JP3155430B2 - Dental photopolymer resin material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photopolymer resin material for dental use which is used in a process of manufacturing a pattern material, for example, a clasp pattern, a crown bridge pattern, an inlay pattern and the like, particularly in the field of dental technology.

[0002]

2. Description of the Related Art Dental materials using photopolymerized resin materials are:
Some are already commercialized and commercially available. Related techniques in this field are also known. For example, the present invention relates to a photopolymerizable resin composition for producing a clasp pattern (Japanese Unexamined Patent Publication No.
No. 110609), and a material for producing a similar pattern, in which a powder such as polystyrene is mixed with a urethane acrylate resin liquid (JP-A-62-115013).

Further, the inventors have filed an application for this kind of photopolymerizable resin material (Japanese Patent Application No. 3-323914).
Application, Japanese Patent Application No. 3-323942, Japanese Patent Application No. 5-71241
issue).

[0004]

According to experiments conducted by the inventors of the present invention, a pattern material made of a dental photopolymerization resin that is currently in practical use has a low viscosity before polymerization and is inferior in moldability and operability. What is easy to be deformed after polymerization hardening, What is easy to break when detached from the tooth model when the strength after polymerization hardening is weak and made into a thin shape like a clasp, Adhesive in the state before polymerization hardening, Some stick to the instrument.

The present invention has been made to solve such a problem, and the operability before curing by polymerization is substantially equal to that of wax conventionally used as this kind of material, and sufficient toughness after polymerization is required. A dental photopolymerizable resin material that satisfies the conditions that it does not break when attached to and detached from an artificial tooth plaster model and that it does not deform after polymerization.

The present inventors have further studied after filing the above-mentioned application, and as a result, by adding polycaprolactone (hereinafter abbreviated as PCL) as an organic filler, the breaking strength after polymerization and curing is improved. Focusing on what you can do,
The present invention has been made.

[0007]

According to the present invention, there is provided a method for preparing a polyethylene glycol dimethacrylate from 25% to 35% by weight, a methyl methacrylate macromonomer from 40% to 60% by weight, a polycaprolactone from 5% to 35% by weight, The photopolymerization initiator and the photopolymerization auxiliary are mixed in a range of 0.5% by weight to 2% by weight.

Further, the present invention relates to a method for producing a poly (ethylene glycol) dimethacrylate comprising 25% to 35% by weight and a methyl methacrylate macromonomer comprising 40% to 60% by weight.
% By weight, 3% to 1% by weight of polymethyl methacrylate
5% by weight, 5% by weight to 20% by weight of polycaprolactone, and 0.5 to 2% by weight of a photopolymerization initiator and a photopolymerization aid.

[0009]

A photopolymerization initiator and a photopolymerization assistant are added to polyethylene glycol dimethacrylate (hereinafter abbreviated as PEGDM), methyl methacrylate macromonomer (hereinafter abbreviated as MMA macromonomer) and PCL, and the kneaded resin mixture is It has a state very similar to wax before polymerization by irradiation with visible light, and has high toughness and hardly breaks after polymerization and curing.

PEGDM, MMA macromonomer, polymethyl methacrylate (hereinafter abbreviated as PMMA), P
A photopolymerization initiator and a photopolymerization assistant are added to CL, and the kneaded resin mixture has properties very similar to wax before polymerization by irradiation with visible light, good shape retention after molding, and polymerization. After hardening, it has high toughness and hardly breaks.

[0011]

An embodiment of the present invention will be described below. 34.5% by weight of PEGDM solution as a photopolymerizable monomer, 55.2% by weight of MMA macromonomer powder as an organic filler, P
9.0% by weight of CL powder, 2,4-diethylthioxanthone (hereinafter abbreviated as DETX-S) as a photopolymerization initiator
0.65% by weight, 0.65% by weight of ethyl 4-dimethylaminobenzoate (hereinafter abbreviated as EPA) as a photopolymerization aid
0.62% by weight of hydroquinone as a polymerization inhibitor and a trace amount of a red pigment were added thereto and mixed to form a light-transmitting and clay-like material. The reason for the light transmittance is to allow light to penetrate deep into the resin material, so that the polymerization reaction is sufficiently performed. The photopolymerized resin having such a composition obtained results satisfying each condition of molding operability before polymerization, breaking strength after polymerization, operability such as attachment / detachment to a model, incineration residue, polymerizability, and storage stability. Incidentally, visible light is particularly effective as an irradiation light source.

The criterion for accepting the above conditions is as follows. Molding operability before polymerization: Viscosity Its properties are similar to wax. That is, it is easy to form and build with a spatula, chisel, etc. and does not adhere to them. Operability and strength after polymerization: Fully polymerized and hardened to the deep part, and strength and toughness that do not break even when deformed when removed from the model (for example, expanded deformation force when removed from the undercut). After releasing the deformation force, return to the original shape. Incineration residue: Zero residue after incineration with auto furnace at 700 ° C for 1 hour. The residue on burning 3 g of material before incineration shall be zero on a 0.1 mg precision balance. Polymerizability: One visible light is applied to a resin sheet (25 × 20 × 2 mm).
Polymerize completely when irradiated for 1 minute. The light irradiator used was a water light (trade name, manufactured by Morten Medical Co., Ltd.). Storage: No change for more than one month in a dark place at room temperature.

Regarding the breaking strength, the following test was separately conducted. Visible light was applied to a resin sheet (60 × 10 × 3.2 mm) and completely polymerized and cured.
mm on two fulcrums, press the pointed shaft from the center between the fulcrums at a speed of 2 mm / min, and measure the bending strength and the distance from the line connecting the two fulcrums to the position where the sheet breaks. did. As a result, the photopolymerized resin having the above composition had a maximum bending strength of 2.5 kgf / cm ² and did not break even when pushed down to 12 mm. However, when it was pushed down to 12 mm, the bending strength decreased. In contrast, the photopolymerized resin sheet containing no PCL and having substantially the same other components had a maximum bending strength of 1.1 kgf / cm ² and broke at a pushing distance of 4 mm.

The mixing ratio of PEGDM, which is a photopolymerizable material (liquid), is suitably in the range of 25% by weight to 35% by weight. If the content is less than 25% by weight, the amount of the powder filler increases by the reduced amount. As a result, the powder filler becomes in a flaky state, deteriorating moldability and workability, and slows down the polymerization and curing by light irradiation. On the other hand, if it exceeds 35% by weight, it is too soft and the shape retention after molding is poor, and the work operability such as sticking to a finger is poor.

The MMA macromonomer, which is an organic filler, is mixed to give the material a wax-like property, and is suitably in the range of 40% by weight to 60% by weight. If the content is less than 40% by weight, the fluidity increases, and the material becomes too soft, resulting in poor moldability and sticking to hands, resulting in poor operability. On the other hand, if it exceeds 60% by weight, there arises a problem that it becomes too hard, is inferior in molding operability, and is easily broken.

The organic filler PCL is used to improve the bending strength of the material after the polymerization and to prevent the material from being broken, and to allow the separately molded article to be bonded with a commercially available acrylic adhesive before or after the polymerization. Used for
The mixing ratio is desirably in the range of 5% by weight to 35% by weight. If the amount is less than 5% by weight, the shapeability deteriorates,
If the flexural strength exceeds 35% by weight, a property as an elastic body appears, and even if it is pressed and molded with a finger or the like, it rebounds and returns. In addition, since the color is white, if this is increased, the light transmittance deteriorates, and the polymerization rate may decrease.

The photopolymerization initiator DETX-S and the photopolymerization assistant EPA are preferably used in a range of 0.5% by weight to 2% by weight. If the amount is less than 0.5% by weight, the polymerizability is reduced, and there is a problem that the polymerization is poor or the polymerization takes a long time. If the amount is more than 2% by weight, the phenomenon that the polymerization curing reaction is reduced appears. The problem that stability is lost arises.

When the above materials are mixed and kneaded to form a clay, if the polymerization inhibitor hydroquinone is mixed in an amount of about 0.01 to 0.02% by weight, the stability over time of the polymerization reaction of the materials is improved. . About 0.02% by weight of a suitable red pigment
Can be added to give a light red color.

In order to further improve the maintenance of the shapeability of the molded body before the polymerization, a material having the following composition may be used. This will be described below as another embodiment. 30.4% by weight of PEGDM solution as a photopolymerizable monomer, 48.6% by weight of MMA macromonomer powder as an organic filler, P
7.9% by weight of MMA powder, 11.9% by weight of PCL powder, 0.58% by weight of photopolymerization initiator DETX-S, 0.58% by weight of EPA photopolymerization aid, 0.02% by weight of polymerization inhibitor hydroquinone
And a small amount of a red pigment was added thereto and mixed to form a clay.

For the resin having the above-mentioned composition, as in the case of the above-mentioned one embodiment, each of the molding operability before polymerization, the breaking strength after polymerization, the operability such as attachment / detachment to a model, incineration residue, polymerizability, and storage stability was obtained. The conditions were tested and satisfactory results were obtained.

In the above embodiment, especially by mixing PMMA powder, the shaping property when molding the clay-like resin, that is, the operability with a chisel, a finger or the like is good, and the molded portion rebounds. An advantage is obtained that the shape once formed is kept with good stability without any trouble.

In the above embodiment, PEGDM, MMA
The macromonomer, the photopolymerization initiator and the photopolymerization auxiliary are in the same range as in the first embodiment, that is, PEGDM2.
5% to 35% by weight, MMA macromonomer 40
% To 60% by weight, DETX-S and EPA 0.5
It is used in the range from 2% by weight to 2% by weight.

The PCL is preferably used in the range of 5% by weight to 20% by weight. If the amount is less than 5% by weight, the strength is reduced. On the other hand, if the amount is more than 20% by weight, rebound is generated even when molded.

The PMMA powder is used in an amount of 3 to 15% by weight.
Preferably, it is used in the range of weight%. If the amount is less than 3% by weight, the shapeability deteriorates, and the precision of the molded body deteriorates. If the amount exceeds 15% by weight, the curing proceeds with time.

As a result of performing the above-described fracture strength measurement test on the resin mixed and formed with the above-mentioned composition, the maximum bending strength was 2.1 kg.
A value of f / cm ² is obtained, which is about twice the value of the conventional one.

The photopolymerized resin described in the above two embodiments is used as a material for a clasp pattern, a crown bridge pattern, an inlay pattern, an onlay pattern, a bar, a skeleton, and a stipple sheet. That is, the above resin material is used in place of the wax in the conventional lost wax method, buried in a sand mold, and after incineration, the dental metal is poured and cast.

The above-mentioned materials include a personal tray, a base plate, a temporary crown (a material that is temporarily inserted until a cast crown is put on a tooth-cut cavity), an orthodontic appliance, a bruxism prevention device, a dental rebase material, It can be used as a material for temporary dentures.

[0028]

According to the present invention, since PCL is used as a component of the photopolymerizable resin, the bending strength is improved and the finger,
Even when a tool or the like is polymerized and cured, it does not easily break. Therefore, even if it is formed in the undercut portion of the model such as the clasp, it can be expanded and removed.

Further, according to the present invention, the use of the above PCL makes it possible to adhere with an acrylic adhesive. Therefore, the separated denture part before polymerization or after polymerization,
It can be easily adhered to other denture parts, making it easier to manufacture dentures.

Further, according to the present invention, in addition to PCL, PM
By mixing MA, the shapeability of the molded body before polymerization is improved. That is, molding with a finger, an instrument or the like is easy, and there is no rebound after molding, and the shape is stably maintained for a long time.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-256130 (JP, A) JP-A-5-132408 (JP, A) JP-A-4-211602 (JP, A) JP-A-Heisei 4- 216858 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) A61K 6/08-6/083 A61C 5/08-5/10 A61C 13/00-13/32

Claims (2)

(57) [Claims] 1. Polyethylene glycol dimethacrylate is 25 to 35% by weight, methyl methacrylate macromonomer is 40 to 60% by weight, polycaprolactone is 5 to 35% by weight, a photopolymerization initiator and a photopolymerization aid. A photopolymerizable resin material for dental use, characterized in that the agent is mixed in the range of 0.5% by weight to 2% by weight. 2. 25% to 35% by weight of polyethylene glycol dimethacrylate, 40% to 60% by weight of methyl methacrylate macromonomer, 3% to 15% by weight of polymethyl methacrylate, 5% by weight of polycaprolactone. 20% by weight of a photopolymerization initiator and a photopolymerization aid mixed in a range of 0.5 to 2% by weight.