JP2023009286A - Dental glass ionomer cement liquid and dental glass ionomer cement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dental glass ionomer cement liquid that can give hardened cement having high physical strength while ensuring adequate time of operation for clinical use.

SOLUTION: According to the present invention, a dental glass ionomer cement liquid contains a polycarboxylic acid polymer, water and a water reducing agent.

SELECTED DRAWING: None

COPYRIGHT: (C)2023,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a dental glass ionomer cement liquid and a dental glass ionomer cement which are used by mixing with a dental glass ionomer cement powder component containing aluminosilicate glass as a main component.

A dental glass ionomer cement is used by reacting a polymeric acid containing an acid such as polycarboxylic acid as a main component with a glass powder for glass ionomer cement in the presence of water to harden the mixture. Glass ionomer cement has extremely good affinity for the living body, and the hardened body is translucent and has excellent aesthetics. In addition, glass ionomer cement has excellent adhesive strength to tooth substances such as enamel and dentin. It has excellent characteristics such as being Therefore, glass ionomer cement is widely used in the field of dentistry for filling caries cavities, joining crowns, inlays, bridges and orthodontic bands, lining of cavities, sealers for filling root canals, constructing abutments and preventive filling. material.

As for the form of dental glass ionomer cement, it is common to use a powder component containing fluoroaluminosilicate glass and a liquid component containing polycarboxylic acid polymer (see, for example, Patent Document 1). This cement is used by mixing and kneading a powder component and a liquid component to form a kneaded product, applying it to the treatment site and then curing it.

JP 2007-91689 A

Here, in order to obtain a hardened dental glass ionomer cement having high physical strength, it is necessary to mix and knead a powder component containing an aluminosilicate glass and a liquid component containing a polycarboxylic acid polymer. It is conceivable to increase the ratio of However, when the ratio of the powder component is increased, the cement hardens too quickly, resulting in a problem of lack of time for clinical use. In other words, it has been difficult to obtain a hardened cement body with high physical strength while ensuring an adequate operating margin for clinical use.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a dental glass ionomer cement solution that can provide a hardened cement having a high physical strength while securing an operation margin time suitable for clinical use.

One aspect of the present invention is a dental glass ionomer cement liquid containing a polycarboxylic acid-based polymer, water, and a water reducing agent.

According to the dental glass ionomer cement liquid according to one aspect of the present invention, it is possible to obtain a cement hardened body having high physical strength while securing an operation margin time suitable for clinical use.

Next, the form for implementing this invention is demonstrated.
<Dental Glass Ionomer Cement Liquid>
The dental glass ionomer cement liquid of this embodiment contains a polycarboxylic acid-based polymer, water, and a water reducing agent.

The polycarboxylic acid-based polymer is a component necessary for reaction with the aluminosilicate glass powder contained in the powder components described below. By mixing and kneading the dental glass ionomer cement liquid and the powder component, an acid-base reaction occurs in which aluminum ions eluted from the aluminosilicate glass powder and the conjugate base of the polycarboxylic acid-based polymer ionically crosslink, and harden. .

Polycarboxylic acid polymers are polymers of α-β unsaturated monocarboxylic acids or α-β unsaturated dicarboxylic acids. For example, one or more selected from acrylic acid, methacrylic acid, 2-chloroacrylic acid, 3-chloroacrylic acid, aconitic acid, mesaconic acid, maleic acid, itaconic acid, fumaric acid, glutaconic acid, and citraconic acid Examples of polycarboxylic acid-based polymers include copolymers or homopolymers containing Two or more of these may be used.

The polycarboxylic acid-based polymer preferably does not contain a polymerizable ethylenically unsaturated double bond.

The polycarboxylic acid polymer preferably has a weight average molecular weight of 5,000 to 40,000. When the weight average molecular weight is 5,000 or more, the physical strength of the cured product is increased, and the adhesive strength to tooth substance is also improved. When the mass average molecular weight is 40,000 or less, the dental glass ionomer cement liquid has an appropriate viscosity and is easily kneaded.

The blending amount of the polycarboxylic acid-based polymer is preferably 5 to 60% by mass in the dental glass ionomer cement solution. When the blending amount of the polycarboxylic acid-based polymer is 5% by mass or more, the adhesiveness to tooth substance, which is a feature of the dental glass ionomer cement, is improved. When the blending amount of the polycarboxylic acid-based polymer is 60% by mass or less, the durability of the cured product is improved. More preferably, it is 20 to 50% by mass.

Water is a necessary component for the acid-base reaction between the aluminosilicate glass powder and the polycarboxylic acid polymer.

The amount of water to be blended may be the balance of other components, but it is preferably 30 to 80% by mass in the dental glass ionomer cement solution. If the water content is 30% by mass or more, the kneadability is improved. When the water content is 80% by mass or less, the physical strength of the cured product increases. More preferably, it is 40 to 70% by mass.

The water reducing agent has the effect of suppressing excessive hardening of the cement in the acid-base reaction caused by mixing and kneading the dental glass ionomer cement liquid and the powder component, even if the ratio of the powder component is increased.

Examples of water reducing agents include ligninsulfonate-based, oxycarboxylate-based, naphthalenesulfonate-based, melaminesulfonate-based, polystyrenesulfonate-based, and polycarboxylate-based water reducing agents.

More specific examples include water reducing agents such as ligninsulfonates, oxycarboxylates, naphthalenesulfonates, melaminesulfonates, polystyrenesulfonates, and polycarboxylates.

The polycarboxylate-based water reducing agent is a polymer or copolymer containing a structural unit composed of an α-β unsaturated monocarboxylic acid polymer, or a structural unit composed of an α-β unsaturated dicarboxylic acid polymer. and these may be water-soluble salts.

More specifically, polycarboxylate-based water reducing agents include, for example, water-soluble salts of copolymers of chain olefins having 5 to 6 carbon atoms and ethylenically unsaturated carboxylic acid anhydrides, polyalkylene glycol mono A water-soluble salt of a copolymer of (meth)acrylic acid ester and (meth)acrylic acid, a copolymer of (meth)acrylic acid amide, acrylic acid ester and (meth)acrylic acid having a sulfone group at the end Water-soluble salts, water-soluble salts of copolymers of a monomer having a sulfone group and (meth)acrylic acid and other monomers, a monomer having an aromatic ring substituted with a sulfone group and maleic acid A water-soluble salt of a copolymer of , a copolymer of a monomer having a sulfone group at the end, a polyalkylene glycol mono(meth)acrylic acid ester, a polyalkylene glycol mono(meth)acrylic acid ether and (meth)acrylic acid Examples thereof include water-soluble salts of the combination, and water-soluble salts of a copolymer of a monomer having a polyoxyethylene chain and (meth)acrylic acid. Two or more of these may be used.

In the above, the polyoxyethylene chain can be represented as (-(OC ₂ H ₄ ) _n -H)). Here, n is the number of repetitions of the polyoxyethylene unit structure, preferably in the range of 50-200, more preferably 80-190, even more preferably 120-180.

Commercially available polycarboxylate-based water reducing agents include, for example, Melflux (registered trademark; hereinafter the same) AP 101F, Melflux 2641F, Melflux 2651F, Melflux 5581F, Melflux 4930F, Melflux 6681F, Melflux BF 11F, Melflux 1F 1F BF. (FM) (manufactured by SKW East Asia) and the like.

Examples of commercially available melamine sulfonate-based water reducing agents include MELMENT F10M and MELMENT F4000 (manufactured by SKW East Asia).

Commercially available naphthalenesulfonate-based water reducing agents include, for example, POWERCON-100 (manufactured by SKW East Asia).

Examples of commercially available ligninsulfonate-based water reducing agents include SODIUM LIGNOSULFNATE ARBO N18 and NORLIG SA (manufactured by SKW East Asia).

The content of the water reducing agent is preferably 0.01 to 10% by mass in the dental glass ionomer cement solution. When the amount of the water reducing agent is 0.01% by mass or more, the hardening of the cement is prevented from becoming too fast, and the operating margin time becomes longer. When the amount of the water reducing agent is 10% by mass or less, it becomes easier to ensure operability in clinical use. The blending amount of the water reducing agent is more preferably 0.1 to 5% by mass, more preferably 0.5 to 3.5% by mass.

The dental glass ionomer cement solution of this embodiment may further contain a pH buffer component. By including a pH buffering component in the dental glass ionomer cement solution, it becomes easier to maintain a low pH (acidic conditions) and the curing reaction proceeds smoothly.

pH buffer components include tartaric acid, citric acid, malic acid, ethylenediaminetetraacetic acid, lactic acid, butyric acid, barbituric acid, phosphoric acid, acetic acid, and oxalic acid, and water-soluble salts thereof (e.g., sodium salt, potassium salt, etc.). ) and the like. Two or more of these may be used in combination.

When the pH buffering component is contained, the blending amount is preferably 0.1 to 10% by mass in the dental glass ionomer cement solution. When the blending amount of the pH buffering component is 0.1% by mass or more, there is an advantage that it is easy to secure an operation margin time for clinical use. If the blending amount of the pH buffering component is 15% by mass or less, there is an advantage of sharp curing. The blending amount of the pH buffering component is more preferably 1 to 10% by mass.

The dental glass ionomer cement solution of the present embodiment may further contain a filler such as silica, a (meth)acrylate, a thickener, and the like. Thereby, it is possible to make the paste into a paste, and to improve the operability.

In the specification and claims of the present application, (meth)acrylate means various monomers, oligomers or prepolymers of acrylate or methacrylate, and has one or more (meth)acryloyloxy groups. A (meth)acryloyloxy group means a methacryloyloxy group and/or an acryloyloxy group.
<Powder component>
The powder component is mixed with the dental glass ionomer cement liquid according to the present embodiment and used to give a hardened dental glass ionomer cement.

The powder component includes an aluminosilicate glass powder.

The aluminosilicate glass powder contains aluminum and silicon as constituents of the glass. Therefore, when the dental glass ionomer cement liquid and the powder component are mixed, an acid-base reaction occurs between the aluminosilicate glass powder and the polycarboxylic acid polymer. Due to this acid-base reaction, the aluminum ions eluted from the aluminosilicate glass powder and the conjugate base of the polycarboxylic acid-based polymer are ionically cross-linked and cured.

The aluminosilicate glass powder is preferably fluoroaluminosilicate glass, which further contains fluorine as a constituent of the glass. The inclusion of fluorine improves the anti-caries effect of the dental glass ionomer cement.

The aluminosilicate glass powder may further contain calcium, phosphorus, strontium, lanthanum, sodium, potassium, nitrogen, magnesium barium, phosphorus, boron, zirconium, tantalum, etc. as components constituting glass.

The average particle size of the aluminosilicate glass powder is preferably 0.02 to 20 μm. If the average particle size exceeds 20 μm, the texture tends to be poor when used as a filling cement, and the wear resistance tends to decrease. On the other hand, if the fine powder has an average particle size of less than 0.02 μm, kneading becomes extremely difficult and operability tends to deteriorate. In addition, this average particle size is the average value of the major axis and the minor axis (long and short average diameter).

The refractive index nd of the aluminosilicate glass powder is preferably in the range of 1.42-1.47. If the refractive index nd is within this range, the difference from the refractive index nd (approximately 1.42) of the matrix component of the practically useful dental glass ionomer cement will be small, and the hardened dental glass ionomer cement will be obtained. becomes more transparent.

The powder component may further include polycarboxylic acid powder, similar to the dental glass ionomer cement liquid. The operability is improved by including the polycarboxylic acid powder in the powder component as well.

When polycarboxylic acid powder is contained in the powder component, the blending amount of polycarboxylic acid powder is preferably 0.1 to 10% by mass.

The powder component of the present embodiment may be further blended with water, (meth)acrylate, or the like. Thereby, it is possible to make the paste into a paste, and to improve the operability.

When at least one of the dental glass ionomer cement liquid and the powder component of the present embodiment contains (meth)acrylate, a polymerization initiator or a photopolymerization initiator is further added to at least one of the dental glass ionomer cement liquid and the powder component. It may be blended. As a result, a resin-reinforced glass ionomer cement capable of polymerizing (meth)acrylate by light irradiation or the like can be obtained, and a cement hardened body having high physical strength can be obtained.

At least one of the dental glass ionomer cement liquid and the powder component of the present embodiment may further contain a contrast agent, an antibacterial agent, a fluorescent agent, a fragrance, a pigment, and the like, if necessary.

<Preparation of mixture of dental glass ionomer cement>
The mass ratio (powder-to-liquid ratio) of the powder component to the dental glass ionomer cement liquid when preparing the kneaded product of dental glass ionomer cement is preferably 1-5. When the powder-to-liquid ratio is 1 or more, the physical strength of the hardened dental cement is improved. When the powder/liquid ratio is 5 or less, the operability of the dental cement is improved. A more preferable powder-liquid ratio is 3-4.5, and a further preferable powder-liquid ratio is 3.2-4.

The dental glass ionomer cement is used by mixing and kneading the powder component and the liquid component to form a kneaded product, applying the kneaded product to the treatment site and then curing it. Here, it is necessary to move the kneaded material to the treatment site with a spatula or the like and further adjust the form before the kneaded material becomes a hardened body.

In the present invention, the time from the start of kneading until the shape of the kneaded material can no longer be adjusted is defined as "operating margin time".

An operation margin time suitable for clinical use is, for example, 75 seconds or more and 600 seconds (10 minutes) or less, more preferably 90 seconds or more and 360 seconds (6 minutes) or less.

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

<Production of aluminosilicate glass powder>
27.5 g silica, 12.7 g alumina, 16.7 g aluminum fluoride, 18.6 g strontium fluoride, 8.8 g aluminum phosphate, 4.2 g sodium fluoride, 5.6 g potassium fluoride, 5.6 g lanthanum fluoride. 9 g was thoroughly mixed in a mortar. The resulting mixture was placed in a magnetic crucible and allowed to stand in an electric furnace. After heating the electric furnace and melting at 1300° C. and sufficiently homogenizing it, it was poured into water to form an aluminosilicate glass block. The obtained lumpy glass was pulverized with a ball mill for 20 hours and passed through a 120-mesh sieve to obtain an aluminosilicate glass powder.
<Preparation of powder component>
100 parts by mass of the aluminosilicate glass powder was mixed with 100 parts by mass of a 1% aqueous solution of aluminum phosphate to prepare a slurry, which was dried at 120°C. A powder component was obtained by mixing polyacrylic acid powder (average molecular weight: 30,000) with the obtained powder so as to be 3% by mass.
<Preparation of dental glass ionomer cement solution>
Each component was mixed according to the formulation shown in Table 1 to prepare dental glass ionomer cement solutions of Examples 1 to 13 and Comparative Examples 1 and 2. In addition, the unit of the compounding amount is % by mass.

The details of the components in Table 1 are as follows.
Polyacrylic acid powder: Polyacrylic acid powder with an average molecular weight of 25,000 (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.)
Melflux 5581F: Water soluble salt of copolymer of methacrylic acid and acrylic acid with polyoxyethylene chains from SKW East Asia Melflux 4930F: Copolymer of methacrylic acid and acrylic acid with polyoxyethylene chains from SKW East Asia Water-soluble salt of polymer Melment F4000: Water-soluble salt of copolymer of methacrylic acid and acrylic acid having polyoxyethylene chain manufactured by SKW East Asia <Operating margin time>
In a constant temperature room adjusted to 23° C. and 50% RH, the dental glass ionomer cement solutions and powder components of Examples 1 to 13 and Comparative Examples 1 and 2 were prepared at the powder-to-liquid ratio shown in Table 1, and a spatula was used. and kneaded for 30 seconds.

The kneaded material was collected in one mass, and 75 seconds after the start of kneading, a spatula was attached to the kneaded material, and the state of adhesion was confirmed when the mass was pulled up. After that, the state of adhesion to the spatula was checked every 7.5 seconds, and the time from the start of kneading until the kneaded product stopped adhering to the spatula or the form of the kneaded product could not be adjusted even if it adhered. It is considered as the operating margin time.

The criteria for determining the operating margin time are as follows.

Excellent: When the operational margin time is 90 seconds or more and 360 seconds (6 minutes) or less Good: When the operational margin time is 75 seconds or more and less than 90 seconds, or exceeds 360 seconds and is 600 seconds (10 minutes) or less Impossible if there is: If the operation margin time is less than 75 seconds, or if it exceeds 600 seconds <Three-point bending strength test>
The dental glass ionomer cement solutions of Examples 1 to 13 and Comparative Examples 1 and 2 and powder components were mixed at the powder-to-liquid ratio shown in Table 1 and kneaded. The kneaded product was placed in a stainless steel mold having a cavity of 2 mm×2 mm×25 mm, and pressed against a glass plate via cellophane. The obtained cured product was immersed in distilled water at 37° C. for 24 hours, and then polished with #320 waterproof abrasive paper to obtain a test sample.

The obtained specimen was tested using a universal testing machine (trade name: Autograph, manufactured by Shimadzu Corporation) at a crosshead speed of 1 mm/min. A three-point bending strength test was performed.

Criteria for determining the three-point bending strength are as follows.

Excellent: When the three-point bending strength is 40 MPa or more Good: When the three-point bending strength is 35 MPa or more and less than 40 MPa Poor: When the three-point bending strength is less than 35 MPa Table 1 shows the operation margin time and the three-point bending strength. The test evaluation results are shown.

表１より、実施例１～１３の歯科用グラスアイオノマーセメント液を用いた場合には、操作余裕時間、三点曲げ強度の何れの評価結果も優又は良となった。この結果より、臨床使用上適切な操作余裕時間を確保しながら、物理的強度の高いセメント硬化体が得られることがわかる。

From Table 1, when the dental glass ionomer cement liquids of Examples 1 to 13 were used, the evaluation results of both the operating margin time and the three-point bending strength were excellent or good. From this result, it can be seen that a hardened cement body having high physical strength can be obtained while securing an operation margin time suitable for clinical use.

On the other hand, in the case of using the dental glass ionomer cement solution of Comparative Example, when the powder-to-liquid ratio was 3.4, the three-point bending strength was low (Comparative Example 1). Further, when the powder-to-liquid ratio was 3.8, the hardening was too fast and kneading itself could not be performed, and the operating margin time and the three-point bending strength could not be measured (Comparative Example 2).

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the claims.

This application claims priority from Basic Application No. 2019-013735 filed on January 30, 2019 with the Japan Patent Office, the entire contents of which are incorporated herein by reference.

Claims (2)

A dental glass ionomer cement solution containing a polycarboxylic acid polymer, water and a water reducing agent. A dental glass ionomer cement containing a polycarboxylic acid-based polymer, water, a water reducing agent, and an aluminosilicate glass.