JPS5924128B2 - dental cement curing liquid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel dental cement curing liquid, and more specifically, it uses tetrahydrofurantetracarboxylic acid, has good kneading operability, and can freely adjust the curing time. The present invention relates to a novel dental cement curing liquid that is flexible and has excellent physical properties.

Dental cements that have been widely used for the purpose of bonding crowns, inlays, orthodontic bands, etc. include zinc phosphate cement, glass ionomer cement, and carboxylate cement.

The main components of these cement hardening solutions are phosphoric acid for zinc phosphate cement, and acrylic acid homopolymer or copolymer for glass ionomer cement and carboxylate cement, but these hardening solutions have various problems. It is known that there are many points that need to be improved.

For example, polyacrylic acid is a polymer electrolyte, and generally a curing liquid containing polyacrylic acid as a main component has a power consumption of 1000 cps.
Because of the above high viscosity, it can be said that there are difficulties in kneading operability.

On the other hand, phosphoric acid used in the curing solution of zinc phosphate cement is a strong acid and generates considerable heat when mixed with cement powder.

Therefore, in order to realize the physical properties inherent to cement, the powder must be divided and kneaded to suppress the heat of reaction.

Phosphoric acid also has a strong stimulating effect on living tissues.

Therefore, as a result of intensive studies to improve the kneading operability and create a new cement hardening liquid with excellent physical properties, we have developed a dental cement hardening liquid using tetrahydrofuran tetracarboxylic acid with a low viscosity. We have completed the present invention by discovering that it is an aqueous solution, which allows the curing properties to be freely adjusted, has excellent crushing resistance and solubility, and can be conveniently used clinically as a dental cement.

A typical example of tetrahydrofuran tetracarboxylic acid (T, HoF, T, C) used in the present invention is tetrahydrofuran-2,3,4,5-tetracarboxylic acid, which has the structural formula (1). It is a tetrabasic acid.

This tetrahydrofuran tetracarboxylic acid is water-soluble, and is soluble in water at room temperature without heating, so an aqueous solution can be easily prepared.

However, the physical properties of a cured product kneaded with a hardening liquid at a high concentration of more than 70% by weight deteriorate.

This is thought to be because THFTC becomes supersaturated in the solution and precipitates, leaving unreacted acid in the cured product.

Furthermore, a curing liquid with a low concentration of less than 30% by weight will contain too much moisture, resulting in poor physical properties of the cured product and lack of durability.

Therefore, when THFTC is used alone, its concentration is 30~
When the content is in the range of 70% by weight, it can be suitably used as a dental cement hardening fluid, and hardening fluids outside this range are usually not suitable.

Furthermore, a cement hardening liquid containing both THFTC and primary phosphate exhibits even better performance.

In this case, the primary phosphate is particularly preferably a water-soluble primary phosphate.

Water-soluble primary phosphates include, for example, aluminum monophosphate, magnesium monophosphate, manganese monophosphate, sodium monophosphate, and the like.

Furthermore, the fact that primary phosphate is contained in the solution means that
Although the primary phosphate may be dissolved, this also indicates that primary phosphate ions and metal ions coexist.

For example, mixing phosphoric acid with metals, oxides, salts, etc.
It is within the scope of the present invention if there is a possibility that primary phosphate may be formed to some extent in the curing liquid.

Alternatively, a diphosphate salt or a diphosphate salt and phosphoric acid may be included in the curing liquid to generate a primary phosphate salt.

Therefore, the phosphates contained in the curing liquid are not limited to primary phosphates, and other phosphates may also be used if primary phosphates may be generated to some extent. Bye.

Note that phosphate may be mixed into cement powder according to the present invention.

This method is particularly preferred when using an insoluble phosphate.

In addition, the concentration of the curing solution using phosphate and THFTC is
Preferably, the total aqueous concentration of THFTC and phosphate is 30 to 70% by weight.

The water-soluble polybasic carboxylic acid used in the present invention refers to a water-soluble carboxylic acid having two or more carboxyl groups in one molecule, such as malic acid, tartronic acid, tartaric acid, benzenepentacarboxylic acid, Examples include benzenehexacarboxylic acid.

By dissolving one or more polybasic carboxylic acids such as these in water together with THFTC, an excellent cement hardening solution can be prepared.

At this time, an aqueous solution in which the total concentration of polybasic carboxylic acid and THFTC is 30 to 70% by weight is in a preferable concentration range.

Dental cements require cement powders that harden when mixed with a cement hardening solution.

This cement powder is not particularly limited in the present invention, but it must be able to form a hardened product when the powder and liquid are kneaded together.

For example, metal oxides, hydroxides, silicates, fluorides, etc. can usually be used, but particularly preferred cement powders are those containing zinc oxide as the main component, calcined and ground together with other oxides and fluorides. Examples include powder and fluoroaluminosilicate glass powder.

Such cement powders are preferably powders that pass through an 80-mesh sieve, and particularly fine powders that pass through a 150-mesh sieve are suitable.

Note that the curing liquid containing THFTC does not necessarily have to be a liquid and may be supplied in the form of a paste.

Hereinafter, the present invention will be explained in detail by giving Examples.

Example 1 50 g of tetrahydrofuran-2,3,4,5-tetracarboxylic acid was dissolved in 50 g of pure water at room temperature, and 50 g of THFTC was added.
A 0% by weight aqueous solution was prepared.

This aqueous solution 0.4? and aluminosilicate glass powder (
G, manufactured by C1, trade name, Fuji Ionomer Type I powder) 1.1' was kneaded to prepare a hardened cement body.

In addition, JIS standard T regarding dental zinc phosphate cement
6602, the crushing force and curing time after one day were measured to be 780 kg/c4 and 4 minutes 50 seconds,
This curing liquid was found to have clinically acceptable physical properties.

Example 2 A cement hardening solution was prepared by mixing the 50% by weight THFTC aqueous solution 302 obtained in Example 1 and 70 g of the 50% by weight monoaluminum phosphate aqueous solution at room temperature.

0.4L of this aqueous solution? was kneaded with aluminosilicate glass powder (G, manufactured by C1 company, trade name, Fuji ionomer type ■ powder) 1.1, and the crushing force and curing time were measured according to Example 1, and the result was 1680 kg/crA and 3. Minute O
I got the value of seconds.

These are clinically relevant physical properties.

Example 3 25 g of tetrahydrofuran-2,3,4,5-tetracarboxylic acid and 30 g of tartronic acid were mixed with 40 g of water. A cement hardening solution was prepared by dissolving the cement at room temperature.

This curing liquid 04y' was mixed with aluminosilicate glass powder (
G, C, company, trade name, powder of Fuji ionomer type ■) 1.1' was kneaded and the crushing resistance and curing time were measured according to Example 1, 850 kg/c4 and 4 minutes 10
It was seconds.

These were clinically qualified.

Example 4 0.41% of the cement hardening liquid obtained in Example 3 was mixed with cement powder containing ZnO as the main component (product name: Carbolyt 100 powder, manufactured by G, C) and aluminosilicate glass powder (G, C). , manufactured by company, product name, Fuji ionomer type■
) was kneaded with powder 1.01 mixed at a ratio of 1:1, and the crushing resistance and curing time were measured according to Example 1.
kg/ca, and 2 minutes O seconds.

Claims (1)

[Claims] 1. The content of tetrahydrofuran tetracarboxylic acid is 3.
A dental cement curing liquid characterized by being an aqueous solution containing more than 0% by weight and up to 70% by weight. 2. A dental cement curing liquid, which is an aqueous solution containing a total of more than 30% by weight and up to 70% by weight of tetrahydrofuran tetracarboxylic acid and water-soluble primary phosphate. 3. A dental cement curing liquid, which is an aqueous solution containing a total of more than 30% by weight and up to 70% by weight of tetrahydrofuran tetracarboxylic acid and a water-soluble polybasic carboxylic acid.