JPH0555559B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is a dental treatment with excellent adhesive properties used for bonding between living tooth tissue and materials for repairing the tissue (metal materials, organic polymer materials, ceramic materials, etc.). The present invention relates to an adhesive composition for [Prior Art] Traditionally, in the field of dental materials, various metal materials (for example, gold, silver, platinum,
alloys, amalgams, etc.), organic polymer materials (e.g.
polymethyl methacrylate, polycarbonate,
polymethyl methacrylate, polycarbonate,
polyfunctional vinyl cured products, composite resins, etc.),
Ceramic materials (eg, porcelain, implant materials, etc.) are used. However, these materials do not inherently adhere to living tooth tissue. Therefore, for the purpose of adhesion between the restorative material and the living tooth tissue, we aim to improve the interaction with the main inorganic components such as apatite (calcium phosphate) or the main organic components such as collagen (protein) that form the dental tissue. Dental adhesive compositions have been proposed in which the adhesive component is a compound having various polar groups (phosphoric acid group, hydroxyl group, acid anhydride group, etc.). [Problems to be Solved by the Invention] However, although the above-mentioned conventional technology has a certain degree of adhesion to enamel in living tooth tissue, it has no adhesion performance to dentin at all. This is due to physical and chemical structural factors of living dentin. In other words, dentin has a structure in which countless dentinal tubules run and are filled with fluid, and the ratio of proteins such as collagen is considerably higher than that of enamel, making it difficult to bond. It can be said that the environment is extremely harsh. Therefore, in the adhesives according to the prior art described above, apatite, which is the main inorganic component, is pretreated with an etching agent such as phosphoric acid in order to achieve a certain degree of adhesiveness to living dentin through the so-called anchor effect. However, since the adhesive strength is still insufficient, over a long period of time, gaps may form between the restorative material and the dentin, and in some cases, the restorative material may even fall off. However, it cannot be said that sufficiently high adhesiveness is obtained. The purpose of the present invention is to have a strong adhesive force to enamel in the living tooth tissue, and to avoid the troublesome etching agent such as phosphoric acid, which is essential in conventional methods, in bonding dentin and restorative materials. The object of the present invention is to provide a novel dental adhesive composition that does not require pretreatment, has a practically sufficient adhesive strength, and is photopolymerizable. [Means for Solving the Problems] That is, the dental adhesive composition of the present invention comprises (a) an isocyanate group-containing urethane prepolymer represented by the following structural formulas (1), (2) and (3). (b) one or more radically polymerizable unsaturated monomers; (b) one or more radically polymerizable unsaturated monomers;
and (c) a dental adhesive composition containing a photopolymerization initiator as a main component. (In the formula, m is an integer of 1 to 100, n is an integer of 1 to 100, and n/(m+n) is 0.40 to 0.80, and the propylene oxide units and ethylene oxide units may be bonded randomly. ) [Function] The isocyanate group-containing urethane prepolymer which is the component (a) of the present invention has 2 isocyanate groups (-NCO) in the molecule relative to the polyol compound.
It is obtained by reacting a compound having more than one isocyanate, that is, a polyisocyanate, so that some of the isocyanate groups remain. As the polyol compound, a polyether polyol containing ethylene oxide units and propylene oxide units in a specific composition ratio is used. This polyether polyol can be obtained by a known method. The polyether polyol can be prepared by a known method.
ethylene glycol, propylene glycol,
Adding an alkali catalyst such as caustic potash or caustic soda to an active hydrogen compound such as 1,6-hexanediol,
It can be obtained by addition polymerizing alkylene oxide such as ethylene oxide, propylene oxide, butylene oxide, etc. to this. The polyol compound preferably has a hydroxyl group at its terminal in order to obtain excellent adhesive properties. Specifically, such an isocyanate group-containing urethane prepolymer is
In the presence of a known catalyst such as a tertiary amine or dibutyltin laurate, an organic diisocyanate such as tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, etc. is added in an amount such that the NCO group is present in excess. It is obtained by reacting at a NCO/OH equivalent ratio. Among these urethane prepolymers, propylene glycol is used as the active hydrogen compound,
Urethane prepolymers represented by the structural formulas (1), (2), and (3) obtained by using diols obtained by addition polymerizing ethylene oxide and propylene oxide thereto are preferably used. In particular, urethane prepolymers having at least two free isocyanate groups in one molecule obtained by using tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate or hexamethylene diisocyanate as the terminal isocyanate agent are particularly high. This is preferable because adhesive strength can be obtained. Further, the urethane prepolymer preferably has free isocyanate groups at both ends. The molecular weight of these urethane prepolymers is preferably 400 to 50,000, especially in order to obtain good solubility and excellent adhesion to radically polymerizable unsaturated monomers.
Particularly preferred is 400 to 20,000. In addition, in the isocyanate group-containing urethane prepolymers represented by formulas (1) to (3), the ratio of ethylene oxide units to the total amount of propylene oxide units and ethylene oxide units constituting the main chain of the prepolymer is 40 to 80. It is a prepolymer made hydrophilic or water-soluble by setting the mole %, that is, n/(m+n), to 0.40 to 0.80. Isocyanate group-containing urethane prepolymers contain isocyanate groups present in the molecule, organic components (particularly collagen containing many active hydrogen groups in the molecule), which are the main components of dentin in living tooth tissue, and water (body fluids). ) to develop adhesion with the restorative material, and in particular, urethane prepolymers containing two or more free isocyanate groups in one molecule are effective in achieving excellent adhesion. , is preferably used. The isocyanate group-containing urethane prepolymer can be used alone, but in order to improve workability when using the composition, it may be used with a diluent that is inert with respect to isocyanate groups, such as acetone, methyl ethyl ketone, ethyl acetate, toluene, Xylene, trichloroethane, etc. may also be added. The dental adhesive composition of the present invention basically comprises (a)
Although it is possible to obtain conventional adhesive strength using only the components, for example, when adhesive work is intended for use in the oral cavity, there are often time constraints on curing the adhesive layer. However, the radically polymerizable unsaturated monomer, component (b) of the present invention, is a necessary component for quickly solidifying the adhesive layer by light irradiation in the presence of the photopolymerization initiator, component (c). Any radically polymerizable unsaturated monomer that does not interfere with the adhesive performance of component (a) can be used, and monofunctional or polyfunctional monomers may be used. Specific examples of monofunctional unsaturated monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-
Hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate, benzyl (meth)acrylate, vinyl acetate, styrene, acrylonitrile, glycidyl methacrylate, among others, methyl acrylate, methyl methacrylate, 2-hydroxyl methacrylate and vinyl acetate. is preferably used. In addition, as an example of a bifunctional unsaturated monomer, the following general formula (4) (In the formula, R ¹ is a hydrogen atom or a methyl group, p is 1
~20 integer. ) Polyethylene glycol di(meth)acrylate etc. can be used, and specific examples include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tetraethylene. Glycol di(meth)acrylate, pentaethylene glycol di(meth)acrylate, hexaethylene glycol di(meth)acrylate, heptaethylene glycol di(meth)acrylate, octaethylene glycol di(meth)acrylate, nonaethylene glycol di(meth)acrylate acrylate, decaethylene glycol di(meth)acrylate, polyethylene glycol(meth)diacrylate with p=14,
Examples include polyethylene glycol di(meth)acrylate with p of 17, polyethylene glycol di(meth)acrylate with p of 19, etc.
Among them, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, nonaethylene glycol di(meth)acrylate, and polyethylene glycol di(meth)acrylate with p=14 are preferably used. Also, the following general formula (5) (In the formula, R ¹ is a hydrogen atom or a methyl group, R ² is an alkylene group having 1 to 8 carbon atoms or

〔Effect of the invention〕

According to the dental adhesive composition of the present invention, there is no need for complicated pretreatment with an etching agent such as phosphoric acid, which was essential in the conventional technology, when bonding living tooth tissue, especially dentin, and a restorative material. Adhesion strength sufficient for practical use can be obtained. Furthermore, since it has photopolymerizability, it can be solidified in a short time by light irradiation before its original adhesive strength is exerted, and it is also easy to handle in the oral cavity. [Examples of the Invention] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. [Restoration material-A (visible light curing composite resin)
Manufacturing of]

[Table] A mixture (paste) consisting of a multifunctional monomer, an inorganic fuel, and a visible light polymerization initiator shown in the above formulation, that is, a visible light curing composite resin, was produced in a dark room, and Restorative Material-A was prepared. Obtained. [Manufacture of restorative material-B (visible light-curable dental crown resin)] 2,2-bis[4-(3-methacryloxy-2)
-Hydroxypropoxy)phenyl}propane (hereinafter abbreviated as Bis-GMA)...40g 3G...60g Camphorquinone...0.7g Isoamyl 4-(N,N-dimethylamino)benzoate...2.8g The above combination formula A mixture consisting of a polyfunctional monomer shown by the formula and a visible light polymerization initiator, that is, a visible light curing resin for dental crowns was produced in a dark room to obtain a restorative material-B. [Adhesion evaluation procedure and adhesive strength measurement method] (1) Cut the fresh morning tooth immediately after tooth extraction with a precision cutter (Isometric, manufactured by Bühler) to expose the dentin and enamel planes; Polish thoroughly under running water using No. 1000 waterproof abrasive paper. In some cases, the enamel plane is etched by a conventional method using a phosphoric acid etching agent (manufactured by Shishi Dental Industry Co., Ltd.). (2) Apply the dental adhesive composition to the dentin or enamel plane, and if volatile components such as solvents are present, let the volatile components evaporate and scatter with an air flow for about 10 seconds. (3) After installing a cylindrical silicone ring (one side can be opened) with an inner diameter of about 5 mm, a height of about 5 mm, and a wall thickness of about 3 mm on the flat surface coated with the dental adhesive composition, the liquid inside this silicon ring is The height of the repair material is approximately 3
Fill it to 1 mm. (4) Attach a visible light irradiator (GC light,
Co., Ltd.) and irradiate it with visible light for 60 seconds to harden the restoration material and adhesive. (5) After about 10 minutes, remove the silicone ring and obtain an adhesive test piece with the repair material adhered to the surface of the sample to be adhered. (6) After storing the entire adhesive test piece in water at 37°C for a predetermined period, a spacer for adhesion testing (an acrylic rod with the same diameter as the restoration material) was placed on top of the restoration material. First,
(manufactured by Dentistry Kogyo Co., Ltd.), set it in a specified test holder, and conducted a tensile test.
Adhesive strength was measured. The measurement conditions are shown below. Tensile tester: Toyo Baldwin Tensilon Crosshead speed (tensile speed): 0.5mm/
min Chart speed: 10mm/min Full scale: 5KgW or 20KgW [Synthesis of isocyanate group-containing urethane prepolymer] By ring-opening copolymerization of propylene oxide and ethylene oxide using a known method using propylene glycol as an active hydrogen compound. Various polyether glycols listed in Table 1 were produced having different molar ratios of ethylene oxide units (hereinafter abbreviated as EO) and propylene oxide units (hereinafter abbreviated as PO) and average molecular weights. Next, tolylene diisocyanate (2,4/2,6 isomer ratio: 80/
20, hereinafter abbreviated as TDI), 4,4-diphenylmethane diisocyanate (hereinafter abbreviated as MDI) and hexamethylene diisocyanate (hereinafter abbreviated as MDI).
(abbreviated as HDI) and polyether glycol isocyanating agent at a molar ratio of 1:2 and reacted to obtain various urethane prepolymers containing isocyanate groups at both terminals and having the abbreviations shown in Table 1.

[Table] [Preparation of mixtures of radically polymerizable unsaturated monomers and visible light polymerization initiators] Mixtures of various radically polymerizable unsaturated monomers and visible light polymerization initiators were prepared in a dark room using a general-purpose mixer. Tables 2 to 4 show the compositions and abbreviations of these mixtures. In addition, the abbreviation EDMA shown in the column of radically polymerizable unsaturated monomer species in the table indicates urethane dimethacrylate having the following structural formula.

【table】

【table】

[Table] Examples 1 to 64 The same weight of various urethane prepomer containing isocyanate groups at both terminals and LC-15, a mixture of radically polymerizable unsaturated monomer and visible light polymerization initiator, prepared by prepolymer synthesis The mixture was mixed to obtain an adhesive composition. Regarding these adhesive compositions, the adhesion of Restorative Material-A to the dentin surface of bovine teeth that was not subjected to etching treatment was evaluated according to the above-described adhesion evaluation procedure and adhesive strength measurement method, and the results are shown in Table 5. Indicated. Similarly, various isocyanate group-containing urethane prepolymers and LC-16, LC-22 or LC-23
Tables 5 to 8 show the evaluation results for adhesive compositions using the following.

【table】

【table】

【table】

【table】

[Table] Examples 65 to 97 The isocyanate group-containing urethane prepolymer TPT-11 produced by prepolymer synthesis and a mixture of various radically polymerizable unsaturated monomers and visible light polymerization initiators were mixed in equal weights and bonded. A drug composition was obtained. The adhesion of these adhesive compositions to Restorative Material-A was evaluated in the same manner as in Example 1, and the results were
It is shown in Tables to Table 10.

【table】

[Table] Examples 98 to 109 Examples 1, 17, 33 or An adhesive composition was obtained in exactly the same manner as No. 49, and its adhesiveness was evaluated.
The results are shown in Table 11.

[Table] Examples 110 to 117 Using the adhesive compositions obtained in Examples 4 and 36,
Adhesion to the following types of repair materials was evaluated in the same manner as in Example 1. The results are shown in Table 12.

【table】

[Table] Comparative Examples 1 to 14 Adhesive compositions were prepared in exactly the same manner as in Example 1, except that various polyether glycols produced by prepolymer synthesis were used instead of the urethane prepolymer containing isocyanate groups at both terminals. The product was obtained and its adhesiveness was evaluated. The results are shown in Table 13.

[Table] Comparative Examples 15 to 20 Adhesive compositions were prepared in exactly the same manner as in Example 1, except that various polyester glycols produced by prepolymer synthesis were used instead of the urethane prepolymer containing isocyanate groups at both ends. was obtained and its adhesion was evaluated. The results are shown in Table 14.

[Table] Comparative Examples 21 to 23 Examples except that instead of the urethane prepolymer containing isocyanate groups at both ends, various urethane prepolymers containing radically polymerizable vinyl groups at both ends, which were produced by prepolymer synthesis, were used.
An adhesive composition was obtained in exactly the same manner as No. 125, and its adhesiveness was evaluated. The results are shown in Table 15.

[Table] Comparative Examples 24 to 29 Example 1, except that instead of the trifunctional isocyanate group-containing urethane prepolymer, various trifunctional radically polymerizable vinyl group-containing urethane prepolymers produced by prepolymer synthesis were used.
An adhesive composition was obtained in exactly the same manner as above, and its adhesiveness was evaluated. The results are shown in Table 16.

[Table] Comparative Examples 30 to 37 Adhesive compositions containing only mixtures of various radically polymerizable unsaturated monomers and visible light polymerization initiators were obtained, and their adhesive properties were evaluated in exactly the same manner as in Example 1. The results are shown in Table 17.

【table】

Claims (1)

[Scope of Claims] 1 (a) One or more isocyanate group-containing urethane prepolymers represented by the following structural formulas (1), (2), and (3), or a composition in which an inert diluent is bonded to the urethane prepolymers. (b) one or more radically polymerizable unsaturated monomers;
and (c) a dental adhesive composition containing a photopolymerization initiator as a main component. (In the formula, m is an integer of 1 to 100, n is an integer of 1 to 100, and n/(m+n) is 0.40 to 0.80, and the propylene oxide units and ethylene oxide units may be bonded randomly. )