DE2751057C2 - Use of photopolymerizable compositions for dental coating compositions or dental restoration compositions - Google Patents

Description

2. Use according to claim 1, characterized in that the monomer resin a) consists of bis-GMA consists.

3. Use according to claim 1, characterized in that the diluent monomer bj ^ ds a consists of mono-, di- or trifunctional acrylate or methacrylate, in particular of 1,6-hexanediacryate.

4. Use according to claim 1, characterized in that the initiator c) consists of an α-diketone or a derivative thereof, in particular of benzil.

5. Use according to one of the preceding claims, characterized in that the accelerator d) consists of an amine, in particular a tertiary atom.

6. Use according to claim 5, characterized in that the tertiary amine from trihexylamine consists.

The invention relates to the use of certain compositions for photopolymerizable one-component dental coating compositions or one-component dental restoration compositions.

X, Photopolymerizable dental compositions used in dentistry generally contain thermosetting acrylic esters of bisphenol compounds, an acrylic monomer as a diluent and a combination of a photopolymerization initiator and an accelerator. Compositions of this type are usually two-component systems. In US-PS 37 09 866 such a system described in which a component containing the initiator is kept separate from the rest of the mass.

The two components are used by the dentist in a defined ratio immediately before use mixed. This procedure is necessary in order to allow sufficient storage time for such dental materials enable. Homogeneity in such a mixture is almost impossible if there is a drop of initiator is mixed with an almost solid-like composite material. If not a homogeneous mixture is obtained, it may lead to irregularities within the restored part. According to US Pat. No. 3,759,807, a combination of an organic carbonyl compound and an amine, in particular a combination of benzophenone and a tertiary amine, is used as an initiator or accelerator. Although these compositions are photopolymerizable, they cannot be used as guide materials for tooth cavities due to their slow hardening. Composite Dental Systems That contain a derivative of the diglycidyl ether of bisphenol A, an acrylic binder and a filler, were already crosslinked according to US-PS 35 39 533 with benzoyl peroxide or another suitable catalyst. It was found, however, that they have a pressure resistance of only 1830 kg / cm ² (cf. column 5, line 64). The currently available composite dental materials are still systems of two phases, ie paste-paste, paste-liquid, liquid-liquid or powder-liquid. The two phases are brought together and mixed according to certain proportions.- The properties of the End product depend on how well and how quickly the mixing is carried out. When mixing of the two phases, air is incorporated into the compounds, which acts as a polymerization inhibitor. It forms mechanical casting scars in the restoration material. Furthermore, the material is slow to harden. Furthermore, the non-uniformity of mixing can degrade the quality of the fillings. From GB-PS 14 08 265 are photopolymerizable one-component compositions made of a monomer resin, a diluent monomer, an initiator and an accelerator known to be used for production of photopolymerizable films or foils should be suitable. A reference to dental materials will be the However, expert not mediated.

It is the object of the invention to specify the use of compounds for a one-component dental compound which has a sufficiently long shelf life and in particular also by means of light with a wavelength of more than 320 nm is photopolymerizable with the shortest possible curing times while achieving a high compressive strength.

Furthermore, the dental compound should be usable as a restoration compound or tooth filling compound by means of a filler additive which is impermeable to X-rays and which also has a high filler content Enables the greatest possible hardening depth. When using the dental compound as a coating compound, a good adhesion when closing holes and cracks, as well as when used for lining of cavities can be achieved.

According to the invention, this object is achieved by the subject matter of claim 1. Advantageous further developments of the invention are the subject of the subclaims.

Particular advantages of the invention are to be seen in the fact that the use of such a one-component mass eliminates the difficulties that resulted from the previously required mixing of the two components of known two-component dental masses, and that the photopolymerization not only under Use of UV light, but also with the help of irradiation with light in a wavelength range between 360 and 450 nm is feasible.

The compositions to be used according to the invention typically contain a monomer resin, which contains unsaturated sites which can undergo polymerization, a diluent monomer in order to control the viscosity of the resin, in the case of dental restorative compositions a filler or a combination of fillers, and an initiator which delivers free radicals when exposed to actinic radiation, which then react with the double bond of the monomer to initiate the polymerization, and an accelerator that increases the rate of photoreaction of the mass. The resin that is used to make this single paste may differ from the reaction of diglycidyl ethers of bisphenol A with Derive methacrylic acid or acrylic acid:

HH CH ₃ HH CH ₃

I I 'I

-OCC - CH 2CH ₂ + ₂ = C-COOH

H ₂ C CCO- <f> -C

N /

H ^ CO HHH CH ₃ HHHO CH ₃

Ί »Mi ^ -χ Ι ^^ ill IM

CH ₂ = CC-OC-CCO- ^ / ~ ^c ~ \ yO-CCCO- CC = CH ₂ H CH ₃ H

H 25

OH OH

This glycidyl methacrylate derivative of bisphenol A is known as bisphenol A bis (3-methacrylate-2-hydroxypropyl) ether. The resin serves as a binder for the photopolymerizable dental material. It is hereinafter referred to as Bis-GMA. Modifications of this resin can also be used.

The diluent monomers used can be selected from the group consisting of alkyl methacrylates, alkylene dimethacrylates, Trimethacrylates, aticylacrylates, alkylene diacrylates and triacrylates can be selected. Some suitable monomers are e.g. B. the following:

"Methyl methacrylate

Ethyl methacrylate butyl methacrylate n-propy 1 m ethacry lat Isopropyl methacrylate

lp-butylene dimethacrylate

Ethylene glycol monomethacrylate Ethylene glycol dimethacrylate Triethylene glycol dimethacrylate 1,6-Hexangly kold iacry lat

Tetraethylene glycol diacrylate Tetramethylene glycol dimethacrylate etc.

One or more of these monomers can be used. The diluent monomers copolymerize with the Bis-GMA resin upon exposure to actinic light in the presence of a photoinitiator and an accelerator. The accelerator increases di? Speed of response. so

Another component that is present in the bulk is a polymerization inhibitor, which is the premature Polymerization of the Bis-GMA resin and the diluent monomer prevented. It is only available in small quantities. Suitable polymerization inhibitors are hydroquinone (HQ), methyl ethers of hydroquinone (MEHQ), butylated hydroxytoluene (BHT) and triphenylstyrene.

Photoinitiators are generally photosensitive carbonyl compounds. The initiators used according to the invention are α-diketones and their derivatives with the following general formula:

R-COCO-R '

wherein R and R ', which can be the same or different, mean aliphatic or aromatic groups and their derivatives. Examples of such connections are:

CH ₃ COCOCH ₃ biacetyl CH ₃ COCOCH ₂ CH ₃ 2,3-pentanedione C ₆ H ₅ COCOC ₆ H ₅ benzil CH ₃ OC ₆ H ₄ COCOC ₆ H ₁ OCh., 4,4'-dimethoxybencil

(C ₆ H ₅ COCOC ₆ Hj) ₂ O 4.4'-oxydibenzil

These photoinitiators are slightly yellow in color. Since they are present in small amounts, it is polymerized End product almost colorless.

Photo accelerators are chemical compounds that, in the presence of initiators, trigger the photo reaction

accelerate. The accelerators help the polymerization penetrate a recovery, which has been placed in a preparation of a deep cavity The accelerators are amines (primary, secondary and tertiary) and diamines. Some examples are dimethylparatoluidine, Ν, Ν'-dimethylbenzylamine, N-methyldibutylamine, triethylamine, trihexylamine, etc. Examples of suitable diamines are Ν, Ν, Ν ', Ν'-tetraethylethylenediamine and N, N, N ', N'-tetramethyl-1,6-hexanediamine.

In the absence of the aforementioned photoinitiators, these amines do not induce photopolymerization.

Although all amines in combination with the above-mentioned photoinitiators to a certain extent Accelerate extent, it has been found that the tertiary amines (e.g. triethylamine, trihexylamine, etc.) the best are to effect polymerization deep into the composite. Amines with aromatic Groups are not appropriate as they will have a slight coloration after prolonged exposure result.

When benzophenone and amine combinations that are known are used in the Bis-GMA system, then either they do not cause the polymerization or they cure only slowly. It was found that the Unique combination of an a-diketone as a photoinitiator with an amine as a polymerization accelerator and the use of actinic radiation as an activator creates a filling with high compressive strength results.

The photopolymerizable dental restorative composition can contain up to 85% refractory filler.

At least 25% of the filler consists of barium aluminum silicate, although 100 "can also be used. The presence of this filler gives the reconstituted material the properties of sufficient radiopacity to contrast with the bone tissue, provided that the product contains a minimum of 6.5% barium oxide. The other filler can be lithium aluminum silicate. The particle size distribution of these fillers varies from less than 5 to about 40 µm. These fillers must be silanized, ie to increase the bond between the inorganic filler and the organic matrix material. The silane binding agents have the general formula RSiX ₃ , R ₂ SiX ₂ and R ₃ SiX, where X is halogen, alkoxy or hydroxy and R is vinyl, methacrylate, allyl, methallyl, itaconate, maleate, acrylate, itaconate, maleate acrylate aconitrate, fumarate, alkyl, aryl, alkenylcrontonate, cinnamate and citraconate, sorbate or glyridyl. When the silanization is complete, a monomolecular coating of the binder is present on the filler surface, which improves the adhesion between the filler and the resin matrix. Many other suitable fillers, such as quartz and alumina, could also be used.
The dental restorative used in the present invention is polymerized by exposure to an energy source that activates a photoreaction. The source of this actinic radiation can be a known ultraviolet diagnostic lamp, e.g. B. a high pressure mercury vapor lamp with 100 W and a wavelength range between 320 and 420 nm, which is cooled by a fan. An average amount of the mass of 0.2 to 0.3 g polymerizes completely on irradiation for 20 to 30 seconds when the mass is arranged at a distance of about 10 cm from the lamp. Under these conditions, the material polymerized to a depth of about 2 mm in tests carried out.
There are examples with various ingredients in the following. Area carried out:

Parts by weight
_4J resin (including the inhibitor) 10 to 25

Diluent monomer (including the inhibitor) 2 to 5

ff-diketone or its derivative 0.001 to 1

Amine 0.01 to 2

Filler 70 to 85

The mixed material is made as follows:

The resin is mixed with the diluent monomer, photoinitiator and accelerator. The ingredients are mixed well in a glass jar. If the mixture is fairly uniform, then barium aluminum silicate is added and mixed well with it. Finally, add the remainder of the filler in three or four additions and mix well with it. The mixture is allowed to stand for a week before the test. The well mixed heavy paste is placed in a cylindrical polytetrafluoroethylene mold with a height of 12.5 mm and a diameter of 6 mm, which is open at both ends. The top and bottom are covered with polyester film and pressed to get a smooth surface. The ends covered with the foil are exposed to the light of the lamp at a distance of approx. 10 cm. The mold is then opened and each side of the sample is exposed to actinic radiation for 15 seconds. The total exposure time is 1 minute and the polymerized mixed product is tested after aging for 10 minutes. It has a strength of around 1898 to 2320 kg / cm ² . The strength increases to 2812 kg / cm ² when the cured sample is aged for two weeks. After prolonged aging, the strength reaches values of up to

to 3163 kg / cm ² .

Example I.

Wt%

Bis-GMA resin (including 200 ppm MEHQ) 18

Methyl methacrylate (including 100 ppm MEHQ) 3 ^?

4,4'-oxydibenzil 0.2

Trihexylamine 0.2

Barium aluminum silicate 23

Lithium aluminum silicate 55.6

This composite product was made according to the method described above. After exposure, the strength of the polymerized material was determined. After half a minute of exposure, the material reached a strength of 1757 kg / cm ² . After 1 minute exposure the strength was 2109 υ kg / cm ² and after 5 minutes exposure it was 2580 kg / cm ² .

Example 2

Wt% 20

Bis-GMA resin (including 200 ppm MEHQ) 18

1,3-butylene dimethacrylate (50 ppm MEHQ) 3

4,4'-dimethoxybenzil 0.08

N-methyldibutylamine 0.2 25

Barium aluminum silicate 23

Lithium aluminum silicate 55.72

The strength of this mixed product was measured as described above. After exposure for 30 minutes, it was found that the strength was 2109 kg / cm ² .

Example 3

Wt% 35

Bis-GMA resin (including 200 ppm MEHQ) 18 Triäihvlenalvkokiime'haTviii · 'rci · Pine ^ hinR vnn lflfl nnm
MEHQ) 3

Benzil 0.08 40

N-methyldibutylamine 0.2

Barium aluminum silicate 23

Lithium aluminum silicate 55.72

The strength of the polymerized material after exposure over a total period of 1 minute is 2074 kg / cm ² .

Example 4

In Example 3, the diluent monomer is replaced by the same amount of 2-ethylhexyl acrylate. D ^: ~ measured strength after exposure for one minute is 2250 kg / cm ² . In general, the acrylate monomers are more reactive than the methacrylate and dimethacrylate monomers.

Example 5 55

Wt%

Bis-GMA resin (including 200 ppm MEHQ) 18

Methyl methacrylate (including 100 ppm MEHQ) 3 _M

Benzophenone 0.4

Triethylamine 0.4

Barium aluminum silicate - 23

Lithium aluminum silicate 55.2 ₆₅

No hardening of this mixture was found after 4 minutes of exposure

Example 6

Example 5 was repeated with benzil instead of benzophynone. As usual, the mixed product was packed in a 1.27 cm mold and exposed to the lamp for a total of 1 minute. The strength of the polymerized material is 2320 kg / cm ² .

Example 7

Example 5 was _{repeated with diphenyltriketone C 6} H ₅ COCOCOC ₆ H ₅ instead of benzophenone. After one minute of exposure, the strength is only 520 kg / cm ² .

Example 8

Wt%

¹⁵ Bis-GMA resin (including 200 ppm MEHQ) 18

Methyl methacrylate (including 100 ppm MEHQ) 3

4,4'-oxydibenzil 0.05

Tetraethylethylenediamine 0.09

²⁰ burium aluminum silicate? 3

Lithium aluminum silicate 55.86

A diamine is used in this example. The strength of the polymerized material after exposure over a total period of 1 minute is 2109 kg / cm ² .

Example 9

Wt%

- '° Bis-GMA resin (including 200 ppm MEHQ) 18

Methyl methacrylate (including 100 ppm MEHQ) 3

4,4'-oxydibenzii 0.2

Diisopropylamine 0.2

³⁵ barium aluminum silicate 23

Lithium aluminum silicate 55.6

In this case a secondary amine is used. After mixing, the mixed product is turned into a

40 packaged as described above with the dimensions 12.5 mm x 6 mm. The ones covered with foil The ends are exposed for 15 seconds each. When the mold was opened the specimen was broken in the middle, which also indicated that the reaction was slow. Therefore, the ends covered with the film became 30 each exposed for a long time. After opening the mold without damaging the size and shape of the specimen, each side was exposed for a further 30 seconds. The total exposure time was therefore 2 minutes.

45 speed under these conditions was 1828 kg / cm ² .

. Example 10

Example 9 was repeated with a primary amine, namely n-butylamine. The strength after exposure for 2 minutes to 50 minutes is 1125 kg / cm ² . It follows that the tertiary amine is the most suitable amine.

Example 11

55 A different form of resin is used in this example. The glycidyl ether of bisphenol A is reacted with ice-acrylic acid. The reaction product, namely bisphenol-A-bis- (3-acrylato-2-hydroxypropyl> ether, is used to make the mixed product.

% ^{By weight 60} bisphenol-A-bis- (3-acrylato-2-hydroxypropyl) -ether (with

Inclusion of 100 ppm MEHQ) 18

1,6-hexanediol diacrylate (including 200 ppm HQ) 3

Benzil 0.08

65 Trihexylamine 0.2

Barium aluminum silicate 23

Lithium aluminum silicate 55.72

This mixed product was examined in the same manner as above. After exposure for a total of 1 minute, a material with a pressure or bursting strength of 2214 kg / cm ^{2 was} obtained.

Example 12

Wt%

Bis-GMA resin (including 200 ppm MEIIQ) 23.9

1,6-hexanol diacrylate (including 200 ppm HQ) 3.9

Benzil 0.1

Trihexylamine 0.26

Silica 72.34

The compressive strength of this composite product after exposure over a total period of <> 1 min is 1898 kg / cm ² .
The most suitable formulation for a dental filling material is given below:

Bis-GMA resin (including 200 ppm MEHQ) 18- °

1,6-hexanediol diacrylate (including 100 ppm MEHQ) 2.8

Benzil 0.08

Trihexylamine 0.2

Barium aluminum silicate 23 * ^;

Lithium aluminum silicate 55.82

2.27 kg of the above mixture was prepared using a mechanical stirrer and tested in the manner described above. The polymerized material was found to have a compressive strength of 2250 kg / cm ² after exposure for a total of 1 minute.

The composite product made by the best method has been used in the dark for over 3 years aged long at room temperature and retested. The hardening and strength properties of the fresh Materials could be achieved. This confirms the long shelf life of the product.

Since the dentist can use the composite product without any additions or mixing measures, reconstitutions that are essentially free of entrapped air bubbles are possible. This eliminates a large amount of mechanical defects and improves the final appearance of the restoration by obtaining a smoother solid surface. A smooth surface is less prone to staining and bacterial build-up, and it gives the tongue a smoother feel. AO

Radiation with a wavelength of 297 to 320 nm can cause cutaneous sunburn and c'rinogenesis induce. This:? Long volume is responsible for "phototoxic reactions". The polymerization reaction was repeated completely up to 320 nm after filtering the radiation. There was no change the strength of the polymer is observed.

By inserting various optical filters between the lamp and the material, it was found that the most efficient polymerization with light from 400 to 450 nm, i.e. H. in the visible area.

The curing test was repeated with a tungsten halogen lamp, a source of visible light. That Light was focused onto the material through a 0.15 meter long fiber ribbon. It was found that the Material hardened more effectively with the tungsten halogen lamp than with the mercury lamp.

In addition to the composite restorative material, the present invention results in the manufacture provision of single-phase (in contrast to the known two-phase systems) hole and crack sealants, Bonding agents, lining agents of the cavities and restoration glazes, all under The collective term coating compounds are summarized. All of these masses are contained in the essentially a photopolymerizable aromatic resin such as Bis-GMA, a diluent monomer such as Methacrylate, dimethacrylate, acrylate or diacrylate, a photoinitiator and an accelerator. These dental crowds differ from the restoration materials mentioned above in that they do not contain any Contain fillers or have reduced filler contents. These masses polymerize in the Oral environment by applying actinic radiation.

The hole and crack sealant, the lining agent for cavities, the glaze material or the Binders generally contain 70 to 80% by weight of Bis-GMA resin, 30 to 20% of methyl methacrylate, inhibited with 100 ppm MEHQ, 0.01 to 1% photoinitiator and 0.01 to 1% accelerator.

The best formulation is:

Bis-GMA resin (inhibited with 200 ppm MEHQ) 75 parts

Methyl methacrylate (inhibited with 100 ppm MEHQ) 25 parts.

Benzil 0.5 part

Trihexylamine 0.5 part

This unfilled mixture can be used as a hole sealant, sealant, binder, lining agent Voids and restorative glaze material can be used. Although any other Methacrylate, acrylate, dimethacrylate, diacrylate or triacrylate as a diluting monomer for the above preparation can be used, that preparation with methyl methacrylate has the best property as Thin film. The amount of methyl methacrylate could be varied to adjust the viscosity of the mixture. This one-component sealing system has a shelf life in airtight and lightfast bottles from 1 year.

The formulas can be varied, increasing the amount of diluent increasing the viscosity reduced. Increasing the amount of filler increases the strength, but thickens the paste. The strength is also increased by increasing the amount of benzil. Too much benzil should be avoided, however it gives a yellow color and can cause polymerization when exposed to incident light will. The described initiator and accelerator combination can be used for photopolymerization A variety of monomer resins can be used.

The dental material according to the invention therefore gives the dentist the ability to use visible light effectively to use to polymerize the material, reducing the potential risk of using ultraviolet rays (See Journal of American Dental Association, Vol. 92, April 1976).

Claims (1)

Patent claims: 1. Use a mass off a) a monomer resin b) a diluent monomer c) an initiator d) an accelerator ίο for photopolymerizable one-component dental coating compounds or with the addition of e) Barium and / or lithium aluminum silicate as a filler for one-component dental restoration materials.