JP2602567Y2 - 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 for forming a denture by molding a thermoplastic resin.

[0002]

2. Description of the Related Art As a method of manufacturing a denture by molding and processing a thermoplastic resin, a compression molding method using a thermoplastic resin having a high processing temperature such as polysulfone, polyethersulfone, or polycarbonate as a denture base material is known. ing.
In the above method, a dental prosthesis that reproduces the oral impression of a patient is made into a wax denture in accordance with the usual dental practice, and primary embedding, spacer installation, secondary embedding, and dewaxing are performed to produce a gypsum mold for denture molding I do. After placing the resin on the gypsum model of the mold for the lower flask of the flask obtained in this way and heating the resin to a softened state of the resin capable of compression molding, compression molding is performed by combining the molds of the upper flask of the flask. Is performed to form a denture. However, in this method, since gypsum is used in the molding tool of the denture, in the step of heating the resin to a softened state of the resin capable of being compression-molded, plasticized water and crystal water in the gypsum are vaporized to evaporate heat. Not only is it difficult for the temperature of the gypsum to rise, but also the vaporized vapor hinders the softening of the resin. Therefore, in a method of manufacturing a denture formed by molding a thermoplastic resin, a treatment of heating and drying the gypsum mold is performed prior to the resin softening step.

[0003] However, water having a large heat capacity contained in gypsum forming a molding die reaches about 20% by weight of the gypsum weight, so that it takes a long time to heat and dry the gypsum mold prior to the resin softening step. Cost. In addition, when rapid heating is aimed at shortening the time, the pressure of the generated steam
The plaster mold of the flask is broken or the plaster model rises from the flask.

[0004]

[Problems to be solved by the present invention] The present invention relates to a dental flask which can improve the heat-drying efficiency of a molding die and increase the productivity of a denture when compression densification of a thermoplastic resin is produced. The purpose is to provide.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The dental flask of the present invention is characterized in that a window formed in the lower ring of the flask is provided with a bottomed plate provided with a number of holes for draining water and steam. I do. As a result, even when the gypsum mold for denture molding is rapidly heated, generated steam escapes from both the open surface of the flask lower ring and the hole of the flask lower ring, so that the steam is difficult to permeate into the model buried in the open surface. Even when the mold layer is formed, it is difficult to increase the vapor pressure inside the gypsum mold of the lower flask wheel, and as a result, there is no problem that the gypsum mold of the lower flask wheel is broken or the gypsum model rises from the flask. Therefore, when using the flask of the present invention, even when a gypsum mold containing a lot of plasticized water or water of crystallization is heated, the gypsum mold of the lower ring of the flask is destroyed before heating, or a gypsum model rises from the flask. The drying step for removing the plasticizing water and the water of crystallization, which causes the above, can be omitted, and the heating temperature can be directly increased to the desired heating temperature, and the heating time of the gypsum mold can be greatly reduced. Further, in the present invention, it is preferable that a breathable sheet is laid on the bottomed plate.

Hereinafter, an example of a dental flask according to the present invention will be described with reference to the drawings. FIG. 1 shows an example in which holes are formed entirely in the lower ring of the flask and the bottom plate, and FIG. 2 shows an example in which holes are formed only in the bottom plate of the lower ring of the flask. FIG. 3 is a sectional view of one side of a split mold for forming a denture manufactured in the flask of FIG. 1 to 3, reference numeral 1 denotes a lower ring of a dental flask, 2 denotes a bottomed plate, 3 denotes a hole, 4 denotes a model, 5 denotes an investment material,
Reference numeral 6 denotes a breathable sheet. When the model is buried in the flask lower ring, the air-permeable sheet laid on the inner surface of the flask lower ring is broken by the weight of the investment material containing water so that the investment material does not escape from the hole when the model is buried in the flask lower ring. The size is not particularly limited as long as it is not large, but when tissue paper is used as the air permeable sheet, the hole diameter is 3 to 5
mm is preferred.

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

EXAMPLE In FIG. 1, a piece of tissue paper was laid on the lower ring of the flask to cover the hole, and then a gypsum model (120 g) was buried with gypsum according to the usual dental practice. The weight of the investment material used for the investment was 200 g, but the weight of the investment material after curing was 1 g.
95 g, and about 5 g of plasticized water was discharged from the hole in the lower ring of the flask through the burial operation. After the investment material has hardened, the gypsum-resin separation material of the polysulfone compression molding method (Ubi denture system) is applied to the model, and the lower ring of the flask is heated to the heating temperature of the Ubi denture system model (28
(5 ° C.). As a result, in 10 out of 10 cases, there was no problem such as peeling of the separation material or destruction of the model, and the temperature of the model was reduced to a temperature (2
70 ° C. or higher).

[0008]

[Comparative Example 1] A model was buried in the same manner as in the example using a flask lower ring having the same size as that of the example without a hole in the flask lower ring. After the investment material has hardened, 28
Heated directly at 5 ° C. As a result, the temperature of the model was 270 ° C
The time required to reach was 70 minutes, which was only 10 minutes longer than that of the example. However, peeling of the separation material was observed in 10 of 10 cases, and 1
In 7 out of 0 cases, the model was lifted or destroyed, suggesting the necessity of performing a drying step before heating to remove plasticizing water and crystallization water, which cause problems.

[0009]

Comparative Example 2 A model was buried in the same manner as in the example, except that the lower ring of the flask was the same size as that of the example without a hole in the lower ring of the flask. After the investment material was cured, the model of the lower ring of the flask dried at 130 ° C. for 90 minutes was placed in a 285 ° C. heating chamber according to the manual of the Ubi Denture System. As a result, in 10 of the 10 cases, no problems such as peeling of the separation material and destruction of the model occurred, but the temperature of the model was 270 ° C.
Was 50 minutes, and drying and heating required 140 minutes.

[0010]

[Effects of the present invention] If a dental flask provided with holes for draining water and steam is used in the lower ring of the flask of the present invention, the time required for the gypsum-shaped heating and drying process for producing a thermoplastic resin is possible. Can be shortened, and the productivity of the denture is greatly improved.

[0011]

[Brief description of the drawings]

FIG. 1 is an example in which holes are formed in all views of the lower ring of a flask.

FIG. 2 is an example in which holes are formed only in a bottom punching plate of a lower ring of a flask.

FIG. 3 is an AA sectional view of a split mold for forming a denture manufactured in the flask of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower ring of dental flask 2 Bottom plate 3 Hole 4 Model 5 Investment material 6 Breathable sheet

──────────────────────────────────────────────────続 き Continued on the front page (56) References JP-A-4-104818 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) A61C 13/16

Claims (2)

(57) [Scope of request for utility model registration] 1. A bottomed plate provided with a large number of holes for draining water and steam is provided in a window formed in a lower ring of a flask .
Dental flask, characterized in that. (2) Laying a breathable sheet on the bottom punched plate
The dental flask according to claim 1, wherein the dental flask is prepared.