KR20060026863A - Self Curing Glass Carbomer Composition - Google Patents

Abstract

The present invention treats a fluorosilicate glass powder with (a) a poly (dialkylsiloxane) having a terminal hydroxy group, wherein the alkyl group has from 1 to 4 carbon atoms, (b) an aqueous acid solution, and (c) A self-curing glass carbomer composition obtained by separating a treated fluorosilicate glass powder from an aqueous acid solution. The glass carbomer compositions according to the invention have, for example, good rigidity and strength and excellent fluoride release performance. In addition, the glass carbomer compositions according to the present invention exhibit no shrinkage and expansion and have high strength and long term durability which are essential for providing a common filler. Furthermore, the glass carbomers according to the invention have a low sensitivity to erosion and abrasion, high rigidity, smooth surface, good color fixation, for example good adhesion to bone tissue and low sensitivity to water.

Description

Self-curing glass carbomer composition {SELF HARDENING GLASS CARBOMER COMPOSITION}

The present invention relates to glass carbomer cements having improved properties, to methods of making the glass carbomer cements and to high stress applications of glass carbomer cements, such as tooth restoration, dentin replacement, crowns It relates to clinical and dental applications, including bone core build-ups, ie bone and dental cement, and use as industrial applications.

Glass ionomer cements are known in the art and have been used for quite some time in clinical and dental applications, for example as permanent filling materials. For example, US 4.376.835, which is incorporated herein by reference, has an average particle diameter of 0.5 μm or more and an amount of calcium at the surface of the powder particles compared to the amount of calcium present in the core region of the powder particles. Small, the ratio of the Si / Ca atomic ratio at the surface of the powder particles to the Si / Ca atomic ratio at the central region of the powder particles is 2.0 or more, and the calcium content is increased as asymptotically from the surface to the central region. Phosphorus calcium aluminum fluorosilicate glass powder is disclosed. Calcium aluminum fluorosilicate glass powder according to US 4.376.835 has a low susceptibility to water during and after the setting reaction, and the calcium aluminum fluorosilicate glass powder, polycarboxylic acid and chelating agent It is used in self-curing glass ionomer cements comprising an aqueous mixture, wherein the polycarboxylic acid promotes the solidification or curing reaction of calcium aluminum fluorosilicate glass powder, and the chelating agent promotes and enhances the solidification reaction or curing reaction. . US 5.063.257, which is incorporated herein by reference, describes for example the disadvantages of some glass ionomer cements known in the art. One of the most significant drawbacks of these materials is that the control of the solidification reaction or the curing reaction is difficult, resulting in a cement that is brittle on the surface and thus weak in strength. US 5.063.257 discloses fluorosilicate glass powders, polymers of α, β-unsaturated carboxylic acids such as poly (acrylic acid), polymerizable organic compounds with unsaturated carbon-carbon bonds, polymerization catalysts, water, surface active agents ( The use of glass ionomer cements, which include a surface active agent and a reducing agent, provides a solution to this problem. Solidification and curing of this composition occurs by the normal neutralization of the fluorosilicate glass powder and the polymerization of unsaturated groups present in the polymers of α, β-unsaturated carboxylic acids and polymerizable organic compounds, thereby solidifying and curing In the early stages of the glass ionomer cement is obtained which is much less sensitive to water. According to Examples 6, 8 and 14-16, the fluorosilicate glass powder is pretreated with ethylenically unsaturated alkoxysilanes, for example vinyltris (p-methoxyethoxy) silane.

및 GC Corp의 Fuji IX

가 있다. US 5.453.456, US 5.552.485 and US 5.670.258, all of which are incorporated by reference, disclose fluorosilicate glass powders which are treated with aqueous silanol treatment solutions and further organic compounds as necessary. The fluorosilicate glass powder thus treated can produce cement with improved strength. The aqueous silanol treatment solution is preferably an acidic ethylenically unsaturated alkoxysilane, i.e. an instant valence of an alkoxy silane having preferably at least one hydrolyzable alkoxy group, at least one ethylenically unsaturated group and at least one carboxyl group. Prepared from decomposition. Commercially available products are for example KetacMolar from 3M ESPE.

And Fuji IX by GC Corp

There is.

However, glass ionomer cements known from the prior art still have several disadvantages. For example, the strength, rigidity and hardness of glass ionomer cements according to the prior art are often not sufficient. For example, when used as a dental filling material, upon curing, the surface of known cement is not very smooth, which makes it difficult to polish. Another disadvantage of known glass ionomer cements is that the solubility of the hardened cement is high, resulting in wear of the dental filling material. Cured cements also exhibit poor adhesion to bone tissue. As a result, there is still a need for an improved glass ionomer cement that can address these drawbacks.

In conclusion, the glass ionomer compositions according to the prior art are particularly inferior in terms of sensitivity to erosion and aesthetic properties. Furthermore, they often exhibit insufficient strength.

Accordingly, the object of the present invention is a glass ionomer composition having improved properties when cured over conventionally known glass ionomers (in the description of the invention generally referred to as glass carbomer compositions, although both terms are interchangeably Is used).

Summary of the Invention

Conventional known methods for providing improved glass ionomer compositions are all difficult and complex. The present invention provides a solution to this technical problem without a bad effect. The glass carbomer compositions according to the invention are prepared from conventional commercially available materials and exhibit excellent performance in comparison with the glass ionomer compositions known by the prior art, in either uncured or cured state. The glass carbomer compositions according to the invention have, for example, good toughness and strength and excellent fluoride release performance. In addition, the glass carbomer composition according to the present invention shows no shrinkage or expansion, and has high strength and long term durability, which are essential properties for providing a filler for the cavity.

In addition, the glass carbomer compositions according to the invention have a particularly high hardness, low susceptibility to erosion and abrasion, very high rigidity, low solubility, smoother surfaces, better colorfastness, for example when cured For example, better adhesion to bone tissue and lower sensitivity to water. Another advantage of the glass carbomer composition according to the present invention is that when cured it can be more easily polished compared to known glass ionomer compositions. A further advantage of the glass carbomer composition according to the present invention is that the uncured glass carbomer composition is excellent in fluidity, making it easier to fill the cavity, better processability and shorter curing time. In addition, the glass carbomer composition according to the present invention is more easily used as a sealing material. All these advantages are confirmed from basic clinical trials.

Therefore, the present invention provides a fluorosilicate glass powder,

(a) a poly (dialkylsiloxane) having a terminal hydroxy group, wherein the alkyl group has 1 to 4 carbon atoms,

(b) treatment with an aqueous acid solution,

(c) a self-curing glass carbomer composition obtainable by separating the treated fluorosilicate glass powder from an aqueous acid solution.

Detailed description of the invention

The fluorosilicate glass powder particles used in the present invention generally have a reduced amount of calcium on their surface, so that the ratio between the atomic ratio Si / Ca on the surface of the powder particles and the atomic ratio Si / Ca on the central region is reduced. 2.0 or more, preferably 3.0 or more, and most preferably 4.0 or more. The calcium content of the powder particles of the invention increases gradually from the surface to the central region.

The depth of the depletion zone depends on the conditions given in each individual case. However, the reduction region preferably extends to at least about 10 nm deep, more preferably to at least about 20 nm, and most preferably to at least about 100 nm. These ranges are particularly suitable when using fluorosilicate glass powder in dentistry. For other purposes, such as bone cement, the reduction area may be deeper, for example 200 to 300 nm.

As is known in the prior art, fluorosilicate glass powder is prepared by surface treatment of a glass powder having a composition corresponding to the central region of the powder. During surface treatment the number of silicon atoms per unit volume remains substantially constant. Thus, the actual change in the absolute number of atoms per unit volume of other types of atoms is obtained by calculating the ratio of the relative atomic ratio to the percent silicon ratio. Thus, the ratio of atomic ratio Si / Ca at the surface to atomic ratio Si / Ca at the central region is a useful value for characterizing fluorosilicate glass powders.

Surface measurement for determining Ca reduction of the glass powder of the present invention is suitably carried out by photo electron spectroscopy for chemical analysis (ESCA). This method is described by Critical Reviews in Analytical Chemistry, Vol. S. Swingle II and W. M. Riggs. 5, Issue 3, pp. 267-321, 1975 and K. Levsenin's "Chemie in unserer Zeit", Vol. 40, 48-53, 1976. The measurement data underlying the description given above are summarized in US 4.376.835.

The fluorosilicate glass powder has an average particle size (weight average) of at least 0.5 μm, preferably at least 1.0 μm, most preferably at least 3.0 μm. For dental use the average particle size (weight average) is 1.0 to 20.0 μm, preferably 3.0 to 15.0 μm, most preferably 3.0 to 10.0 μm. The particles have a maximum particle size of 150 μm, preferably 100 μm, in particular 60 μm. For dental bonding cements, the maximum particle size is 25 μm, preferably 20 μm. Particle size distributions that are not excessively narrow are advantageous in order to achieve good mechanical properties, and in general, this is achieved, for example, by grinding and classifying, for example, particles of coarse.

The fluorosilicate glass powder is made from glass powder having an average composition of the central region of the powder of the invention. For this purpose the glass powders described, for example, in DE A 2.061.513 and in Table 1 are suitable. Glass powders used as starting materials are typically obtained by fusing the starting components together at temperatures above 950 ° C., quenching and then grinding. The starting components can be, for example, compounds described in a quantitative range suitable for DE A 2.061.513.

Then, the powder obtained in this way is surface-treated. Powders of the invention can be obtained, for example, by removing Ca with a suitable chemical reagent.

For example, the starting glass powder is surface treated with acid, preferably at room temperature. For this purpose, substances having acidic groups, substances producing soluble calcium salts, are used. The poor water solubility of each calcium salt can be compensated to some extent by using a large amount of liquid per unit powder. The reaction time varies from several minutes to several days depending on the strength and concentration of the acid used.

Thus, for example, hydrochloric acid, sulfuric acid, nitric acid, acetic acid and perchloric acid can be used in the preparation of the powder.

The acid is used at a concentration of 0.01 to 10% by weight, preferably 0.05 to 3% by weight.

After each reaction time the powder is separated from the solution and washed thoroughly so that insoluble calcium salt remains substantially on the surface of the powder particles. Finally the powder is preferably dried at 70 ° C. or higher and the required particle size is selected.

The stronger the acid used, and the longer the selected acid acts on the powder, the longer the processing period after mixing with the mixed fluid.

Advantageous powder surface properties enable high powder / fluid ratios, especially in cement mixing, which allows high strength hardening materials to be obtained. In particular, the possibility of using a reactive mixed fluid has the same effect. Furthermore, the process time of the cement of the present invention can be tailored to meet the requirements of the user. Since the length of the process time has little effect on the subsequent curing time, rapid solidification and initial water insensitivity to water are achieved even with long process times.

The glass powder may be mixed with conventional aqueous polycarboxylic acid solutions, for example, as described in DE A 2.061.513, DE A 2.439.882 and DE A 2.101.889 to form dental cement or bone cement. Can be. Suitable polycarboxylic acids are polymaleic acid, polyacrylic acid and mixtures or copolymers thereof, in particular maleic acid / acrylic acid copolymers and / or acrylic acid / itaconic acid copolymers. When using highly reactive glass powders, less reactive polycarboxylic acids will be used to achieve satisfactory curing properties.

In order to promote and improve the curing of the glass ionomer cement, chelating agents can be added during mixing according to the method known by DE A 2.319.715. Since the solid materials do not react with each other, the glass powder can be premixed with the micronized dry polycarboxylic acid in the corresponding ratio, instead of using the usual polycarboxylic acid aqueous solution as the mixed fluid. In this case, water is used as the mixed fluid, preferably with an aqueous chelating agent solution, if appropriate, in combination with conventional additives such as bacteriostatic agents.

In order to avoid measurable errors and to achieve optimum mechanical properties, the powder can be used in preformulated form. For example, the glass powder is weighed into a plastic container. The cement can then be mechanically mixed in the plastic capsule or the container can be emptied to prepare the mixture by hand. In this case, the polycarboxylic acid aqueous solution is metered into, for example, a dripping bottle or a syringe. Use of the powders of the invention is suitable, for example, so-called shaker capsules corresponding to DE A 2.324.296. A predetermined amount of powder is prepared in a so-called main compartment and the fluid is contained in a separate cushion underneath the lateral clip. By applying pressure on the clip, the fluid is injected through the hole into the main compartment and used for mechanical mixing. For both types of capsules, pure glass powder can be replaced with a mixture of a predetermined amount of glass powder and dry polycarboxylic acid. The fluid component is an aqueous solution of water or chelating agent.

When pelletizing a mixture of glass powder and dry polycarboxylic acid, it is particularly advantageous to use the mixture. For this purpose, the dry polycarboxylic acid is used in micronized form after the coarse parts have been removed. The polycarboxylic acid powder can be thoroughly blended with the glass powder and then pelletized in a conventional pelletizing machine. The compacting pressure should be chosen such that after adding the mixed fluid (water or aqueous tartaric acid solution), the pellets are still capable of working with cement while on the other hand have sufficient mechanical stability for transport. The pellets produced in this way make it possible, in particular, to simply dissolve in the corresponding amounts of tartaric acid solution and then simply mix them with the cement paste. The mixed fluid can be added, for example, from a dropping bottle or from a syringe.

In the present invention, the poly (dialkylsiloxane) may be linear or cyclic. In addition, it may be a blend of different poly (dialkylsiloxanes), for example, a blend of poly (dimethylsiloxane) having a high kinematic viscosity and a poly (dimethylsiloxane) having a low kinematic viscosity. Furthermore, it is preferable that the alkyl group of the said poly (dialkylsiloxane) is a methyl group. The kinematic viscosity is preferably from about 1 cSt to about 100.000 cSt [about 1 to about 100.000 mm ² / s] at 25 ° C., preferably from about 100 cSt to about 10.000 cSt [about 100 to about 10.000 mm ² / s], even more preferably in the range of about 500 cSt to about 5000 cSt [about 100 to about 10.000 mm ² / s] at 25 ° C. Best results are obtained when the viscosity at 25 ° C. is about 1000 cSt [about 1000 mm ² / s].

In the present invention, the fluorosilicate glass powder particles are from about 0.5 μm to about 200 μm, more preferably from about 3 μm to about 150 μm, even more preferably from about 3 μm to about 100 μm and especially from about 20 μm to Have an average size of about 80 μm.

It is preferable that an acid aqueous solution contains an inorganic acid or an organic acid. It is further preferred that the aqueous acid solution contains an organic acid, which is preferably a polymer, for example polyacrylic acid. In the present invention, the acid aqueous solution has a pH in the range of 2 to 7.

The present invention also relates to a method of making a self-curing glass carbomer composition. In the process according to the invention, a fluorosilicate glass powder,

(a) a poly (dialkylsiloxane) having a terminal hydroxy group, wherein the alkyl group has 1 to 4 carbon atoms,

(b) then treated in the order of aqueous acid solution,

(c) The treated fluorosilicate glass powder is separated from the acid aqueous solution.

The invention also relates to the use of the self-curing glass carbomer compositions according to the invention as (temporary) dental filling materials, dental bonding cements and bone cements. The self-curing glass carbomer composition according to the present invention may be used as a coating material for bone replacement materials such as implants or joint cavities in orthopedic surgery.

Example 1

The following composition was prepared from the following ingredients.

(a) a polydimethylsiloxane represented by S20, having a kinematic viscosity of 1000 cSt,

(b) conventional fluorosilicate glass powders and

(c) Ordinary acrylate aqueous solution.

The fluorosilicate glass powder and aqueous acrylate solution used in the preparation of the composition were obtained from A3 APLICAP capsules of 3M ESPE.

The amounts of the components are shown in Table 1, where the 5% by weight additional fluorosilicate glass powder is equivalent to about 0.015 g fluorosilicate glass powder, and 0.0015 g S20 is the amount of ordinary acrylate aqueous solution (about 0.0920 g) It is equivalent to about 1.6% additional liquid added to.

product Composition for Content in Commercial A3 APLICAP Capsules S20 (g) Additional Fluorosilicate Glass Powder (% by weight) 5P 0.0015 5.00 5P 0.0015 6.25 6P 0.0015 7.50 8P 0.0015 10.00 12P 0.0045 15.00

Example 2

The composition according to Example 1 was evaluated by in vitro abrasion testing in an ACTA wear machine, a three body wear system designed to mimic wear occurring in the oral cavity (de Gee et al., 1994, 1996).

이다)을 시험하였다. 이 시험에서는, 2개의 바퀴(wheels) (시험하려는 시료를 함유하는 첫 번째 바퀴와 안타고니스트인 두 번째 바퀴)를, 원주에서 근접하게 접촉되도록 하면서, (슬립으로 지칭되는) 원주 속도(circumferential speed)의 차이를 15%로 하여 서로 다른 방향으로 회전시킨다. 시험 시료를 첫 번째 바퀴의 원주 위에 배치한다. 2개의 바퀴가 서로에 대하여 작용하는 힘을 1t 약 15 N으로 조정한다. 기장을 완충액 내에 분사하는 동안, 2개의 바퀴를 미분(rice flour)과 껍질의 슬러리 내에 배치한다. 마모 시험 중에, 음식을 바퀴들 사이에서 압착하여 마모 궤적(wear track)을 시험 시료 상에 만들고, 마모를 결정하기 위하여 참조 재료의 양쪽 면에는 손상되지 않은(untouched) 영역을 남겼다. 프로필로미터(profilometer)로 10개의 시료를 평가함으로써 마모에 의하여 손상된 재료를 결정하였다. Reference material of species (IFMC and KPFA; KPFA is KetacMolar of 3M ESPE for comparison)

Is tested. In this test, two wheels (the first wheel containing the sample to be tested and the second antagonist second wheel) were brought into close contact at the circumference, while at the circumferential speed (called slip). Rotate in different directions with a difference of 15%. The test sample is placed on the circumference of the first wheel. Adjust the force that the two wheels exert on each other to 1 t about 15 N. While spraying the millet into the buffer, two wheels are placed in a slurry of rice flour and shells. During the abrasion test, food was pressed between the wheels to create a wear track on the test sample, leaving untouched areas on both sides of the reference material to determine wear. The materials damaged by wear were determined by evaluating 10 samples with a profilometer.

Samples were prepared within the first wheel (size approximately 10 x 15 x 3 mm). During solidification, the composition according to Example 1 was stored in an oven at 37 ° C. with a relative humidity of 100%. After solidification, the sample was adhered onto the first wheel using cyanoacrylate adhesive. The sample wheel was then wet ground until a uniform cylindrical outer surface was obtained. Wear grinding was performed up to 1000 grit in a wear test machine with a carburondrum and diamond wheels. During this process a layer of 100 μm was removed from the outer surface. Then, the abrasion test was performed at 37 ° C. and pH 7.0. Wear data was obtained after 1, 4 and 8 days. The obtained data is shown in Table 2, the smaller the data value, the higher the hardness, and the ratio of 60 or less is acceptable.

 Hours IFMC KPFA 5P 6P 8P 12P One 135.7 49.5 57.8 54.1 53.9 71.5 4 68.2 43.1 47.7 42.8 45.2 57.4 8 62.7 41.5 43.8 42.7 40.0 57.4

The data in Table 2 shows that the hardness of the sample increases with time. From the data in Table 2, it was determined that IFMC was inferior to all test samples prepared from the compositions according to the invention. In addition, KPFA shows that it is inferior to the sample 8P according to the present invention.

Example 3

In this example, solubility tests were performed. This test was performed as follows. The weight of the cured sample having a diameter of about 0.4 to about 0.6 cm and a thickness of about 1 to about 1.5 mm was measured as the reference material. In the test, these samples were immersed in aqueous solutions of various pH, with pH adjusted with citric acid. Tested at pH 2.5, which mimics the pH that may appear between molars. This test was conducted for a period of about 15 days. The weight of the test sample was determined at several time intervals, meaning that the greater the weight loss, the greater the solubility of the material. The data is presented in Table 3 as% solubility (calculated from original weight and weight lost for the indicated period).

Time (hours) pH 2.5 pH 3.2 pH 7.0 KPFA 5P KPFA 5P KPFA 5P 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.5 12.1 11.7 7.1 5.0 - - 72.0 20.2 16.9 10.9 8.0 2.6 1.1 144.0 25.2 19.2 19.9 14.2 - - 360.0 27.4 21.6 19.9 16.3 5.5 1.8

The data in Table 3 showed that samples prepared from the compositions according to the invention showed improved solubility performance over commercially available material KPFA.

Claims (10)

Fluorosilicate glass powder, (a) a poly (dialkylsiloxane) having a terminal hydroxy group, wherein the alkyl group has 1 to 4 carbon atoms, (b) treatment with an aqueous acid solution, (c) separating the treated fluorosilicate glass powder from an aqueous acid solution. The self-curing glass carbomer composition of claim 1 wherein the poly (dialkylsiloxane) is linear or cyclic. The self-curing glass carbomer composition according to claim 1 or 2, wherein the alkyl group of the poly (dialkylsiloxane) is a methyl group. 4. The self-curing glass carbomer composition of claim 1, wherein the poly (dialkylsiloxane) has a kinematic viscosity in the range of about 1 to about 100.000 cSt at 25 ° C. 5. 5. The self-curing glass carbomer composition according to claim 1, wherein the particles of fluorosilicate glass powder have an average size of about 0.5 to about 200 μm. 6. The self-curing glass carbomer composition according to any one of claims 1 to 5, wherein the aqueous acid solution contains an inorganic acid or an organic acid. 7. The self-curing glass carbomer composition according to claim 6, wherein said organic acid is a polymer. 8. The self-curing glass carbomer composition according to claim 1, wherein said acid aqueous solution has a pH in the range of 2-7. 9. Fluorosilicate glass powder, (a) a poly (dialkylsiloxane) having a terminal hydroxy group, wherein the alkyl group has 1 to 4 carbon atoms, (b) treatment with an aqueous acid solution, (c) separating the treated fluorosilicate glass powder from an aqueous acid solution, Method for producing a self-curing glass carbomer composition. Use of the self-curing glass carbomer composition according to claim 1 as a dental filling material, dental bonding cement, bone cement or bone replacement material.