JPH10139617A - Alginate impression material - Google Patents

Abstract

(57) [Summary] [Problem] To provide an alginate impression material in which fluidity (drip) changes little by its own weight with respect to changes in water mixture ratio during kneading. SOLUTION: This alginate impression material comprises an alginate, a gelling agent, a gelling agent and a diatomaceous earth, wherein the diatomite has a water absorption of 1.0 or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an alginate impression material. More specifically, every time the impression material is used in the dental clinic, the impression material powder and water are kneaded to form a paste, but a suitable impression paste can be obtained without depending on the water mixture ratio at this time. Impression materials. The alginate impression material is preferably used mainly for molding during restoration of dental treatment.

[0002]

2. Description of the Related Art Alginate impression materials are used for various types of molding of teeth, etc., based on the fact that a gel-like hardened body can be obtained by combining a gelling agent such as calcium sulfate based on alginate. Have been. Alginate impression materials are classified into two types, powder type and paste type, according to their product form. The paste type is bulky and heavier than the powder type and is unsuitable for distribution and transportation, since the main type is a paste in which alginate and an inert powder or the like are previously made into a homogeneous paste with water. For these reasons, the current mainstream of products is powder type.

[0003] The powder type is a powder mixture containing the above-mentioned components as a main component, and a dentist or a dental hygienist kneads a specified amount of impression material powder and water immediately before use to form a paste. , Powder for each use on the chair side
Since the operation of accurately weighing water is complicated, it is common practice to measure and use an appropriate amount based on empirical rules such as the user's eye size and the feel during kneading. However, it is difficult for an inexperienced hygienist to obtain an impression material paste having an appropriate viscosity in a unit amount, and when the viscosity of the impression material once formed into a paste is inappropriate, the impression material powder or water may be appropriately removed. It is difficult to add and adjust because the gelation time of the impression material itself is relatively short.

[0004] The manufacturer's instruction manual recommends a simple method of weighing powder with a spoon and water with a cup in a fixed volume. However, since the powder itself tends to be compacted by its own weight, the actual weight is greatly different even if the same volume is weighed at the top and bottom of the powder storage container. Therefore, even when weighed in this way, variation in the water mixture ratio is inevitable, and the obtained impression material paste has different physical properties every time it is used.

[0005] When the paste is obtained with an improper water mixture ratio, when the paste is pressed against a part to be molded in a molding operation subsequent to the kneading operation, for example, a tooth in an oral cavity, fluidity is insufficient. If the impression material does not spread to the most necessary details of the tooth, or if the impression material has too much fluidity, the impression material paste drips by its own weight before gelation. As a result, the impression part cannot have a sufficient thickness, and the strength of the obtained impression is insufficient, which causes inconvenience to the impression object. In more extreme cases, it can flow into the patient's pharynx, which can result in a very uncomfortable and dangerous situation.

[0006]

DISCLOSURE OF THE INVENTION The present invention aims to provide an alginate impression material of a powder type in which the fluidity (sag) of the powder due to its own weight is small with respect to the change of the water mixture ratio during kneading. Things.

[0007]

Means for Solving the Problems As a result of intensive studies for the above purpose, the present inventors have found that the use of a specific diatomaceous earth reduces the fluctuation of the flow due to its own weight with respect to the fluctuation of the water mixture ratio during kneading. The inventors have found that a small amount of alginate impression material can be obtained, and have reached the present invention. That is, the gist of the present invention resides in an alginate impression material characterized in that the diatomaceous earth has a water absorption of 1.0 or more in an impression material containing an alginate, a gelling agent, a gelling agent and diatomaceous earth. Hereinafter, the present invention will be described in detail.

[0008] The impression material of the present invention contains an alginate, a gelling agent, a gelling agent and diatomaceous earth. For example,
Alginates include water-soluble salts such as sodium, potassium, ammonium or triethanolamine. The amount used is usually 3 to 30% by weight, preferably 5 to 25% by weight of the impression material. Examples of the gelling reagent include calcium sulfate such as calcium sulfate dihydrate, calcium sulfate hemihydrate, and calcium sulfate anhydrous. The amount used is usually 3 to 40% by weight, preferably 5 to 30% by weight of the impression material. Examples of the gelling agent include tertiary phosphates such as sodium and potassium, phosphates such as pyrophosphate, tripolyphosphate and hexametaphosphate, silicates, carbonates and oxalates. The amount used is 0.1 to 5% by weight, preferably 0.2 to 4% by weight of the impression material.

Diatomaceous earth is generally a fine porous body mainly composed of silica derived from a single-cell plant diatom, and is a natural product. Since the surface has countless fine pores, it can absorb and hold a considerable amount of liquid. Diatomaceous earth has a different particle shape depending on whether the diatom is from seawater or freshwater, and depending on the place of production. Further, purity, particle shape, particle size, and the like differ depending on a treatment method such as a firing method or a pulverizing condition. Since impurities in diatomaceous earth may affect the gelation reaction of alginate, a flux-baked product is usually used for the alginate impression material. The ability of diatomaceous earth to absorb and retain liquid varies greatly depending on the particle shape and treatment method.

The powdered alginate impression material is mixed with water immediately before use and kneaded to form a homogeneous paste. The alginate as the main component is dissolved by the addition of water and simultaneously ionized with a divalent or higher valent metal ion. The viscosity gradually increases to start crosslinking. When the amount of water added at the time of kneading is large, the concentration of alginate and divalent or higher valent metal ions is relatively low, so that the crosslinking speed is slightly reduced, and the viscosity rise of the impression material sol is delayed. This increases the fluidity of the impression material paste due to its own weight.

The diatomaceous earth in the powder alginate impression material absorbs and retains part of the water added during kneading. Therefore, even if the amount of water added to the impression material increases or decreases, it is absorbed by the diatomaceous earth, and does not directly affect the concentration of alginate or the like. However, if the amount of water absorbed by diatomaceous earth is small, the amount of water absorbed is small, and the effect on the concentration of alginate and the like will be relatively large. Therefore, in the present invention, diatomaceous earth having a water absorption of 1.0 or more is used.

The water absorption in the present invention indicates the water absorption when diatomaceous earth is forcibly absorbed. Specifically, diatomaceous earth is gradually mixed while giving vibration to water weighed in a predetermined amount, and expressed as a ratio of the weight of water absorbed by the diatomaceous earth to the weight of diatomaceous earth at the time when water floating is no longer observed. Diatomaceous earth having a water absorption of 1.0 or more, preferably 1.01 or more, more preferably 1.03 or more can be used. When the water absorption is too small, when the ratio (water mixture ratio) between the impression material powder and water at the time of using the alginate impression material deviates from an appropriate value, the fluidity due to its own weight greatly differs. In other words, when water is small and fluidity is low, the fluidity to the details of the tooth is reduced, so the accuracy of the originally required details is reduced, and when the water is too large and the fluidity is too large, the impression obtained is The strength of the model is insufficient due to lack of thickness, or it flows into the patient's pharynx, causing discomfort. Although the upper limit of the water absorption is not particularly limited, it is usually 5.0.
Or less, preferably 3.0 or less, more preferably 2.0 or less. If the water absorption is too large, selecting diatomaceous earth will inevitably increase the particle size of the diatomaceous earth, leading to a reduction in kneadability.

The diatomaceous earth preferably has an average particle diameter of 25 μm or less as measured by a laser diffraction scattering method. Since diatomaceous earth particles tend to destroy their pores by pulverization, classification, and the like, the larger the average particle diameter, the greater the water absorption. However, when the average particle diameter is more than this, the feel during kneading of the impression material becomes poor, and the texture of the kneaded impression material paste becomes coarse and the appearance becomes poor, which is inappropriate for a precise impression. . The lower limit of the average particle diameter is usually 1 μm or more, preferably 5 μm or more. Below this, it is difficult to obtain diatomaceous earth having the desired water absorption.

The content of diatomaceous earth in the impression material powder is usually 30.
８５85% by weight, preferably 40-85% by weight.
In addition, other fillers can also be used together within a range that does not impair the present invention. Examples of the filler include known talc, silica, aluminum hydroxide, and the like. The amount used is preferably 20% by weight or less of the total amount of diatomaceous earth and other fillers.

The impression material of the present invention may further contain, in addition to the above components, a fluoride such as sodium hexafluorotitanate, potassium hexafluorozirconate, or a silicofluoride in order to improve compatibility with the model gypsum. Can also be used, surfactants, dust inhibitors such as ethylene glycol, polyethylene glycol, polypropylene glycol, liquid paraffin, magnesium oxide, zinc oxide,
Additives such as metal oxides such as aluminum hydroxide, metal hydroxides, coloring agents, and fragrances can be blended. The method for producing the impression material of the present invention is not particularly limited and can be appropriately selected from known methods and used. For example, all the raw materials may be simultaneously charged into a mixer and mixed,
It may be manufactured by dividing and mixing according to the purpose.

[0016]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which do not limit the present invention, and all modifications that do not depart from the gist of the present invention are included in the technical scope of the present invention. Is done. (Examples 1 to 3, Comparative Examples 1 and 2) According to the mixing ratio (parts by weight) shown in Table 1, they were mixed by a blender. The physical properties of the diatomaceous earth used were measured by the following methods. Table 1 shows the physical properties.

(1) Water absorption of diatomaceous earth 10.0 g of distilled water is accurately measured in a beaker. Diatomaceous earth is gradually added while giving a weak vibration to this. It is added until no water floats on the diatomaceous earth even if left for a while, and the added amount of the diatomaceous earth is weighed. The ratio of the weight of the water absorbed by the diatomaceous earth to the weight of the diatomaceous earth is defined as the water absorption. (2) Average particle size of diatomaceous earth Each diatomaceous earth was sufficiently dispersed in pure water and measured by a laser diffraction scattering method (LA-500, manufactured by Horiba, Ltd.). The obtained impression material was evaluated according to the following method.

(1) Gelation time (second) The gelation time was based on JIS-6505 (dental alginate impression material). 8.0 g of the impression material powder was kneaded with 20 g of water. (2) Sauce (mm) Sauce is 27 x 2 of impression material paste kneaded on a glass plate.
The glass plate is raised to 0 × 10 mm, and the glass plate is set upright one minute after the start of the kneading of the impression material. After the impression material gels, measure the total length of the impression material, the first impression material length is 20 mm
The value obtained by subtracting is the sag. The sauce was kneaded with 8.0 g of the impression material powder and mixed with 18 g, 20 g, and 22 g of water at different mixing ratios, and measured. In addition, when kneading with 18 g of water,
The difference in sag when kneading with 2 g was determined.

(3) Pressing Flow (mm) The pressing flow is such that the kneaded impression material is formed into a cylindrical shape of 20φ × 31.5 mm, and a load of 120 g is applied one minute after the start of kneading the impression material, and the gel is applied. After the formation, the diameter of the disk was measured. Pressurizing flow was performed by adding 8.0 g of impression material powder to 18 g, 20 g, and 2 g of water.
Kneading and measurement were carried out while changing the mixture ratio to 2 g. Also,
The difference between the pressurized flows when kneading with 18 g of water and when kneading with 22 g of water was determined. Table 1 also shows the evaluation results of the examples and comparative examples.

[0020]

[Table 1]

From Table 1, it is found that Examples 1 to 3 and Comparative Examples 1 and 2
Pressure difference of 11mm when the mixture ratio was changed
It is almost the same as the degree. The pressurized flow is the spread when a load is applied, and correlates with the touch (kneadiness) when kneading while spreading the impression material paste. Therefore, even if these change the mixing ratio of impression material powder and water,
The difference in hand was evaluated to be comparable. In addition, the appearance of the impression material paste was evaluated as good.

In Examples 1 to 3, when the water mixture ratio was changed within the above range, the difference in the dripping ratio due to the water mixture ratio was small, and the samples could be used without worrying about inflow into the pharynx of the patient. However, in Comparative Examples 1 and 2, the difference in sag was as large as 20 mm or more, and the thickness of the impression object could not be obtained.
There were practical problems, such as concerns about inflow into the pharynx of patients. From this result, it was found that, in the case of an impression material containing diatomaceous earth having a low water absorption, even if kneaded to the same degree in the sense of kneading, there is a practical problem due to a slight difference in water mixing ratio.

[0023]

According to the present invention, it is possible to provide an impression material in which a change in fluidity (drip) due to its own weight is small even when a mixing ratio of a powder type impression material with water is changed. It became. As a result, even if the impression material paste is kneaded according to an empirical rule such as the touch and appearance of the impression material paste without being accurately weighed each time it is used at the dental treatment site, the impression material paste is injected into the patient's mouth at the time of impression acquisition A suitable impression can be obtained without worrying about sagging.

Claims (2)

[Claims] 1. An alginate impression material comprising an alginate, a gelling agent, a gelling agent and a diatomaceous earth, wherein the diatomaceous earth has a water absorption of 1.0 or more. 2. The impression material according to claim 1, wherein the diatomaceous earth has an average particle size of 25 μm or less.