JPS6317816A - Photo-setting dental composition - Google Patents

Abstract

PURPOSE:The titled one paste type composition, containing a copolymer obtained from an ethylenically unsaturated compound, fine inorganic filler particles, photopolymerization initiator and acrylic unsaturated monomer and fine organic filler particles and having improved clinical operability, etc. CONSTITUTION:The titled composition containing a copolymer obtained from an ethylenically unsaturated compound, e.g. methacrylic acid derivative, fine inorganic filler particles, preferably hydrophobized silica having 1-100mmu particle diameter, photopolymerization initiator and unsaturated monomer expressed by the formula (R1 is H or CH3; R2 is 1-4C alkyl or phenyl; n is 1-15), e.g. methoxyethyl (meth)acrylate, and fine organic filler particles. The composition is of one paste type and excellent in aspects of clinical operability and mechanical strength and low shrinkage. A polymer, containing >=80wt% methyl methacrylate units and having <=100mu particle diameter is preferred for the organic filler particles.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a one-paste type dental composition that can be polymerized and cured by irradiation with light. In the present invention, the dental composition includes dental crown materials, denture base materials, dental adhesive restorative materials, dental impression materials, etc., which contain ethylenically unsaturated compounds.

The present invention provides a one-paste type photocurable dental composition that is particularly excellent in mechanical strength, low shrinkage, and clinical operability.

<Prior art> Conventionally, these dental compositions include a heat polymerization type using benzoyl peroxide as a polymerization initiator, an immediate polymerization type using a redox initiator combining benzoyl peroxide and a tertiary amine, etc. It has been known.

<Problems to be solved by the invention> In the heat polymerization type and instant polymerization type described above, since the kneading method is a powder-liquid type or a paste-paste type, air bubbles easily enter the cured resin and the mechanical strength deteriorates. However, there were drawbacks such as decreased water resistance.

In addition, the heating polymerization type has complicated polymerization operations and requires a long time for counting, and the immediate polymerization type has problems in terms of clinical operability, such as rapid curing and short operation time. One paste type composition using a photopolymerization initiator is known as an attempt to obtain a dental composition free of such drawbacks, but mechanical strength,
It has been difficult to obtain a composition that is excellent in both low shrinkage and clinical operability.

<Means for Solving the Problems> As a result of repeated research in order to obtain a dental composition free from the above-mentioned drawbacks, the present inventors discovered that an ethylenically unsaturated compound, fine inorganic filler particles and , a photopolymerization initiator, and the following general formula (11% formula% (1) (however, Ro is hydrogen or a methyl group, R2 is a carbon number of 1 to
represents an alkyl group of 4 or a phenyl group, and n is an integer of 1 to 15. A one-paste type photocurable dental composition comprising a copolymer (B) obtained by copolymerizing the unsaturated monomer (A) shown in ) and fine organic filler particles (C). I will provide a.

The present invention will be explained in more detail below.

As the ethylenically unsaturated compound used in the present invention, all ethylenically unsaturated compounds conventionally used in dental compositions can be used; examples thereof include methacrylic acid derivatives such as methyl methacrylate, 2-
Hydroxyethyl methacrylate, neopentyl glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanethiol dimethacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, propylene Glycol dimethacrylate, dipropylene glycol dimethacrylate, tripropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, tetramethylolmethane trimethacrylate, tetramethylolmethanetetramethacrylate, 2,2-bis(4-methacryloxyphenyl)propane, 2,2 -bis(4-methacryloxyethoxyphenyl)propane, 2,2-bis(4-methacryloxypolyethoxyphenyl)propane, 2,2-bis(4-
(3-methacryloxy-2-hydroxypropoxy)phenyl]propane, 1,2-bis(3-methacryloxy-2-hydroxypropoxy)ethane, 2,2-bis(
4-methacryloxyphenyl)propane, 2-hydroxy-1,3-dimethacryloxypropane, di-2-methacryloxyethyl-2,2,4-trimethylhexamethylene dicarbamate, 2-hydroxy-3-phenoxypropyl methacrylate , 2-hydroxy-3-pt
-butylphenoxypropyl methacrylate, methacryloxyethylphenylphosphorin acid, 4-methacryloxyethyl trimellitate anhydride, and the like. In addition, acrylic acid derivatives, styrene and its derivatives, maleic acid derivatives, fumaric acid derivatives, etc. can also be used in the present invention. Furthermore, polymerizable oligomers having (meth)acrylate groups, maleate groups, fumarate groups, allyl groups, etc. can also be used in the present invention.

As the fine inorganic filler particles used in the present invention, any metal oxide preferably having a particle size of 1 to Loomμ can be used, but in particular dimethyldichlorosilane, hexamethyldisilazane, octyltrimethoxysilane ,
Silica that has been hydrophobized with a treatment agent such as silicone oil is transparent to light.

Preferable in terms of water resistance and thixatropy.

The copolymer (B) used in the present invention has the general formula (
All copolymers of the unsaturated monomer (A) shown in 1) can be used, but copolymers with (meth)acrylic acid esters are particularly effective in improving mechanical strength, low shrinkage, and clinical operability. Are better.

Specific examples of the unsaturated monomer (A) represented by general formula (1) include methoxyethyl (meth)acrylate, phenoxyethyloxyethyl (meth)acrylate, methoxydiethylene glycol (meth)acrylate, methoxytetraethylene glycol ( meth)acrylate, isobutoxytetraethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, isopropoxypolyethylene glycol (meth)acrylate, isobutoxypolyethylene glycol (meth)acrylate, phenoxypolyethylene The copolymer (B) of the present invention includes the unsaturated monomer (A) and methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, etc. It can be obtained by copolymerization with a (meth)acrylic acid ester such as acrylate, but as a polymerization method, usual solution polymerization, suspension polymerization, emulsion polymerization, etc. using a radical polymerization initiator are preferred for commercial use. Moreover, the molecular weight of the copolymer (B) of the present invention is
From the viewpoint of solubility and low tackiness, the range is preferably 10,000 to 500,000.

As the fine organic filler particles (C) used in the present invention, any material can be used as long as it has excellent transparency and low solubility in the ethylenically unsaturated monomer, but it is particularly suitable for dental use. A polymer comprising methyl methacrylate units is
Preferable in terms of transparency, safety, and stability. As a method for producing the fine organic filler particles (C) of the present invention, suspension polymerization using a common radical polymerization initiator, emulsion polymerization, etc. are preferable for commercial use. In addition, from the viewpoint of low adhesiveness and stability, the molecular weight is 50,000 or more, and the methyl methacrylate unit is 80% by weight.
As mentioned above, particles with a particle size of 100 μm or less are preferable. Furthermore, particles cross-linked with a crosslinking agent such as diethylene glycol dimethacrylate or trimethylolpropane trimethacrylate are excellent in terms of particle stability.

As the photopolymerization initiator used in the present invention, for example, benzophenone, benzoin alkyl ether, etc. can be used for ultraviolet curing. Furthermore, for light having a wavelength of 350 to 450 nm, benzophenone group-containing polyhydric peroxyesters represented by the following general formula (II) can be used.

0 0...(II) (However, R
,, R2' are each a tertiary alkyl group having 4 to 8 carbon atoms or a tertiary aralkyl group having 9 to 12 carbon atoms, R2, R
, 'represent a hydrogen atom, a tertiary alkoxy group having 4 to 8 carbon atoms, or a 37th alkyloxy group having 9 to 12 carbon atoms, respectively. ) Specific examples of the benzophenone group-containing polyhydric peroxyesters represented by the general formula (n) include 3.3', 4.4'-tetra-(t-butylperoxycarbonyl)benzophenone, and 3.3'.

4.4'-tetra-(t-amylperoxycarbonyl)benzophenone, 3.3',4.4'-tetra(
t-hexylperoxycarbonyl)benzophenone,
3,3', 4,4'-tetra(t-octylperoxycarbonyl)benzophenone, 3,3', 4,4'
-tetra(cumylperoxycarbonyl)benzophenone, 3.3', 4゜4'-tetra(p-isopropylcumylperoxycarbonyl)benzophenone, carbonyl-bis-(mono-t-butylperoxyphthalate), carbonyl-bis- (mono-t-hexyl peroxyphthalade), etc.

Furthermore, for curing with visible light of 400 nm or more, a photopolymerization initiator that is a combination of an organic peroxide and a pyrylium salt or a thiopyrylium salt represented by the general formula (Ill) can be used.

(However, R, R2 and R are each hydrogen atom, halogen, alkyl group, haloalkyl group, ethylenyl group, styryl group, alkoxy group, phenyl group, naphthyl group, alkylphenyl group, alkoxyphenyl group, hydroxyphenyl group) (Y represents an anionic functional group) Specific examples of the organic peroxide of the present invention include benzophenone group-containing polyhydric peroxyesters represented by the general formula (n) above. Furthermore, methyl ethyl ketone peroxide, acetylacetone peroxide, tertiary butyl hydroperoxide, diisopropylbenzene hydroperoxide, tertiary butyl cumyl peroxide, acetyl peroxide, benzoyl peroxide, tertiary butyl peroxybenzoate, ditertiary butyl peroxy isophthalate. , tritertiary butyl peroxytrimellitate, etc. can also be used.

Specific examples of the compound represented by the general formula (m) include 4-(4-butoxyphenyl)-2゜6-bis(4-
methoxyphenyl)pyrylium verchlorate, 4-(
Examples include 4-butoxyphenyl)-2,6-cyphenylthiopyrylium fluoroborate and 4-(4-butoxyphenyl)-2,6-bis(4-methoxyphenyl)thiopyrylium fluoroborate.

Further, a photopolymerization initiator formed by combining a benzophenone group-containing polyhydric peroxyester represented by the general formula (Il) with α-diketones can also be used for curing with visible light of 400 nm or more. Examples of α-diketones include acenaphthenequinone, 9,10-phenanthrenequinone, camphorquinone, and β-naphthoquinone.

Photopolymerization initiators using α-diketones in combination with a reducing agent are also available.
Can be used for visible light curing of 0 nm or more.

Examples of reducing agents include amines and barbic acid derivatives.

The dental composition of the present invention contains 20 to 70 parts by weight of one or more of the ethylenically unsaturated compounds, 10 to 50 parts by weight of one or more of the fine inorganic filler particles, and 10 to 50 parts by weight of one or more of the fine inorganic filler particles. 10 to 10 types of filler particles (C) or two or more types of filler particles (C)
40 parts by weight, one or more copolymers (B) 0
．． Preferably, it contains 1 to 20 parts by weight as an active ingredient.

Outside this range, the paste becomes sticky, has low viscosity and lacks shape stability, or does not form into a paste state, which is undesirable. Further, as a polymerization initiator, it is desirable to contain 0.01 to 5 parts by weight of one or more of the above-mentioned photopolymerization initiators as an active ingredient; less than 0.01 parts by weight will not cure sufficiently; If it exceeds 1 part by weight, it is not preferable because it may not dissolve in the composition or the physical properties of the cured product may deteriorate.

The dental composition of the present invention may optionally contain, in addition to the fine inorganic filler particles, soda glass, quartz, silica gel, borosilicate glass, alumina, and radioactive opaque fillers such as barium oxide and zirconium glass. It may be used in addition. These fillers may also be spherical, pulverulent, platelets, fibers, whiskers, or have an irregular shape. Furthermore, if necessary, in addition to the above ingredients, polymerization inhibitors, antioxidants, stabilizers, pigments,
A dye or the like may be added as appropriate.

The dental composition of the present invention contains a photopolymerization initiator, and can be polymerized and cured by irradiation with ultraviolet light or visible light. Such light sources include mercury lamps, fluorescent lamps, xenon lamps, halogen lamps, tungsten lamps, and lasers.

The dental composition of the present invention is mixed in advance into one paste by a supplier, and supplied to doctors and dental technicians in a light-shielded container. After a doctor or a dental technician applies, fills or molds the dental composition of the present invention, it can be polymerized and cured using light emitted from an irradiator.

<Effects of the Invention> The dental composition of the present invention is a one-paste type photocurable dental composition containing a photopolymerization initiator, and contains a specific copolymer CB) and an inorganic and organic filler. Because of this, it has excellent clinical operability, and the cured product also has excellent mechanical strength and low shrinkage.

<Example> The present invention will be explained in more detail below with reference to Production Examples, Examples, and Comparative Examples. These examples are provided for illustrative purposes and are not intended to limit the invention in any way.

Example of production of copolymer (B) Methoxydiethylene glycol monomethacrylate 50
Parts by weight, 40 parts by weight of methyl methacrylate, 10 parts by weight of methoxytetraethylene glycol monomethacrylate by a normal solution polymerization method using 2,2-azobisisobutyronitrile as a polymerization initiator and benzene as a solvent. Synthesized. Further, the mixture was precipitated with petroleum ether to obtain a solid copolymer (B)-1. (B)-1
The weight average molecular weight as determined by GPC method was 150,000. Similarly, copolymer (B)-2 was synthesized with a composition ratio of 60 parts by weight of methyl methacrylate, 20 parts by weight of methoxypolyethylene glycol monomethacrylate (n=9), 15 parts by weight of isobutoxydiethylene glycol monomethacrylate, and 5 parts by weight of butyl methacrylate. did. The weight average molecular weight was 100,000.

Production example of fine organic filler particles (C) 95 parts by weight of methyl methacrylate, 3 parts by weight of butyl methacrylate
Polymer particles were obtained by a conventional suspension polymerization method using poval, calcium carbonate, and sodium dodecylbenzenesulfonate as dispersants and benzoyl peroxide as a polymerization initiator in a composition ratio of parts by weight. This was fractionated by sedimentation and dispersion, and particles of 50 μm or less were collected and designated as fine organic filler particles (C)-1. Similarly, fine organic filler particles (C)-2 having a particle size of 20 μm or less were obtained with a composition ratio of 95 parts by weight of methyl methacrylate, 3 parts by weight of butyl methacrylate, and 2 parts by weight of diethylene glycol dimethacrylate.

A predetermined photopolymerization initiator and copolymer (B) were dissolved in an ethylenically unsaturated compound at the composition ratio shown in Table 1.This solution was charged into a kneader and finely divided. Inorganic filler particles and fine organic filler particles (C) were gradually added and kneaded at normal pressure for 2 hours.The mixture was further kneaded for 2 hours under reduced pressure to 2 Q mmHg or less while defoaming to obtain a paste.

A paste having the composition ratio shown in Example Table 1 was irradiated with light for a predetermined period of time using an irradiator equipped with four halogen lamps (150 W) to obtain a cured product. The impact strength, bending strength, and polymerization shrinkage rate of the cured product were measured by the following methods.

The tackiness of the paste surface was measured by finger touch.

(Impact strength) Cellophane is lined in a designated stainless steel mold, and the paste is press-fitted onto it. Place cellophane on top of the paste and press a slide glass to make the paste surface even and flat. Remove the glass slide and shine light from the top for 10 minutes.
Irradiate for several minutes to fully cure. The cured product was taken out of the mold and ground into a flat plate with a length of 1.5 cm, a width of 10 cm, and a thickness of 3 am, which was used as a test specimen. An impact test was conducted 24 hours after the paste was photopolymerized. The test was carried out using a Dynstat tester, and the impact strength was the average value of five test specimens, and the results are shown in Table 2.

(bending strength) A cured product was obtained using the same procedure as for the impact strength described above.

This was ground into a flat plate with a length of 60IIfi, a width of 10m, and a thickness of 2.5mm, which was used as a test specimen. The paste was photopolymerized and then flexurally tested 24 hours later. The distance between the fulcrums of the test specimen was 50 m, and measurements were taken at a crosshead speed of 2 mm/min using a bending test device attached to an autograph.

The bending strength was determined using the following formula.

FI Bending strength kg/ci)=- 2bd.

However, F: Maximum stress applied to the test specimen ■: Distance between fulcrums b: Width of the test specimen d: Thickness of the test specimen The average value of the five specimens is taken as the bending strength, and the results are shown in Table 2. Ta.

(Polymerization Shrinkage Rate) The density of the cured product cured by the same procedure as the paste and impact strength described above was measured by an underwater displacement method using pure water at 23° C., and the polymerization shrinkage rate was determined by a linear equation.

α = (1p force x 100 (%)) However, ρ: Density of paste ρF: Density of cured product (comparative example) The compositions shown in Table 1 were tested in the same manner as in the examples. It is shown in Table-2.

It is clear from the Examples and Comparative Examples that the polymerization shrinkage rate is effectively reduced by containing the fine organic filler particles (C). On the other hand, when the valve polymer (B) is not contained, the impact strength and bending strength are significantly reduced, but when the copolymer (B)
It is clear that impact strength and bending strength are improved by containing. Furthermore, it is clear from the evaluation of the adhesiveness of the paste that the composition of the present invention is excellent in mechanical strength, low shrinkage, and clinical operability.

(Margin below) ← one idea ;”t　　　　　　A Reality peeling

Claims (1)

[Claims] 1) Ethylenically unsaturated compound, fine inorganic filler particles, photopolymerization initiator, and the following general formula [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼... [I] ( However, R_1 represents hydrogen or a methyl group, R_2 represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, and n represents 1
is an integer from 15 to 15. A one-paste type photocurable dental composition comprising a copolymer (B) obtained by copolymerizing the unsaturated monomer (A) shown in ) and fine organic filler particles (C). . 2) The dental composition according to claim 1, wherein the fine organic filler particles (C) are a polymer having a particle size of 100 μm or less and containing 80% by weight or more of methyl methacrylate units. thing. 3) The dental composition according to claim 1 or 2, wherein the copolymer (B) is a copolymer of an unsaturated monomer (A) and a (meth)acrylic ester. 4) Claim 1, wherein the fine inorganic filler particles are hydrophobized silica having a particle size of 1 to 100 mμ.
The dental composition according to item 1, 2 or 3. 5) 20 to 70 parts by weight of one or more of the ethylenically unsaturated compounds, 10 to 50 parts by weight of one or more of the fine inorganic filler particles, and the fine organic filler particles (C ) 10 to 40 parts by weight of one or more of the above photopolymerization initiators, 0.01 to 5 parts by weight of one or more of the photopolymerization initiators,
One or more of the copolymers (B) is 0.1 to 20
The dental composition according to claim 1, 2, 3 or 4, comprising parts by weight.