JP3293250B2 - Dental flask - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dental flask that can easily and accurately produce an acrylic resin denture (acrylic denture) in a short time.

[0002]

2. Description of the Related Art In general, an acrylic denture is prepared by filling a gypsum mold prepared by a usual dental method with a dough obtained by mixing an acrylic polymer and a monomer, and then heating and polymerizing the resin in boiling water. There is a wet heat polymerization method of curing, a microwave polymerization method of heating and curing the resin by heating the gypsum mold filled with dough with microwave irradiation such as a microwave oven,
Various flasks have been proposed for use in microwave polymerization.

A flask used for microwave polymerization is disclosed in, for example, JP-A-61-76149 and JP-A-6-76149.
Japanese Patent Application Publication No. 1-26347 discloses a flask comprising an upper lid, a middle ring and a lower ring made of fiber reinforced plastic (FRP). However, since the dough is put between the gypsum split molds and the test pressure is repeated, the upper lid, the middle ring and the lower ring of the flask are tightened with bolts and nuts, so that it is not possible to supply the resin which compensates for the polymerization shrinkage of the monomer. In addition, the manufactured denture shrinks and the fitting accuracy is inferior.

Japanese Patent Application Laid-Open No. 63-22086 discloses an injection flask in which a part of a metal flask is removed so that a gypsum mold in the flask is irradiated with microwaves. However, in this flask, since a portion where the microwave is shielded by the metal is formed, the polymerization becomes nonuniform, the resin is deformed, and the fitting accuracy of the manufactured denture is inferior.

Japanese Patent Application Laid-Open No. 2-124155 discloses an injection type FRP flask as a flask capable of supplying a resin for compensating polymerization shrinkage and performing uniform polymerization. However, in this flask, wax dentures made in accordance with common dental practice are primarily buried in the lower ring of the flask with gypsum, then the upper ring of the flask is covered with the lower ring of the flask, and the secondary investment material is injected from the open part of the upper ring of the flask. The secondary investment material is used in a method in which the secondary investment material is covered with a lid in a flowing state, and is waited for the secondary investment material to harden while being compressed and fixed by a clamp or the like. At that time, a gap is created between the upper flask ring and the lower flask ring due to the vibration when the secondary investment material is injected or the pressure from inside the flask when the lid is covered and compressed. It hardens in the gap. Since this secondary investment material can be easily removed by the flask splitting and dewaxing operation in the subsequent process, the dewaxing is completed, the flask is combined, and the plaster mold for denture molding inside the flask is combined, the upper ring of the flask and the lower ring of the flask And a gap is created between them. Therefore, when the flask is tightened with the attached bolts and nuts, the gypsum mold for molding is distorted and the resin leaks from the gypsum mold when the resin is injected. If the tightening force is increased so that the resin does not leak, the flask and the bolt are damaged. In addition, a detachable attachment for resin injection is provided on the mating surface of the upper and lower rings of the flask, but this attachment must be secured each time the primary is buried so that it does not move due to vibration during secondary burial. However, there is a drawback in that it must be fixed to the lower ring of the flask.

[0006]

SUMMARY OF THE INVENTION The present invention provides a dental flask made of FRP that can easily and accurately produce an acrylic resin denture (acrylic denture) in a short time. The present invention relates to an FRP that can improve the difficulties of the dental flasks conventionally proposed by the microwave polymerization method.
Provide a dental flask made of:

[0007]

SUMMARY OF THE INVENTION The present invention relates to an injection-type fiber-reinforced plastic dental flask for producing an acrylic resin bed denture by a microwave polymerization method, wherein the flask comprises an upper ring and a lower ring. and has, substantially in the central portion hollowed plaster supply of the flask on wheels provided, hollowed fixable lid after tightening the upper wheel and the lower wheel is provided on the portions, the resin in the portion other than the lid of the flask on wheels The present invention relates to a dental flask provided with an injection hole.

In the present invention, a gypsum supply hollow portion is provided substantially at the center of the upper ring of the flask, and a lid which can be fixed after tightening the upper wheel and the lower wheel is provided. There is no gap between the upper flask ring and the lower flask ring due to vibration during injection or pressure from inside the flask when the lid is covered and compressed. Therefore, it is possible to eliminate a difficulty caused by a gap between the upper wheel and the lower wheel through a series of processes. In addition, since there is no space between the upper wheel of the flask and the lower wheel of the flask, the upper wheel and the lower wheel can be securely fixed with a small force.

In a plaster mold for molding a denture, a model reproducing an oral impression is held in gypsum on the lower ring of the flask, and artificial teeth of wax dentures arranged in the denture are held in gypsum on the lower ring of the flask. In order to produce a denture with good fitting accuracy, it is necessary to accurately return the positional relationship between the upper and lower rings of the flask before molding. In the present invention, since the lid can be fixed to the hollow portion of the flask upper ring after tightening the upper ring and the lower ring of the flask, even if a flask or bolt made of FRP is used, the upper ring and the lower ring of the flask can be fixed. It is easy to reliably return the positional relationship before molding.

[0010] In the present invention, the resin injection hole may be provided in a portion other than the lid of the flask on wheels, be provided on the upper surface of the other cover of the flask on wheels, also of the flask on the wheel cover
It may be provided on any other side. Parts other than the lid of the flask upper ring
Since the resin injection hole is provided separately, even if the resin injection hole is fixed on the upper surface and the resin is injected from above, the mold will not be broken, and the resin can be securely filled to every corner of the mold. Also, even if the resin injection hole is fixed on the side of the frame and the resin is injected, the plaster integrated with the flask is continuously in front of the injection hole up to the opposite side of the flask, so the flask will not be broken Absent.

If an acrylic resin is polymerized from the model surface to the artificial tooth side while injecting the uncured resin so as to compensate for the volume shrinkage of the resin caused by the polymerization, a denture with good fitting accuracy can be obtained. Also, in the method of manufacturing a denture by microwave polymerization, a model is made by mixing aluminum powder that generates heat with microwave to the model material, and the microwave is applied from the direction of the lower ring of the flask in which the model is buried, and the temperature of the model is reduced. If the temperature is raised above the temperature of other gypsum molds and polymerized from the model surface, the matching accuracy will be improved. Therefore, it is preferable that the resin is injected into the gypsum mold for denture production at the upper ring of the flask opposite to the model surface.

An FRP flask is usually made of a sheet metal.
It is manufactured by molding such as ruden compound (SMC) and bulk molding compound (BMC). However, when molded using BMC, the dimensional accuracy of the flask itself is poor, and there is a danger that the positional relationship of the denture changes. is there. Therefore, in the present invention, it is desirable to provide unevenness for positioning on the mating surface of the upper and lower rings of the flask in addition to the bolt holes for tightening the flask so that the positional relationship of the flask does not change. As positioning irregularities, holes were dug by precision machining in two or more places corresponding to both the upper and lower rings of the flask, and one of them was rapidly heated by microwaves such as a microwave oven. A method of fixing a rod-shaped object made of a material such as a hard resin or ceramics that is not used is preferable. At that time, the length of the rod-like material protruding from the mating surface of the flask may be a length required for positioning the flask, and is usually 5 m.
m or less, preferably 1 to 3 mm.

[0013] As a positioning method, three irregular tapers are attached to the outer periphery of the mating surface of the upper and lower rings of the flask,
A method in which the upper and lower rings of the flask can be positioned at a single point when tightened is also effective. Next, the present invention will be described in detail with reference to the drawings showing an example of the flask of the present invention.

FIG. 1 is a perspective view of a flask showing one embodiment of the present invention. FIG. 2 is a vertical cross-sectional view of the upper flask of the present invention. FIG. 3 is a bottom view of the flask upper ring in the present invention. FIG. 4 is a plan view of the lower flask ring in the present invention. FIG.
FIG. 3 is a vertical sectional view of a lower flask ring in the present invention.

In FIG. 1, the flask comprises an FRP upper flask wheel 1, an FRP lower flask wheel 2 and a lid 3. A resin injection attachment 4 is fixed to the upper frame portion other than the lid of the upper flask ring 1. The attachment 4 is provided with a resin injection hole 12. The tip of the resin injection hole 12 reaches the depression 13 as shown in FIG. The attachment 4 is preferably made of a material that does not adhere to the acrylic resin, such as polyacetal and tetrafluoroethylene (Teflon). Although not shown, the resin injection hole 12 may be provided with a resin injection hole by fixing the resin injection attachment 4 to a side frame other than the lid of the flask upper ring 1. The lower frame portion of the upper flask wheel 1 is provided with a notch 7 for accommodating forceps and the like when dividing the flask. This makes flask splitting very easy.

The upper wheel 1 and the lower wheel 2 of the flask are fastened with bolts 5 and nuts 6. The lid 3 is provided with a hole 8 for discharging and overflowing the gypsum of the secondary investment material.
After the secondary investment material is injected, when the lid 3 is fixed, excess gypsum overflows and hardens, and the gypsum that has overflowed and hardened becomes a gypsum mold when the upper ring 1 and the lower ring 2 of the flask are divided. Has an effect of producing an anchoring effect for preventing falling from the upper wheel 1 of the flask. Further, a secondary investment material is injected into the lid 3, and the upper ring 1 and the lower ring 2 of the flask are tightened with the bolts 5 and the nuts 6. is there.

2 and 3, a recess 13 for receiving a secondary investment material or the like from a hollow portion 11 is provided in the upper flask ring 1 of the flask.
And a bolt hole 5b and a positioning projection 10 are provided.

4 and 5, the lower flask ring 2 is provided with a bolt hole 5a, a recess 14 for receiving gypsum of primary investment material, wax teeth, and the like, and a positioning hole 9 is provided.

Next, with reference to the drawings, an example in which a denture is manufactured using the flask of the present invention will be described. (1) A wax denture is primarily buried in the depression 14 of the lower flask ring 2 according to the usual dental practice. (2) After the gypsum separating material is applied to the primary immersed gypsum, the positioning protrusion 10 of the upper flask wheel 1 is aligned with the positioning hole 9 of the lower flask wheel 2, and the upper flask wheel 1 is placed on the lower flask wheel 2. You. (3) Pass the bolt 5 through the bolt holes 5a and 5b and use a wrench or the like to tighten the nut 6 with the upper flask ring 1 and the lower flask ring 2.
And fix both.

(4) Insert the tip of the sprue attached to the wax tooth into the resin injection hole 12 opened in the depression 13 of the upper ring of the flask, and fix the sprue to the resin injection hole 12 with wax. (5) The flask is placed on the vibrator, and ordinary plaster as a secondary investment material is injected from the gypsum supply hollow portion 11 of the upper wheel 1 of the flask until the depression 13 of the upper wheel 1 is filled. (6) The lid 3 is placed on the gypsum supply hollowed portion 11 of the upper flask wheel 1, and the lid 3 is fixed to the upper flask wheel 1 by engaging the lid 3 and the screw 15 of the hollowed portion 11. When fixed, part of the gypsum overflows from the hole 8.

(7) After the ordinary plaster of the secondary investment material has hardened, the flask is placed in hot water to soften the wax of the wax denture embedded with the gypsum. (8) Remove the flask from the boiling water, loosen the bolt 5,
A forceps or the like is inserted into a notch 7 provided at a lower portion of the upper flask wheel 1 to divide the upper flask wheel 1 and the lower flask wheel 2. (9) After the dewaxing and the application of the resin separating material to the denture mold in accordance with the usual method of dentistry, the flask upper ring 1 and the flask lower ring 2 are fixed again by bolts 5 and nuts 6.

(10) The resin injection attachment 4
Attach a resin injection machine containing an acrylic resin dough,
An acrylic resin dough is press-fitted through the resin injection hole 12. (11) After the dough is press-fitted, the resin injection hole 12 of the resin injection attachment 4 is closed with a resin screw, rod, or the like (not shown). (12) Next, the flask is placed in a microwave oven with the lower wheel 2 of the flask facing upward, the power is turned on, and the acrylic resin dough is cured by the heat of microwaves. (13) After curing, remove the flask from the microwave,
After cooling, remove the acrylic denture from the flask according to the usual dental practice.

In a series of operations (1) to (13),
There is no gap between the upper flask ring 1 and the lower flask ring 2, and the flask is not broken,
The positional relationship between the upper flask ring 1 and the lower flask ring 2 could be accurately returned to the state before molding, the positioning was easy, and an acrylic denture with good fitting precision was obtained.

[0024]

According to the dental flask made of FRP of the present invention, an acrylic denture can be easily and accurately produced in a short time by using a microwave such as a microwave oven.

[0025]

[Brief description of the drawings]

FIG. 1 is a perspective view of a flask showing one embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of an upper flask of the present invention.

FIG. 3 is a bottom view of an upper flask of the present invention.

FIG. 4 is a plan view of a lower flask ring in the present invention.

FIG. 5 is a longitudinal sectional view of a lower flask ring in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper flask ring 2 Lower flask ring 3 Lid 4 Attachment for resin injection 5 Bolt 6 Nut 7 Notch 8 Hole 9 Positioning hole 10 Positioning protrusion 11 Gypsum supply hollow 12 Resin injection hole 13 Depression 14 Depression 15 Screw

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61C 13/16

Claims (2)

(57) [Claims] 1. An injection-type fiber-reinforced plastic dental flask for producing an acrylic resin bed denture by a microwave polymerization method, wherein the flask comprises an upper ring and a lower ring. A hollow part for gypsum supply is provided in the center, a lid that can be fixed after tightening the upper ring and the lower ring is provided in the hollow part, and a resin injection hole is provided in a part other than the lid of the upper ring of the flask. And dental flask. 2. An injection-type fiber-reinforced plastic dental flask for producing an acrylic resin bed denture by a microwave polymerization method, wherein the flask is composed of an upper ring and a lower ring. A hollow part for gypsum supply is provided in the center, a lid that can be fixed after tightening the upper ring and the lower ring is provided in the hollow part, and an attachment
A dental flask having a resin injection hole provided in an attachment .