JPH0310603B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a composite composition, particularly a composite composition suitable for dental use. For more details, see wear resistance,
The object of the present invention is to provide a composite composition that has excellent lubricity, high surface hardness, and is easy to polish. Currently, bisphenol A glycidyl methacrylate (addition product of bisphenol A and glycidyl methacrylate, hereinafter abbreviated as Bis-GMA), which is said to have relatively small polymerization shrinkage, is used as a composite composition, such as a dental composite restorative material. Generally, a large amount of glass beads or pulverized quartz with a particle diameter of several micrometers is mixed with the acrylic monomer liquid as the main component, and a polymerization initiator that decomposes at room temperature is added to polymerize and harden in the oral cavity. It is used in many ways. Because the above-mentioned restorative materials use optically transparent inorganic powder as a filler, they suffer from shrinkage and transparency during polymerization compared to resin-based restorative materials made of acrylic polymer and the same monomer. It is characterized by its excellent linear expansion coefficient and mechanical strength, and is widely used by clinicians. However, they are far inferior to natural teeth in terms of mechanical strength, wear resistance, surface smoothness, and surface hardness, and there are still points that need to be improved. In order to improve the various drawbacks mentioned above, the present inventors have conducted extensive research, especially regarding inorganic fillers.
As a result, mechanical strength and abrasion resistance are improved, and the surface smoothness is improved by using a combination of spherical particles with an inorganic filler particle size within an appropriate range and a uniform particle size distribution. I found something to do. Furthermore, surprisingly, by using spherical particles of uniform particle size, the surface hardness is higher than that of known fillers, such as those using ultrafine particle fillers. It is very easy to finish, and it can produce a variety of unexpected effects, such as being able to easily obtain a smooth, glossy surface. That is, the present invention is a spherical inorganic oxide with a particle size in the range of 0.1 to 1.0 μm, and a composite composition consisting of a mixed inorganic oxide consisting of at least two groups with different average particle sizes and a polymerizable vinyl monomer. It is a thing. One component of the dental composite composition of the present invention is a polymerizable vinyl monomer. The vinyl monomer is not particularly limited, and any vinyl monomer can be used as long as it can be polymerized. For example, known materials commonly used as dental restorative materials can be used. The most typical vinyl monomer is a polymerizable vinyl monomer having an acrylic group and/or a methacrylic group. Specific examples of vinyl monomers having acrylic and/or methacrylic groups include bisphenol A diglycidyl methacrylate, methyl methacrylate, bismethacryloethoxyphenylpropane,
Preferred are triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tetramethylol triacrylate, tetramethylolmethane trimethacrylate, trimethylethane trimethacrylate, and the like. Also preferably used is a vinyl monomer having a urethane structure represented by the following structural formula. However, in the above formula, R ₁ , R ₂ , R ₃ , and R ₄ are the same or different H or CH ₃ , and (-A)- is (-CH ₂ )- ₆ ,

[Formula] or

[Formula] is preferred. Since these vinyl monomers are known as dental materials, they may be used alone or in combination as required. Other components of the composite composition of the present invention are inorganic oxides. The inorganic oxide used in the present invention has a particle size of
They are spherical particles in the range of 0.1 to 1.0 μm. Any inorganic oxide having a particle size within the above range can be used without particular limitation. Specific examples of inorganic oxides having the above particle size range that are generally preferably used include, for example, amorphous silica; It is an inorganic oxide or the like whose main constituents are at least one selected metal component and a silicon component. The inorganic oxide used in the present invention needs to be a mixture of at least two groups having different average particle diameters. The mixture of inorganic oxides may be the same or different types of inorganic oxides,
The groups having different average particle diameters are not necessarily limited to two groups, but may be three groups or more. The particle size distribution of the inorganic oxide is not particularly limited, but the purpose of the present invention is best achieved by a sharp distribution with a standard deviation value within 1.30. Both the particle size and the particle shape are very important factors, and the object of the present invention cannot be achieved if any of the conditions are absent. For example, the particle size of inorganic oxide is 0.1μm
If it is smaller, the viscosity will increase significantly when it is kneaded with the polymerizable vinyl monomer to form a paste mixture, and if you try to prevent the increase in viscosity by increasing the blending ratio, the operability will deteriorate, so Therefore, it cannot be used as a material for practical use. Also, the particle size is
If it is larger than 1.0 μm, it is not preferable because the resin obtained by polymerizing and curing the vinyl monomer has defects such as a decrease in abrasion resistance or surface smoothness, and further a decrease in surface hardness. In addition, if the standard deviation value of the particle size distribution becomes larger than 1.30, the operability of the composite composition may deteriorate, so generally, it is preferable to use a particle size distribution with a standard deviation value of 1.30 or less. is preferred. Furthermore, the inorganic oxide has the above particle size.
Even if the particle size is within the range of 0.1 to 1.0 μm and the standard deviation value of the particle size distribution is within 1.30, if the shape of the particle is spherical, the above-mentioned effects of the present invention, especially wear resistance and surface The smoothness, surface hardness, etc. of these materials cannot be satisfactory. Next, the difference in particle size of the mixed inorganic oxides made up of at least two groups having different average particle sizes is not particularly limited, but it is generally preferred that the difference is two times or more. In addition, the mixing ratio of the first group inorganic oxide and the second group inorganic oxide in the mixed inorganic oxide consisting of the first group inorganic oxide and the second group inorganic oxide depends on the difference in particle size. It varies, but generally it's weight,
It is preferable that the amount of inorganic oxides in the first group is greater than the amount of inorganic oxides in the second group, and the amount of inorganic oxides in the first group is in the range of 1.2 to 10 times the amount of inorganic oxides in the second group. suitable. Furthermore, it is a spherical inorganic oxide with a particle size range of 0.1 to 1.0 μm and a standard deviation value of particle size within 1.30, and the average particle size is approximately half the average particle size of the second group of inorganic oxides. The following third group of inorganic oxides may be mixed in the mixed inorganic oxide. The method for producing the inorganic oxide used in the present invention is not particularly limited, and any production method may be used as long as the inorganic oxide has the above particle size and shape. Generally, industrially, a method of producing by hydrolysis of silicate ester (Inorganic Materials Research Institute Report No. 14, pages 49 to 58 (1977)) is suitably employed. Further, it contains a hydrolyzable organosilicon compound and a hydrolyzable organic compound of at least one metal selected from the group consisting of metals of Groups 1, 2, 3, and 3 of the periodic table. The mixed solution is added to an alkaline solvent that dissolves the organosilicon compound and the organic compounds of metals of Groups, Groups, and Groups of the Periodic Table, but does not substantially dissolve the reaction products, and performs hydrolysis. The main constituents are at least one metal oxide selected from the group consisting of metal oxides of Groups 1, 2, 3, and 3 of the periodic table, obtained by precipitating a reaction product, and silica. A method for producing an inorganic oxide is preferably employed. In general, it is preferable to reduce the number of silanol groups on the surface of industrially obtained inorganic oxides in order to maintain surface stability. For this purpose, the spherical inorganic oxide is further heated to 500 to 1000℃ after drying.
A method of firing at a temperature of During the firing, some of the inorganic oxides may sinter and aggregate, so it is usually preferable to use a crusher, vibrating ball mill, jet pulverizer, etc. to loosen the aggregated particles. In general, in order to maintain stability, the fired inorganic oxide is most preferably used after surface treatment using an organic silicon compound. The surface treatment method described above is not particularly limited, and may be performed using a known method such as using silica particles and a known organosilicon compound such as γ-methacryloxypropyltrimethoxysilane or vinyltriethoxysilane.
A method is adopted in which the solvent is removed after contacting for a certain period of time in a mixed solvent of alcohol/water. The particle size and shape of the inorganic oxide used in the present invention can be confirmed by taking a microscopic photograph, and the standard deviation value of the particle size distribution can be determined within the unit area of the microscopic photograph or the unit field of view of the microscope. It can be calculated from the number of particles existing in and the diameter of each particle using the calculation formula described below. The above-mentioned microscopic photograph may be any photograph as long as the particle shape of the inorganic oxide can be observed, but scanning electron micrographs, transmission electron micrographs, etc. are generally suitable. In addition, if the inorganic oxide is mixed with another liquid substance such as a polymerizable vinyl monomer to form a paste mixture, the liquid substance is extracted and removed using an appropriate organic solvent, and then the inorganic oxide is oxidized by the same operation as described above. It is good to investigate the properties of things. As described above, the inorganic oxide used in the present invention is a spherical particle, but whether or not it is spherical can be confirmed by measuring the specific surface area of the inorganic oxide in addition to the above-mentioned microscope. I can do it. For example, if the specific surface area of an inorganic oxide having a particle diameter in the range of 0.1 to 1.0 μm is about 4.0 to 40.0 m ² /g, it almost matches the specific surface area calculated assuming a perfect spherical shape. Therefore, the inorganic oxide used in the present invention preferably has a specific surface area of 4.0 to 40.0 m ² /g. The composite composition of the present invention is used by mixing the polymerizable vinyl monomer component and the specific inorganic oxide. For example, when using the above composite composition as a dental restorative material, not only the operability is an important factor, but also the mechanical strength, abrasion resistance, surface smoothness, etc. of the resulting cured composite resin. Must be well maintained. For this reason, it is generally preferable to select the amount of inorganic oxide added to be in the range of 70 to 90%. In addition, when used as the above-mentioned dental composite restorative material, a paste-like mixture consisting of an inorganic oxide, a polymerizable vinyl monomer, and a polymerization accelerator (for example, a tertiary amine compound), an inorganic oxide, a vinyl monomer, and a polymerization initiator is generally used. A suitable method is to prepare a paste-like mixture of the above agents (for example, an organic peroxide such as benzoyl peroxide) in advance, and knead and harden the two immediately before the repair operation. The composite resin obtained by curing the composite composition of the present invention has mechanical strength such as compressive strength that is comparable to conventional resins, and has excellent abrasion resistance and surface smoothness, as well as high surface hardness. It has many excellent features such as being very easy to polish the surface. However, the reason why such characteristics appear is not necessarily clear at present, but the inventors of the present invention think as follows. That is, first, it is necessary to use a combination of inorganic oxides having a uniform particle size, such that the particle shape is spherical, the particle size is 0.1 to 1.0 μm, and preferably the standard deviation value of the particle size distribution is within 13.0. This allows the inorganic oxide to be more uniformly and densely filled in the composite resin obtained by curing, compared to the conventional case of simply using a filler with a wide particle size distribution and irregular shape. Second, by using particles with a particle size in the range of 0.1 to 1.0 μm, compared to the case of using conventional inorganic fillers with particle sizes of several tens of μm, the composite resin after curing is The polished surface becomes smooth, and the total specific surface area of the filler is smaller than when using ultrafine particle fillers mainly composed of fine particles of several tens of nanometers. Possible reasons include the ability to fill a large amount of filler. By blending the specific inorganic oxide and a polymerizable vinyl monomer, the composite composition of the present invention exhibits a number of previously unanticipated advantages as described above. The composite composition of the present invention exhibits the above merits by combining two components, a polymerizable vinyl monomer component and a specific inorganic oxide component, but in addition to these components, it is generally used as a dental restorative material. Additional components to be used can also be added as necessary. Typical of these additive components are as follows. Examples include radical polymerization inhibitors, coloring pigments for color matching, and ultraviolet absorbers. EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples below, but the present invention is not limited to these Examples. In addition, measurements of various properties (particle size, standard deviation value of particle size distribution, specific surface area) of inorganic fillers containing inorganic oxides shown in the following Examples and Comparative Examples, preparation of paste of composite restorative materials, and The curing method and the physical property values (compressive strength, bending strength, toothbrush wear depth, surface roughness, surface hardness) of the cured composite resin were measured according to the following methods. (1) Standard deviation value of particle size and particle size distribution Take a scanning electron micrograph of a powder, and calculate the number of particles observed within a unit field of view of the photograph (n),
and the particle diameter (diameter x _i ), which is calculated using the following formula. Standard deviation value = x + σ _o-1 /x However (2) Specific surface area Shibata Chemical Equipment Co., Ltd. Rapid surface measuring device SA−
1000 was used. The measurement principle is the BET method. (3) Preparation and curing method of paste of composite restorative material First, amorphous silica surface-treated with γ-methacryloxypropyltrimethoxysilane and vinyl monomer are placed in an agate mortar in a predetermined ratio to form a uniform paste. Knead thoroughly until smooth.
Next, the paste was divided into two equal parts, and a polymerization accelerator was further added to one paste and thoroughly mixed (this was referred to as paste A). Further, an organic peroxide catalyst was added to the other paste and thoroughly mixed (this is referred to as paste B). Next, equal amounts of paste A and paste B were kneaded for about 30 seconds, filled into a mold, and hardened. (4) Compressive strength Paste A and paste B were mixed, polymerized for 30 minutes at room temperature, and then immersed in water at 37°C for 24 hours to prepare test pieces. Its size and shape are cylindrical with a diameter of 6 mm and a height of 12 mm.
This test piece was tested using a testing machine (manufactured by Toyo Baudouin).
UTM-5T) and crosshead speed
Compressive strength was measured at 10 mm/min. (5) Bending strength Mix paste A and paste B and
After polymerizing for 30 minutes, the test piece was immersed in water at 37°C for 24 hours. Its size and shape are 2
It has a prismatic shape with dimensions of 2 x 25 mm. The bending test was conducted using a bending test device with a distance between fulcrums of 20 mm attached to Toyo Baudouin's UTM-5T, and a bending speed of 0.5 mm/min. (6) Toothbrush wear depth and surface roughness Mix paste A and paste B and
After polymerizing for 30 minutes, the test piece was immersed in water at 37°C for 24 hours. Its size and shape are
It is a plate shape of 1.5 x 10 x 10 mm. After abrading the test piece for 1500 m with a toothbrush under a load of 400 g, the ten-point average roughness was determined using a surface roughness meter (Surfcom A-100). In addition, the wear depth was determined by dividing the wear polymerization by the density of the composite resin. (7) Surface hardness Mix paste A and paste B and heat at room temperature.
After polymerizing for 30 minutes, the test piece was immersed in water at 37°C for 24 hours. Its size and shape are
It is a disc-shaped object measuring 2.5 x 10 mm. The measurement used a micro Brinell hardness test. In addition, the abbreviations used in Examples and Comparative Examples are as follows unless otherwise specified. Example 1 Tetraethylsilicate (Si(OC ₂ H ₅ ) 4manufactured by _Nippon Colcoat Chemical Co., Ltd., product name: Ethylsilicate
28) 500 g and 1.2 methanol were placed in a beaker with a capacity of 3 and mixed. (This solution is hereinafter referred to as the supply solution.) In another glass container with a capacity of 10, methanol 6.0 and ammonia water (ammonia concentration 25
~28%) 650g was prepared. (This solution is referred to as the reaction tank liquid.) The temperature of the reaction tank liquid was maintained at 20°C, and the feed liquid was added over 30 minutes while stirring. After the reaction was completed, the solvent was removed from the cloudy reaction tank liquid using an evaporator, and the mixture was dried and calcined at 1000°C for 1 hour. After firing, the fired product was crushed in an agate mortar to obtain silica particles. The particle size of these silica particles was determined by observation using a scanning electron microscope.
The average particle size is in the range of 0.18-0.24μm.
The particle diameter was 0.20 μm, the shape was a perfect sphere, the standard deviation value of the particle size distribution was 1.04, and the specific surface area was 20.6 m ² /g. The obtained silica particles were further surface-treated with γ-methacryloxypropyltrimethoxysilane. The treatment was carried out by adding 6 wt% of γ-methacryloxypropyltrimethoxysilane to the silica particles, refluxing in a water-ethanol solvent at 80°C for 2 hours, removing the solvent with an evaporator, and drying in vacuum. Ivy. Next, silica particles having different particle size distributions were prepared by changing the feed liquid composition and the reaction tank liquid composition in the same manner as above. These results are summarized in Table 1.

[Table] Next, the No. 2 silica particles and No. 3 silica particles shown in Table 1 are mixed to make a mixed inorganic oxide (the mixing ratio is No. 2 silica particles/No. 3 silica particles). 2 silica particles = 2.4), and a mixture of bisphenol A diglycidyl methacrylate (hereinafter referred to as Bis-GMA) and triethylene glycol dimethacrylate (hereinafter referred to as TEGDMA) as vinyl monomers (the mixing ratio is Bis-GMA/
TEGDMA=3/7 molar ratio. ) and sufficiently kneaded to obtain a paste-like composite restorative material. At this time, the filling amount of silica particles in the composite restorative material is
The viscosity of the paste was 78.5 wt%, which was appropriate for operation. Next, divide the paste into two equal parts, add N,N-dimethyl-P-toluidine as a polymerization accelerator to one side, and add 1wt% of benzoyl peroxide as a polymerization initiator to the other side, based on the vinyl monomer. Paste A (former) and paste B (latter) were prepared. The physical properties of paste A and paste B were mixed in equal amounts at room temperature for 30 seconds and cured. As a result, the compressive strength was 4100 Kg/cm 2 and the bending strength was 4100 Kg/cm ² .
The weight was 760 kg/cm ² , the surface roughness was 0.5 μm, the surface hardness was 70.0, and the toothbrush wear depth was 4.0 μm. When the surface was polished using Soft Flex (manufactured by 3M), a smooth surface was easily obtained without excessively abrading the surface of the composite resin. Examples 2 to 3 A mixed inorganic oxide was prepared using the silica particles in Table 1 at the mixing ratio shown in Table 2, and a paste was prepared in the same manner using a vinyl monomer with the same composition as in Example 1. Then, the physical properties of the composite resin were measured after curing. The results are summarized in Table 2.

[Table] Examples 4 to 6 Mixed inorganic oxides consisting of silica particles No. 2 and silica particles No. 3 in Table 1 (mixing ratio is by weight,
Using No. 3 silica particles/No. 2 silica particles = 2.4), U-4HMA as the vinyl monomer component,
U-4TMA, U-4BMA, Tetramethylolmethane triacrylate (hereinafter referred to as TMMT)
A paste composite restorative material was prepared in the same manner as in Example 1, except that methyl methacrylate (hereinafter referred to as MMA) was used. The mixing proportions of the vinyl monomer components are shown in Table 3.
The paste-like composite restorative material was further cured in the same manner as in Example 1, and its physical properties were measured. The results are also shown in Table 3.

[Table] Example 7 4.0 g of water and 158 g of the same tetraethyl silicate used in Example 1 were dissolved in 1.2 methanol.
This solution was hydrolyzed at room temperature with stirring for about 2 hours. Thereafter, this was added to a solution of 40.9 g of tetrabutyl titanate (Ti(O-nC ₄ H ₉ ) ₄ , manufactured by Nippon Soda) dissolved in 0.5 g of isopropanol with stirring, and the hydrolyzate of tetraethyl silicate and tetrabutyl titanate were combined. A mixed solution was prepared. Next, introduce 2.5 methanol into a glass reaction vessel with an internal volume of 10 and a stirrer, add 500 g of ammonia aqueous solution (concentration 25 wt%) to this to prepare an ammonia alcohol solution, and make silica seeds in this. A solution of 4.0 g of tetraethyl silicate dissolved in 100 ml of methanol was added as an organosilicon compound solution for about 5 minutes. 5 minutes after the addition was completed, when the reaction liquid was slightly milky, the above mixture was added to the reaction vessel. The reaction product was precipitated by adding the reaction product over about 2 hours while maintaining the temperature at 20°C. Thereafter, a solution containing 128 g of tetraethyl silicate and 0.5 g of methanol was added over about 2 hours to the system in which the reaction product had precipitated. After the addition was completed, stirring was continued for an additional hour, and then the solvent was removed from the milky white reaction liquid using an evaporator, and the mixture was further dried at 80°C under reduced pressure to obtain a milky white powder. Further, this milky white powder was calcined at 900°C for 4 hours and then ground in an agate mortar to obtain an inorganic oxide whose main components were silica and titania. Observation using a scanning electron microscope reveals that the particle size of this inorganic oxide is in the range of 0.10 to 0.20 μm, with an average particle size of
The particle size was 0.13 μm, and the shape was a perfect sphere. Furthermore, the standard deviation value of the particle size distribution was 1.08, and the specific surface area was 20 m ² /g. The obtained inorganic oxide was further surface-treated with γ-methacryloxypropyltrimethoxysilane in the same manner as in Example 1. Next, inorganic oxides with different particle size distributions were obtained by changing the composition of the ammonia alcohol charged into the reaction vessel in the same manner as above. These results are summarized in Table 4. Next, a mixed inorganic oxide consisting of No. 5 inorganic oxide and No. 6 inorganic oxide in Table 4 (the mixing ratio is by weight, No. 6 inorganic oxide/No. 5 inorganic oxide thing=
It is 2.4. ) with Bis at the same mixing ratio as in Example 1.
- A paste-like composite restorative material was obtained by blending a mixture of GMA and TEGDMA and thoroughly kneading it. At this time, the filling amount of inorganic oxide in the composite restoration material is
The viscosity of the paste was 78.5 wt%, which was appropriate for operation. This composite restorative material was cured in the same manner as in Example 1, and the physical properties of the cured material were measured. As a result, the compressive strength was 4100 Kg/cm ² , the bending strength was 740 Kg/cm ² ,
The surface roughness was 0.5 μm and the toothbrush wear depth was 3.0 μm.

[Table] Example 8 Mixed inorganic oxide consisting of inorganic oxide No. 5 and inorganic oxide No. 7 in Table 4 (mixing ratio is by weight,
No. 7 inorganic oxide/No. 5 inorganic oxide = 2.5. ), a paste was prepared in a similar manner using the same vinyl monomer as in Example 7. At this time, the filling amount of inorganic oxide in this paste is
At 78.0 wt%, the viscosity of the paste was appropriate for operation. The composite resin was further cured and its physical properties were measured. As a result, the compressive strength was 4220Kg/cm ² and the bending strength was
The weight was 790 kg/cm ² , the surface roughness was 0.6 μm, and the toothbrush wear depth was 3.0 μm. Examples 9 to 11 No. 5 inorganic oxide and No. 6 inorganic oxide in Table 4 (mixing ratio is by weight, No. 6 inorganic oxide/No. 5
of inorganic oxide = 2.4. ) and the vinyl monomers are U-4HMA, U-4TMA, U-4BMA,
A paste composite restorative material was prepared in the same manner as in Example 7 except that TMMT and MMA were used.
The mixing ratio of the vinyl monomer components is as shown in Table 5. The paste-like composite restorative material was further cured in the same manner as in Example 7, and its physical properties were measured.
The results are also shown in Table 5.

[Table] Example 12 208 g of the same tetraethyl silicate used in Example 1 and 5.4 g of sodium methylate were dissolved in 1.0 methanol, and this solution was dissolved under dry nitrogen.
A mixed solution was prepared by heating under reflux at 80°C for 30 minutes and then cooling to room temperature. Next, the internal volume with a stirrer
Fill 10 glass reaction vessels with 2.5 methanol and add 500 g of ammonia aqueous solution (concentration 25 wt).
%) to prepare an ammoniacal alcohol solution, and to this solution, the previously prepared mixed solution of tetraethyl silicate and sodium methylate was added over about 2 hours while keeping the temperature of the reaction vessel at 20°C, and the reaction product was The substance was precipitated. After the addition was completed, a solution containing 104 g of tetraethyl silicate and 0.5 g of methanol was added over about 2 hours to the system in which the reaction product had precipitated. After the addition was completed, stirring was continued for another 1 hour, and then the solvent was removed from the milky white reaction liquid using an evaporator, and the mixture was calcined at 700°C for 2 hours. After firing, the fired product was ground in an agate mortar to obtain an inorganic oxide. The particle size of this inorganic oxide is found to be in the range of 0.22 to 0.34 μm, the average particle size is 0.30 μm, and the shape is a perfect sphere.
Further, the standard deviation value of the particle size distribution was 1.05, and the specific surface area was 13 m ² /g. The obtained inorganic oxide was further subjected to the same surface treatment as in Example 1. Next, inorganic oxides with different particle size distributions were obtained by changing the composition of the ammoniacal alcohol charged into the reaction vessel in the same manner as above. These results are summarized in Table 6.

[Table] Next, a mixed inorganic oxide consisting of No. 8 inorganic oxide and No. 9 inorganic oxide in Table 6 (mixing ratio is by weight, No. 9 inorganic oxide/No. 8 Inorganic oxide =
2.5) with Bis-GMA at the same mixing ratio as in Example 1.
A paste-like composite material was obtained by blending a mixture of and TEGDMA and thoroughly kneading the mixture. On this occasion,
The filling amount of inorganic oxide in the composite restorative material is 78.0wt%,
The viscosity of the paste was appropriate for operation. This composite restorative material was cured in the same manner as in Example 1, and the physical properties of the cured material were measured, resulting in compressive strength.
4050Kg/cm ² , bending strength 770Kg/cm ² , surface roughness
The toothbrush wear depth was 0.6 μm, the toothbrush wear depth was 3.0 μm, and the surface hardness was 65. Example 13 Same ethyl silicate used in Example 1
208g and aluminum tris sec.butoxide
24.6 g was dissolved in 1.4 g of isopropanol, this solution was heated under reflux at 80° C. for 30 minutes, and then cooled to room temperature to prepare a mixed solution. Next, 2.5 methanol was added to a glass reaction vessel with an internal volume of 10 with a stirrer.
Fill this with 500g of ammonia aqueous solution (conc.
25 wt%) to prepare an ammoniacal alcohol solution, and to this solution was added the previously prepared mixed solution of tetraethyl silicate and aluminum sec-butoxide, while keeping the reactor temperature at 20°C.
It was added over time to precipitate the reaction product. After the addition is complete, continue adding tetraethyl silicate.
A solution consisting of 0.5 methanol containing 104 g was added over a period of about 2 hours to the system in which the reaction product was precipitated. After the addition was completed, stirring was continued for another hour, and the solvent was removed from the milky white reaction solution using an evaporator.
It was baked at 900°C for 2 hours. After firing, the fired product was crushed in an agate mortar to obtain an inorganic oxide. Next, inorganic oxides with different particle size distributions were obtained by changing the composition of the ammoniacal alcohol charged into the reaction vessel in the same manner as above. These results are summarized in Table 7.

[Table] Next, mix inorganic oxides consisting of No. 10 inorganic oxide and No. 11 inorganic oxide in Table 7 (mixing ratio is by weight, No. 11 inorganic oxide/No. 10 inorganic oxide). Inorganic oxide = 2.2)
Bis-GMA with the same mixing ratio as in Example 1 and
A paste-like composite restorative material was obtained by blending the TEGDMA mixture and thoroughly kneading it. On this occasion,
The filling amount of inorganic oxide in the composite restorative material is 78.5wt%,
The viscosity of the paste was appropriate for operation. This composite restorative material was cured in the same manner as in Example 1, and the physical properties of the cured material were measured. As a result, the compressive strength was 4070 Kg/cm ² , the bending strength was 800 Kg/cm ² , and the surface roughness was
The toothbrush wear depth was 0.7 μm, the toothbrush wear depth was 2.5 μm, and the surface hardness was 66. Example 14 Mixed inorganic oxide consisting of inorganic oxide No. 10 and inorganic oxide No. 12 in Table 7 (in terms of mixing ratio and weight ratio, No.
No. 12 inorganic oxide/No. 10 inorganic oxide = 2.8. ), a paste was prepared in a similar manner using the same vinyl monomer as in Example 7. At this time, the filling amount of inorganic oxide in this paste is
At 78.0 wt%, the viscosity of the paste was appropriate for operation. The composite resin was further cured and its physical properties were measured. As a result, the compressive strength was 4090Kg/ ^cm2 , and the bending strength was 4090Kg/cm2.
The weight was 850 kg/cm ² , the surface roughness was 0.5 μm, the toothbrush wear depth was 3.5 μm, and the surface hardness was 67. Example 15 Same ethyl silicate as used in Example 1
208 g and 31.1 g of barium bisisopentoxide were dissolved in 1.0 g of isoamyl alcohol, and this solution was heated under reflux at 90° C. for 30 minutes, and then cooled to room temperature to prepare a mixed solution. Next, fill a glass reaction vessel with an internal volume of 10 with a stirrer with 2.5 methanol, and add 500 g of ammonia aqueous solution (conc.
25 wt%) to prepare an ammoniacal alcohol solution, and the previously prepared mixed solution of tetraethyl silicate and barium bisisopentoxide was added to this solution over about 2 hours while keeping the temperature of the reaction vessel at 20°C. The reaction product was precipitated.
After the addition is complete, continue adding tetraethyl silicate.
A solution consisting of 0.5 methanol containing 104 g was added over a period of about 2 hours to the system in which the reaction product was precipitated. After the addition was complete, stirring was continued for another 11 hours, and the solvent was removed from the milky white reaction solution using an evaporator.
It was baked at 1000°C for 2 hours. After firing, the fired product was crushed in an agate mortar to obtain an inorganic oxide. The average particle size, particle size range, standard deviation value, and specific surface area of the inorganic oxide are shown in 8. (Inorganic oxide No. 13 in Table 8) Next, inorganic oxides with different particle size distributions were obtained by changing the composition of the ammoniacal alcohol charged into the reaction vessel in the same manner as above. These results are summarized in Table 8.

[Table] Next, a mixed inorganic oxide consisting of inorganic oxide No. 13 and inorganic oxide No. 15 in Table 8 (the mixing ratio is by weight, inorganic oxide No. 15/No. 13 Inorganic oxide =
It was set to 2.0. ) with Bis at the same mixing ratio as in Example 1.
- A paste-like inorganic oxide composite restorative material was obtained by blending a mixture of GMA and TEGDMA and thoroughly kneading it. At this time, the filling amount of inorganic oxide in the composite restorative material was 77.8 wt%, and the viscosity of the paste was appropriate for operation. This composite restorative material was cured in the same manner as in Example 1, and the physical properties of the cured material were measured. As a result, the compressive strength was 4000 Kg/cm 2 and the bending strength was 4000 Kg/cm ² .
The weight was 710 kg/cm ² , the surface roughness was 0.5 μm, the toothbrush wear depth was 3.1 μm, and the surface hardness was 63. Example 16 Mixed inorganic oxide consisting of inorganic oxide No. 14 and inorganic oxide No. 15 in Table 8 (mixing ratio is by weight,
No. 15 inorganic oxide/No. 14 inorganic oxide = 2.5. ), a paste was prepared in a similar manner using the same vinyl monomer as in Example 7. At this time, the filling amount of inorganic oxide in this paste is
At 78.2 wt%, the viscosity of the paste was appropriate for operation. The composite resin was further cured and its physical properties were measured. As a result, the compressive strength was 4100Kg/ ^cm2 , and the bending strength was 4100Kg/cm2.
The weight was 790Kg/cm ² , the surface roughness was 0.5μm, the toothbrush wear depth was 3.0μm, and the surface hardness was 65. Example 17 Mixed inorganic oxide consisting of inorganic oxide No. 5 in Table 4, inorganic oxide No. 6 and inorganic oxide No. 9 in Table 6 (mixing ratio is by weight, Inorganic oxide: No.
Inorganic oxide No. 6: Inorganic oxide No. 9 = 1:2:4
And so. ), a paste was prepared in a similar manner using the same vinyl monomer as in Example 7. At this time, the filling amount of inorganic oxide in this paste was 81.0 wt%, and the viscosity of the paste was appropriate for operation. The composite resin was further cured and its physical properties were measured. As a result, the compressive strength was 4300Kg/cm ² and the bending strength was 780.
Kg/cm ² , surface roughness 0.7μm, toothbrush wear depth
It had a surface hardness of 3.0 μm and a surface hardness of 75.

Claims (1)

[Scope of Claims] 1 A spherical inorganic oxide with a particle size in the range of 0.1 to 1.0 μm, comprising a mixed inorganic oxide consisting of at least two groups with different average particle sizes and a polymerizable vinyl monomer. A dental composite composition characterized by: 2. The mixed inorganic oxide consists of at least two groups, and the average particle size difference between the average particle size of the inorganic oxide of the first group and the average particle size of the inorganic oxide of the second group is two times or more. The dental composite composition according to claim 1, which comprises: 3. The dental composite composition according to claim 1, wherein the standard deviation value of the particle diameter of the inorganic oxide is within 1.30. 4. The dental composite composition according to claim 1, wherein the inorganic oxide is amorphous silica. 5. An inorganic oxide whose main constituents are at least one metal component selected from the group consisting of Groups 1, 2, 3, and 3 of the periodic table, and a silicon component. The dental composite composition according to claim 1. 6. The dental composite composition according to claim 1, comprising 70 to 90 wt% of the inorganic oxide. 7. The dental composite composition according to claim 1, wherein the inorganic oxide is surface-treated with an organic silicon compound. 8. The dental composite composition according to claim 1, wherein the polymerizable vinyl monomer is a vinyl monomer having an acrylic group or a methacrylic group.