JPH0528683B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a composite restorative material characterized by using mixed particles of at least three specified types as a filler. Composite restorative materials are used, for example, throughout the dental field, and are either filled or applied to the tooth to be treated intraorally and then polymerized, or are given an appropriate form outside the oral cavity, polymerized, and then placed on the tooth. There are things that are glued or joined together. [Prior art and problems to be solved by the invention] Composite restorative materials used in dentistry are different from ordinary composite materials due to their special characteristics in use; their main components are liquid polymerizable monomers and inorganic materials. It is delivered to the user in the form of a paste-like mixture with fillers, and after polymerization and hardening during various intra-oral or extra-oral operations by a doctor, it becomes a conventional hard composite material. Therefore, the performance required for such a composite restorative material is divided into the performance required for a pasty mixture and the performance required for a hard material after polymerization and hardening. In other words, the former relates to the operational performance of kneading, filling, and forming paste into tooth shapes, while the latter relates to mechanical and physical properties such as compressive strength and tensile strength required of ordinary materials. It is. In order to enhance the various performances required of such composite restorative materials, many innovations and improvements have been made in terms of the chemical structure of polymerizable monomers, the material, particle size, shape, etc. of fillers. It's here. For example, the polymerizable monomer may be an acrylate compound or a methacrylate compound, the material of the filler may be an inorganic oxide, a resin or a composite resin, and the particle size may be a combination of fillers of various sizes. In addition, fibrous, spherical, rod-like, amorphous, etc. shapes are being considered, and materials with better performance than conventional materials made of polymerizable monomers alone are now being obtained. However, on the other hand, composite restorative materials used in dentistry have gone from being used simply for filling and restoring carious cavities, to recently being used for filling cavities in the roots of teeth after pulp extraction, for example. At the same time, attempts have been made to apply it to the restoration of areas where metal materials have traditionally been used, such as to restore the form of lost tooth crowns. When applied to such special uses,
In addition to the performance required of conventional composite restorative materials, new performance is required. For example, when used for constructing an abutment after pulp extraction as described above, a composite restorative material with particularly excellent performance is desired in the following respects. First of all, at the stage of paste-like composite restorative material before hardening, first of all, when filling the dental pulp cavity with the restorative material after pulp extraction, it goes without saying that it can be easily inserted into the cavity, but also that it can be easily inserted into the pulp cavity wall. It is important to have fluidity that quickly spreads to the inside of the minute dentinal tubules that exist. Second, in order to perform the function of restoring the lost shape of the tooth crown, in addition to fluidity, appropriate hardness of the paste is required to facilitate shaping. Next, the paste that has been filled and formed in this way undergoes a polymerization and hardening reaction to become a hard composite restorative material that can withstand various forces in the oral cavity. This is accompanied by a contraction in volume. That is, the smaller the degree of shrinkage during curing (hereinafter referred to as polymerization shrinkage rate), the smaller the strain and gap at the interface between the tooth and the composite restorative material, and the better the adhesive and sealing properties of the restorative material. Furthermore, the polymerized and hardened composite restorative material is surrounded by ivory tissue and metal materials and is exposed to the harsh conditions of oral cavity trauma. It is a characteristic of In other words, the closer the coefficient of thermal expansion of the restorative material is to that of the surrounding ivory tissue or metal material, the lower the local stress at the interface, and the better the restorative material. Furthermore, for example, X-ray photography is often used to observe the state of hardened resin in the oral cavity, and for such purposes, it is desirable that the filling material be X-ray opaque. The volumetric shrinkage rate and coefficient of thermal expansion after curing of the composite restorative material as described above are also related to the type of polymerizable monomer, which is one of the components of the composite restorative material, but the degree of is small and largely depends on the content of the other component, the inorganic filler. That is, the higher the content of the inorganic filler, the lower the polymerization shrinkage rate and the lower the coefficient of thermal expansion. As mentioned above, the content of the inorganic filler is as high as possible, and at the same time, it has the appropriate hardness to facilitate the fluidity and shape that can reach not only the inside of the dental pulp cavity but also the inside of the dentinal tubules on the inner wall of the cavity. In order to obtain a paste-like composite restorative material, various studies have been made, particularly regarding the size, particle size distribution, shape, etc. of the filler, but no solution has yet been reached. For example, in Special Publication No. 44-19388,
It has been proposed to use inorganic spherules with a size of 1 to 100 μm as a filler, but such a method that uses only fillers with a relatively large particle size of 1 μm or more requires increasing the filler content. However, at the same time, the fluidity decreases and prompt filling of details becomes insufficient. Also, German Patent Publication No.
No. 2403211 proposes the use of a filler with a diameter of 0.7 μm or less, but in this case, fluidity is improved but it is difficult to give shape. moreover,
In JP-A No. 57-120506, 10 to 55% of fillers smaller than 0.5 μm, preferably 0.1 μm or less, and 0.5%
It has been proposed to use a filler with a thickness of ~0.8 μm. However, when using ultrafine particles of about 0.02 μm, which are specifically used in this publication, a high filler content is achieved in the entire pulp cavity, but in small localized areas such as dentinal tubules. In the cavity, the filling material with a large particle size in the mixed filling material remains in the pulp cavity, and only the composite restorative material with a low content of inorganic filler consisting of ultrafine particle portions and polymerizable monomers enters. The filler content in the composite restorative material in local voids such as dentinal tubules (hereinafter referred to as detailed filler content) is related to the sealing and adhesion of the interface between the tooth tissue and the hardened composite restorative material. This is an important factor. In other words, when the content of the detailed filling material decreases, the volume shrinkage due to polymerization and hardening of the composite restorative material within the local voids increases, resulting in distortion and voids between the tooth structure and the sealing and adhesion of the interface. decreases. For these reasons, the method proposed in the above-mentioned publication cannot be said to provide sufficient sealing and adhesion at the interface, and a method is desired that further increases the content of the fine filler. [Means for Solving the Problems] In order to solve the problems desired in dental composite restorative materials as described above, the present inventors have specifically developed a filling material, which is one of the components of the composite restorative materials. As a result of intensive research on the shape and particle size distribution, we found that by using a mixture of particles with at least three types of average particle diameters as a filling material, we were able to achieve a high content of the filling material while also being able to penetrate the inside of the tubules in the wall of the pulp cavity. It has sufficient fluidity to penetrate into the tooth, has a high content of small filler in the part that has entered the inside of the tubule, has excellent adhesion and sealing properties to the tooth structure, and is hard enough to form the shape of the tooth crown. At the same time, we have completed a paste-like composite restorative material, which we have proposed here. That is, the present invention provides a composite restorative material containing a polymerizable monomer, a filler, and a polymerization initiator, which includes (a) non-spherical particles having an average particle size of 1.0 to 100 μm as the filler;
(A) 10 to 90% by weight and (b) spherical particles with an average particle size of 1.0 to 100 μm (B)
45 to 5% by weight and (c) spherical particles with an average particle size of 0.1 to 1.0 μm (C)45
This is a dental composite restorative material characterized by using a filler containing ~5% by weight. The polymerizable monomer used in the present invention is not particularly limited, and for example, known monomers used as dental composite restorative materials can be used. Examples of generally preferred polymerizable monomers include various acrylic acid compounds, methacrylic acid compounds, acrylic ester compounds, methacrylic ester compounds, urethane compounds, styrene compounds, etc. that can be used for dental purposes. Polymerizable compounds can be used without limitation. More specifically, examples of the above compounds include 2,2-bis[4(2-hydroxy-3-methacryloxypropoxy)phenyl]propane, methyl methacrylate, bismethacryloethoxyphenylpropane, triethylene glycol dimethacrylate, Diethylene glycol dimethacrylate, tetramethylolmethane triacrylate, tetramethylolmethanetetraacrylate, tetramethylolmethane trimethacrylate, trimethylolethane trimethacrylate,
There are also urethane compounds 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 ,

[expression] or

〔Effect of the invention〕

When the composite restorative material obtained by the present invention is used in the dental field, the filler content can be increased to 80% by weight or more, so the volumetric shrinkage rate during polymerization and curing is small, and the thermal expansion after curing is low. It has a significantly small coefficient, has excellent mechanical strength, and can also have X-ray contrast properties. In particular, despite such a high filler content of over 80% by weight, the restorative material according to the present invention does not lose its fluidity and can be filled into the fine details of the pulp cavity. The filling material content in the restorative material is high, and it has excellent adhesion to the tooth structure.
It has excellent performance not found in conventional dental composite materials, such as maintaining operability when shaping the crown of a tooth, and its effects are remarkable. [Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. In addition, the definitions of various quantities related to the properties of materials shown in the text and examples and the methods for measuring them are as follows. (1) Standard deviation value of particle size and particle size distribution Take a scanning or transmission electron micrograph of a powder, and calculate the number (n) of particles observed within a unit field of view of the photograph, and the particle diameter (diameter Xi ) is calculated using the following formula. Standard deviation value = X + σn-1/X However, (2) Average symmetry value of particles Take a scanning electron micrograph of a powder, and calculate the number of particles (n), the maximum width of the particles as the major axis (L), and the major axis (L) as observed within the unit field of view of the powder. With the maximum width in the direction orthogonal to the minor axis (B), n, L, and B are calculated using the following formula. (3) Specific surface area A rapid surface area measuring device SA-1000 manufactured by Shibata Kagaku Kiki Kogyo Co., Ltd. was used. The measurement principle is the BET method. (4) Compressive strength Depending on the type of polymerization initiator, the paste-like composite restorative material can be polymerized at 37℃ for 30 minutes, or it can be cured using a commercially available visible light irradiator “Opteirax” (manufactured by Demetron). After polymerization by light irradiation for 37 min,
A test piece was immersed in water at ℃ for 24 hours. Its size and shape are cylindrical with a diameter of 4 mm and a height of 10 mm. This test piece was mounted on a testing machine (Toyo Baudouin, UTM-5T), and the compressive strength was measured at a crosshead speed of 10 mm/mm. (5) Tensile strength Depending on the type of polymerization initiator, the paste-like composite restorative material may be polymerized at 37℃ for 30 minutes, or a commercially available visible light irradiator "Opteirax" (manufactured by Demetron) may be used to After polymerization by light irradiation for 37 min,
A test piece was immersed in water at ℃ for 24 hours. Its size and shape are cylindrical with a diameter of 6 mm and a height of 6 mm. This test piece was attached to a testing machine (Toyo Baudouin, UTM-5T), and the tensile strength was measured at a crosshead speed of 10 mm/mm. (6) Bending strength Depending on the type of polymerization initiator, the paste-like composite restorative material may be polymerized at 37°C for 30 minutes, or it may be After polymerization by light irradiation for 37 min,
The test piece was immersed in water at ℃ for 24 hours.
Its size and shape are 2 x 2 x 25 mm prismatic. The bending test was conducted using a bending test device with a distance between fulcrums of 20 mm mounted on a UTM-5T manufactured by Toyo Baudouin, and a crosshead speed of 0.5 mm/mm. (7) Surface hardness Depending on the type of polymerization initiator, the paste composite restorative material may be polymerized at 37°C for 30 minutes, or a commercially available visible light irradiator “Opteirax” (manufactured by Demetron) may be used to cure the paste. After polymerization by light irradiation for 37 min,
A test piece was immersed in water at ℃ for 24 hours. Its size and shape are plate-like, 2.5 x 10 x 10 mm. The measurement used a micro Brinell hardness test. (8) Coefficient of thermal expansion Depending on the type of polymerization initiator, paste composite restorative materials are polymerized at 37°C for 24 hours, or by irradiation for 1 minute using the visible light irradiator mentioned above. was used as the test piece. Its size and shape are the same as those used in the compression test. The measurement was performed using Thermoflex manufactured by Rigaku Denki Co., Ltd., and was determined by the coefficient of linear expansion between 20°C and 50°C. (9) Water absorption rate Depending on the type of polymerization initiator, the paste-like composite restorative material is polymerized at 37°C for 30 minutes, or after polymerization by irradiating it with light for 1 minute using the visible light irradiator described above, After polishing the surface with abrasive paper (Nihon Kenshi, No. 1000), it was stored in an anhydrous magnesium sulfate desiccator at 37°C until it reached its final volume. Thereafter, it was immersed in water at 37°C, and its weight was measured 24 hours later. The increased weight (mg) is divided by the surface area (cm ² ) of the test piece before immersion, and the value is taken as the water absorption rate. The size and shape of this test piece are
It has a plate shape of 1.0 x 10 x 10 mm. (10) Paste flow rate Approximately 0.2 ml of paste composite restorative material was inserted into a plastic syringe with an inner diameter of 5 mm, a length of 20 mm, and an outlet diameter of 1 mm, the piston was pushed into the cylinder approximately 3 mm, and the piston was fixed with a stopper. Then, a 700g load was applied to the piston and a dial gauge was attached. The piston used here has an outer diameter of 5
It was made of plastic with a length of 70 mm, but the part that came into contact with the composite material was made of rubber. The distance traveled by the piston 10 seconds after the stopper was removed was measured using a dial gauge, and the distance was expressed as the amount of paste flow. The larger the distance traveled, the easier it is to flow and the lower the viscosity of the composite restorative material. (11) Pressure filling rate A plastic cylinder with an inner diameter of 4 mm, a length of 12 mm, and an outlet diameter of 1 mm and a plastic piston with an outer diameter of 4 mm and a length of 70 mm were used. However, the piston had four vertical elliptical grooves with a radius of 1 mm and a center angle of 40 degrees, so that the cross section of the piston was cross-shaped. In a room at 23°C, the cylinder was filled to the brim with paste-like composite restorative material, taking care not to introduce any air bubbles. Then, push the piston at a speed of 1 mm per second,
The length of the paste-like composite restorative material flowing out from the outlet of the cylinder was measured. This operation was repeated five times, the average value of the outflow length was taken as Lmm, and the pressure filling rate was calculated using the following formula. Pressure filling rate = L / 12 × 100 (%) Composite restoration materials that are difficult to build up or give shapes to, and are difficult to apply pressure to, tend to flow out from the piston groove, and the amount of composite restoration material that flows out to the cylinder outlet is As a result, the pressure welding filling rate becomes low. (12) Detailed filling material content A fresh bovine tooth was cut approximately 5 mm from the root side and the pulp was extracted. The pulp cavity was etched with a 35% orthophosphoric acid aqueous solution for 30 minutes, washed with water, and then washed with water in an ultrasonic cleaner for 10 minutes. Furthermore, after washing with methanol, it was dried with air blow. Five bovine teeth treated in this way were filled with a paste-like composite restorative material from the tooth root side using a dental restorative filling syringe, and then raised to a thickness of 3 mm, and then covered with polypropylene film (50 μm thick). did. A load of 5 kg was applied from above the cover for 1 minute, and then depending on the type of polymerization initiator, polymerization was carried out by irradiating it with light for 1 minute using a visible light irradiator, or polymerization was carried out at 37° C. for 12 hours. This was left in a 12N hydrochloric acid aqueous solution at 25°C for 7 days to completely dissolve and remove the dentin, thereby recovering only the hardened composite restorative material.After washing with water, the thin fibrous parts corresponding to dentinal tubules were recovered. and the part corresponding to the dental pulp cavity. Among these, the thin fibrous portion was further washed with methanol, air-dried, and then dried under reduced pressure for 12 hours. The fibrous hardened product obtained in this way was placed on a thermobalance (DT-30, manufactured by Shimadzu Corporation).
Using this, the content of the inorganic filler contained in the cured product was calculated as a percentage from the weight loss rate at 700°C, and this was defined as the detailed filler content. (13) Polymerization shrinkage rate One end has an inner diameter of 2mm, the other end has an inner diameter of 1.5mm,
A Pyrex glass tube with a length of 24,000 mm was coated with mold release agent and silicone oil and wiped off thoroughly. The glass tube was filled to the brim with the composite restorative material kneaded in a room at 23°C and stored in a heated greenhouse at 37°C for 3 hours or irradiated with light for 1 minute. 37℃
When stored in a constant temperature room, the composite restoration material was taken out after 3 hours and cooled to room temperature in a room at 23°C, and its length was measured with a micrometer. The difference between this length and the length of the glass tube divided by the length of the glass tube was multiplied by 100, which was taken as the polymerization shrinkage rate. Example 1 A surface-treated filler ( A-1). Zirconia powder (non-spherical particles) with an average particle size of 17 μm and an average symmetry value of 0.37 (manufactured by Hanui Chemical Co., Ltd., reagent special grade)
is surface-treated in the same manner as (A-1), and is used as a surface-treated filler (A-2). Surface treated filler (B
−1). Ethyl silicate (manufactured by Nippon Colcoat) 350
A solution of g dissolved in 20 methanol is called solution A.
Solution B is a mixed solution of 0.9% of 28% ammonia water and 3.6% of methanol. Keep liquid A and liquid B at 20°C.
While stirring Solution B with a stirrer equipped with a bladed stirring rod, Solution A was added dropwise to Solution B at a rate of 7 ml per minute. As the amount dropped increased, the color of liquid B became white. The white solution was rotary evaporated to remove the solvent and yield a white powder. This powder is calcined at 1000℃ for 1 hour, and the particle size range is
0.21~0.35μm, average particle size 0.25μm, standard deviation value
It was a spherical powder with an average uniformity value of 1.08 and 0.99. This powder was surface-treated with 5% by weight of γ-methacryloxypropyltrimethoxysilane, and this was designated as a surface-treated filler (C-1). 28 parts by weight of triethylene glycol dimethacrylate (hereinafter referred to as TEGDMA) and 2,2-bis[P-(γ-methacryloxy-P-hydroxypropoxy)phenyl]propane (hereinafter referred to as Bis-GMA)
42 parts by weight of TMM3A) and 30 parts by weight of tetramethylolmethane triacrylate (hereinafter referred to as TMM3A) were mixed and divided into two parts. Thereafter, 1.5 parts by weight of N,N-diethanol-P-toluidine was mixed in one part, and 1.8 parts by weight of benzoyl peroxide was mixed in the other part. These are used as polymerizable monomers for paste A and paste B, respectively. 40 parts by weight of the filler is (A-1), 20 parts by weight is (A-2), 20 parts by weight is (B-1), and further 20 parts by weight is (C-1), A polymerizable monomer for Paste A or a polymerizable monomer for Paste B was blended and sufficiently kneaded in an alumina mortar to obtain a Paste A or Paste B composite repair material, respectively. At this time, the content of the silanized filler in the composite restorative material was 86.2% by weight, and the viscosity of the paste was appropriate for operation. The paste flow rate of this composite restorative material is 1.7 mm,
The pressure filling rate was 93.5%, the detail filler content was 73%, and the polymerization shrinkage rate was 0.16%. The properties of paste A and paste B were taken in equal amounts and kneaded at room temperature for 30 seconds and cured. As a result, the coefficient of thermal expansion was 18.0 ppm/°C, and the water absorption rate was
0.18mg/cm ² , surface hardness 70.0, compressive strength 3820Kg/
cm ² , tensile strength of 620 Kg/cm ² , and bending strength of 1210 Kg/cm ² . Examples 2 to 10 Barium sulfate (manufactured by Wako Pure Chemical Industries, reagent special grade) with an average particle diameter of 5 μm and an average uniformity value of 0.33 was added to 1% by weight of γ.
- A surface treated filler (A-3) that has been surface treated with methacryloxypropyltrimethoxysilane.
shall be. (A-4) is α-quartz (manufactured by Ryumori Co., Ltd., Crystallite) having an average particle diameter of 40 μm and an average symmetry value of 0.35, which was surface-treated in the same manner as (A-1). Zirconia (manufactured by Magnesium Electron) with an average particle diameter of 20 μm and an average symmetry value of 0.46 was (A-
(A-5) which was surface treated in the same manner as in 1).
shall be. Alumina (manufactured by Harima Firebrick Co., Ltd.) having an average particle diameter of 50 μm and an average uniformity value of 0.97 was surface-treated in the same manner as (A-1) and is designated as (B-2). Silica (manufactured by Harima Firebrick Co., Ltd.) having an average particle diameter of 10 μm and an average uniformity value of 0.97 was surface-treated in the same manner as (A-1) and is referred to as (B-3). Glass beads (manufactured by Toshiba Balloteini) having an average particle diameter of 18 μm and an average symmetry value of 0.95 were surface-treated in the same manner as (A-1) and are designated as (B-4). In the method for producing (C-1) described in Example 1,
A particle size range of 0.20 to 0.60 μm, average particle Spherical particles were obtained with a diameter of 0.31 μm, a standard deviation value of 1.61, and an average symmetry value of 0.80. After that, (C-
(C-
2). Surface treated filler (A-1) and/or (C-1) of Example 1 and polymerizable monomer, Bis-GMA and TEGDMA, and/or (A-3), (A-
4), (A-5), (B-2), (B-3), (B-4
),
and/or (C-2), and/or tetramethylolmethanetetraacrylate (hereinafter
TMM4A) was used to prepare a paste in the same manner as in Example 1, and the paste flow rate, pressure filling rate, and detail filler content were measured. Furthermore, the physical properties of the cured composite restorative material were measured, and the results are summarized in Table 1. Example 11 Ethyl silicate (manufactured by Nippon Colcoat Co., Ltd.) 350
Dissolve g in methanol 2.0, add 30 g of water,
The solution heated to 60°C and then cooled to room temperature is referred to as Solution A. 22 g of strontium metal (manufactured by Hanui Chemical Co., Ltd.) is added to 500 ml of purified methanol, and the strontium and methanol are reacted. This reaction solution will be referred to as Solution B. 28% ammonia water 0.9
A mixed solution of 3.6 methanol and 3.6 methanol is called liquid C. Solution B was added to solution A while stirring. This solution was called Solution D, and while keeping Solution C and Solution D at 20°C, stirring Solution C with a stirring rod equipped with a bladed stirring rod,
Solution D was added dropwise to Solution C at a rate of 7 ml per minute. As the amount dropped increased, the color of liquid C became white. The white solution was rotary evaporated to remove the solvent and yield a white powder. This powder was heated to 1000℃ for 1
For time-calcined products, the particle size range is 0.25~
They were spherical particles with an average particle size of 0.40 μm, an average particle diameter of 0.33 μm, a standard deviation value of 1.10, and an average symmetry value of 0.99. This powder was surface-treated with 5% by weight of γ-methacryloxypropyltrimethoxysilane, and this was used as a surface-treated filler (C-3). Surface treated fillers (A-1) and (B-
1), a polymerizable monomer, and (C-3),
A paste was prepared in the same manner as in Example 1, and the paste flow rate, pressure filling rate, and detail filler content were measured. Furthermore, the physical properties of the cured composite restorative material were measured, and the results are summarized in Table 1.

【table】

[Table] Examples 12 to 16 Surface treated filler (A-1) described in Examples 1 to 11,
(A-3), (A-4), (B-3), (C-1), (
C
-2) and (C-3), 28 parts by weight of TEGDMA, 42 parts by weight of Bis-GMA, and 30 parts by weight of TMM3A, in which the polymerization initiator listed in Table 2 is dissolved. A paste was prepared in the same manner as in Example 1, and the paste flow rate, pressure filling rate, and detail filler content were measured. Furthermore, the physical properties of the cured composite restorative material were measured, and the results are summarized and shown in Table 2.

【table】

[Table] Comparative Examples 1 to 4 Ultrafine particle silica (manufactured by Aerosil Co., Ltd., Aerosil
130), BET specific surface area of 130 m ² /g and average particle size of approx.
Surface-treated Erosil was obtained by surface-treating 16 μm with 10% by weight of γ-methacryloxypropyltrimethoxysilane. Polymerizable monomer, Bis-GMA, TEGDMA,
TMM3A and surface treated filler (A-1), (B-
3), (B-4), (C-1), (C-2), and/or surface-treated Erosil, a paste was prepared in the same manner as in Example 1, and the paste flow rate and pressure filling rate were Also, the detailed filler content and polymerization shrinkage were measured. Furthermore, the results of measuring the physical properties of the cured composite restorative material are summarized in Table 2.

【table】

【table】

Claims (1)

[Scope of Claims] 1. In a composite restorative material containing a polymerizable monomer, a filler, and a polymerization initiator, as a filler, (a) non-spherical particles having an average particle size of 1.0 to 100 μm;
(A) 10 to 90% by weight and (b) spherical particles with an average particle size of 1.0 to 100 μm (B)
45 to 5% by weight and (c) spherical particles with an average particle size of 0.1 to 1.0 μm (c)45
A dental composite restorative material characterized by using a filler containing ~5% by weight. 2. The dental composite restorative material according to claim 1, wherein the non-spherical particles (A) are an X-ray opaque inorganic compound. 3. The dental composite restorative material according to claim 2, wherein the X-ray opaque inorganic compound is zirconium oxide, barium oxide, barium sulfate, lanthanum oxide, hafnium oxide, or a composite oxide containing at least one component thereof. . 4. The dental composite restorative material according to claim 1, wherein the non-spherical particles (A) are a mixture of an X-ray opaque inorganic compound and an X-ray transparent inorganic compound. 5. The dental composite restorative material according to claim 1, wherein the standard deviation value of the spherical particles (C) is 1.30 or less.