JPH03284606A - Surface-coated cement powder - Google Patents

Abstract

PURPOSE:To obtain the subject powder improving easiness to grind, fluidity and curing properties and suppressing reduction of fluidity till attaining to an operable time without deteriorating properties of cement by covering the surface of cement powder for dentistry or bone cement powder with metal oxide. CONSTITUTION:The surface of cement powder for dentistry or bone cement powder is covered with a layer of metal oxide by a hydrolysis reaction of metal alkoxide, etc., a dehalogenation reaction of metal halide, etc., or a condensation reaction of metal hydroxide, etc., preferably an oxide of Al, Si, Ti, Zr, Sn, B and/or Zn, or more preferably with at least a double-layer composed of an upper layer of said metal oxide and a lower layer of an alkaline earth metal oxide on the surface to afford the aimed surface-covered cement powder having improved operable time and quickly curing properties with keeping almost constant fluidity without delaying initial curing time of the cement.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the surface modification of cement powders used in medicine and dentistry, in particular zinc phosphate cements, carboxylate cements, glass ionomer cements and bone cement powders. .

Conventional technology As cements used in dentistry, zinc phosphate cement and silicate cement have been known for a long time. It is used for a wide range of purposes, including construction.

These cements are liquids whose main component is phosphoric acid, and are used to knead zinc phosphate cement powder whose main component is zinc oxide or silicophosphate cement powder whose main component is aluminosilicate. It is impossible to completely eliminate irritation to the inner mucosal tissue or pulp tissue, and cement hardening can occur! The residual effects of phosphoric acid remain and are thought to be a cause of pain. Also, tooth structure (enamel, dentin) or
Chemical adhesion with metal or other prostheses cannot be expected at all, and mechanical fitting has been relied upon, which eventually leads to the prosthesis falling off or leaking, which is thought to be the cause of secondary caries.

In recent years, research has been carried out to improve these points, and instead of phosphoric acid solutions, polycarboxylic acids such as polyacrylic acid and/or
Also, carboxylate cements and glass ionomer cements using aqueous solutions of copolymers thereof have appeared.

These cement powders use almost the same composition as the zinc phosphate cement powder and silicate cement powder, but since phosphoric acid does not have the inhibitory effect on living organisms, they have extremely good biocompatibility and are suitable for teeth. Demand is gradually shifting to these cements due to their good chemical adhesion to the texture (enamel, dentin) and prosthesis, good margin sealing properties, and intraoral resistance.

For bone cement used in medicine, calcium phosphate powder is mixed with organic acids such as malic acid, citric acid,
It is kneaded and hardened with an aqueous solution such as tartaric acid, and is used as a substitute for bone by being used as a substitute for artificial bone, for joining and filling artificial joints with autologous bone, and for implanting in bone defects.

In either case, the hardening reaction caused by the reaction between an inorganic salt and an acid, the so-called cement reaction, is used, so the kneading is a combination of powder and aqueous solution, and in general, as much powder as possible is used for the same composition. This shortens the curing time and increases strength. In addition, it is said that the particle size distribution of the powder should be as narrow as possible in order to improve the kneading feeling during kneading and to reduce the coating thickness. As a result, the operability time and film thickness become problematic when adhering prosthetics, etc., and the curing characteristics generally require a long time from operable time to initial curing, and from initial curing to final curing. Since it takes time, the surface of the kneaded material collapses due to contact with saliva, and sufficient final strength cannot be obtained. Many researchers have investigated various methods to solve these problems.

That is, according to JP-A No. 56-37965, by adding a hydroxycarboxylic acid such as tartaric acid to an aqueous polycarboxylic acid solution, calcium ions and aluminum ions eluted at the early stage of the reaction are converted into carboxylic acid salts such as calcium tartrate. There is a method to suppress the reaction with polycarboxylic acid to suppress the increase in viscosity and improve operability, but this method has its limitations and has disadvantages such as increasing the initial curing time when the addition concentration increases. There is.

Furthermore, according to Japanese Patent Application Laid-Open No. 17943/1983, there is a method of treating calcium on the surface of fluoroaluminosilicate glass powder with an acid solution to remove calcium on the glass surface and reduce reactivity. In this method, since the glass surface is resistant to corrosion over a wide range, it has drawbacks such as a decrease in crushing resistance.

Problems to be Solved by the Invention Conventional methods, particularly the surface repurposing method disclosed in JP-A-56-17943, use hydrogen chloride, nitric acid, sulfuric acid, and acetic acid to form soluble calcium salts and dissolve and remove calcium. , exemplifies the use of propionic acid and perchloric acid, but salt remains in the corrosion-resistant micropores even after thorough water washing after treatment, and when cement powder and polycarboxylic acid solution are kneaded, First, because the calcium salt remaining in these micropores reacts with the polycarboxylic acid solution, the expected effect of extending the operable time, that is, the effect of suppressing the rapid decline in fluidity, is not achieved, and the corrosion resistance of the surface is Due to the fine pores, the crushing resistance after cement is also low. It is easier to use as a cement, in other words, it has the effect of suppressing the rapid decrease in fluidity until the operable time, and it has the effect of suppressing the rapid decrease in fluidity until the operable time reaches the initial hardening. There is a need for high-strength cement that takes a long time (time) and a short time to harden.

Means for Solving the Problems In order to solve the above-mentioned problems, the inventor of the present invention proceeded to study cement powder, and discovered that by reacting a metal alkoxide (alcolade), a gold halokenide, and a metal hydroxide on the surface of a glass powder, Depending on the extent to which the metal oxide film is formed, it is possible to maintain strength without reducing the properties of the cement, increase the fluidity of the kneaded mixture, suppress the decline in fluidity up to the operable time, and reduce the hardening time. They discovered that it can be controlled freely and completed the present invention.

That is, the present invention relates to dental cement powder and bone cement powder whose surfaces are coated with metal oxides, and a method for producing the same.

The cement powder used in the present invention is a cement powder conventionally used in the fields of dentistry and surgery,
For example, for zinc phosphate cement powder and carboxylate cement powder, typical compositions include 100 to 751 parts by weight of zinc oxide, 0 to 13 parts by weight of magnesium oxide, 0 to 5 parts by weight of silicic acid, and 0 to 10 parts by weight. range,
-Many products use 1 degree of oxide such as magnesium oxide for every 9 parts of zinc oxide. Some also contain barium sulfate, etc. as an X-ray contrast agent, which is not related to the direct reaction.

In addition, phosphoric acid cement powder and glass ionomer cement powder contain 15 to 60 parts by weight of silicic acid, 10 to 50 parts by weight of aluminum oxide, 0 to 40 parts by weight of calcium oxide, 0 to 10 parts by weight of phosphorus pentoxide, and 0 to 10 parts by weight of fluorine. 40 parts by weight,
A typical composition range is 0 to 10 parts by weight of sodium oxide, and many products use fluoride as a fluxing agent for glass.

Furthermore, for bone cement powder, general 2〇a-+z (P 04
) zO-+ is calcium phosphate represented by n=2 to 4.5.

Among these cement powders, glass ionomer cement powder is particularly preferred. Although the particle size of the cement powder is not particularly limited, it is usually 0.1 to 50 μm, preferably 0.5 to 20 μm.

Examples of the metal oxide coating the surface of the cement powder include oxides of one or more metals selected from the group consisting of aluminum, silicon, titanium, zirconium, tin, boron, zinc, etc. Particularly preferred metal oxides include silicon, titanium, and aluminum.

The coating thickness of the metal oxide is not particularly limited, but is usually 1
0 to 1,000 A, preferably 50 to 500 A. Generally, if it is less than 10 Å, the reaction delay effect due to the coating effect will be poor, and if it exceeds 1,000 A, the delay effect will exceed the clinical range and the metal oxide alone will cause a delay effect. Grain growth increases and becomes less useful.

The metal oxide coating layer is usually a single layer, but if desired, it can be multi-layered, for example, an alkaline earth metal oxide layer as the lower layer, and aluminum, silicon, titanium, zirconium, tin,
Boron and/or may have a multilayer structure with a zinc oxide layer as an upper layer.

The thickness of the lower layer is usually 10-500, preferably 20-2
00 people, and the thickness of the upper layer is 10-1000 people, preferably 50-500 people.

By employing such a multilayer structure, unique hardening characteristics can be imparted to the cement powder. In other words, the cement powder in the core has a composition that provides maximum physical properties when mixed with the cement solution, and the reaction rate is adjusted by:
This is done in a layer of metal oxide, so if the reaction of cement powder in the core is slow, the top layer is coated with fast-reacting magnesium oxide, calcium oxide, etc., and the top layer is coated with slow-reacting silicon oxide. It can be coated with titanium oxide, titanium oxide, etc.

Note that the cement powder may be coated with a plurality of such layers.

The method of manufacturing the dental cement powder and bone cement powder surface-coated with metal oxides according to the present invention is not limited, but a particularly preferred method is to prepare the dental cement powder and the bone cement powder surface-coated with metal oxides by applying the steps of: The cement powder is produced by carrying out a hydrolysis reaction of a metal alkoxide or its partial hydrolysis, a dehalogenation reaction of a metal halide or its partial dehalogenation, or a condensation reaction of a metal hydroxide or its partially dehydrated condensation prepolymer. This method forms a metal oxide coating layer on the surface.

Examples of metal alkoxides include the following compounds: tetraethoxysilane, tetramethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetraisobutoxysilane, tetra-5ec-butoxysilane. , trimethoxychlorosilane, triethoxychlorosilane, triisopropoxychlorosilane, trimethoxyhydroxysilane, dimethoxyjethoxysilane, jetoxydichlorosilane, dimethoxydichlorosilane, diisopropoxydichlorosilane, jetoxydihydroxysilane, dimethoxydichlorosilane, tetramethoxy Titanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, tetrabutoxytitanium, trimethoxychlorotitanium, triethoxychlorotitanium, triglovirchlorotitanium, triisopropoxychlorotitanium, trimethoxyhydroxytitanium, tri Ethoxymethoxytitanium, Jetoxydimethoxytitanium, Tritoxyethoxytitanium, Trilowpropoxymethoxytitanium, Di-n-globoxydimethoxytitanium, Trilowpropoxyethoxytitanium, Triethoxy-n-propoxytitanium, Jetoxydi-n-propoxytitanium, Trimethoxy- n-propoxytitanium, triethoxyisopropoxytitanium, jetoxydiimpropoxytitanium, trimethoxyisopropoxytitanium, tetramethoxyzirconium, tetranidoxyzirconium, tetra-
n-propoxyzirconium, tetraisopropoxyzirconium, tetrabutoxyzirconium, trimethoxyaluminum, triethoxyaluminum, tripropoxyaluminum, tributoxyaluminum, tetramethoxytin, tetraethoxytin, tetrapropoxytin, tetrabutoxytin, dimethoxyzinc, jetoxy Zinc, dipropoxyzinc, dibutoxyzinc, trimethoxyzinc, triethoxyzinc, tripropoxyzinc, trypoxyzinc, dimethoxycalcium, jetoxycalcium, dipropoxycalcium, dibutoxycalcium, jetoxycalcium, jetoxy Magnesium, jetoxycalcium, dibutoxymagnesium, etc. Examples of metal halides include the following compounds: silicon tetrachloride, titanium tetrachloride, zirconium tetrachloride, tin tetrachloride, aluminum chloride, boron chloride, magnesium chloride, calcium chloride, silicon tetrabromide, titanium tetrabromide,
These include zirconium tetrabromide, tin tetrabromide, aluminum bromide, boron bromide, and magnesium bromide.

Examples of metal hydroxides include the following compounds, which include metal hydrated oxides and water hydroxides.

Namely, silicon hydroxide (silicon oxide hydrate), titanium hydroxide (titanium oxide hydrate), zirconium hydroxide (zirconium oxide hydrate), aluminum hydroxide (aluminum oxide hydrate), hydroxide These include tin (ffI tin hydrate), zinc hydroxide, magnesium hydroxide, calcium hydroxide, and the like.

The reaction conditions for the above-mentioned hydrolysis reaction, dehalogenation reaction, and condensation reaction may be selected appropriately depending on the reaction component composition and the type of cement powder, but the reactions that occur here are extremely complex, and there are various theories. Although there is no such thing, metal alkoxides and metal chlorides undergo hydrolysis in the presence of water and become hydroxides to oxides, but during the reaction they condense, and due to the hydroxyl groups on the surface of the core material. It is assumed that hydrogen bonds occur and some form of water remains.

Now let's talk about silicon (halide) SiCI, +H20 → Si (OH), + HC1 (hydroxide) Sl (OH) 4-5i02 + H20 (alcolade) S 1 (OR), 10H, O → S 1 (OHXOR)x
+ ROH// = S 1(OH)2(OR
)z + ROH〃 →S 1(OHXOR)+
ROH〃 →Si(OH), 3+ ROH (dehydration reaction) -5i-OH+ HO-5i-→ -5i-0-5i
-+ H2O (dealcoholization reaction) -5i-OH+R-0-5i-→-5i-0-Si-+
ROHR: A mechanism such as an alkyl group is considered, but on the surface of the core material, a bond as shown in FIG. 1 is considered.

The synthesis of dimetal alkoxide utilizes one of the following reactions.

(1) Reaction between component alkoxides MOR+AI(OR)! -M[Al(OR)4]M: alkali metal, R: alkyl group (2) Another metal alkoxide that is being formed by dissolving metal alkoxide and metal M: 2 (fB gold metal R: alkyl group (3 ) Reaction of metal halide with dimetal or single alkali alkoxide M'[M''(OR)x]: For example, K[AI(1-O
CsHy)4]M: Various divalent, trivalent, or tetravalent metals The coating step for modifying cement powder according to the present invention can be carried out by various methods (including conventional coating methods).

In the liquid phase method, for example, metal alkoxides are hydrolyzed by dispersing and stirring cement powder in a water-soluble solvent such as alcohol in the presence of water (acid or alkali catalysts are used as necessary, often hydrochloric acid or aqueous ammonia). (sometimes added as a catalyst), metal hydroxides, metal oxides, or intermediate condensates of these are formed on the surface of the cement powder to form a coating, but the final step is to heat and evaporate the solvent, etc. dry. Also, after impregnating cement powder with a small amount of water, metal alkoxide is heated while stirring and mixing in a suitable mixer to cause hydrolysis.

Water and alcohol can be evaporated and coatings similar to those described above can be made. Alternatively, a metal halide can be hydrolyzed to produce a metal hydroxide, which can be treated in the same manner as the metal alkoxide. The same applies when metal hydroxide is used.

In the gas phase method, a metal halide or metal alkoxide is brought into contact with cement powder in a gaseous state, and a dehalogenation reaction, dealcoholization reaction, and dehydration reaction (
Condensation reaction). For example, it is sufficient to place silicon tetrachloride or tetraethoxysilane and cement powder in separate open containers in a closed container and then place them in the original container. In this state, the metal compound vaporizes under the partial pressure at that temperature and maintains an adsorption equilibrium on the powder. If the reaction progresses on the powder surface,
The partial pressure decreases and the metal compound is vaporized and supplied.

The required amount is covered by such wire turning.

In the gas phase method, a coating is formed based on this principle, but it is necessary to take measures to speed up the reaction rate and ensure uniform coating on the powder surface.

In other words, cement powder that has been slightly moistened with water is
This can be carried out by floating the metal alkoxide or metal halide in a closed closed container heated if necessary, and introducing the metal alkoxide or metal halide in a mixture with a carrier gas. The gas supply rate is appropriately determined depending on the vapor pressure of the metal compound, the type of cement powder, the capacity of the reaction vessel, etc., but preferably for 30 minutes to 100 hours.
It is preferable to make adjustments so that you can arrive at least 20 hours in advance.

As the carrier gas, an inert gas such as nitrogen or argon is preferable, but a mixed gas of air, water vapor, methanol vapor, or ethanol vapor in the state of gas molecules may also be used. Of course, the metal compound and the carrier gas can also be introduced separately and mixed within the reaction vessel.

EXAMPLES The present invention will be described below with reference to Examples, but the present invention is not limited thereto.

As a test method for cement, IS○7489 Den
tal grass polyalkenoate c
Initial curing time, film thickness, and crushing resistance were measured according to the element test method. In addition, the operable time is determined by applying the term of coating thickness, gradually shifting the load application time, plotting the coating thickness at that time and the load start time, and calculating the coating thickness by 25 μm.
The point at which m was reached was defined as the operable time.

In addition, regarding the consistency measurement method that indicates the fluidity of kneaded products, ISO
Since it is not specified in the standard, the ADA (American Dental Association Standard for Dental Materials) N○21 standard regarding dental silicate cement was adopted. However, take an appropriate amount of cement mud for 1.0 g of cement liquid, mix it with a metal spatula for 1 minute on a glass mixing board, weigh out 0.5 pieces of cement mud, and 2 minutes after the start of mixing, load 220 g on top of this cement mud. 10 minutes later, the average expanded diameter was measured. In addition, the consistency at which this spreading diameter was 33±1 m+n was defined as the standard consistency.

Example 1 30 g of powdered glass ionomer cement (trade name "Glass Ionomer Cement-C" manufactured by Shofu Co., Ltd.) and 200 mff of ion-exchanged water were placed in a three-piece 0797 reaction vessel equipped with a stirring rod and a reflux condenser, and the mixture was stirred and suspended. As a cloudy liquid,
After raising the liquid temperature to 80℃ in a water bath,
Tetraethoxysilane 0 in 50mQ of ethyl alcohol
．． A solution containing 9 g was added dropwise using a separatory funnel over about 1 hour. After the dropwise addition was completed, the mixture was refluxed for 6 hours, and then filtered under reduced pressure using a Nutsche filter, and the obtained powder was dried in a dryer at 150° C. for 12 hours. Next, it was ground in a porcelain mortar and passed through a 125m/s sieve at a temperature of 23°0±1.
After leaving it in a constant temperature room at ℃ and humidity 50±1O% for 24 hours,
A test was conducted using the product name "Glass Ionomer Cement J Liquid Material" (Shofuzoku Co., Ltd.) as the polycarboxylic acid solution. The results are shown in Table 1.

In addition, when the surface conditions of the cement powder before the surface coating treatment and the cement powder after the treatment were compared using scanning electron micrographs, no significant visual change was observed between the two.

Example 2 Into a three-piece 0797 reaction vessel equipped with a stirring rod and a reflux condenser, 30 g of powder of glass ionomer cement (trade name: "Class Ionomer Cement iCJ manufactured by Shofu Co., Ltd.") and 200 m of ion-exchanged water (2) were charged, and After making a cloudy liquid and raising the liquid temperature to 80℃ in a water bath, add 50ml of ethyl alcohol (1.2ml of tetraethoxysilane in 2
A solution containing g was added dropwise using a separating funnel over about 1 hour. After the dropwise addition was completed, the mixture was refluxed for 6 hours, then filtered under reduced pressure using a Nutsche filter, and the resulting powder was dried in a dryer at 150°C for 12 hours. Next, it was ground in a porcelain mortar and passed through a sieve at 125+o/s.
After being left in a constant temperature room at ±1°C and humidity of 50±1O% for 24 hours, the physical properties were determined using the same test method as in Example I.

The measurement results are shown in Table-1.

Example 3 30 g of glass ionomer cement powder (trade name: "Glass Ionomer Cement - manufactured by CJ Shofu Co., Ltd.") and 200 ml of ion-exchanged water were placed in a three-piece 0797 reaction vessel equipped with a stirring rod and a reflux condenser, and suspended. After raising the liquid temperature to 80°C in a water bath, a solution of 0.5 g of silicon tetrachloride dissolved in distilled and purified anhydrous ethanol 5oIIIQ was added dropwise in a separatory funnel over a period of about 10 minutes. In order to neutralize the hydrogen ion concentration in the reaction system, an appropriate amount of dilute ammonia solution was added.Then, reflux was performed for 6 hours, vacuum filtration was performed using a Nutsche filter, and the obtained powder was placed in a dryer at 150°C. Drying was performed for 12 hours.

Next, the powder was crushed in a porcelain mortar and passed through a sieve at 125 m/s, and then left in a constant temperature room at a temperature of 23.0 ± 1°C and a humidity of 50 ± 10% for 24 hours, followed by the same test as in Example 1. The physical properties were determined using the method. The measurement results are shown in Table I.

Example 4 30 g of powder of glass ionomer cement (trade name "Glass Ionomer Cement-〇" manufactured by Shofu Co., Ltd.) and 200 ml of ion-exchanged water were charged into a three-north flask reaction vessel equipped with a stirring rod and a reflux condenser, and a suspension was prepared. After raising the liquid temperature to 80'Ct in a water bath, titanium tetrachloride was added to 50mβ of distilled absolute ethanol.
．． 6g of the solution was added dropwise in a separatory funnel over about 2 minutes, and then in order to neutralize the hydrogen ion concentration in the reaction system,
An appropriate amount of dilute ammonia solution was added. Thereafter, the mixture was refluxed for 6 hours, filtered under reduced pressure using a Nutsche filter, and the obtained powder was dried in a dryer at 150° C. for 12 hours.

Next, the powder was crushed in a porcelain mortar and passed through a sieve at 125 m/s, and then left in a thermostatic chamber at a temperature of 23.01°C and a humidity of 50 soil JQ% for 24 hours, and then subjected to the same test method as in Example 1. The physical properties were determined. The measurement results are shown in Table-1.

Example 5 30 g of powdered glass ionomer cement (trade name: "Class Ionomer Cement-〇" manufactured by Shofu Co., Ltd.) and ion exchange water 20011Q were placed in a three-piece 1791 reaction vessel equipped with a stirring rod and a reflux condenser, and the mixture was stirred and suspended. As a cloudy liquid,
After raising the liquid temperature to 90℃ in a water bath,
A solution of 0.69 ml of ethyl silicate (tetraethoxysilane) hydrolyzate (trade name: "Ethyl Silicate 40" manufactured by Colcoat Co., Ltd.) dissolved in 50 mQ of ethyl alcohol was added dropwise using a separating funnel over about 1 hour. After completion of the dropwise addition, the mixture was refluxed for 6 hours, and then filtered under reduced pressure using a Nutsche filter, and the resulting powder was dried in a dryer at 150° C. for 12 hours. Next, crush it in a porcelain mortar to 125 m
/s sieve, temperature 23.0±1℃, humidity 50±
After being left in a thermostatic chamber at lO% for 24 hours, physical properties were measured in the same manner as in Example 1. The results are shown in Table-1.

Example 6 30 g of glass ionomer cement powder (trade name: U Glass Ionomer Cement-C, manufactured by Shofu Co., Ltd.) was placed in a reaction tube, the temperature inside the tube was maintained at 90'C, and the pressure inside the reaction tube was reduced using an aspirator. Tetraethoxysilane 109
A mixed vapor of water 19 and water was introduced into the reaction tube using helium as a carrier gas, and a contact reaction was carried out for 6 hours.

Thereafter, the powder was taken out and dried in a 150'c dryer for 12 hours. Next, crush it in a porcelain mortar.12
After passing through a 5 m/s sieve and leaving it in a constant temperature room at a temperature of 23°0 ± I'O1 and a humidity of 50 ± 10% for 24 hours, Example 1
The physical properties were measured using the same method. Table the results.
Shown in 1.

Example 7 30 g of powder of glass ionomer cement (trade name: "Glass Ionomer Cement-c" manufactured by Shofusha Co., Ltd.) was charged into a pressure-resistant gas phase reactor, and compressed air (3-4K9f/
While blowing glass ionomer powder into the device and suspending the glass ionomer powder, heat Jetanol 50 + aQ to 90'O.
0.6 g of tetraethoxysilane dissolved in the solution was sprayed with air spray over 30 minutes. Thereafter, the powder was suspended for an additional 4 hours while maintaining the temperature inside the device at 90°C, and then dried for 12 hours in a 150'c dryer.

Next, the powder was ground in a porcelain mortar, passed through a sieve at 125 m/s, and then left in a constant temperature room at a temperature of 23.0±1°C5 and a humidity of 5o±10% for 24 hours, followed by the same method as in Example I. The physical properties were measured. The results are shown in Table-1.

Example 8 Anhydrous ethyl alcohol 509 was placed in a four-flask reaction vessel equipped with a stirring bar and a reflux condenser, and while dry nitrogen was passed through it, 0°39 of metallic calcium was added, and after heating under reflux for 10 hours, tetraethoxy Silane 0.9
g was added thereto, and the mixture was further heated and refluxed for 4 hours. This is called liquid A. Next, a Mitsu 179 equipped with a stirring bar and a reflux condenser
Glass ionomer cement (product name:
Add 30g of powder of Glass Ionomer Cement-c (manufactured by Shofu Co., Ltd.) and ion exchange water 200+A12 and stir to make a suspension.After raising the liquid temperature to 90℃ in a water bath, separate the previous liquid A. The mixture was added dropwise using a liquid funnel over a period of about 1 hour. After the dropwise addition was completed, reflux was carried out for 6 hours, and then 0% of tetraethoxysilane was added in 501nQ of ethyl alcohol.
．． A solution containing 6 g was added dropwise using a separating funnel over about 1 hour. After the dropwise addition was completed, reflux was further carried out for 6 hours, and then vacuum filtration was carried out using a Nutsche filter.
Drying was carried out in a 'C dryer for 12 hours. Next, it was ground in a porcelain mortar, passed through a sieve at 125 m/s, and then placed in a constant temperature room at a temperature of 23°C and a humidity of 5o±10% for 2 hours.
After standing for 4 hours, physical properties were measured in the same manner as in Example 1. The results are shown in Table-1.

Example 9 0.9 g of water and 104 g of tetraethquinsilane were dissolved in 0.5Q methanol, and this solution was hydrolyzed with stirring at room temperature for about 2 hours. was added to a solution of calc in 0.5Q of Ingropanol with stirring, and a mixed solution of tetraethoxysilane hydrolyzate and tetra-n-butoxysilane (A
) was prepared.

Next, 43 g of tetramethoxymagnesium and 54 g of tetraethoxysilane were dissolved in 1.0 Q of methanol, and the solution was refluxed at 75° C. in a nitrogen atmosphere for 30 minutes, and then allowed to return to room temperature to prepare a mixed solution (B).

2.5 methanol in a 10ff glass reaction vessel with a stirrer
Add 500g of 25wt% ammonia water to Q to make an ammoniacal alcohol solution, and then add glass ionomer (product name: "Glass Ionomer Cement C" manufactured by Shofu Co., Ltd.)
5000 g of powder was added, and the previously prepared solution B was added over about 2 hours at a temperature of 20°C. Thereafter, the liquid temperature was raised to 80° C., and Solution A was immediately added over about 2 hours, followed by refluxing for 4 hours.

Thereafter, the powder obtained by vacuum filtration was dried in a dryer at 150°C for 12 hours, pulverized, and passed through a 125 m/s sieve.
The sample was left in a constant temperature room at a temperature of 23±1° C. and a humidity of 50±10% for 24 hours, and its physical properties were measured in the same manner as in Example 1. The results are shown in Table-1.

(Hereinafter, blank space) Comparative Example 1 The powder and liquid materials of the glass ionomer cement ("Glass Ionomer Cement-C" manufactured by Shofu Co., Ltd.) used in Example 1 were used in Example 1. ! - A similar test was conducted. The results are shown in Table-3.

Comparative Example 2 200 g of 0-15 wt% hydrogen chloride solution was put into a three-flask reaction vessel equipped with a stirring bar and a reflux condenser, and the liquid temperature was raised to 80°C in a water bath while stirring. After adding 30 g of powder of glass ionomer cement (trade name: "Glass Ionomer Cement-C" manufactured by Shofusha Co., Ltd.) and heating and stirring for one hour, vacuum filtration was performed, and the obtained powder was washed with ion-exchanged water. After thoroughly washing until neutral, it was dried in a dryer at 150° C. for 12 hours. Next, crush it in a porcelain mortar at 125 m/s.
After passing through a sieve, the temperature is 23.0 ± 1℃ and the humidity is 50% and 10%.
% in a constant temperature room for 24 hours, then the physical properties were measured in the same manner as in Example 1. The measurement results are shown in Table 3.

When the surface after treatment was examined using a scanning electron microscope, it was found that small cracks had occurred.

Comparative Examples 3 and 4 Product name: “Glass Ionomer Cement-〇” DL-tartaric acid was added to liquid material made by Shofu Co., Ltd. at 12.5 wt% and 18.7 wt%.
The physical properties were measured in the same manner as in Example 1 using a liquid material that was added and prepared so as to have a concentration of It is shown in Table-3.

Examples 10 to 2I Example 10.1112.13 is obtained by performing the reflux time L 2.4.8 hours in Example 1, and further uses 0.009 g of 35% hydrochloric acid (1% based on tetraethoxysilane) as a catalyst. Example 14.15.1 was prepared by adding 0.045 g (5% based on tetraethoxysilane) to ethyl alcohol and refluxing for 1.2.4.6 hours.
6.17 and 18.19.20.21, were treated in the same manner, and their physical properties were measured. The results are shown in Table-2 and Table-3.

(Hereinafter, blank space) Example 22 Calcium carbonate and γ-calcium phosphate were mixed at a molar ratio of 2, heated at a rate of 20°C/min, and heated to 1250°.
After holding at C for 2 hours, the mixture was cooled at a rate of 40°C/min, and the average particle size was adjusted to 6.5 μm to obtain bone cement powder.

Citric acid 40% by weight Tartaric acid 10% by weight Ion exchange water 50%
A weight percent solution was prepared and used as a bone cement solution.

The physical properties of the kneaded product were measured using JIS T6602 Test Method for Dental Zinc Phosphate Cement, and the following results were obtained.

Powder-liquid ratio (for standard consistency, 5 Operable time (minutes) 2゜5
Clotting time (min) 6.5 Crushing drag force (kgf/cm”
) 120 This bone cement powder was replaced with the glass ionomer powder of Example 1 and treated in the same manner.

When this powder was kneaded with the above solution and the same test was conducted, the results were as follows.

Powder-liquid ratio (standard consistency) 1.8 Operable time (minutes) 4゜0
Clotting time (minutes) 7.0 minutes Crushing drag force (kgf/cm2 1600 However, since the operable time is not specified by the JIS standard, it was measured by the method described above.

The cement powders according to Examples 1 to 9 can be operated without delaying the initial hardening time at the same consistency compared to the cement powders according to Comparative Examples 1 to 4, and also compared to the untreated and treated cement powders according to Example 10. This dramatically improves the possible time, increases the fracture resistance, and maintains the coating thickness for a long time, making it possible to fuse multiple prostheses together during kneading, and to achieve the same level of stability during filling. If it has a high consistency, more powder can be added, which increases the crushing resistance and allows for more operation time.
It is excellent as dental cement and bone cement as it allows sufficient time to form.

Effects of the Invention It is extremely important for clinical applications that kneading, fluidity, and hardening properties are improved by reacting metal alkoxides (alcolades), metal halides, metal oxides, etc. on the surface of cement powder.

That is, firstly, the initial hardening time of cement is not delayed, the fluidity (flow value) is kept almost constant, the operable time is increased, and the cement has rapid hardening properties. Therefore, it is now possible to fuse multiple prostheses in one go, which was previously impossible.

Secondly, because the initial reaction is suppressed, the conventional factors that affect the coating thickness are powder particle size and powder reactivity, but the present invention solves these conflicting factors.

Thirdly, the obtained kneaded product has high fluidity, so it is easy to knead, and individual differences between kneading operators are reduced, and stability in physical properties etc. is obtained.

Due to these facts, when used for bonding a prosthesis, the thickness of the cement coating can be made thinner than in the past. In other words, in the conventional technology, the powder was made finer as a way to reduce coating dust, but by making finer particles,
There are limits to miniaturization, such as an increase in the specific surface area, an increase in surface energy, and a shortening of usable time due to acceleration of reactions. Inconveniences often occurred.

Furthermore, it has become possible to provide unique curing properties by applying not only single-component or single-layer coatings but also mixed-component or multi-layer coatings.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of the reaction mechanism when alkylquine silane forms a surface coating film on an inorganic core material.

Claims (1)

[Claims] 1. Dental cement powder whose surface is coated with metal oxide. 2. Bone cement powder surface coated with metal oxide. 3. The cement powder according to claim 1 or 2, wherein the metal oxide is an oxide of aluminum, silicon, titanium, zirconium, tin, boron and/or zinc. 4. An alkaline earth metal oxide layer as the lower layer, Claim 2
3. Cement powder according to claim 1 or 2, coated with at least one multi-layer overlying a metal oxide layer as described above. 5. Hydrolysis reaction of metal alkoxide or its partial hydrolyzate, dehalogenation of metal halide or its partial dehalogenation on the surface of dental cement powder or bone cement powder in liquid phase or gas phase. The method for producing cement powder according to any one of claims 1 to 4, characterized in that a reaction or a condensation reaction of a metal hydroxide or a partially dehydrated condensation prepolymer thereof is carried out.