JPH085768B2 - Urethane-based dental resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dental resin in which a polymer has an excellent impact absorbing ability, and a dental polymer obtained by polymerizing the same.

[Conventional technology]

BACKGROUND ART Dental resins (which are referred to as monomers in the present specification) are widely used in the field of dental treatment, and the usage states thereof include, for example, the following modes.

(1) Filling / restoration Here, the dental resin is used as a main raw material for a polymer (polymer material) that fills the holes vacated by caries and repairs a part of the tooth that was missing due to an accident. To be done. Dental resin is polymerized in situ (tooth).

(2) Adhesion Here, the dental resin is used as an adhesive for adhering an artificial tooth crown made of metal, ceramic, or synthetic resin to a natural tooth. The dental resin is polymerized in situ (adhesion surface), and the adhesive force is developed by the polymerization.

(3) Dental Crown Here, the dental resin is used as a main raw material of a main polymer (polymer material) that constitutes an artificial crown such as a front crown. The dental resin is polymerized at the same time as or before molding.

(4) Denture base Here, the dental resin is used as a main raw material of a main polymer (polymer material) which constitutes a base of a denture, that is, a denture. The dental resin is polymerized at the same time as or before molding.

(5) Artificial tooth Here, the dental resin is used as a main raw material of a main polymer (polymer material) that constitutes a temporary crown or the like of an artificial tooth of a denture, a so-called denture. The dental resin is polymerized at the same time as or before molding.

Note that it is necessary to use various auxiliary materials together with the dental resin depending on the usage mode.

By the way, as a specific example of such a dental resin,
First the following structural formula: A liquid methyl methacrylate having is proposed and has been utilized as a polymer (polymer material) by vinyl polymerization in any of the usage modes.

However, the methyl methacrylate polymer is disliked in terms of abrasion resistance and strength.

Therefore, UDMA, which is a bacterial and unsaturated urethane monomer, has been proposed as a dental resin. UDMA is a product obtained by reacting 2-hydroxyethymethacrylate as a hydroxy compound and trimethylhexamethylene diisocyanate as a polyisocyanate in stoichiometrically equivalent amounts, and a hydroxy group (OH) and an isocyanate group ( Urethane bond (-NHCOO
-).

UDMA is a stable liquid that has no active NCO group anymore, but it is one of the monomers that has two ethylenically unsaturated double bonds, and it is vinyl polymerized into a solid resin (polymer). be able to.

Therefore, UDMA alone or other monomer (including crosslinkable monomer having two or more ethylenically unsaturated double bonds)
At the same time, polymerization is optionally performed in the presence of an inorganic or organic filler (for example, silica powder) to obtain a polymer having excellent abrasion resistance and strength.

[Problems to be Solved by the Invention]

However, all of these resins are premised on being used for jacket crowns, front crowns, continuous crowns, etc. Therefore, the impact absorbing ability of the polymer is not taken into consideration, and the impact absorbing ability is low. There was a problem.

This problem is because there is no equivalent to the periodontal ligament of natural teeth when the artificial root is implanted in the jawbone and the crown is mounted on it, and the crown is inferior in shock absorption capacity. The occlusal pressure is directly transmitted to the alveolar bone, causing discomfort during mastication, and stress may be concentrated on the alveolar bone, which may cause bone resorption.

Therefore, an object of the present invention is to enhance the impact absorbing ability of a polymer of a dental resin.

[Means for solving problems]

Therefore, the present invention is firstly represented by the following general formula I: Or general formula II: A polymerizable urethane dental resin represented by the following is provided.

However, in the formula, R ₁ , R ₂ , R ₅ and R ₆ , which may be the same or different, represent CH ₂ ═CHOO— group or CH ₂ ═C (CH ₃ ) COO— group, and R ₃ , R ₄ , R ₇ and R ₈ , which may be the same or different, each represents H or CH ₃ , and X, X ₁ and X ₂ may be the same or different and each have a polyisocyanate residue. Y, Y ₁ and Y ₂ , which may be the same or different, each represent a polyester polyol or a residue of the polyester polyol.

The Y may be of the general formula: Y ₃ —R ₉ —Y ₄ , in which case R ₉ is a polymethylene chain: — (CH ₂ ) _n — (n ≧ 2), and Y ₃ and Y _{4's, which} may be the same or different, represent a residue of a polyether polyol or a polyester polyol.

Secondly, the present invention provides a dental polymer obtained by polymerizing the dental resin of the general formulas I to II.

The dental resin of general formula I is synthesized, for example, as follows.

First, (1) polyester polyol or polyether polyol 1 widely used in polyurethane resin technology
An isocyanate (-NCO) group-terminated oligomer is synthesized by reacting 2 equivalents of polyisocyanate with 2 equivalents of (2) β-hydroxyethyl (meth) acrylate or β-hydroxypropyl (meth). React urethane with acrylate.

In the present specification, the expression “(meth) acry ...” means one or both of “methacry ...” or “acry ...” (mixture).

Further, the dental resin of the general formula II is synthesized, for example, as follows.

First, (1) 2 equivalents of a starting material generally used in polyurethane resin technology: 2 equivalents of polyester polyol or polyether polyol are reacted with 1 equivalent of polyisocyanate to give a terminal hydroxyl (-OH) group or carboxyl group (-). COOH) oligomer,
Then (2) 2 equivalents of β-hydroxyethyl (meth) acrylate or β-hydroxypropyl (meth)
An etherification or esterification reaction with an acrylate gives a dental resin of the general formula II.

In this case, a general formula that can be one of the starting materials: Y ₃
The precursor of the organic group of -R ₉ -Y ₄ is, for example, polymethylene glycol (generally having 2 to 8 carbon atoms) widely used in polyurethane resin technology as an initiator, and a cyclic ester or oxirane compound is ring-opened therein. It can be synthesized by addition polymerization.

For example, the following materials are used as the raw materials for the above manufacturing method.

(1) Polyisocyanate: Aliphatic isocyanates such as ethylene diisocyanate, propylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, transcyclohexane diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate (hydrogenated MDI), methylenebis (4- Cyclohexyl isocyanate), methylcyclohexane diisocyanate, bicycloheptane triisocyanate trimethylhexamethylene diisocyanate (including 2,2,3-trimethyl and 2,3,3-trimethyl, and mixtures of both are used), etc. Diisocyanate, toluylene diisocyanate, naphthylene-1,5-diisocyanate, diphenyl Tan diisocyanate, polymethyl polyphenyl polyisocyanate, methylbenzene diisocyanate, aliphatic or aromatic polyisocyanates such as xylylene diisocyanate.

Depending on the form of use, it is also possible to use a blocked polyisocyanate whose isocyanate groups are blocked and which are released by the heat during polymerization.

(2) Polyether polyol: For example, ethylene glycol, diethylene glycol,
Aliphatics such as propylene glycol, 1,4-butylene glycol, glycerin, hexanetriol, trimethylolpropane, pentaerythritol, sorbitol, sucrose, dibropyrene glycol, neopentyl glycol, 1,6-hexamethylene glycol, decamethylene glycol or Using an alicyclic polyhydric alcohol or an aliphatic or alicyclic polyamine such as methyldiethanolamine, ethyldiisopropanolamine, triethanolamine, ethylenediamine, hexamethylenediamine or bis (p-aminocyclohexyl) methane as an initiator, A polymer having a molecular weight of about 100 to 6000 obtained by addition-polymerizing one or more aliphatic oxides such as ethylene oxide, propylene oxide and butylene oxide.

(3) Polyester polyol: Polyhydric alcohol and aliphatic or alicyclic polyvalent carboxylic acid (for example, malonic acid, maleic acid, succinic acid, adipic acid, glutaric acid, pimelic acid, sebacic acid, oxalic acid, hexa) Hydrophthalic acid, etc.) with a molecular weight of 100 to 6000 obtained by continuous esterification with.

Alternatively, those having a molecular weight of about 100 to 6000 obtained by ring-opening polymerization of cyclic esters such as propiolactone, butyrolactone and caprolactone.

(4) Cyclic ester: propiolactone, butyrolactone, caprolactone and the like.

(5) Oxirane compound: ethylene oxide, propylene oxide, butylene oxide and the like.

When reacting the polyol and the polyisocyanate, an active hydrogen compound may be used in some cases. Examples of such active hydrogen compounds include ethylene glycol, diethylene glycol, propylene glycol, 1,4-butylene glycol, glycerin, hexanetriol, trimethylolpropane, pentaerythritol, sorbitol, sucrose, dipropylene glycol, neopentyl glycol, 1 Examples include 6,6-hexamethylene glycol, decamethylene glycol, 1,2-polybutadiene polyol, 1,4-polybutadiene polyol, polychloroprene polyol, butadiene-acrylonitrile copolymer polyol, polydimethylsiloxane dicarbinol and the like.

Most of the dental resin of the present invention is liquid, but solid (powder) resin should be used by being dissolved or dispersed in other liquid resin (monomer) or solvent depending on the usage form. preferable.

The dental resin of the present invention is characterized by being capable of vinyl polymerization and being cured by it. Therefore, the resin of the present invention can be used in various ways as described in (1) to (5) in the section "Prior Art". In that case, the dental resin of the present invention is not limited to a solid one, and other dental resins such as methyl methacrylate (MMA) and UDMA can be used depending on the application.
It can be used as a mixture with.

When polymerizing and curing the resin of the present invention or a mixture with other resin (monomer), organic or inorganic filler such as silica powder, glass powder, PMMA (polymethylmethacrylate) pearl, crosslinked PMMA powder, quartz powder, and optionally Fine ceramic powder or the like may be mixed.
The filler can increase the hardness and abrasion resistance of the polymer or reduce the water absorption of the polymer depending on the type and amount.

The resin of the present invention or a mixture with another resin (monomer) or a polymer obtained by polymerizing a mixture of these resins with an organic or inorganic filler is pulverized into a filler by a conventional method, The resin of the present invention or another resin or a mixture of both may be used for dental treatment.

Depending on the mode of use, it is necessary to polymerize the resin of the present invention or a mixture with other resin (monomer) at room temperature, and therefore tri-n-butylborane peroxide, peroxide-as a polymerization initiator or a polymerization accelerator. A tertiary amine redox catalyst or the like is used.

Since the polymerization is initiated at room temperature, it is mixed just prior to use and the mixture polymerizes in situ on or within the tooth.

Since it is busy and the workability is poor, polymerization is sometimes carried out by irradiating with ultraviolet rays or recently with visible rays.In this case, a polymerization initiator of the type that decomposes with light, for example, d, 1-camphor, is used. Quinone, α-diketone and the like are used. In this case, the composition containing the resin of the present invention is filled inside the tooth or placed on the surface of the tooth, and then irradiated with light to polymerize and harden (solidify).

Since the polymer of the present invention has excellent impact absorbing ability, it is particularly useful for dental crowns, artificial teeth, denture bases and the like to be attached to an implanted dental implant.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

[Example 1 ... Example of claim 1] (1) Adipic acid and ethylene glycol were ester-reacted at an approximate ratio of 1: 1.2 to synthesize a polyester polyol (bifunctional) having a molecular weight of about 1500.

(2) Next, 1 equivalent of the polyol was reacted with 2 equivalents of isophorone diisocyanate to synthesize an oligomer (prepolymer) having an isocyanate (—NCO) group at the end.

(3) 2 equivalents of β-for 1 equivalent of the oligomer (bifunctional)
The dental resin of this example was synthesized by carrying out urethane reaction with hydroxyethyl methacrylate.

This resin was liquid and contained two C = C2 double bonds per molecule, and was capable of vinyl polymerization.

[Example 2 ... Example of claim 1] (1) Commercially available polyethylene propylene glycol having a molecular weight of about 1500 (bifunctional and the molar ratio of ethylene propylene is 1:
I got 1).

(2) Next, 1 equivalent of the polyol was reacted with 2 equivalents of isophorone diisocyanate to synthesize an oligomer (prepolymer) having an isocyanate (—NCO) group at the end.

(3) 2 equivalents of β-for 1 equivalent of the oligomer (bifunctional)
The dental resin of this example was synthesized by carrying out urethane reaction with hydroxyethyl methacrylate.

This resin was liquid and contained two C = C2 double bonds per molecule, and was capable of vinyl polymerization.

[Example 3 ... Example of claim 2] (1) Using trimethylene glycol as an initiator, γ-butyrolactone was subjected to ring-opening addition polymerization to give a molecular weight of about 10
00 polyester polyol (bifunctional) was synthesized.

(2) Next, 1 equivalent of the polyol was reacted with 2 equivalents of isophorone diisocyanate to synthesize an oligomer (prepolymer) having an isocyanate (—NCO) group at the end.

(3) 2 equivalents of β-for 1 equivalent of the oligomer (bifunctional)
The dental resin of this example was synthesized by carrying out urethane reaction with hydroxyethyl methacrylate.

This resin was liquid and contained two C = C2 double bonds per molecule, and was capable of vinyl polymerization.

[Example 4 ... Example of claim 2] (1) Using ethylene glycol as an initiator, propylene oxide was subjected to ring-opening addition polymerization to give a molecular weight of about 800.
Was synthesized (bifunctional).

(2) Next, 1 equivalent of the polyol was reacted with 2 equivalents of isophorone diisocyanate to synthesize an oligomer (prepolymer) having an isocyanate (—NCO) group at the end.

(3) 2 equivalents of β-for 1 equivalent of the oligomer (bifunctional)
The dental resin of this example was synthesized by carrying out urethane reaction with hydroxyethyl methacrylate.

This resin was liquid and contained two C = C2 double bonds per molecule, and was capable of vinyl polymerization.

[Example 5: Example of claim 3] (1) By reacting 2 equivalents of the polyester polyol synthesized in (1) of Example 1 with 1 equivalent of isophorone diisocyanate, the terminal is a hydroxyl (-OH) group. The oligomer (prepolymer) of was synthesized.

(2) 2 equivalents of β-to 1 equivalent of the oligomer (bifunctional)
The dental resin of this example was synthesized by performing an etherification reaction with hydroxyethyl methacrylate.

This resin was liquid and contained two C = C2 double bonds per molecule, and was capable of vinyl polymerization.

[Example 6 ... Example of claim 3] (1) By reacting 2 equivalents of the polyether polyol obtained in (1) of Example 2 with 1 equivalent of isophorone diisocyanate, the terminal is hydroxyl (-OH). A group oligomer (prepolymer) was synthesized.

(2) 2 equivalents of β-to 1 equivalent of the oligomer (bifunctional)
The dental resin of this example was synthesized by performing an etherification reaction with hydroxyethyl methacrylate.

This resin was liquid and contained two C = C2 double bonds per molecule, and was capable of vinyl polymerization.

[Example 7 ... Example of polymer] 100 parts by weight of the resin of Examples 1 to 6 was prepared, and 1 part by weight of benzoyl peroxide as a polymerization initiator was added to and uniformly mixed with the resin. Polymerization was carried out by heating for 15 minutes.

 The physical properties of the obtained polymer are shown in Table 1 below.

Incidentally, in Table 1, the comparative examples use commercially available UDMA as the resin as it is.

[Example 8: Example of polymer] 100 parts by weight of the resin of Examples 1 to 6 was prepared, and SiO ₂ fine powder (average particle size 1 to 50 µm) was added to this as an inorganic filler.
Parts by weight and 1 part by weight of benzoyl peroxide as a polymerization initiator were added and mixed uniformly, and this mixture was heated at 120 ° C.
Polymerization was carried out by heating for 15 minutes.

 The physical properties of the obtained polymer are shown in Table 2 below.

In Table 2, the comparative example is a product obtained by using commercially available UDMA as it is as a resin.

[Example 9 ... Example of polymer] The polymer obtained in Examples 7 to 8 was pulverized to obtain an average particle diameter.
No filler of 10-50 μm, 80 parts by weight of this filler
100 parts by weight of UDMA and 1 part by weight of benzoyl peroxide as a polymerization initiator were further added and uniformly mixed, and the mixture was heated at 120 ° C. for 15 minutes to polymerize.

 The physical properties of the obtained polymer are shown in Table 3 below.

Incidentally, in Table 3, the comparative example uses the commercially available UDMA as it is as the resin.

[Effects of the Invention] As described above, the resin of the present invention, when polymerized, provides a polymer having a high flexural modulus, that is, an excellent impact absorbing ability. Therefore, the resin and polymer of the present invention are particularly useful as a main material for a dental crown, an artificial tooth, a denture base, etc. to be attached to an artificial tooth root.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Masatoshi Naoi Masatoshi Naoi 1-406-1, Yoshino-cho, Omiya-shi, Saitama Inside Shin-Etsu Polymer Co., Ltd. (72) Hideki Nishida 4-10-1 Nihonbashi-honcho, Chuo-ku, Tokyo Mitani Building in Mitani Sangyo Co., Ltd. (56) Reference JP-A-63-170348 (JP, A) JP-A-63-150207 (JP, A) JP-A-61-95019 (JP, A)

Claims (4)

[Claims] (1) The following general formula (I): A polymerizable urethane dental resin represented by. However, in the formula, R ₁ and R ₂ , which may be the same or different, each represent a CH ₂ ═CHOO— group or a CH ₂ ═C (CH ₃ ) COO— group, and R ₃ and R ₄ are the same. Or may be different, and represents H or R ₃ , and X ₁ and X ₂ may be the same or different and represents a polyisocyanate residue, and Y is a residue of a polyether polyol or a polyester polyol. Represents 2. The polymerizable urethane-based dental resin according to claim 1, wherein the Y is represented by the general formula: Y ₃ —R ₉ —Y ₄ . However, in the formula, R ₉ is a polymethylene chain, and Y ₃ and Y ₄ , which may be the same or different, each represent a residue of a polyether polyol or a polyester polyol. 3. The following general formula II: A polymerizable urethane dental resin represented by. However, in the formula, R ₅ and R ₆ , which may be the same or different, each represent a CH ₂ ═CHOO— group or a CH ₂ ═C (CH ₃ ) COO— group, and R ₇ and R ₈ are the same. Or may be different, represents H or CH ₃ , X represents a polyisocyanate residue, and Y ₁ and Y ₂ may be the same or different, but are a residue of a polyether polyol or a polyester polyol. Represents 4. A dental polymer obtained by polymerizing the dental resin according to any one of claims 1 to 3.