JP3102619B2 - How to make acrylic dentures - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an acrylic denture with improved precision by polymerizing a dough injected into a denture mold by a simple method while maintaining the pressure of the dough.

[0002]

2. Description of the Related Art In general, an acrylic denture is prepared by filling a gypsum mold prepared by an ordinary method of dentistry with a dough obtained by mixing an acrylic polymer and a monomer, followed by heat polymerization. As a method of filling the dough, a method of injecting the dough after closing the mold is widely used clinically as a method for preventing the occlusal height of the manufactured denture from being changed. At that time, a method has been developed and publicly known in which a dough is polymerized in a pressurized state in order to compensate for polymerization shrinkage of the monomer, thereby increasing the fitting accuracy of the acrylic denture. As a method for performing polymerization while the dough is pressurized, a method is generally used in which polymerization is performed while the flask is attached to a resin injection jig.

However, in this method, it is necessary to fix the flask to the injection jig until the dough polymerization is completed.
As a result, the productivity of the denture decreases. Further, for the purpose of improving productivity, a system (cosmo denture system) capable of injecting dough into a large number of flasks at once has been developed, but the apparatus is large and expensive.

[0004] In addition, literature (Dental Materials and Instruments Vol.1)
0, No. 3, 1991) and Japanese Patent Application Laid-Open No. 1-256954, as a method for removing a flask from an injection jig and polymerizing the flask, removing the flask from the injection jig, taking out the flask from the injection jig, and setting the injection port of the flask. And pressurizing the dough by tightening bolts. However, in this method, the pressure of the dough changes every time the volume of the screwed-in bolt and the volume of the denture base of the denture to be manufactured change, and not only the necessary pressure is not always obtained, but also the hardening after polymerization. There is a disadvantage that the resin remains on the screw portion and it takes time for cleaning.

For the purpose of remedying such a drawback, the present inventors attached a flask to an injection jig, cut off the resin injection path between the injection jig and the flask while maintaining the pressure of the dough, and set an acrylic resin. A method for polymerizing under pressure was developed. However, in order to further increase the quality and dimensional accuracy of the acrylic denture, it is desired to start the polymerization with the dough pressure further increased.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an acrylic denture for polymerizing an acrylic resin injected into a denture mold by a simple method while maintaining the pressure of the dough, thereby improving the fitting accuracy of the acrylic denture. The production method of is provided.

[0007]

The present invention relates to a method for polymerizing an acrylic resin dough by injecting an acrylic resin dough from the outside of a flask using an injection jig and then removing the flask from the injection jig. Place the cylinder on a metal frame and place the injection jig and resin in the metal frame.
Insert the flask with the stopper attached, and insert the injection jig.
The present invention relates to a method of manufacturing an acrylic denture, which is fixed to a frame with a frame .

In more detail, the resin injection port of the flask is suspended from the frame, and a large force applied to the cylinder during resin injection is applied to the frame other than the flask, so that the flask is not deformed without deforming the flask. It is a method of injecting.

[0009] Thereafter, a method described in Japanese Patent Application No. 5-264573, that is, a resin stopper is inserted to shut off the injection jig and the resin injection path of the flask while the pressure of the dough is maintained, and the flask is injected. Use the method of removing from the tool.

According to the method of the present invention, since the injection jig does not strongly press the flask, the pressure of the dough due to the return of the flask when the flask is removed from the injection jig is small, and as a result, the pressure during the resin injection is reduced. The acrylic resin can be polymerized in a state where the above is substantially maintained, and an acrylic denture with good quality can be obtained.

As a method of not directly transmitting a large force applied to the cylinder itself to the flask during resin injection, the cylinder is fixed to a strong metal frame such as iron or stainless steel, and only the pressure of the resin in the cylinder is reduced. The method involving the flask is employed. The frame of the present invention is desirably integrated with a strong metal material, but it is not necessarily required to be integrated.For example, a frame having the same shape as the frame by passing a metal plate on a support may be used. Alternatively, the shape may be a U-shape.

Next, an example of manufacturing an acrylic denture by the method of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram of an apparatus for injecting an acrylic resin. The flask 5 equipped with the injection jig 2 and the resin stopper 3 is placed in a slidable metal frame 4 attached to the frame of the press 6 and slidable.
A cylinder 1a containing a predetermined amount of an acrylic resin dough is fitted into the injection jig 2 through a hole formed in the frame 4. afterwards,
The press 6 is raised, and the resin in the cylinder 1 a rising together with the frame 4 is extruded into the flask 5 by a push rod 1 b fixed to the upper plate of the press 6. At this time, a force of 1 ton or more is applied to the cylinder 1a, but since the force is received by the frame 4, the deformation of the flask 5 due to the compressive force hardly occurs. Rather, the injection jig 2 and the flask 5 are applied with a force to be spread by the pressure of the injected resin. Therefore, after compressing and injecting the resin, the resin stopper 3 is pushed into the injection jig 2 to cut off the resin injection path of the resin of the cylinder 1a and the flask 5, and the flask 6 is injected even if the press 6 is loosened and the flask 5 is taken out. The pressure of the applied resin is kept high.

FIG. 2 is a sectional view showing a state in which the flask 5 and the injection jig 2 and the injection jig 2 and the cylinder 1a are joined. The injection jig 2 fixed to the flask 5 with a gypsum mold and bolts of the flask 5 is sealed with an O-ring 9. The injection jig 2 is fixed to the frame 4 with screws 7, and the cylinder 1 a is installed on the frame 4 with the packing 8 interposed therebetween. If a force of 1 ton or more applied to the cylinder is directly applied to the flask 5 and the injection jig 2 when injecting the resin, the mating surface of the flask 5 and the micro gap between the flask 5 and the injection jig 2 are reduced. When the injection force is released, the contracted gap returns, and only a small compressive force is applied to the flask 5 and the injection jig 2.
However, in the present invention, when the resin is injected, a force that swells the flask 5 or the gap between the flask 5 and the injection jig 2 due to the internal pressure of the resin. Therefore, after the resin is compressed and injected, the resin stopper 3 is pushed into the injection jig 2 to cut off the resin injection path of the resin of the cylinder 1 a and the flask 5. Even if the press 6 is loosened and the flask 5 is taken out, the resin remains in the flask 5. The pressure of the injected resin is kept high.

[0014]

According to the method of the present invention, it is possible to carry out polymerization while maintaining the pressure of the dough of the acrylic resin injected into the denture mold, thereby improving the fitting precision of the acrylic denture.

[0015]

Next, the present invention will be described more specifically with reference to examples and comparative examples.

Example In accordance with the general practice of dentistry, a mold for an upper denture was made of plaster in a flask 5 and a pressure sensor was placed in the mold. An acrylic resin polymer and a monomer were mixed to prepare a dough, which was injected into the flask 5 of FIG. Resin pressure 6
After holding at 0 kg / cm ² for 1 minute, resin stopper 3
Is pressed into the injection jig 2 to cut off the resin injection path between the cylinder 1a and the flask 5, and the press 6 is loosened to release the flask 5
Was taken out of the press 6, and a pressure change for 3 minutes was observed. As a result, there was no pressure drop immediately after being removed from the press 6, and there was a time-dependent pressure drop of about 5 kg / cm ² for 1 minute, which is considered to be due to the detailed transfer of the resin in the flask, and then at about 55 kg / cm ² Equilibrium has been reached.

COMPARATIVE EXAMPLE The frame 4 was removed from the apparatus of the example, and the pressure applied to the cylinder 1a was directly applied to the flask 5 during the injection of the resin. As a result, immediately after the press 6 was loosened, the pressure of the resin in the flask 5 was reduced to about 30 kg / cm ² by half, and the equilibrium state was maintained thereafter.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an apparatus for injecting an acrylic resin.

FIG. 2 shows a flask 5, an injection jig 2, and an injection jig 2.
FIG. 4 is a cross-sectional view showing a joint state between the cylinder and a cylinder.

[Explanation of symbols]

 1a cylinder 1b push rod 2 injection jig 3 resin stopper 4 frame 5 flask 6 press 7 screw 8 packing 9 O-ring

Claims (4)

(57) [Claims] In a method of injecting an acrylic resin dough from the outside of a flask using an injection jig and then removing the flask from the injection jig and polymerizing the acrylic resin dough, a cylinder is formed of a metal frame. Can be placed on top and slidable
Place the injection jig and resin stopper in a functional metal frame
A method for producing an acrylic denture, which is characterized by placing a flask attached . (2) Acrylic resin dough from outside the flask
After injecting using the injection jig, place the flask in the injection jig.
Method to polymerize acrylic resin dough
Place the cylinder on a metal frame and press
In a slidable metal frame 4 attached to the frame
Flask 5 equipped with injection jig 2 and resin stopper 3
And a cylinder with a predetermined amount of acrylic resin dough
1a is inserted into the injection jig 2 through a hole formed in the frame 4,
After that, raise the press 6 and move it together with the frame 4.
The resin in the cylinder 1a is fixed to the upper plate of the press 6.
And push it into the flask 5 with the push rod 1b
A characteristic method of producing acrylic dentures. (3) Acrylic resin dough from outside the flask
After injecting using the injection jig, place the flask in the injection jig.
Method to polymerize acrylic resin dough
Place the cylinder on a metal frame and press
In a slidable metal frame 4 attached to the frame
Flask 5 equipped with injection jig 2 and resin stopper 3
And a cylinder with a predetermined amount of acrylic resin dough
1a is inserted into the injection jig 2 through a hole formed in the frame 4,
After that, raise the press 6 and move it together with the frame 4.
The resin in the cylinder 1a is fixed to the upper plate of the press 6.
Extruded into the flask 5 with the push rod 1b
After compression injection, press resin stopper 3 on injection jig 2
The resin in the cylinder 1a and the resin in the flask 5
Break the road, loosen the press 6 and remove the flask 5
The method for producing an acrylic denture characterized by the following. (4) In addition, the injection jig is fixed to the frame with screws
The method according to any one of claims 1, 2, or 3, wherein
The method of making the acrylic dentures mentioned above.