JPH0912422A - Gypsum composition for dental model - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a gypsum composition for dental models capable of preventing from bacterial infections and excellent in preservation stability by blending a chlorinated isocyanuric acid and a specific compound capable of generating an active halogen. SOLUTION: In this gypsum composition for dental models, 0.02-3wt.% of at least one compound capable of generating an active halogen selected from a group consisting of a chlorinated isocyanuric acid and its salt and a halogenated dimethylhydantoin is blended to gypsum. The composition expresses expected bactericidal and disinfecting effects in its use. As the chlorinated isocyanuric acid and its salt, e.g. trichloroisocyanuric acid, dichloroisocyanuric acid, etc., can be cited. As the halogenated dimethylhydantoin, 1,3-dibromo-5,5- dimethylhydantoin, 1,3-dichloro-5,5-dimethylhydantoin, etc., can be cited. The compound capable of generating an active halogen can be preferably granular and >=95% of the compound comprise particles having 0.15-0.60mm particle size.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a plaster composition for a dental model having a sterilizing / disinfecting property.

[0002]

2. Description of the Related Art In dentistry, a female tooth mold is made in a patient's mouth by using a flexible silicone rubber plastic material, and then water-mixed plaster is poured into the female tooth mold and hardened. The tooth model is made by removing the plaster from the female tooth model.

In the process of manufacturing such a tooth model, bacteria contained in the carrier's blood such as infectious bacteria and body fluids are transferred from the female tooth model to the plaster tooth model, so these are handled. For dentists and dental technicians, there was a risk of bacterial infection, and there was a problem in safety and health management of workers.

As a means for solving such a problem, Japanese Unexamined Patent Publication (Kokai) No. 2-17110 discloses an antibacterial agent such as benzethonium chloride, benzalkonium chloride, sodium hypochlorite, calcium hypochlorite, etc. It has been proposed to formulate compounds with action. Further, JP-A-2-223505 discloses a dental gypsum composition containing a drug having an antimicrobial action such as antibacterial property, antifungal, antivirus, etc., and sodium hypochlorite, Calcium chlorite, sodium-p-toluenesulfone chloramide, antibacterial zeolite and the like are used.

[0005]

Among the conventionally known agents of this kind, organic compounds have a relatively slow sterilizing / disinfecting action, so that it is difficult to exert a sufficient sterilizing / disinfecting effect. . Also, inorganic compounds that generate active chlorine such as sodium hypochlorite and calcium hypochlorite are
Since the loss of active chlorine in the state of being mixed with gypsum is remarkable, it was inevitable to mix the gypsum and the drug prior to use, and the handling thereof was extremely complicated. INDUSTRIAL APPLICABILITY The present invention can be stored stably for a long time in a state in which a drug is mixed with gypsum, and exerts a desired sterilizing and disinfecting effect at the time of use, and can avoid the risk of infection by bacteria or the like in dental technicians. The present invention provides a plaster composition for a dental model.

[0006]

Means for Solving the Problems As a result of intensive studies conducted in view of such circumstances, the present inventors have found that at least one selected from the group consisting of chlorinated isocyanuric acid and its salts, and halogenated dimethylhydantoin. It has been found that the intended purpose can be achieved by incorporating one kind of a compound generating active halogen into gypsum in the range of 0.02 to 3% by weight, and the present invention has been completed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Typical examples of the chlorinated isocyanuric acid and its salt used in the practice of the present invention include trichloroisocyanuric acid, dichloroisocyanuric acid, sodium dichloroisocyanuric acid and its hydrate, and dichloroisocyanuric acid. Examples of the halogenated dimethylhydantoin include 1,3-dibromo-5,5-dimethylhydantoin and 1,3-dichloro-5,5-, which are potassium, calcium dichloroisocyanurate, magnesium dichloroisocyanurate, and the like. Examples thereof include dimethylhydantoin and 1-bromo-3-chloro-5,5-dimethylhydantoin.

The compounding amount of the compound generating active halogen to be added to gypsum should be determined by the total amount of the minimum amount required for sterilizing and disinfecting action and the amount consumed until the gypsum is hardened. On the other hand, the compound generating active halogen should be added in a proportion of 0.02 to 3% by weight, preferably 0.1 to 0.5% by weight. When the compounding amount of the compound generating active halogen added to gypsum is less than 0.02%, sufficient sterilizing effect cannot be obtained, and it is difficult to secure its safety. If the addition amount of the compound to be added exceeds 3% by weight, the strength of the hardened gypsum decreases, which is not preferable.

The active halogen-generating compound compounded in the gypsum preferably has a particle size of 95% or more in the range of 0.15 mm to 0.60 mm. If the particle size of the compound generating active halogen is smaller than 0.15 mm, the concentration of active halogen will be remarkably reduced when compounded in gypsum, and if the particle size exceeds 0.60 mm, those compounded in gypsum will be When the compound is kneaded with water, it does not dissolve completely and the strength of the gypsum model decreases.

[0010]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. [Example 1] 99.5 parts by weight of a commercially available model plaster and an effective chlorine content of 63.5%, 95% of which has a particle diameter of 0.3 to 0.
0.5 part by weight of granular sodium dichloroisocyanurate in the range of 4 mm was uniformly mixed and sealed and stored in a polyethylene bag laminated with aluminum foil. 20% by weight of water was added to the gypsum composition, and the mixture was kneaded. The change with time in the active chlorine concentration in the kneaded state was measured by an iodometric analysis method, and the results are shown in Table 1. Also,
In order to evaluate the storage stability of the gypsum composition sealed in a polyethylene bag, the gypsum composition was stored in a thermo-hygrostat at a temperature of 40 ° C. and a relative humidity of 85%, and the change with time of the active chlorine concentration was measured. It was as shown in 2.

[Example 2] In Example 1, the effective chlorine content was changed to 9 instead of sodium dichloroisocyanurate.
A gypsum composition was prepared under exactly the same conditions as in Example 1, except that 0.4% and 95% of trichloroisocyanuric acid having a particle size in the range of 0.2 to 0.3 mm were used, and an evaluation test thereof was conducted. As a result, changes in the active chlorine concentration in the water-mixed state with time are as shown in Table 1, and the active chlorine concentration when the composition sealed in a polyethylene bag was stored at a temperature of 40 ° C. and a relative humidity of 85%. The change with time was as shown in Table 2.

Example 3 In Example 1, 54.3% of the effective halogen content (calculated as the effective chlorine content) was used instead of sodium dichloroisocyanurate, 95% thereof.
A gypsum composition was prepared under exactly the same conditions as in Example 1 except that 1-bromo-3-chloro-5,5-dimethylhydantoin having a particle diameter of 0.45 to 0.55 mm was used. The evaluation test was conducted, and the time-dependent change of the active halogen concentration in the water-mixed state was as shown in Table 1. When the composition sealed in a polyethylene bag was stored at a temperature of 40 ° C. and a relative humidity of 85%. The change with time of the active halogen concentration of was as shown in Table 2.

[0013]

[Table 1]

[0014]

[Table 2]

Example 4 The gypsum compositions prepared in Examples 1 to 3 were kneaded with water in the same manner as described above,
2mm thick and 30m on each side using the cured product after 2 days
A square test piece of m was prepared, a steel cylinder having a diameter of 5 mm was pressed against the test piece, and the applied load when the test piece broke was measured. The results are shown in Table 3.

[0016]

[Table 3]

Comparative Example 1 96.0 parts by weight of gypsum used in Example 1 and effective chlorine content of 63.5%, part 9
4 parts by weight of 0% of granular sodium dichloroisocyanurate having a particle diameter in the range of 0.3 to 0.4 mm was uniformly mixed, and the mixture was hermetically stored in a polyethylene bag laminated with aluminum foil. 20% by weight of water was added to this gypsum composition and kneaded to obtain 2
After being left for a day, the cured product is 2 mm thick and 30 m on a side.
A square test piece of m was prepared and its breaking strength was measured in the same manner as in Example 4. The test results are shown in Table 4.
As shown in FIG.

[Comparative Example 2] In Comparative Example 1, instead of sodium dichloroisocyanurate, trichloroisocyanuric acid having an effective chlorine content of 90.4%, 90% of which is in the range of particle size 0.2 to 0.3 mm Except that
When the treatment was performed under the same conditions as in Comparative Example 1 and the breaking strength was measured, the results were as shown in Table 4.

[Comparative Example 3] In Comparative Example 1, in place of sodium dichloroisocyanurate, an effective halogen content (converted as an effective chlorine content) was 54.3%, 90% thereof.
The breaking strength was measured by performing the same treatment as in Comparative Example 1 except that 1-bromo-3-chloro-5,5-dimethylhydantoin having a particle diameter of 0.45 to 0.55 mm was used. The result was as shown in Table 4.

[Comparative Example 4] 20% by weight of water was added to the gypsum used in Example 1 and kneaded, and this was left standing for 2 days using a cured product to form a square test piece having a thickness of 2 mm and a side of 30 mm. Was prepared and the breaking strength was measured in the same manner as in Comparative Example 1, and the results were as shown in Table 4.

[0021]

[Table 4]

[Comparative Example 5] 99.5 parts by weight of commercially available model plaster and effective chlorine content of 63.5%, 75% of which is uniform with 0.5 parts by weight of sodium dichloroisocyanurate having a particle size of less than 0.15 mm. The mixture was mixed with and sealed and stored in a polyethylene bag laminated with aluminum foil. 20% by weight of water was added to this gypsum composition, and the mixture was kneaded. The change with time in the active chlorine concentration in the water-mixed state was measured by an iodometric analysis method, and the results are shown in Table 5. Further, in order to evaluate the storage stability of the gypsum composition sealed in a polyethylene bag,
Store in a constant temperature and humidity chamber at a temperature of 40 ° C and a relative humidity of 85%,
When the change with time of the active chlorine concentration was measured, it was as shown in Table 6.

[Comparative Example 6] In Comparative Example 5, the effective chlorine content was changed to 9 instead of sodium dichloroisocyanurate.
A gypsum composition was prepared in the same manner as in Comparative Example 5 except that 0.4%, and 90.0% of trichloroisocyanuric acid having a particle diameter smaller than 0.15 mm was used, and the evaluation test was conducted. The change with time of the active chlorine concentration in the kneaded state is
As shown in Table 5, when the composition sealed in a polyethylene bag was stored at a temperature of 40 ° C. and a relative humidity of 85%, the change with time of the active chlorine concentration was as shown in Table 6.

[0024]

[Table 5]

[0025]

[Table 6]

[Comparative Example 7] 99.5 parts by weight of a commercially available model gypsum has an effective chlorine content of 67.3%, 90% of which is a granular hypochlorous acid having a particle diameter of 0.4 to 0.5 mm. 0.5 parts by weight of calcium acid was uniformly mixed and hermetically stored in a polyethylene bag laminated with aluminum foil. 20% by weight of water was added to the gypsum composition, and the mixture was kneaded. The change with time in the active chlorine concentration in the kneaded state was measured by an iodometric analysis method, and the results are shown in Table 7. Further, in order to evaluate the storage stability of the gypsum composition sealed in a polyethylene bag,
Store in a constant temperature and humidity chamber at a temperature of 40 ° C and a relative humidity of 85%,
The change with time of the active chlorine concentration was measured and is as shown in Table 8. This gypsum composition was one in which active chlorine was significantly lost during storage.

[0027]

[Table 7]

[0028]

[Table 8]

[0029]

The gypsum composition for dental models obtained by the present invention exhibits an excellent bactericidal and disinfecting action due to the generation of active halogen, prevents bacterial contamination during the production of a plaster tooth mold, and protects the operator. Safety is secured. In addition, the gypsum composition of the present invention has good compounding stability of gypsum and a compound that generates active halogen, and thus can be stored for a long period of time and can be handled very easily.

Claims (1)

[Claims] 1. A plaster containing 0.02 to 3% by weight of a compound generating at least one active halogen selected from the group consisting of chlorinated isocyanuric acid and salts thereof, and halogenated dimethylhydantoin. A plaster composition for a dental model, which comprises: