JPH0517315A - Alginic acid salt impression material composition for dental use - Google Patents

Abstract

PURPOSE:To provide the subject composition containing an alginic acid salt having low molecular weight and a hydroxyl compound, having high affinity to water and improved kneadability, and giving a formed gypsum having improved surface smoothness and gel strength. CONSTITUTION:The objective alginic acid salt impression material composition for dental use is produced by compounding 8-30wt.% (preferably 10-25wt.%) of an alginic acid salt having low molecular weight (e.g. having a viscosity of about 5-100cPs measured as 1% aqueous solution at 20 deg.C using a type-B rotary viscometer) and combining the salt with a hydroxyl compound (e.g. polyethylene glycol, glycerol or hydroxypropyl cellulose). The composition has improved kneading workability since an alginic acid salt having low molecular weight can easily be swollen or dissolved in water to give a solution having low viscosity. Furthermore, the properties such as strength can be improved because the alginic acid salt content can be increased compared with conventional composition. The coating with the hydroxyl compound is effective for increasing the swelling property and solubility of the impression material in water and improving the kneading workability.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a dental alginate impression material composition which is excellent in all properties required for an impression material such as kneadability, strength, surface smoothness, combined impression and dimensional stability. It is about things.

[0002]

2. Description of the Related Art Impression materials are frequently used in the field of dentistry and are required to be excellent in various properties such as kneadability, strength, surface smoothness, combined impression and dimensional stability. Be done. However, the impression materials currently used are
None of them satisfy all of the above characteristics, which is not sufficient.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is an impression material having miscibility, strength, surface smoothness, combined impression, and dimensional stability. The present invention aims to provide a dental alginate impression material composition which is excellent in all the properties required for.

[0004]

The dental alginate impression material composition of the present invention is an alginate impression material composition containing an alginate and a hydroxy compound, and is 8 to 3
The gist is that 0 wt% (hereinafter simply expressed as%) of a low molecular weight alginate and a hydroxy compound are blended.

[0005]

The present invention is characterized in that a low molecular weight alginate is used. Low molecular weight alginate easily swells and dissolves in water, and since the viscosity when dissolved is low, workability during kneading is improved, and since the content of alginate can be increased more than usual, Properties such as strength are improved.
Further, by coating with the hydroxy compound, the swelling property and the solubility of the impression material in water are increased, and the kneading property is improved.
This will be described in more detail below.

The type of the low molecular weight alginate used in the present invention is not particularly limited, but the viscosity is about 5 when a 1% aqueous solution is measured at 20 ° C. using a B type rotational viscometer.
It is used in an amount of 8 to 30%, preferably 10 to 25%. If the blending ratio is too low, sufficient strength cannot be obtained, and if the blending ratio is too high, the amount of the filler becomes too small, resulting in poor dimensional stability and the like.
Alginate, which is commonly used at present, has a viscosity of 200 to 1000 cps when measured under the above conditions, and the compounding amount is 5 to 15% by weight. That is, the conventionally used alginate has a high viscosity and cannot be kneaded if the blending ratio is increased, so that the blending ratio must be low. However, in the present invention, since the one having a low viscosity is used, the blending ratio can be increased, resulting in an increase in strength, an improvement in water retention, and an improvement in dimensional stability in water and air. You can It should be noted that a medium or high molecular weight alginate may be added together within a range that does not impair the effects of the present invention.

Further, in the present invention, a hydroxy compound is contained. By coating the filler with the low molecular weight alginate and the hydroxy compound, the swelling property and the solubility in water are improved, the compatibility with water is improved, and the kneading property is improved. Further, since alginate is almost completely dissolved in water, when it is hardened, it is easily replaced with calcium salt, and the surface smoothness and gel strength of the gypsum surface are improved. The amount of the hydroxy compound added is preferably 0.5% by weight or more in order to achieve the above object. The kind of the hydroxy compound is not particularly limited, and for example, polyethylene glycol, glycerin, hydroxypropyl cellulose or the like can be appropriately selected.

Other gelling agents, fillers and the like added to the alginate impression material composition are not particularly limited,
Known materials can be used as appropriate.

The present invention will be described in more detail with reference to the following examples, but the following examples do not limit the present invention.
All modifications and implementations are included in the technical scope of the present invention without departing from the spirit of the description below.

[0010]

[Examples and Comparative Examples]

Examples 1-5 and Comparative Examples 1-4 Various alginate impression materials were prepared and their physical properties were investigated. In Examples and Comparative Examples in which the hydroxy compound was added, a part of the alginate and the filler (diatomaceous earth) was mixed in a mixer, the hydroxy compound was added while continuing mixing, and the remaining filler and gelling agent were mixed. To produce an alginate salt impression material. Further, in the comparative example in which the hydroxy compound was not added, all the raw materials were inserted into the mixer at once and mixed.
Table 1 shows the names of the hydroxy compounds and the like, the addition ratios, and the physical properties of the impression materials obtained. Each physical property was examined by the following methods.

(Evaluation method) * Gelation time, permanent strain, elastic strain and compressive strength were measured according to JlS T-6505 (dental alginate impression material). The powder-liquid ratio was 21 g / 48 ml (water).

* Dimensional changes American Dental Association Specificati
on) The measurement was carried out according to the measurement method of No. 19. The dimensional change in the atmosphere is the value measured after immersion in water at 23 ° C. for 1 hour, and the positive value indicates linear expansion and the negative value indicates linear contraction.

* Surface roughness Acrylic board with smooth surface with alginate impression material (20 x 30
An impression of (5 mm) was taken, after curing the alginate impression material, the acrylic plate was removed, gypsum was immediately injected, and it was left at room temperature as it was. One hour after the gypsum injection, the hardened gypsum was removed, and the surface roughness of the impression surface of the acrylic plate was measured with a surface shape measuring instrument (Surfcom 50A, manufactured by Tokyo Seimitsu Co., Ltd.).

[0014]

[Table 1]

As shown in Table 1, Examples 1 to 5 are excellent in all properties of wettability to water, miscibility, gelation time, elastic strain, permanent set, compressive strength, dimensional stability and surface roughness. Was there. On the other hand, in Comparative Example 1, since the hydroxy compound was not added, the wettability and the surface roughness were slightly inferior. In Comparative Example 2, since alginic acid having a medium viscosity was used, the amount of alginate added could not be increased sufficiently, and the elastic strain, permanent set, compressive strength, dimensional stability and surface roughness were inferior. Since no hydroxy compound was further added to Nos. 4 and 4, the kneadability was also poor.

[0016]

The present invention is constituted as described above, and provides an alginate impression material excellent in all properties such as kneading property, strength, surface lubricity, combined impression property, and dimensional stability. I was able to do it.

Claims (1)

Claim: What is claimed is: 1. An alginate impression material composition containing an alginate and a hydroxy compound, wherein the dental composition comprises 8 to 30% by weight of a low molecular weight alginate. Alginate impression material composition for use.