JP2017218403A - Dental composition, dental mill blank, dental member and process for producing the same, and denture base and method for producing the same, and plate denture and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dental composition having excellently balanced toughness, flexural strength, and flexural modulus and suppressing decrease in bending strength and flexural modulus of the composition due to immersion in water even after polishing.SOLUTION: According to the present invention, there is provided a dental composition comprising: a polymer (A) comprising a structural unit having a functional group having at least one ring selected from the group consisting of an aromatic ring and an aliphatic ring and a hydrogen bond-accepting group; and an inorganic filler (B) having an average thickness of 0.1 μm to 160 μm and an average aspect ratio of 2.0 to 65. Here, the dental composition has a bending strength of 115 MPa or more after immersion in water at 37°C for 2 days and a water absorption rate of 2 mass% or less by an immersion test at 37°C for 30 days.SELECTED DRAWING: None

Description

  The present invention relates to a dental composition, a dental mill blank, a dental member and a manufacturing method thereof, a denture base and a manufacturing method thereof, and a denture base and a manufacturing method thereof.

  Conventionally, metal members have been used as dental members such as dental prostheses (dental restorations) and denture members. In recent years, from the viewpoint of aesthetics, weight, feeling of wearing, prevention of metal allergy, etc., it has been considered to use a resin material or a composition of a resin material and an inorganic material instead of metal as a material for a dental member. ing.

For example, as a composition used for a dental restoration, the Mohs hardness is 3.0 to 4.5, the inorganic compound is a particle having an average size of less than 15 μm, and the refractive index is 1.53 to 1.56. A composition comprising a methacrylate resin having a Mohs hardness of 2.0 to 4.0 during curing is known (see, for example, Patent Document 1).
In addition, in an organic-inorganic composite material used for manufacturing dental materials and the like, (A) in 100 parts by mass of a thermoplastic resin containing at least one selected from a polyaryl ketone resin and a polysulfone resin as a main component, (B) 60 to 300 parts by mass of the inorganic particle mixture is dispersed, the particle content in the inorganic particle mixture in the range of 200 to 700 nm is 25% by volume or more, and the particle size is 40 to 100 nm. An organic-inorganic composite material having a content of particles in the range of 10 vol% or more is known (see, for example, Patent Document 2).
Moreover, it consists of hardened | cured material of a curable composition containing polymerizable monomers (A), such as (meth) acrylic acid ester, and the spherical inorganic filler (B) whose average primary particle diameter is 0.1 micrometer or more and less than 1 micrometer. A dental mill blank is known (for example, see Patent Document 3).
Further, in the bracket made of a synthetic resin main body having a slot for guiding or fixing the archwire, the synthetic resin main body is a member formed of a polyamide material and having a mounting surface on a tooth surface, and the polyamide Is a transparent member that transmits light, and a polyamide orthodontic bracket having a specific chemical structure is known (see, for example, Patent Document 4).
Also, a dental molded product having a predetermined shape used in the oral cavity, the molded product comprising a dicarboxylic acid component containing a terephthalic acid residue, and 2,2,4,4-tetramethyl-1 A dental molded body is known which is molded from a polyester resin comprising a 1,3-cyclobutanediol residue and a glycol component containing a 1,4-cyclohexanedimethanol residue (see, for example, Patent Document 5). .

U.S. Pat. No. 4,020,557 JP 2013-144778 A International Publication No. 2012/042911 International Publication No. 2012/020810 International Publication No. 2013/061462

The dental member is required to have bending strength and bending elastic modulus in order to withstand the operation of mastication. On the other hand, dental members are also required toughness from the viewpoint of ease of mounting in the oral cavity and ease of desorption from the oral cavity.
However, dental members containing a methacrylate resin may lack toughness.
Further, a dental member containing polyamide or polyester and not containing a filler may have insufficient bending strength and bending elastic modulus. Moreover, even if it is a dental member containing a polyamide or polyester and containing a filler, the bending strength and the bending elastic modulus may be insufficient depending on the size and shape of the filler.
For this reason, development of a dental member having a good balance of toughness, bending strength, and bending elastic modulus is required.

  On the other hand, when manufacturing a dental member, the process of grind | polishing a dental member is often implemented from a viewpoint of ensuring the smoothness of a surface. In this polishing process, the filler contained in the dental member is also removed. Therefore, if there is a site where fillers aggregate together (aggregate of filler), the site is removed, resulting in a large defect on the surface of the dental member. May occur. Since such a dental member is likely to allow moisture to enter from a defective portion, even if it is a dental member having excellent toughness, bending strength and bending elastic modulus, the bending strength and bending elastic modulus are reduced by water immersion. Tend to.

Accordingly, an object of the present invention is to provide a dental composition and a dental mill that have an excellent balance of toughness, bending strength, and flexural modulus, and that suppress the decrease in flexural strength and flexural modulus due to water immersion even after polishing. To provide a blank.
In addition, the object of the present invention is a dental member excellent in the balance of toughness, bending strength, and bending elastic modulus, and reduced in bending strength and bending elastic modulus due to water immersion even after polishing, and a manufacturing method thereof, It is providing the denture base provided with the dental member, its manufacturing method, and the denture base provided with the said dental member, and its manufacturing method.

Means for solving the above problems are as follows.
<1> a polymer (A) including a structural unit having a functional group having at least one ring selected from the group consisting of an aromatic ring and an aliphatic ring, and a hydrogen bond accepting group;
An inorganic filler (B) having an average thickness of 0.1 μm to 160 μm and an average aspect ratio of 2.0 to 65;
Containing
A dental composition having a flexural strength of 115 MPa or more after water immersion at 37 ° C. for 2 days and a water absorption rate of 2% by mass or less in a water immersion test at 37 ° C. for 30 days.
<2> Bending strength after immersion at 37 ° C. for 2 days, comprising a structural unit having a functional group having at least one ring selected from the group consisting of an aromatic ring and an aliphatic ring, and a hydrogen bond accepting group A polymer (A) having a thickness of 70 MPa or more and a water absorption rate of 2% by mass or less according to a 30 day immersion test at 37 ° C .;
An inorganic filler (B) having an average thickness of 0.1 μm to 160 μm and an average aspect ratio of 2.0 to 65;
A dental composition containing
<3> The dental composition according to <1> or <2>, wherein the polymer (A) has a glass transition temperature Tg of 50 ° C to 250 ° C.
<4> The dental bond according to any one of <1> to <3>, wherein the hydrogen bond accepting group is at least one functional group selected from the group consisting of an ether group, a carbonate group, and a sulfonyl group. Composition.
<5> The dental material according to any one of <1> to <4>, wherein the polymer (A) is at least one polymer selected from the group consisting of polycarbonate, polyarylate, polyphenylene ether, and polysulfone. Composition.
<6> The dental composition according to any one of <1> to <5>, wherein the polymer (A) includes an amorphous resin.
<7> The content of the inorganic filler (B) is 5% by mass to 60% by mass with respect to the total content of the polymer (A) and the inorganic filler (B). The dental composition according to any one of 6>.
<8> The surface of the inorganic filler (B) has <1> to <7> having at least one hydrogen-bonding functional group selected from the group consisting of a hydroxyl group, an ether group, a carbonate group, and a sulfonyl group. The dental composition as described in any one.
<9> A dental mill blank containing the dental composition according to any one of <1> to <8>.
<10> The dental mill blank according to <9>, which is used for manufacturing a dental member selected from an inlay, an onlay, a crown, a bridge, a clasp, a mouthpiece hinge, and a denture frame by cutting.
<11> A dental member comprising the dental composition according to any one of <1> to <8>.
<12> The dental member according to <11>, wherein the arithmetic average roughness Ra (JIS B0601: 2013) of the surface is 0.15 μm or less.
<13> A denture base comprising the dental member according to <11> or <12> and a denture base member fixed to the dental member.
<14> A denture having the denture base according to <13> and an artificial tooth fixed to the denture base member of the denture base of the denture base.
<15> A method for producing a dental member having a cutting step of obtaining a dental member by cutting the dental mill blank according to <9> or <10>.
<16> a cutting process for cutting the dental mill blank according to <9> or <10> to obtain a dental member;
A build-up step of forming a denture base member fixed to the dental member by building a resin material on the dental member;
The manufacturing method of the denture base which has this.
<17> A cutting process for obtaining a dental member by cutting the dental mill blank according to <9> or <10>;
A build-up step of forming a denture base member fixed to the dental member by building a resin material on the dental member;
An artificial tooth fixing step of fixing artificial teeth to the denture base member;
The manufacturing method of the denture which has this.

ADVANTAGE OF THE INVENTION According to this invention, the dental composition and the dental mill blank which were excellent in the balance of toughness, bending strength, and a bending elastic modulus, and the fall of the bending strength and bending elastic modulus by water immersion was suppressed after grinding | polishing. Provided.
In addition, according to the present invention, a dental member excellent in the balance of toughness, bending strength, and bending elastic modulus, and reduced in bending strength and bending elastic modulus due to water immersion after polishing, and a method for producing the dental member, the above Provided are a denture base provided with a dental member and a manufacturing method thereof, and a denture base provided with the dental member and a manufacturing method thereof.

The graph which shows the relationship between the water immersion days in Examples 1-3, and bending strength. The graph which shows the relationship between the inundation days in Examples 5 and 6, and bending strength. The graph which shows the relationship between the water immersion days and bending strength in the comparative examples 4 and 6-8. The graph which shows the relationship between the water immersion days and bending strength in Comparative Examples 9-12. The graph which shows the relationship between the water immersion days in Examples 1-3, and a bending elastic modulus. The graph which shows the relationship between the days of water immersion in Examples 5 and 6, and a bending elastic modulus. The graph which shows the relationship between the water immersion days and bending elastic modulus in the comparative examples 4 and 6-8. The graph which shows the relationship between the water immersion days and bending elastic modulus in Comparative Examples 9-12. The graph which shows the relationship between the content of an inorganic filler and bending strength after the immersion test of the comparative example 1 and Examples 1-3, the 5,000 cycle test of Example 2, and 12,000 cycle test. The graph which shows the relationship between content of an inorganic filler and bending strength after the water immersion test of Comparative Example 3, and a 5,000 cycle test. The graph which shows the relationship between the content of an inorganic filler and the bending elastic modulus after the immersion test of the comparative example 1 and Examples 1-3, the 5,000 cycle test of Example 2, and the 12,000 cycle test. The graph which shows the relationship between content of an inorganic filler and the bending elastic modulus after the water immersion test of Comparative Example 3, and a 5,000 cycle test. The graph which shows the relationship between content of an inorganic filler and bending strength after the water immersion test of Example 2-2 and Example 3-2, and a 5,000 cycle test. The graph which shows the relationship between content of an inorganic filler and bending elastic modulus after the water immersion test of Example 2-2 and Example 3-2 and a 5,000 cycle test.

Hereinafter, embodiments of the present invention will be described in detail.
In this specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value. For example, “numerical value A to numerical value B” has the same meaning as “numerical value A to numerical value B”. In this specification, the term “process” is not limited to an independent process, and is included in this term if the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes. It is.
In this specification, “dental member” means a dental prosthesis (inlay, onlay, crown, bridge, etc.), denture member (clasp, hinge for mouthpiece, denture frame, etc.), oral cavity, etc. It refers to all members used in
Moreover, in this specification, "dental mill blank" refers to the raw material for manufacturing a dental member by cutting.
Moreover, in this specification, a "dental composition" refers to the composition used as a raw material of a dental member or a dental mill blank.

  Hereinafter, the 1st aspect of the dental composition of this embodiment is demonstrated.

[Dental composition of the first aspect]
The dental composition of the first aspect (hereinafter also referred to as “composition of the first aspect”)
A polymer (A) comprising a structural unit having a functional group having at least one ring selected from the group consisting of an aromatic ring and an aliphatic ring, and a hydrogen bond accepting group;
An inorganic filler (B) having an average thickness of 0.1 μm to 160 μm and an average aspect ratio of 2.0 to 65;
Containing
The dental composition has a flexural strength of 115 MPa or more after water immersion at 37 ° C. for 2 days and a water absorption of 2% by mass or less according to a water immersion test at 37 ° C. for 30 days.
According to the composition of the 1st aspect, the dental member excellent in the balance of toughness, bending strength, and a bending elastic modulus can be manufactured.
Moreover, according to the composition of the 1st aspect, the dental member by which the fall of the bending strength and bending elastic modulus by water immersion was suppressed after grinding | polishing can be manufactured.

In the composition of the first aspect, it is considered that dispersibility of the inorganic filler (B) is improved by combining the polymer (A) and the inorganic filler (B). In the composition of the first aspect, the improvement in dispersibility of the inorganic filler (B) is “balance of toughness, bending strength and bending elastic modulus” and “bending strength and bending elasticity due to water immersion even after polishing”. It is thought that it contributes to "suppression of rate reduction".
The reason is presumed as follows.
The polymer (A) is composed of at least one ring selected from the group consisting of an aromatic ring and an aliphatic ring in the structural unit (hereinafter referred to as a ring) from the viewpoint of suppressing a decrease in bending strength and bending elastic modulus due to water immersion. Also referred to as a structure). However, since a polymer having a ring structure tends to have a relatively high viscosity when melted, it is usually difficult to mix with a filler.
Therefore, in the composition of the first aspect, a polymer (A) having the above ring structure and a hydrogen bond accepting group capable of forming a highly flexible hydrogen bond is selected as the polymer. The polymer (A) is combined with an inorganic filler (B) having a specific thickness and aspect ratio. Thereby, a hydrogen bond is formed between the polymer (A) and the inorganic filler (B), and the polymer (A) and the inorganic filler (B) are easily mixed. As a result, it is considered that the dispersibility of the inorganic filler (B) is improved and the mechanical strength improving effect inherent in the inorganic filler (B) is effectively exhibited.
Therefore, according to the composition of the 1st aspect, the dental member excellent in the balance of toughness, bending strength, and a bending elastic modulus can be manufactured.

Further, as described above, the improvement in the dispersibility of the inorganic filler (B) is considered to contribute to “suppression of a decrease in bending strength and bending elastic modulus due to water immersion even after polishing”.
Here, when manufacturing a dental member, the process of grind | polishing (smoothing) a dental member from a viewpoint of ensuring the smoothness of the surface is implemented. In this polishing step, the filler contained in the dental member is also removed. Therefore, if a filler that is more brittle than the polymer (main agent) is present in the form of aggregates, the aggregates are removed and the surface of the dental member is removed. Large defects may occur. Since moisture is likely to enter into such a dental member from a defective portion, it is estimated that the bending strength and the bending elastic modulus of the dental member are likely to be reduced due to water intrusion into the dental member.
On the other hand, in the composition of the first aspect, the dispersibility of the inorganic filler (B) is improved due to the above-described reason. Even when the aggregate of the agent (B) is small and the aggregate of the inorganic filler (B) is formed, the size is considered to be small.
Thereby, generation | occurrence | production of the big defect part on the dental member surface which arises when grinding | polishing a dental member is suppressed. As a result, water intrusion into the dental member is suppressed.
Therefore, according to the composition of the first aspect, it is possible to manufacture a dental member in which a decrease in bending strength and bending elastic modulus due to water immersion is suppressed even after polishing.

  Hereinafter, the characteristics of the polymer (A), the inorganic filler (B), and the composition of the first aspect contained in the composition of the first aspect will be described.

In the composition of the first aspect, the polymer (A) includes a structural unit having a functional group having at least one ring selected from the group consisting of an aromatic ring and an aliphatic ring, and a hydrogen bond accepting group. .
When the polymer (A) includes a structural unit having a functional group having the ring, a decrease in bending strength and bending elastic modulus due to water immersion is suppressed. In addition, since the polymer (A) includes a structural unit having a hydrogen bond accepting group, a hydrogen bond is easily formed between the polymer (A) and the inorganic filler (B). Thereby, the dispersibility of an inorganic filler (B) improves.
Identification of the structural unit of the polymer (A) can be performed using a known method such as NMR.

In the composition of the first aspect, the inorganic filler (B) has an average thickness of 0.1 μm to 160 μm and an average aspect ratio of 2.0 to 65.
By selecting the inorganic filler (B), the bending strength and the bending elastic modulus of the dental member are improved. Moreover, the mixability with the polymer (A) is improved, and as a result, the dispersibility of the inorganic filler (B) is improved.
More specifically, when the average aspect ratio of the inorganic filler (B) is 2.0 or more, the bending strength of the dental member is higher than that when the average aspect ratio of the inorganic filler is less than 2.0. And the flexural modulus is improved.
In addition, since the average aspect ratio of the inorganic filler (B) is 65 or less, a decrease in the smoothness of the surface of the dental member is suppressed as compared with the case where the average aspect ratio of the inorganic filler is more than 65. It becomes easy. In particular, when the average aspect ratio of the inorganic filler (B) is 65 or less, the smoothness of the polished surface when a dental member is polished tends to be excellent.
The superior smoothness of the surface of the dental member is advantageous, for example, from the viewpoint of suppressing the adhesion of plaque to the dental member and improving the wearing feeling of the dental member on the oral cavity.
When the average thickness of the inorganic filler (B) is 160 μm or less, a decrease in the smoothness of the surface of the dental member is easily suppressed as compared with the case where the average thickness is more than 160 μm.
When the average thickness of the inorganic filler (B) is 0.1 μm or more, the bending strength and the bending elastic modulus of the dental member are improved as compared with the case where the average thickness is less than 0.1 μm.

The toughness of the dental member can be confirmed, for example, by measuring the impact strength (for example, Izod impact strength) of the dental member.
The smoothness of the surface of the dental member can be confirmed, for example, by measuring the arithmetic average roughness Ra (JIS B0601: 2013) of the surface of the dental member.

In the composition of the first aspect, the bending strength after immersion at 37 ° C. for 2 days is 115 MPa or more, preferably 135 MPa or more, more preferably 150 MPa or more.
When the bending strength after immersion at 37 ° C. for 2 days is 115 MPa or more, a dental member having excellent bending strength can be easily obtained from the composition. Moreover, it becomes easy to obtain a dental member in which a decrease in bending strength due to water immersion is suppressed even after polishing.
In addition, the measuring method of bending strength is explained in full detail in an Example.

In the composition according to the first aspect, the water absorption by a water immersion test at 37 ° C. for 30 days is 2% by mass or less.
When the water absorption by the water immersion test is 2% by mass or less, it becomes easy to obtain a dental member from which the decrease in bending strength and bending elastic modulus due to water immersion is suppressed even after polishing.
In addition, the measuring method of the water absorption rate by the 37 degreeC and 30 day water immersion test is explained in full detail in an Example.

Moreover, according to the composition of a 1st aspect, it can anticipate also having the following effects other than the effect mentioned above.
Moreover, the composition of a 1st aspect is excellent also in the dimensional accuracy at the time of cutting a dental mill blank by containing the said inorganic filler (B). That is, since heat at the time of cutting can be released by the inorganic filler (B), thermal deformation of the dental member or dental mill blank due to cutting is suppressed.
Moreover, when the composition of a 1st aspect contains the said inorganic filler (B), when cutting a dental mill blank, a composition is hard to get entangled with a cutting member (a drill etc.).

In the present specification, the average thickness of the inorganic filler (B) means the number average value of the thickness of the inorganic filler (B) in the composition.
Moreover, in this specification, the average length of an inorganic filler (B) means the number average value of the length of the inorganic filler (B) in a composition.

In the composition of the first embodiment, the average aspect ratio of the inorganic filler (B) means a value represented by the following formula (1).
Average aspect ratio of inorganic filler (B) = average length of inorganic filler (B) in composition / average thickness of inorganic filler (B) in composition Formula (1)

  Hereinafter, the preferable aspect of the composition of a 1st aspect is demonstrated.

In the composition of the first aspect, the polymer (A) preferably has a glass transition temperature Tg of 50 ° C to 250 ° C.
When the glass transition temperature Tg of the polymer (A) is 50 ° C. or higher, the practicality of the dental member (for example, practicality when the dental member is used in the oral cavity) is excellent.
When the glass transition temperature Tg of the polymer (A) is 250 ° C. or lower, the production suitability (for example, dispersibility) when mixed with the inorganic filler (B) to form a composition is excellent.
In addition, the measuring method of glass transition temperature Tg is explained in full detail in an Example.

  In the composition of the first aspect, the hydrogen bond accepting group is preferably at least one functional group selected from the group consisting of an ether group, a carbonate group, and a sulfonyl group. Thereby, hydrogen bonds are more easily formed between the polymer (A) and the inorganic filler (B). As a result, the dispersibility of the inorganic filler (B) is further improved.

In the composition of the first aspect, the polymer (A) is preferably at least one polymer selected from the group consisting of polycarbonate, polyarylate, polyphenylene ether and polysulfone.
Thereby, the fall of the bending strength and bending elastic modulus by water immersion is suppressed more. Moreover, the mixability with an inorganic filler (B) improves, As a result, the dispersibility of an inorganic filler (B) improves more.

  In the composition of the first aspect, the polymer (A) preferably contains an amorphous resin from the viewpoint of aesthetics (that is, transparency) and moldability of the dental member.

In the composition of the first aspect, the polymer (A) is at least one polymer selected from the group consisting of polycarbonate, polyarylate, polyphenylene ether, and polysulfone, and is an amorphous resin. preferable.
Thereby, the fall of the bending strength and bending elastic modulus by water immersion is further suppressed.

In the composition of the first aspect, the content of the inorganic filler (B) is 5% by mass to 60% by mass with respect to the total content of the polymer (A) and the inorganic filler (B). Is preferably 5% by mass to 50% by mass, more preferably 10% by mass to 50% by mass, and particularly preferably 15% by mass to 45% by mass.
When the content of the inorganic filler (B) is 5% by mass or more, the bending strength and the bending elastic modulus of the dental member are further improved.
The toughness of a dental member improves more as content of an inorganic filler (B) is 60 mass% or less. Moreover, the adhesiveness of a dental member and another member (for example, below-mentioned floor member) improves more as content of an inorganic filler (B) is 60 mass% or less.

In the composition of the first aspect, the surface of the inorganic filler (B) preferably has at least one hydrogen bonding functional group selected from the group consisting of a hydroxyl group, an ether group, a carbonate group, and a sulfonyl group. .
Since the surface of the inorganic filler (B) has the hydrogen bondable functional group, hydrogen bonds are easily formed with the polymer (A), so that the dispersibility of the inorganic filler (B) is further improved.

In the composition of the first aspect, the bending strength of the polymer (A) after water immersion at 37 ° C. for 2 days is preferably 70 MPa or more, more preferably 80 MPa or more, and further preferably 90 MPa or more. .
When the bending strength of the polymer (A) after water immersion at 37 ° C. for 2 days is 70 MPa or more, a dental member having excellent bending strength can be easily obtained from the composition. Moreover, it becomes easy to obtain a dental member in which a decrease in bending strength due to water immersion is suppressed even after polishing.
In the composition of the first aspect, the water absorption of the polymer (A) by a water immersion test at 37 ° C. for 30 days is preferably 2% by mass or less.
When the water absorption rate of the polymer (A) is 2% by mass or less, a dental member in which a decrease in bending strength and bending elastic modulus due to water immersion is suppressed can be obtained from the composition even after polishing. .
The method for measuring the bending strength of the polymer (A) at 37 ° C. after 2 days of water immersion and the method of measuring the water absorption rate of the polymer (A) by a water immersion test at 37 ° C. for 30 days are shown in the examples. Detailed description.

There is no restriction | limiting in particular in the form of the composition of a 1st aspect.
The form of the composition of the first aspect is preferably a solid form such as a powder form or a pellet form.

  Hereinafter, the polymer (A) and the inorganic filler (B) contained in the composition of the first aspect will be described in detail.

<Polymer (A)>
The polymer (A) is a polymer including a structural unit having a functional group having at least one ring selected from the group consisting of an aromatic ring and an aliphatic ring, and a hydrogen bond accepting group.
Preferred examples of the hydrogen bond accepting group are as described above.

The polymer (A) is preferably at least one polymer selected from the group consisting of polycarbonate, polyarylate, polyphenylene ether and polysulfone. Among these, polyphenylene ether (more preferably modified polyphenylene ether) and polysulfone having lower hydrolyzability are preferable from the viewpoint of suppressing a decrease in bending strength and bending elastic modulus due to water immersion.
These polymers (A) may be used alone or in a combination of two or more.

(Polycarbonate)
Examples of polycarbonate include bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, and 2,2-bis (4-hydroxyphenyl). Examples thereof include polymers obtained from butane and the like.

(Polyarylate)
Polyarylate is a polymer obtained from a bisphenol component and an aromatic dicarboxylic acid component. Preferred bisphenols include bisphenol A, bisphenol AP and tetramethylbisphenol A, and aromatic dicarboxylic acid components include terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, 4,4′-dicarboxydiphenyl, bis (p-carboxyphenyl). ) Alkanes. Among these, terephthalic acid and isophthalic acid are most preferably used, and are mixed and used as necessary.

(Polyphenylene ether)
Polyphenylene ether is a polymer containing a structural unit having an ether group (—O— group) and a phenylene group.
The phenylene group may have a substituent. As a substituent, a C1-C6 alkyl group is preferable and a C1-C3 alkyl group is more preferable. The number of substituents is not particularly limited, but is preferably 2 or more and 4 or less, and more preferably 2. The phenylene group having a substituent is preferably a dialkylphenylene group, and more preferably a dimethylphenylene group.
More specifically, as polyphenylene ether (PPE), polyetheretherketone (PEEK) resin, polyetherketone (PEK) resin, polyetherketoneketone (PEKK) resin, polyetheretherketoneketone (PEEKK) resin, Examples include polyether ketone ether ketone ketone (PEKEKK) resin.
Among these, modified polyphenylene ether (m-PPE) is preferable from the viewpoint of more effectively achieving the effect of the composition of the first aspect. Modified polyphenylene ether is a general term for polymer alloys of polyphenylene ether (PPE) and other resins.
As modified polyphenylene ether, polymer alloy (PPE / PS) of polyphenylene ether (PPE) and polystyrene (PS), polymer alloy (PA / PPE) of polyamide (PA) and polyphenylene ether (PPE), polypropylene (PP) And a polymer alloy (PP / PPE) of polyphenylene ether (PPE) and a polymer alloy (PPS / PPE) of polyphenylene sulfide (PPS) and polyphenylene ether (PPE).
Among these, a polymer alloy (PPE / PS) of polyphenylene ether (PPE) and polystyrene (PS), that is, styrene-modified polyphenylene ether is preferable.

(Polysulfone)
The polysulfone, a sulfonyl group _- refers to a polymer containing a structural unit having a (-SO 2 group), preferably a sulfonyl group _- is (-SO 2 group) and the polymer comprising a structural unit having a phenylene group.
More specifically, examples of the polysulfone (PSU) include polyethersulfone (PES) and polyphenylsulfone (PPSU).
Among them, from the viewpoint of more effectively achieving the effect of the composition of the first aspect and from the viewpoint of impact strength of the denture base material (that is, impact resistance when used as a denture base), polyphenylsulfone (PPSU) Is particularly preferred.

<Inorganic filler (B)>
The inorganic filler (B) is an inorganic filler having an average thickness of 0.1 μm to 160 μm and an average aspect ratio of 2.0 to 65.
The average thickness of the inorganic filler (B) is preferably 1.0 μm to 100 μm, more preferably 2.0 μm to 20 μm, and particularly preferably 2.0 μm to 10 μm.
The average aspect ratio of the inorganic filler (B) is preferably 2.0 to 40, more preferably 2.0 to 20, and particularly preferably 3.0 to 15.

The average length of the inorganic filler (B) is preferably 300 μm or less, more preferably 200 μm or less, and particularly preferably 100 μm or less.
The lower limit of the average length of the inorganic filler (B) is preferably 1.0 μm, more preferably 5.0 μm, and particularly preferably 10 μm.

The shape of the inorganic filler (B) is not particularly limited as long as it is a long shape satisfying an average aspect ratio of 2.0 to 65.
Here, the concept of “long shape” includes a fiber shape.

  As described above, the surface of the inorganic filler (B) is at least one selected from the group consisting of a hydroxyl group, an ether group, a carbonate group, and a sulfonyl group from the viewpoint of further improving the dispersibility of the inorganic filler (B). It is preferable to have a hydrogen bonding functional group.

Further, the inorganic filler (B) may be surface-treated with a silane-based surface treatment agent.
Examples of the silane surface treatment agent include silane coupling agents such as vinyl silane surface treatment agents, epoxy silane surface treatment agents, aminosilane surface treatment agents, and allylsilane surface treatment agents. Among these, from the viewpoint of further improving the dispersibility of the inorganic filler (B), a vinylsilane surface treatment agent and an epoxysilane surface treatment agent are preferable.

Examples of the inorganic filler (B) include wollastonite (wollastonite), potassium titanate, alumina / mullite fiber, aluminum borate, silicon carbide, silicon nitride, magnesium borate, zinc oxide, and the like.
Among these, wollastonite is preferable from the viewpoint of further improving the dispersibility of the inorganic filler (B).

In the composition of the first aspect, the total content of the polymer (A) and the inorganic filler (B) is preferably 60% by mass or more, more preferably 70% by mass or more, based on the total amount of the composition, 80 A mass% or more is particularly preferred.
The upper limit of the total content of the polymer (A) and the inorganic filler (B) is not particularly limited, and may be 100% by mass with respect to the total amount of the composition.

<Other ingredients>
The composition of the first aspect may contain other components other than the polymer (A) and the inorganic filler (B).
For example, the composition of the first aspect may contain a coloring material from the viewpoint of aesthetics.
The color material is not particularly limited.
The color material may be any of a pigment, a dye, and a pigment.
Examples of the coloring material include synthetic tar dyes and aluminum lakes thereof, inorganic pigments, natural dyes, and the like.
Moreover, the composition of the first aspect may contain a resin other than the polymer (A), a filler other than the inorganic filler (B), and the like as long as the effects of the present invention are not impaired.

  The method for producing the composition of the first aspect is not particularly limited as long as it is a method capable of mixing the polymer (A) and the inorganic filler (B) (and other components as necessary).

  Hereinafter, the 2nd aspect of the dental composition of this embodiment is demonstrated.

[Dental composition of the second embodiment]
The dental composition of the second aspect (hereinafter also referred to as “composition of the second aspect”)
A structural unit having a functional group having at least one ring selected from the group consisting of an aromatic ring and an aliphatic ring and a hydrogen bond accepting group, and having a bending strength of 70 MPa after water immersion at 37 ° C. for 2 days The polymer (A) having a water absorption rate of 2% by mass or less according to a water immersion test at 37 ° C. for 30 days,
An inorganic filler (B) having an average thickness of 0.1 μm to 160 μm and an average aspect ratio of 2.0 to 65;
Is a dental composition containing
In the composition of the first aspect described above, the bending strength of the composition and the water absorption rate by the water immersion test are limited to a specific range. In the composition of the second aspect, the polymer contained in the composition is included. It differs from the first embodiment in that the bending strength of (A) and the water absorption rate by the water immersion test are limited to a specific range. However, an overlapping portion may exist between the first mode and the second mode.
According to the composition of the 2nd aspect, the dental member excellent in the balance of toughness, bending strength, and a bending elastic modulus can be manufactured.
Moreover, according to the composition of the 2nd aspect, the dental member by which the fall of the bending strength and bending elastic modulus by water immersion was suppressed after grinding | polishing can be manufactured.

In the composition of the second aspect, it is considered that the dispersibility of the inorganic filler (B) is improved by combining the polymer (A) and the inorganic filler (B). In the composition of the second aspect, the improvement in dispersibility of the inorganic filler (B) is “balance of toughness, bending strength and bending elastic modulus”, and “bending strength and bending due to water immersion even after polishing”. This is thought to contribute to the “suppression of a decrease in elastic modulus”.
The reason for this is considered to be the same as in the first aspect, and thus the description thereof is omitted.

The bending strength of the polymer (A) after water immersion at 37 ° C. for 2 days is 70 MPa or more, preferably 80 MPa or more, and more preferably 90 MPa or more.
When the bending strength of the polymer (A) after water immersion at 37 ° C. for 2 days is 70 MPa or more, a dental member having excellent bending strength can be easily obtained from the composition. Moreover, it becomes easy to obtain a dental member in which a decrease in bending strength due to water immersion is suppressed even after polishing.
Moreover, when the water absorption rate of the polymer (A) is 2% by mass or less, a dental member in which a decrease in bending strength and bending elastic modulus due to water immersion is suppressed even after polishing is obtained from the composition. It becomes easy.

The composition of the second embodiment is not limited to the composition of the first embodiment, but the polymer (A) in the second embodiment is the same as the polymer (A) in the first embodiment. The preferred embodiments are also the same.
Moreover, as an inorganic filler (B) in a 2nd aspect, the thing similar to the inorganic filler (B) in a 1st aspect is mentioned, A preferable aspect is also the same.
There is no restriction | limiting in particular in the form of the composition of a 2nd aspect.
The form of the composition of the second embodiment is preferably a solid form such as a powder form or a pellet form.
The composition of the second aspect may contain other components other than the polymer (A) and the inorganic filler (B). Examples of the other components include the same components as the other components in the first aspect.
The method for producing the composition of the second aspect is not particularly limited as long as the method can mix the polymer (A) and the inorganic filler (B) (and other components as necessary).

[Dental mill blank]
The dental mill blank of the present embodiment contains the dental composition of the present embodiment (the composition of the first aspect or the composition of the second aspect). For this reason, the dental member excellent in the balance of toughness, bending strength, and a bending elastic modulus can be manufactured by cutting the dental mill blank of this embodiment. Furthermore, it is possible to manufacture a dental member in which a decrease in bending strength and bending elastic modulus due to water immersion is suppressed even after polishing.

  The dental mill blank of this embodiment is preferably used for the production of dental members selected from inlays, onlays, crowns, bridges, clasps, hinges for mouthpieces, and denture frames by cutting.

The thickness of the dental mill blank of this embodiment is preferably 10 mm to 30 mm.
When the thickness is 10 mm or more, dental members of various sizes can be manufactured.
When the thickness is 30 mm or less, it is possible to reduce a waste portion when manufacturing a dental member by cutting.

There is no restriction | limiting in particular in the shape of the dental mill blank of this embodiment.
Examples of the shape of the dental mill blank of the present embodiment include a disk shape, a rectangular parallelepiped shape (including a cubic shape), an elliptic cylinder shape (including a cylindrical shape), and the like.

Moreover, there is no restriction | limiting in particular also in the manufacturing method of the dental mill blank of this embodiment.
As a manufacturing method of the dental mill blank of this embodiment, the method of shape | molding the dental composition of this embodiment in the shape of a dental mill blank by injection molding etc. is mentioned. Moreover, the method of cutting out the dental mill blank of this embodiment from the round bar-shaped molded object which uses the dental composition of this embodiment as a raw material is also mentioned.

[Dental materials]
The dental member of this embodiment contains the dental composition of this embodiment.
For this reason, the dental member of this embodiment is excellent in toughness, bending strength, and a bending elastic modulus, and the fall of the bending strength and bending elastic modulus by water immersion is suppressed even after grinding | polishing.
Moreover, the dental member of this embodiment tends to be excellent in surface smoothness, aesthetics, and the like.
In addition, the dental member of the present embodiment is advantageous in terms of aesthetics, weight, wearing feeling, prevention of metal allergy, and the like as compared with a metal dental member.

  The dental member of the present embodiment is preferably a dental member selected from an inlay, an onlay, a crown, a bridge, a clasp, a mouthpiece hinge, and a denture frame.

In the dental member of the present embodiment, the arithmetic mean roughness Ra (JIS B0601: 2013) of the surface is preferably 0.15 μm or less, more preferably 0.10 μm or less.
When the arithmetic average roughness Ra on the surface of the dental member is 0.15 μm or less, a dental member excellent in smoothness is easily obtained.
In addition, excellent smoothness of the surface of the dental member is advantageous from the viewpoint of, for example, suppressing adhesion of plaque to the dental member and improving the wearing feeling of the dental member on the oral cavity.
A method for measuring the arithmetic average roughness Ra will be described in detail in Examples.

[Method of manufacturing dental member]
There is no restriction | limiting in particular in the method of manufacturing the dental member of this embodiment.
Examples of the method for producing the dental member of the present embodiment include a method of producing the dental composition of the present embodiment in the form of powder or pellets by a molding method such as injection molding.

Moreover, as a method of manufacturing the dental member of the present embodiment, a method including a cutting process of obtaining the dental member by cutting the dental mill blank of the present embodiment described above can also be mentioned.
The cutting step is preferably a step in which the dental mill blank of the present embodiment described above is cut by a CAD (Computer Aided Design) / CAM (Computer Aided Manufacturing) system to obtain a dental member.
Cutting by the CAD / CAM system can be performed using a CNC (Computer Numerical Control) cutting machine in accordance with a cutting program created by CAD / CAM software, for example.
The cutting program is created based on, for example, information on a three-dimensional shape of a dental member model that is prepared in advance. Information on the three-dimensional shape of the dental member model is obtained, for example, by scanning the dental member model with a 3D scanner.

The manufacturing method of the said dental member may have other processes other than a cutting process as needed.
Examples of other processes include a finishing process by polishing and the like, a coloring process for coloring dental members, and the like.
The dental member formed by the above method for producing a dental member tends to be excellent in surface smoothness even after polishing.

[Denture base]
The denture base of the present embodiment includes the dental member of the present embodiment and a denture base member fixed to the dental member.
The denture base of this embodiment is suitable as a denture base for local dentures (so-called partial dentures).
The denture base of the present embodiment may be a denture base for a maxillary denture (hereinafter also referred to as “maxillary denture base”), or a denture base for a lower denture (hereinafter referred to as “mandibular denture base”). Or a set of an upper denture base and a lower denture base.

Here, the denture base member is a member of the denture base, and refers to a member simulating a gum.
The denture base member preferably contains an acrylic resin and a coloring material.
Here, the acrylic resin is at least one selected from the group consisting of a structural unit derived from acrylic acid, a structural unit derived from methacrylic acid, a structural unit derived from acrylate, and a structural unit derived from methacrylate. Refers to resin containing.

  Moreover, it is preferable that the dental member of this embodiment fixed to the denture base member is a clasp, a mouthpiece hinge or a denture frame.

[Method of manufacturing denture base]
As an example of the method for producing the denture base of the present embodiment, the above-described cutting step of cutting the dental mill blank of the present embodiment to obtain a dental member, and building up a resin material on the dental member, And a build-up step of forming a denture base member fixed to the dental member.
The cutting process in the above example is the same as the cutting process in the dental member manufacturing method described above.

  Moreover, as a resin material in the said build-up process, the composition of acrylic resin or an acrylic resin and a coloring material, etc. are mentioned.

The manufacturing method of the denture base in the above example may have other processes other than the cutting process and the build-up process as necessary.
Examples of the other steps include a step of coloring at least one of a dental member and a denture base member after the build-up step.

[Bed denture]
The denture of the present embodiment includes the denture base of the present embodiment and an artificial tooth fixed to the denture base.
The plate denture of this embodiment is suitable as a local denture.
The plate denture of this embodiment should just be provided with at least one artificial tooth.
Further, the denture of the present embodiment may be an upper denture, a lower denture, or a set of an upper denture and a lower denture.

Examples of the material for the artificial teeth include acrylic resins.
Further, the artificial tooth may contain an inorganic filler or the like in addition to the acrylic resin.

[Method of manufacturing denture]
As an example of the method of manufacturing the denture of the present embodiment, by cutting the dental mill blank of the present embodiment described above to obtain a dental member, and by building a resin material on the dental member, A build-up process for forming a denture base member fixed to the dental member, and an artificial tooth fixing process for fixing an artificial tooth to the denture base member.
The manufacturing method of the plate denture in the above example may have other processes other than the cutting process, the build-up process, and the artificial tooth fixing process as necessary.

The artificial tooth can be fixed by an ordinary method using an adhesive.
As the adhesive, for example, dental adhesive resin cement “Super Bond” (registered trademark) manufactured by Sun Medical Co., Ltd. can be used.
Further, prior to fixing the artificial tooth to the denture base using the adhesive, at least one surface (adhesion surface) of the denture base and the artificial tooth may be subjected to a known surface treatment (easy adhesion treatment) in advance. Good.

The manufacturing method of the plate denture in the above example may have other processes other than the cutting process, the build-up process, and the artificial tooth fixing process as necessary.
Examples of the other steps include a step of coloring at least one of a dental member and a denture base member after the build-up step.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples.

<Raw material>
The raw materials used in this example are as follows.

-Polymer-
Styrene-modified polyphenylene ether a:
“Zylon FD800” (brand name) manufactured by Asahi Kasei Chemicals Co., Ltd. (amorphous styrene-modified polyphenylene ether having a functional group having an aromatic ring and an ether group as a hydrogen bond accepting group, glass transition temperature Tg is 155 ° C.)
Polysulfone a:
"Udel P-1700" (brand) manufactured by SOLVAY (amorphous polysulfone having a functional group having an aromatic ring and a sulfonyl group as a hydrogen bond accepting group, glass transition temperature Tg is 185 ° C)
Polyamide a:
“GRIVORY G21” manufactured by EMS (brand) (amorphous polyamide having an aromatic ring (specifically PA6I-6T), glass transition temperature Tg is 125 ° C.)
Polyester a:
"SKYGREEN KN100" (brand) (manufactured by SK Chemicals) (amorphous polyester having an aromatic ring (specifically glycol-modified polyethylene terephthalate (PETG)), glass transition temperature Tg is 80 ° C)
-Polypropylene a:
"Mostron L3040P" (brand) made by Prime Polymer (polypropylene with glass fiber)

-Inorganic filler-
-Filler a:
“NYGLOS 4W-10222” (brand) (Wollastonite, Japanese name: wollastonite, CaSiO ₃ ), average thickness 4.5 μm, average length 50 μm (after mixing described below, average length 30 μm) The shape is long)
-Filler b:
“NYGLOS 4W-10414” (brand) manufactured by Nyco (wollastonite, average thickness 4.5 μm, average length 50 μm (average length 30 μm after mixing described later), long shape)
-Filler c:
“PC-3” (brand) made by Ishihara Sangyo Co., Ltd.
-Filler d:
Let the glass fiber contained in the said polypropylene a be the filler d. The average thickness of the glass fiber is 12 μm, the average length is 6 mm to 8 mm (average length is 1900 μm after mixing described later), and the shape is long.
-Filler e:
“M60H” (brand) made by Repco (mica, average particle size 160 μm, shape is a scale shape)

  Hereinafter, the second embodiment will be mainly described.

[Example 2]
<Preparation of dental composition and dental mill blank>
A styrene-modified polyphenylene ether a as a polymer and a filler a as an inorganic filler are mixed at a ratio that the content of the inorganic filler is 26% by mass with respect to the total amount of the polymer and the inorganic filler. A pellet made of the composition for use was obtained. The mixing was performed using an extruder “ZSK26” (model number) manufactured by Coperion under the condition of a maximum cylinder temperature of 300 ° C.

<Preparation of dental mill blank>
A disk-shaped molded body (dental mill blank) having a diameter of 100 mm and a thickness of 10 mm was obtained by injection molding using pellets made of the above dental composition. Injection molding was performed using an injection molding machine “SE100EV” (model number) manufactured by Sumitomo Heavy Industries, Ltd. under conditions of a cylinder temperature of 290 ° C. and a mold temperature of 120 ° C.

[Evaluation A]
<Measurement of polymer properties>
The following measurements were performed on the polymers contained in the dental composition and the dental mill blank. The results are shown in Table 1.

(Measurement of glass transition temperature Tg)
10 mg of the dental composition was weighed and measured using a differential scanning calorimeter (DSC-1 manufactured by Perkin Elmer Co., Ltd.) under a temperature increase rate of 10 ° C./min to obtain a melting endothermic curve. The glass transition temperature Tg of the polymer contained in the dental composition was determined from the obtained melting endotherm curve.

(Measurement of bending strength of polymer after water immersion at 37 ° C for 2 days)
In the preparation of the dental composition and dental mill blank of Example 2, a pellet made of a polymer and a disk shape obtained using the pellet by the same method as in Example 2 except that no inorganic filler was mixed. A molded body was prepared.
A test piece having a length of 64 mm, a width of 10 mm, and a thickness of 3.3 mm was cut out from the disk-shaped molded body, and the cut-out test piece was immersed in water at 37 ° C. for 2 days (submerged). The bending strength of the polymer) was measured. The measurement was performed using a tensile / compression universal testing machine 210X manufactured by Intesco. The results are shown in Table 1.

(Measurement of water absorption rate of polymer by water immersion test at 37 ° C for 30 days)
A test piece having a length of 64 mm, a width of 10 mm, and a thickness of 3.3 mm was cut out from the disk-shaped molded body, and the cut out test piece was vacuum-dried at 100 ° C. for 5 hours, and the mass Wdry was measured for the vacuum-dried test piece. did. Then, after the said test piece was immersed in 37 degreeC water for 30 days (water immersion), the water of the surface of the test piece was wiped off, and mass Wwet was measured about the immersed test piece.
The water absorption rate by the 30-day immersion test at 37 ° C. was calculated from the “mass Wwet” and the “mass Wdry” measured by the above procedure according to the following equation (2).
Water absorption rate (%) = ((Wwet−Wdry) / Wdry) × 100 (2)

<Measurement of average aspect ratio after mixing>
First, the average thickness and average length of the inorganic filler after the above mixing were determined as follows.
The resin component in the pellet made of the dental composition was completely dissolved with hexafluoroisopropanol, and the inorganic filler in the pellet was recovered. The recovered inorganic filler was observed with a scanning electron microscope (SEM; Hitachi S-4700 SEM). Based on the obtained SEM image, the thickness and length of the inorganic filler were measured using image analysis software (QWin V3 manufactured by Leica). This measurement was performed on 200 inorganic fillers.
Based on the above results, the number average value of the thicknesses of the 200 inorganic fillers was calculated and set as “average thickness”. Furthermore, the number average value of the lengths of 200 inorganic fillers was calculated and used as “average length”.
Next, the average aspect ratio of the inorganic filler after mixing was determined by dividing the average length by the average thickness (ie, according to the above-described formula (1)).

<Measurement of arithmetic average roughness Ra>
A test piece having a length of 64 mm, a width of 10 mm, and a thickness of 3.3 mm was cut out from the dental mill blank, and one side of the cut-out test piece was polished for 10 minutes using a lathe and three types of polishing paper. Next, the surface polished using a lathe and three types of polishing papers was further polished for 10 minutes using a laser and an abrasive. Next, the arithmetic average roughness Ra of the surface polished with the laser and the abrasive was measured using a surface roughness measuring machine (Surfcom 130A manufactured by Tokyo Seimitsu Co., Ltd.) according to JIS B0601: 2013.
In addition, as the lathe, the abrasive paper, the laze, and the abrasive, the following were used.
·lathe:
ECOMET4 (model number) manufactured by BUEHLER
・ Abrasive paper:
Silicon Carbide Grinding Paper Grit 120 / P120 (model number), Grit400 / P800 (model number), and CarbiMet Grit 600 / P1200 (model number) (above, manufactured by BUEHLER) ・ Raise:
Speedraise α (model number) manufactured by Yoshida Seisakusho
·Abrasive:
All Shine (model number) manufactured by Akiyama Sangyo Co., Ltd.

<Measurement of Izod impact strength>
A test piece having a length of 64 mm, a width of 12.7 mm, and a thickness of 3.2 mm was cut out from the dental mill blank, and the cut out test piece was notched using a notching tool A-4 manufactured by Toyo Seiki Seisakusho. Went. Using the obtained notched specimen, Izod impact strength was measured according to ASTM D256. The measuring device used was a digital impact tester DG-IB manufactured by Toyo Seiki Seisakusho.

<Measurement of water absorption rate of dental mill blank by water immersion test at 37 ° C. for 30 days>
A test piece having a length of 64 mm, a width of 10 mm, and a thickness of 3.3 mm was cut out from the dental mill blank, and the cut-out test piece was immersed in water at 37 ° C. for 30 days. Measure the water absorption rate by water immersion using the above formula (2) for the water-immersed test piece (dental mill blank) in the same manner as the method for measuring the water absorption rate of the polymer by the water immersion test at 37 ° C for 30 days. did.

<Measurement of Bending Strength and Bending Elastic Modulus of Dental Mill Blanks after Submersion at 37 ° C. for 2 Days>
A test piece having a length of 64 mm, a width of 10 mm, and a thickness of 3.3 mm was cut out from the dental mill blank. One side of the cut specimen was polished for 10 minutes using a lathe and three types of abrasive paper. Next, the surface polished using a lathe and three types of polishing papers was further polished for 10 minutes using a laser and an abrasive. Next, the polished test piece was immersed (submerged) in water at 37 ° C. for 2 days, and the bending strength and the flexural modulus of the test piece (dental mill blank) after the immersion were measured.

<Measurement of flexural strength and flexural modulus after saturation>
Extending the number of days of immersion in “Measurement of bending strength and flexural modulus of dental mill blank after 2 days of water immersion at 37 ° C.” above to saturate the dental mill blank with water, and the dental mill blank after saturation The flexural strength and flexural modulus of each were measured.

<Measurement of flexural strength and flexural modulus after 5,000 cycle test>
Using a dental mill blank, the flexural strength and flexural modulus after 5,000 cycle tests were measured. The measuring method is as follows.
Two test pieces having a length of 64 mm, a width of 10 mm, and a thickness of 3.3 mm were cut out from the dental mill blank, and the cut out test pieces were polished by the same method as described above.
Next, one of the cut specimens was subjected to 5,000 cycles of cold water of 5 ° C. and hot water of 50 ° C. every 20 seconds, and then the bending strength and flexural modulus of the specimen after the 5,000 cycle test were determined. Each was measured.
In addition, about the other test piece cut out, it was immersed in 37 degreeC water for 22 days, and the bending strength and bending elastic modulus of the test piece after water immersion were measured, respectively. The measurement results of the bending strength and bending elastic modulus of the other test piece will be described later.

[Examples 1 to 3-6]
The same operation as in Example 2 except that the combination of the type of polymer, the type of inorganic filler, and the content of the inorganic filler was changed as shown in Table 1 (however, the numerical values in Tables 1 and 2) (Limited to items that have). The results are shown in Tables 1 and 2.

[Comparative Examples 1-19]
The same operation as in Example 2 except that the combination of polymer type, inorganic filler type and presence, and inorganic filler content was changed as shown in Table 1 (however, in Tables 1 and 2) (Only for items with numerical values). The results are shown in Tables 1 and 2.

In addition, the average thickness and average length of the filler d (glass fiber) after the said mixing of the comparative example 3 were calculated | required as follows.
A piece was cut out from a dental mill blank produced by injection molding, the cut piece was put in a magnetic crucible, and the resin component was dry ashed in a nitrogen atmosphere (600 ° C. × 2 hours). The glass fiber remaining after the treatment was dispersed on a glass plate. Photographs were taken with an optical microscope (Leica MZ16) so that the number of glass fiber measurements was 400 or more, and the thickness and fiber length of the glass fiber were measured using image processing software (Leica QWin V3). This measurement was performed on 200 glass fibers.
The average thickness, the average length, and the average aspect ratio of the glass fiber after mixing were calculated by the same method as described above.

  Moreover, in the measurement of the water absorption rate of the polyester a contained in the dental mill blank by a 37 ° C., 30 day water immersion test, the test piece is vacuum dried at 50 ° C. for 3 days before being immersed in 37 ° C. water for 30 days. did. Otherwise, the same operation as in Example 1 was performed.

-Explanation of Table 1 and Table 2-
-Content (mass%) of an inorganic filler shows content (mass%) of an inorganic filler with respect to the sum total content of a polymer and an inorganic filler.
-In Table 2, the bending strength after saturation of Examples 1 to 3 (Example 2 is bending strength after further 5000 cycles) and the bending elastic modulus after saturation (Example 2 is bending elasticity after further 5000 cycles) Rate) and the bending strength and bending elastic modulus after 5000 cycles after saturation of Comparative Example 3 are average values when measured a plurality of times (see FIGS. 9 to 12).

As shown in Tables 1 and 2, a polymer including a structural unit having a functional group having an aromatic ring and a hydrogen bond accepting group, an average thickness of 0.1 to 160 μm, and an average aspect ratio of 2. And an inorganic filler that is 0 to 65, the bending strength after immersion at 37 ° C. for 2 days is 115 MPa or more, and the water absorption by an immersion test at 37 ° C. for 30 days is 2% by mass or less. In certain Examples 1-6, it turned out that the bending elastic modulus after 37 degreeC after grinding | polishing and water immersion for 2 days shows a high value in a dental mill blank. In Examples 1 and 2, the toughness (Izod impact strength) was also good.
Further, for Examples 1 to 3, 5, and 6, the bending strength and the bending elastic modulus are hardly lowered even after saturation with respect to the bending strength and the bending elastic modulus after polishing at 37 ° C. for 2 days after polishing. I understood it.
Thereby, it is excellent in the balance of bending strength, a bending elastic modulus, and toughness (Izod impact strength) by cutting out from the dental mill blank of Examples 1-6, and the bending strength and bending by water immersion after grinding | polishing. It was suggested that a dental member in which a decrease in elastic modulus was suppressed can be produced. Moreover, in Examples 1-6, since arithmetic average roughness Ra was also restrained small, it is also suggested that the dental member excellent in surface smoothness can be produced by cutting out from the dental mill blank of Examples 1-6. It was done.
In Examples 1 to 6, a polymer including a structural unit having a functional group having an aromatic ring and a hydrogen bond accepting group, an average thickness of 0.1 μm to 160 μm, and an average aspect ratio of 2. And an inorganic filler that is 0 to 65, the bending strength of the polymer after water immersion at 37 ° C. for 2 days is 70 MPa or more, and the water absorption rate of the polymer by a water immersion test at 37 ° C. for 30 days Satisfies the requirement of 2% by mass or less.

In Comparative Examples 1 and 2 containing no inorganic filler, both showed low values (less than 115 MPa) of bending strength and bending elastic modulus after polishing at 37 ° C. for 2 days after polishing.
In Comparative Examples 4 and 6 containing polyamide a, in the dental mill blank, the bending strength and bending elastic modulus after immersion at 37 ° C. for 2 days after polishing, and the toughness (Izod impact strength) were any. The value was also high. However, in the measurement of the bending strength and the bending elastic modulus by the water immersion test after polishing, it was found that the bending strength and the bending elastic modulus both decreased with time, even when immersed for a predetermined number of days.
Further, in Comparative Examples 9 to 13 and 16 to 19 containing polyester a, the dental mill blank showed a low bending strength (less than 115 MPa) at 37 ° C. after polishing and water immersion for 2 days after polishing. It turned out that the tendency which is inferior to the balance of strength, a bending elastic modulus, and toughness (Izod impact strength) is seen.

In addition, in Example 2 and Comparative Example 3, the bending strength and the flexural modulus after the 5,000 cycle test were compared with the flexural strength and the flexural modulus after saturation in Example 2. Subsequent decrease in bending strength and bending elastic modulus was hardly observed. On the other hand, in Comparative Example 3, the decrease in bending strength and bending elastic modulus after the 5,000 cycle test was as large as 10% and 5%, respectively.
Here, Comparative Example 3 has a low water absorption of 2% by mass or less in a 30 ° C., 30-day immersion test, but does not include a functional group having an aromatic ring or a hydrogen bond accepting group, and an average aspect ratio of 65 It is a dental mill blank containing more than the inorganic filler.
Even in the dental mill blank having a low water absorption of 2% by mass or less as in Comparative Example 3, by performing a 5,000 cycle test after polishing, that is, by a water immersion test under severe conditions after polishing. It has been found that the bending strength and the flexural modulus may be lowered.

[Evaluation B]
<Bending strength and bending elastic modulus due to water immersion>
The measurement results of bending strength and bending elastic modulus due to water immersion will be described in detail with reference to FIGS.

(Bending strength due to water immersion)
FIG. 1 is a graph showing the relationship between the number of days of flooding and bending strength in Examples 1 to 3.
FIG. 2 is a graph showing the relationship between the number of days of flooding and bending strength in Examples 5 and 6.
FIG. 3 is a graph showing the relationship between the number of days of immersion and the bending strength in Comparative Examples 4 and 6-8.
FIG. 4 is a graph showing the relationship between the number of days of flooding and bending strength in Comparative Examples 9-12.
As shown in FIGS. 1 and 2, in Examples 1 to 3 and Examples 5 and 6, it was found that even if the dental mill blank was polished and then immersed for a predetermined number of days, the bending strength hardly decreased.
On the other hand, as shown in FIG. 3, in Comparative Examples 4 and 6, the bending strength after the dental mill blank was polished and immersed for 2 days was high, but the bending strength was increased over time by immersion for a predetermined number of days. Was found to decrease. Moreover, in Comparative Examples 7 and 8, the bending strength tended to decrease over time due to immersion for a predetermined number of days, and the bending strength was less than 115 MPa.
Moreover, as shown in FIG. 4, in Comparative Examples 9-12, it turned out that bending strength will be less than 115 MPa by water immersion for a predetermined number of days. In particular, it was found that even in Comparative Example 12 in which the inorganic filler was increased to 65% by mass, the bending strength was less than 115 MPa due to water immersion.

(Bending elastic modulus due to water immersion)
FIG. 5 is a graph showing the relationship between the number of days of flooding and the flexural modulus in Examples 1 to 3.
FIG. 6 is a graph showing the relationship between the number of days of water immersion and the flexural modulus in Examples 5 and 6.
FIG. 7 is a graph showing the relationship between the number of days of flooding and the flexural modulus in Comparative Examples 4 and 6-8.
FIG. 8 is a graph showing the relationship between the number of days of water immersion and the flexural modulus in Comparative Examples 9-12.
As shown in FIGS. 5 and 6, in Examples 1 to 3 and Examples 5 and 6, it was found that even if the dental mill blank was polished and then immersed for a predetermined number of days, the bending elastic modulus hardly decreased.
On the other hand, as shown in FIGS. 7 and 8, in Comparative Examples 4 and 6 to 8, it is found that the bending elastic modulus tends to decrease with time by immersing the dental mill blank after polishing for a predetermined number of days. It was. Further, in Comparative Examples 9 to 12, the bending elastic modulus hardly decreased even when immersed for a predetermined number of days, but as described above, the bending strength was all less than 115 MPa by the predetermined number of days of water immersion.

<Bending strength and bending elastic modulus after 5,000 cycle and 12,000 cycle tests>
The measurement results of the bending strength and the bending elastic modulus after the 5,000 cycle test will be described in detail with reference to FIGS.
In the measurement of the bending strength and the flexural modulus, the other cut specimen was immersed in water at 37 ° C. for 22 days in Example 2 and 21 days in Comparative Example 3, and the specimen was bent after immersion. Strength and flexural modulus were measured respectively. The bending strength and bending elastic modulus of this test piece were used as comparison objects of the bending strength and bending elastic modulus after the 5,000 cycle test.
Moreover, about the dental mill blank of Example 2, the said 5,000 cycle was changed into 12,000 cycles and the said test was done.

(Bending strength after 5,000 cycles and 12,000 cycles test)
FIG. 9 is a graph showing the relationship between the content of the inorganic filler and the bending strength after the immersion test of Comparative Example 1, Examples 1-3, the 5,000 cycle test of Example 2, and the 12,000 cycle test. is there.
FIG. 10 is a graph showing the relationship between the content of the inorganic filler and the bending strength after the water immersion test and the 5,000 cycle test of Comparative Example 3.
As shown in FIG. 9, in Example 2, the decrease in the bending strength after the 5,000 cycle test was 3% to 4% with respect to the bending strength after immersion for 22 days at 37 ° C. (after saturation). % Was small.
Further, even after the 12,000 cycle test, the decrease in the bending strength was as small as 3% to 4%.
On the other hand, as shown in FIG. 10, in Comparative Example 3, the decrease in the bending strength after the 5,000 cycle test was 10% with respect to the bending strength after 21 days of water immersion (after saturation). It was big.

(Flexural modulus after 5,000 cycles and 12,000 cycles test)
FIG. 11 is a graph showing the relationship between the content of the inorganic filler and the flexural modulus after the immersion test of Comparative Example 1 and Examples 1 to 3, the 5,000 cycle test of Example 2, and the 12,000 cycle test. It is.
FIG. 12 is a graph showing the relationship between the content of the inorganic filler and the flexural modulus after the water immersion test and 5,000 cycle test of Comparative Example 3.
As shown in FIG. 11, in Example 2, a decrease in the flexural modulus after the 5,000 cycle test was not observed with respect to the flexural modulus after immersion for 22 days at 37 ° C. (after saturation). In addition, even after the 12,000 cycle test, no decrease in the flexural modulus was observed.
On the other hand, as shown in FIG. 12, in Comparative Example 3, the decrease in the flexural modulus after the 5,000 cycle test was relatively large at 5% with respect to the flexural modulus after immersion for 21 days at 37 ° C. It was.

<Measurement of flexural strength and flexural modulus after 5,000 cycles test in colored mill dental blank>
By the following method, a dental mill blank with a colored prescription was prepared, and the bending strength and bending elastic modulus after the 5,000 cycle test were measured by the same method as described above. The number of days of immersion was 3 days for Example 2-2 and 31 days for Example 3-2. The results are shown in FIGS.

[Example 2-2]
(Preparation of colored composition dental composition and dental mill blank)
In the preparation of the dental composition of Example 2, when the polymer and the inorganic filler were mixed, 1 wt% of the titanium oxide of the filler c was used as a colorant with respect to the total amount of the polymer and the inorganic filler. Except having added, the pellet which consists of a dental composition was obtained by the method similar to Example 2, and the dental mill blank of the coloring prescription was obtained from this pellet.

[Example 3-2]
(Preparation of colored composition dental composition and dental mill blank)
In the preparation of the dental composition of Example 3, when the polymer and the inorganic filler were mixed, 1 wt% of the titanium oxide of the filler c was used as a colorant with respect to the total amount of the polymer and the inorganic filler. Except for the addition, a pellet made of a dental composition was obtained in the same manner as in Example 3, and a dental mill blank with a colored formulation was obtained from this pellet.

FIG. 13 is a graph showing the relationship between the content of the inorganic filler and the bending strength after the water immersion test and the 5,000 cycle test of Example 2-2 and Example 3-2.
FIG. 14 is a graph showing the relationship between the content of the inorganic filler and the flexural modulus after the immersion test and the 5,000 cycle test of Example 2-2 and Example 3-2.
As shown in FIGS. 13 and 14, in Example 2-2 and Example 3-2, the decrease in the bending strength after the 5,000 cycle test with respect to the bending strength after water immersion at 37 ° C. is as follows. It was as small as 3% to 5%. Further, the decrease in flexural modulus after the 5,000 cycle test was almost zero.
In addition, in the dental mill blank (Example 2-2) of coloring prescription, and the dental mill blank (Example 2) which does not add a coloring agent, the bending strength and bending elasticity after a 5,000 cycle test Both rates of decrease were as small as 3% to 4%. Thereby, it turned out that there is almost no difference of the fall width of the said bending strength and bending elastic modulus by the presence or absence of coloring of a dental mill blank.

-Description of FIGS. 1-14-
-Wollast shows wollastonite (filler a or filler b).
M-PPE represents styrene-modified polyphenylene ether a.
-PSU indicates polysulfone a.
-PP shows polypropylene a.
* GF shows glass fiber (filler d).

Claims (17)

A polymer (A) comprising a structural unit having a functional group having at least one ring selected from the group consisting of an aromatic ring and an aliphatic ring, and a hydrogen bond accepting group;
An inorganic filler (B) having an average thickness of 0.1 μm to 160 μm and an average aspect ratio of 2.0 to 65;
Containing
A dental composition having a flexural strength of 115 MPa or more after water immersion at 37 ° C. for 2 days and a water absorption rate of 2% by mass or less in a water immersion test at 37 ° C. for 30 days. A structural unit having a functional group having at least one ring selected from the group consisting of an aromatic ring and an aliphatic ring and a hydrogen bond accepting group, and having a bending strength of 70 MPa after water immersion at 37 ° C. for 2 days The polymer (A) having a water absorption rate of 2% by mass or less according to a water immersion test at 37 ° C. for 30 days,
An inorganic filler (B) having an average thickness of 0.1 μm to 160 μm and an average aspect ratio of 2.0 to 65;
A dental composition containing   The dental composition according to claim 1 or 2, wherein the polymer (A) has a glass transition temperature Tg of 50C to 250C.   The dental composition according to any one of claims 1 to 3, wherein the hydrogen bond accepting group is at least one functional group selected from the group consisting of an ether group, a carbonate group, and a sulfonyl group.   The dental composition according to any one of claims 1 to 4, wherein the polymer (A) is at least one polymer selected from the group consisting of polycarbonate, polyarylate, polyphenylene ether, and polysulfone. .   The dental composition according to any one of claims 1 to 5, wherein the polymer (A) contains an amorphous resin.   The content of the inorganic filler (B) is 5% by mass to 60% by mass with respect to the total content of the polymer (A) and the inorganic filler (B). The dental composition according to any one of the above.   The surface of the said inorganic filler (B) has at least 1 sort (s) of hydrogen bondable functional group chosen from the group which consists of a hydroxyl group, an ether group, a carbonate group, and a sulfonyl group. The dental composition according to Item.   A dental mill blank comprising the dental composition according to any one of claims 1 to 8.   The dental mill blank according to claim 9, which is used for manufacturing a dental member selected from an inlay, an onlay, a crown, a bridge, a clasp, a mouthpiece hinge, and a denture frame by cutting.   The dental member containing the dental composition of any one of Claims 1-8.   The dental member according to claim 11, wherein the arithmetic average roughness Ra (JIS B0601: 2013) of the surface is 0.15 µm or less.   A denture base comprising the dental member according to claim 11 or 12, and a denture base member fixed to the dental member.   A denture having the denture base according to claim 13 and an artificial tooth fixed to the denture base member of the denture base.   The manufacturing method of the dental member which has the cutting process which cuts the dental mill blank of Claim 9 or Claim 10, and obtains a dental member. A cutting step of cutting the dental mill blank according to claim 9 or 10 to obtain a dental member;
A build-up step of forming a denture base member fixed to the dental member by building a resin material on the dental member;
The manufacturing method of the denture base which has this. A cutting step of cutting the dental mill blank according to claim 9 or 10 to obtain a dental member;
A build-up step of forming a denture base member fixed to the dental member by building a resin material on the dental member;
An artificial tooth fixing step of fixing artificial teeth to the denture base member;
The manufacturing method of the denture which has this.