JP4251371B1 - Dental plaster composition - Google Patents

Abstract

[PROBLEMS] A gypsum used when a dental technician embeds a double model in a flask during the manufacture of a denture is only to fix a wax denture in the flask to create a cavity, but the resin is filled and the polymerization is completed. Excavating the completed denture from the gypsum mass at that time has the disadvantages that the strength of the plaster damages the artificial teeth and denture base, the technician injuries the hand, muscle pain and tendonitis . When digging out of gypsum, there were drawbacks such as high strength and heavy damage.
SOLUTION: When a dental gypsum composition in which 15 to 45 parts by weight of diatomaceous earth is mixed with 100 parts by weight of dental plaster is used, when a dental technician digs out a denture from the plaster, the strength of the gypsum is moderately reduced. It becomes easy to break, the damage of the completed denture is extremely reduced, and the working efficiency is considerably improved. In addition, muscle pain and tendonitis of dental technicians hardly occur. However, the proper strength as a dental plaster is sufficiently maintained, and there is no problem at all. Rather, there is an advantage that the expansion rate is lowered and a denture with higher accuracy can be obtained.

Description

The present invention relates to a composition for dental plaster used by a dental technician when making a denture.

Conventionally, when a dental technician manufactures a denture, first, the state of the teeth and mucous membranes in the patient's oral cavity is obtained with an impression material, and then a plaster model is made, and a wax denture is manufactured on the model. The wax denture is buried in a flask with dental calcined gypsum, and after the plaster has hardened, it is heated to melt and remove the wax part of the wax denture, and after filling the gap with pressure, a certain amount of resin is fixed. Polymerization was carried out for a period of time and time, and the dentures obtained by curing the resin were taken out from the flask by destroying the cured gypsum and polished to complete.
JP-A-10-226558

Gypsum used when a dental technician embeds a double model in a flask when making a denture is for the purpose of fixing the wax denture in the flask to create a cavity, but the denture completed when the resin is filled and the polymerization is completed Excavating the gypsum from the gypsum mass has the drawbacks of damaging the artificial teeth and denture base due to the high strength of gypsum, hurting the hands of technicians, and causing muscle pain and tendonitis. When digging out of gypsum, there were drawbacks such as high strength and heavy damage.

This invention eliminates the said fault, and is a dental gypsum composition containing 15-40 weight part of diatomaceous earth with respect to 100 weight part of dental gypsum, Preferably 25-35 weight part.

According to the present invention, when a dental technician digs out a denture from gypsum, the strength of the gypsum is moderately lowered and easily broken, the damage of the completed denture is extremely reduced, and the working efficiency is considerably improved. . In addition, muscle pain and tendonitis of dental technicians hardly occur. However, the proper strength as a dental plaster is sufficiently maintained, and there is no problem at all. Rather, there is an advantage that the expansion rate is lowered, and a denture with higher accuracy can be obtained.

In this invention, it is a dental gypsum composition in which 15 to 40 parts by weight of diatomaceous earth is mixed with 100 parts by weight of dental gypsum. It is more likely to break when digging, and the dental technician will have muscle pain and tendonitis. On the other hand, when the diatomaceous earth is 40 parts by weight or more, the strength of the gypsum is too low, and defects such as cracks increase when the resin is cured.

The dental plaster may be any plaster conventionally used in dentistry, and JIST6604 dental calcined gypsum can be preferably used. Diatomaceous earth is a light brown powder, but commercially available diatomaceous earth can be used, and there are naturally dried products, fired products, fired products with added flux, and the like. A fired product is preferred, and Radiolite # 200 (trade name) (manufactured by Showa Chemical Industry Co., Ltd., average particle size 200 mesh) can be preferably used.

Hereinafter, the present invention will be specifically described by way of examples. However, the technical scope of the present invention is not limited to these.

According to the test method of Japanese Industrial Standard JIST 6604, 100 parts by weight of dental calcined gypsum and no addition of Radiolite # 200 (trade name) (average particle size 200 mesh manufactured by Showa Chemical Industry Co., Ltd.), 20, 25, 30 , 35, and 50 parts by weight of the test piece were prepared, and the compressive strength was measured and compared. The gypsum and diatomaceous earth used for the test were those that have not passed the expiration date indicated by the manufacturer.

Test conditions Gypsum kneading and testing were all performed in an environment of 23 ± 2 S ° C. and relative humidity (50 ± 10%). The equipment and instruments used for kneading and testing were all clean and dry and confirmed that no gypsum particles were attached. In addition, the test materials and the test equipment were kept at the test temperature in a heat insulating cabinet 15 hours before the test.

Compressive strength test The gypsum used was measured by measuring the required amount of powder (mass) and the required amount of water (volume) specified by the manufacturer, and stirring using a dedicated gypsum mixer.
1 Prepare 5 sets of molds with release agent and place them in the center of the glass plate.
2 Knead 200 ± 0.1g of powder, tilt the compression strength mold held on the glass plate, and add the kneaded product until it rises slightly from the edge.
3 Before the luster disappears from the surface of the kneaded product, press the glass plate coated with the release agent against the upper surface of the mold.
4 45 ± 1 minutes after the start of kneading, remove the sample from the mold and store it in an environment of temperature 23 ± 2 ° C. and relative humidity (50 ± 10%).
5 60 ± 5 minutes after the start of kneading, use a compressive strength tester to break test 5 samples and record the maximum force (F) applied.
S = F / 314 S: Compressive strength (MPa) F: Maximum force (N)

Result Compressive strength value when diatomaceous earth (Showa Chemical Industry Radio Light # 200) is added to dental calcined gypsum (ordinary gypsum) in various proportions

Claims (2)

A dental plaster composition comprising 15 to 40 parts by weight of diatomaceous earth with respect to 100 parts by weight of dental plaster. The dental gypsum composition according to claim 1, comprising 25 to 35 parts by weight of diatomaceous earth.