from the gypsum mold.

(Effect) (i) Tray Since the tray obtained from the resin composition of the present invention is removed from the gypsum tooth mold when it is softened and shows a plasticized state, the stress for pulling out to the gypsum tooth mold is uniform. Since it is dispersed and not concentrated in one place, it can be obtained without damaging the plaster model. Of course, an undercut tooth profile can be obtained without damage. In addition, after the tray is manufactured, it may be necessary to make a correction, and even at that time, it can be easily corrected by heating with the hot water temperature. The tray obtained from the resin composition of the present invention has a sharp manifestation of softening and a high rigidity at room temperature, and therefore a good gypsum model can be produced without impairing dimensional accuracy.

(ii) base plate When the base plate obtained by the resin composition of the present invention is softened and shows a plasticized state, the base plate is removed from the gypsum tooth mold, so that the stress of pulling out to the gypsum tooth mold is uniformly dispersed at one place. It can be obtained without damaging the plaster tooth mold because it is not concentrated on. Further, when the denture model using the base plate is trial-adapted to a patient, it does not soften at the temperature in the oral cavity or easily deformed by external force as in the case of using wax. Further, there are cases where correction is required after the base plate is manufactured, but at that time as well, it can be easily corrected by heating with the hot water temperature. The base plate obtained from the resin composition of the present invention exhibits sharp softening, has high rigidity at room temperature, and therefore can produce a good gypsum model that impairs dimensional accuracy.

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 300 parts by weight of a methyl methacrylate / butyl acrylate copolymer powder containing 4% by weight of benzoyl peroxide and having a glass transition point (Tg) of about 91 ° C., 82% by weight of methyl methacrylate and 16.7 parts by weight of dimethyl adipate. % And N, N′-dimethylparatoluidine 1% by weight, 100 parts by weight of a monomer mixture liquid (hereinafter sometimes simply referred to as a monomer liquid) is placed in a container and mixed with a spatula to form a dough-like mixture. After kneading, this is rolled into a sheet with fingers, pressed onto a working model, and cured at room temperature for 8 minutes at 23 ° C.,
The cured product was removed from the working model to prepare a tray.

The Vicat softening point of this tray is about 55 ° C, 40 ° C
Flexural modulus at 40 ℃ 7.8 × 10 ⁴ Newton /
cm ² , 0.9 × 10 ⁴ Newton / cm ² at 70 ° C., 2.
It was 3 × 10 ⁵ Newton / cm ² , and the pencil hardness was 3H.

A silicone-based impression material was placed in this tray, then inserted into the oral cavity of the patient, and after 5 minutes, the tray was pulled out from the oral cavity.

The hardened impression material having the tooth pattern of this tray was washed with water, and then plaster was poured into the tooth pattern of the impression material to cure the gypsum.

Next, the tray was dipped in hot water at 80 ° C. for 5 minutes together with the plaster tooth mold to soften the tray, and then the plaster tooth mold was easily removed while the tray was in the softened state.

No breakage of the plaster mold was observed.

Examples 2 to 6 and Comparative Examples 1 to 4 A composition was prepared in the same manner as in Example 1 except that the monomer liquid having the composition shown below was used to produce a plaster tooth mold.

Table 1 shows the ease of removing the plaster tooth mold and the presence or absence of breakage of the plaster tooth mold.

Example 2 Methyl methacrylate 82 wt% Di-2-ethylhexyl maleate 16.7 wt% N, N'-Dimethylparatoluidine 1.3 wt% Example 3 Methyl methacrylate 82 wt% Diethyl phthalate 16.7 wt% N, N'-Dimethylparatoluidine 1.3 wt% Example 4 Methyl methacrylate 82 wt% Dioctyl phthalate 16.7 wt% N, N'-Dimethylparatoluidine 1.3 wt% Example 5 Methyl methacrylate 82 wt% Dibutyl maleate 16.7 wt% N, N'-Dimethylparatoluidine 1.3 % By weight Example 6 Methyl methacrylate 82% by weight Dioctyl adipate 16.7% by weight N, N′-dimethylparatoluidine 1.3% by weight Comparative example 1 Methyl methacrylate 98.7% by weight N, N′-dimethylparatoluidine 1.3% by weight Comparative example 2 Methyl Methacrylate DOO 30 wt% dibutyl maleate 68.7 wt% N, N'-dimethyl-p-toluidine 1.3% by weight Comparative Example 3 A company commercially available trays resin commercially available tray Resin Comparative Example 4 B Company Example 7 300 parts by weight of methyl methacrylate / butyl acrylate copolymer powder containing 4% by weight of benzoyl peroxide and having a glass transition point of about 91 ° C., 82% by weight of methyl methacrylate, 16.7% by weight of dimethyl adipate and N ，
100 parts by weight of a monomer liquid consisting of 1.3% by weight of N'-dimethylparatoluidine was put in a container, mixed with a spatula and kneaded into a dough-like shape, which was then rolled into a sheet shape with fingers.
Then, it was pressed onto the working model and cured at room temperature for 8 minutes at 23 ° C., and this was removed from the working model to obtain a base plate.

The Vicat softening point of this base plate is 55 ° C,
Flexural modulus is 7.8 × 10 ⁴ Newton / cm ^{2 at} 40 ℃
0.9 × 10 ⁴ Newton / cm ² at 70 ℃, 2.3 × at 23 ℃
It was 10 ⁵ Newton / cm ² and the pencil hardness was 3H.

A wax pattern was formed on this base plate and artificial teeth were arranged, and then embedded in gypsum in a flask to prepare a gypsum mold. After the gypsum was cured, the gypsum mold was dipped in hot water at 80 ° C. to wash the wax, and then the softened base plate was immediately removed. It was easy to remove the base plate, no damage to the plaster mold was found, and the surface of the obtained plaster was beautiful.

Examples 8 to 12 and Comparative Examples 5 to 9 Monomer liquid 1 containing 300 parts by weight of methyl methacrylate / butyl acrylate copolymer powder having a glass transition point of about 91 ° C. and containing 4% by weight of benzoyl peroxide.
Example 7 except that the composition of 00 parts by weight was changed as follows.
A base plate was produced in the same manner as in 1. and a plaster tooth mold was obtained.

The results are shown in Table 2.

Example 8 Methyl methacrylate 82.0% by weight Di-2 ethylhexyl maleate 16.7% by weight N, N'-dimethylparatoluidine 1.3% by weight Example 9 Methyl methacrylate 82.0% by weight diethyl phthalate 16.7% by weight N, N'-dimethylparatoluidine 1.3% by weight Example 10 Methyl methacrylate 82.0% by weight Dioctyl phthalate 16.7% by weight N, N'-dimethylparatoluidine 1.3% by weight Example 11 Methyl methacrylate 82.0% by weight Dibutyl maleate 16.7% by weight N, N'-dimethylparatoluidine 1.3 % By weight Example 12 Methyl methacrylate 82.0% by weight Dioctyl adipate 16.7% by weight N, N′-dimethylparatoluidine 1.3% by weight Comparative example 5 Methyl methacrylate 98.7% by weight N, N′-dimethylparatoluidine 1.3% by weight Comparative example 6 Methyl Methacrylate 30% by weight Dibutyl maleate 69.7% by weight N, N'-dimethylparatoluidine 1.3% by weight Comparative Example 7 Commercial base plate resin of Company A Comparative Example 8 Commercial base plate resin of Company B [Application Example] Gypsum model obtained in Examples 1 to 7 and Examples 8 to 1
A complete denture was prepared using the resin composition for a base plate used in 2. That is, create a base plate on the obtained gypsum model, then form a wax pattern on it, arranging the dentures separately prepared, the wax model supported by the obtained base plate is embedded in a flask,
After taking a negative mold, the wax was poured out and the base plate was removed, and then a commercially available denture base resin was embedded in the gypsum mold and heat-polymerized to prepare a full denture.

All of these dentures had good compatibility.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Haruhiko Aoi 2-5-2 Marunouchi, Chiyoda-ku, Tokyo Sanryo Yuka Co., Ltd. New Business Department (56) Reference JP-A-53-103691 (JP, A) JP-A-53-110294 (JP, A) JP-B-51-35071 (JP, B1)

Claims (1)

[Claims] 1. A component (A): a polymerizable monomer liquid containing methyl methacrylate as a main component (B) component: a (meth) acrylic resin which dissolves or swells in the monomer liquid (C) component: dibasic acid and carbon Diester compound consisting of lower alcohol of the number 1 to 18 (D) component: Polymerization initiator 15 parts of (B) component to 100 parts by weight of the above (A) component.
~ 420 parts by weight, 0.5 to 60 parts by weight of component (C),
Component (D) is blended in a proportion of 0.2 to 5 parts by weight, and
(B) to 100 parts by weight of the sum of component (A) and component (C)
Dental polymerizable thermoplastic resin composition in which components are blended in a ratio of 10 to 400 parts by weight