DE2751057A1 - PHOTOPOLYMERIZABLE DENTAL RESTORATIVE MATERIAL - Google Patents

Description

DIPL.-PHYS. F. FINALLY - ο-βο34 unterpfaffenhokn Nov. 15, 1977

PATENT LAWYER O P.O. Box

(MUNICH) 84 36 38

DlPL-PHYS. f. FINALLY, D-8O34 UNTERPFAFFENHOFEN, POSTBOX

TELEX: 52 173Ο

S-4330

Sybron Corporation
Rochester, NY, USA

Photopolymerizable dental restorative material

The invention relates to photopolymerizable compositions and in particular to those used in dentistry.

Photopolymerizable compositions used in dentistry generally contain thermosetting acrylic esters of bisphenol compounds, an acrylic monomer as a diluent, and a combination of a photopolyraerization initiator and an accelerator. Compositions of this nature are generally two-part systems. In US-PS 3,709,866 such a system is described in which a component containing the initiator, is kept separate from the rest of the mass. The dentist uses a defined relationship between the two components just mixed before use. This procedure is necessary in order to achieve a certain for such dental materials Maintain storage time. Homogeneity in such a mixture is almost impossible if a drop of the

809821/0840

2 7 5 1 above

Initiator is mixed with an almost solid-like composite material. If a homogeneous mixture is not obtained, then this can 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 filling materials for tooth cavities because of their slow hardening. Composite dental systems containing a derivative of the diglycidyl ether of bisphenol A, an acrylic binder and a filler have already been crosslinked with benzoyl peroxide or another suitable catalyst in accordance with US Pat. No. 3,539,533. However, it was found 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 final product will depend on how well and how quickly the ^v mixing to be carried out. When the two phases are mixed, 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 only slow curing. Furthermore, the non-uniformity of mixing can degrade the quality of the fillings.

The object of the invention is therefore to provide a uniform, single-paste dental filling compound with a long storage time for

809821/0840

to provide the dentist before use needs to be mixed or activated by hand. The intended dental restorative material is intended to be a have high compressive strength. The invention is also intended to provide a new initiator and accelerator composition are made available for the photopolymerization of the acrylic esters. The invention is also intended to provide a dental connection be provided with rapid curing. Furthermore, the invention is intended to provide a system with greater depth of hardening, especially in highly filled and pigmented composite dental materials. Furthermore, the invention is intended to provide a Radiopaque dental material provided that can be cured by the application of actinic radiation.

Furthermore, the invention is intended to provide a one-component dental compound for use as a pitting and crack bonding agent, bonding agent, cavity lining agent, and restoration glaze to provide.

The invention now provides a composition which is a derivative of the diglycidyl ether of bisphenol A, an acrylic diluent, a filler, or a combination of fillers and a combination from an initiator accelerator containing an α-diketone and a tertiary amine.

In recent years, photopolymerizable compositions have been increasingly used as restoration materials Filling of tooth cavities has been used. Such compounds typically contain a monomer resin, which contains unsaturated sites that initiate polymerization

809821 / 08AO

can go, a diluent monomer, to increase the viscosity of the resin to control a filler or a Combination of fillers, an initiator that generates free radicals upon exposure to actinic radiation, the 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 elevated. The resin that is used to make this single paste can be derived from the reaction of the diglycidyl ether of bisphenol A with methacrylic acid or acrylic acid derive:

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 designated. Modifications of this resin can also be used.

The diluent monomers used can be selected from the group of alkyl methacrylates, alkylene dimethacrylates, trimethacrylates, Alkyl acrylates, alkylene diacrylates and triacrylates can be selected. Some suitable monomers are e.g. following:

809821/0840 BATH ORIGINAL

/ IO

Methyl methacrylate

Ethyl methacrylate

Butyl methacrylate

n-propyl methacrylate

Isopropyl methacrylate

1,3-butylene dimethacrylate

Ethylene glycol monomethacrylate

Ethylene glycol dimethacrylate

Triethylene glycol dimethacrylate

1,6 hexane glycol diacrylate

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. Of the
Accelerator increases the speed of the reaction.

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

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

R-COCO-R '

809821/0840

wherein R and R ¹ , which can be the same or different, denote 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

^ g ^^ j 4,4'-dimethoxybenzil (C ₆ H ₅ COCOC ₆ H ₅ ) ₂ O 4,4'-Oxydibenzll

These photoinitiators are slightly yellow in color. There if they are present in small amounts, the final polymerized product will be almost colorless.

Photo accelerators are chemical compounds that accelerate the photo reaction in the presence of initiators. The accelerators help the polymerization penetrate a reconstitute that has been placed in a deep cavity formulation. 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 N, N, N », N · -Tetraethylethylenediamine and N, N, N ·, N · -Tetramethyl-1,6-hexanediamine.

In the absence of the aforementioned photoinitiators, these amines do not induce photopolymerization. Although accelerate all amines in combination with the above photoinitiators to a certain extent, it has been found that the tertiary amines (e.g. triethylamine, trihexylamine, etc.) are the best for a Polymerizes deep into the composite mass

809821/0840

AZ

to effect. Amines with aromatic groups are not appropriate since they give a slight coloration after prolonged exposure.

If benzophenone and amine combinations, which are known, are used in Bis-GMA systems, then they do either do not polymerize or they cure slowly. It was found that the unique combination of a α-Diketons as a photoinitiator with an amine as a polymerization accelerator and the use of actinic Radiation as an activator results in a filling with high compressive strength.

The photopolymerizable dental restorative compound can contain up to Q5% refractory filler. At least 25% of the filler is barium aluminum silicate, although 100% can be used. The presence of this filler provides the reconstituted material with sufficient radiopacity to contrast with bone tissue, provided that the product contains a minimum of 6,596 barium oxide. The other filler could 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 in order to increase the bond between the inorganic filler and the organic matrix material. The silane binding agents have the general formula RSiX ,, RgSiX ₂ and R, 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 glycidyl. When the silanization is complete

809821/0840

is then a monomolecular coating of the binder present on the filler surface, which improves the adhesion between the filler and the resin matrix. It Many other suitable fillers such as quartz and alumina could also be used.

The dental restoration material according to the invention is polymerized by adding an activator, an energy source, which activates a photoreaction is exposed. The source of this actinic radiation according to the invention is one Ultraviolet diagnostic lamp manufactured by Blank Light Eastern, Westbury, Long Island, New York, known as Spectroline B-100 is designated. The Spectroline lamp B-100 is a high pressure mercury vapor lamp with 100 W with a beam length capacity of 3200 to 4200 Å-units. The light bulb used in this lamp is cooled by a fan. An average amount of the material polymerized for filling, i.e. 0.2-0.3 g of the material completely by irradiating the above lamp for 20 to 30 seconds when the material was about 10 cm from was kept away from the lamp. Under these conditions, the material polymerized to a depth of about 2 mm.

Examples were carried out with different components in the following area:

Parts by weight

Resin (including the inhibitor) 10 to 25

Diluent monomer (including the

Inhibitors) 2 to 5

α-diketone or its derivative 0.001 to

Amine 0.01 to

Filler 70 to 85

809821/0840

2751 over 7

The mixed material is made as follows:

The resin is mixed with the diluent monomer, the photoinitiator and the sizing agent. The ingredients are mixed well in a glass jar using a Teflon stick. When the mixture is fairly uniform, the barium aluminum silicate is added and mixed well with it. Finally, add the rest of the filler in three or four additions and mix well with it. The mixture is allowed to stand for a week before testing. The well mixed heavy paste is placed in a split cylindrical polytetrafluoroethylene mold 12.5 mm high and 6 mm in diameter, which is open at both ends. The top and bottom are covered with Mylar strips and pressed to get a smooth surface. The ends covered with Mylar are exposed to the light of the Spectroline-B-100 lamp from a distance of approx. 10 cm. The gap 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 when the cured sample is aged for two weeks. After prolonged aging, the strength reaches values of up to 3163 kg / cm.

example 1

Weight-96

Bis-GMA resin (with inclusion of 200 ppm

MEHQ) 18

Methyl methacrylate (including 100

ppm MEHQ) 3

809821/0840

4,4'-oxydibenzil 0.2

Trihexylamine 0.2

Barium aluminum silicate 23

Lithium aluminum silicate 55.6

This composite product was made by the method described above. After exposure to the Spectroline-B-100 lamp, the strength of the polymerized material was determined. After a half-minute exposure the material reached a strength of 1757

kg / cm. After 1 minute of exposure, the strength was found

ρ ρ

2109 kg / cm and after 5 minutes of exposure 2580 kg / cm. Example 2

Weight-96

Bis-GMA resin (including 200 ppm MEHQ) 1,3-butylene dimethacrylate (50 ppm MEHQ)

4.4 · dimethoxybenzil N-methyldibutylamine barium aluminum silicate lithium aluminum silicate

The strength of this mixed product became as above described, measured. After one minute of exposure to the Spectroline-B-100 lamp, it was found that the strength was 2109 kg / cm.

Example 3

Weight-96

18th 08 3 2 O, O, 72 23 55,

Bls-GMA resin (including 200 ppm MEHQ) 18

809821/0840

2751US7 from

Triethylene glycol dimethacrylate (incl

of 100 ppm MEHQ) 3

Benzil 0.08

N-methyldibutylamine 0.2

Barium aluminum silicate 23

Lithium aluminum silicate 55.72

The strength of the polymerized material after exposure with the Spectrollne-B-100 lamp for an entire period of 1 min is 2074 kg / cm.

Example 4

In Example 3, the diluent monomer is replaced by the same Replaced amount of 2-ethylhexyl acrylate. The measured strength after one minute of exposure to the Spectroline B 100 lamp is 2250 kg / cm. In general, the acrylate monomers are more reactive than the methacrylate and dimethacrylate monomers.

Example 5

Weight %

Bis-GMA resin (with inclusion of 200 ppm MEHQ) 18 methyl methacrylate (with inclusion of 100 ppm

MEHQ) 3

Benzophenone 0.4

Triethylamine 0.4

Barium aluminum silicate 23

Lithium aluminum silicate 55.2

After 4 minutes of exposure to the Spectroline B 100 lamp, no hardening of this mixture was found.

809821/0840

Example 6

Example 5 was repeated with BenzII instead of benzophenone. As usual, the mixed product was packaged in a 1.27 cm form and placed over a total of 1 min exposed to the Spectroline-B-100 lamp. The strength of the polymerized material is 2320 kg / cm.

Example 7

Example 5 was substituted with diphenyltriketone CgHcCOCOCOCgHc of benzophenone repeated. After one minute of exposure to the Spectroline-B-100 lamp, the strength is only 520 kg / cm.

Example 8

Wt-56

Bis-GMA resin (with inclusion of 200 ppm MEHQ) methyl methacrylate (with inclusion of 100 ppm

MEHQJ

4,4'-oxydibenzil tetraethylethylenediamine Barium aluminum silicate lithium aluminum silicate

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

18th 05 3 09 O, O, 86 23 55,

809821/0840

2751Q57

Example 9

Bis-GMA resin (including 200 ppm MEHQ) 18 Methyl methacrylate (including 100 ppm

MEHQ) 3

4,4'-oxydibenzil 0.2

Diisopropylamine 0.2

Barium aluminum silicate 23

Lithium aluminum silicate 55.6

In this case a secondary amine is used. To After mixing, the mixed product is placed in a Teflon mold as described above with the dimensions 12.5 mm 6 mm wrapped up. The ends covered with mylar are respectively Exposure for 15 seconds with the Spectroline B 100 lamp. as When the mold was opened, the sample was broken in the middle, indicating that the reaction was slow. Therefore, the ends covered with Mylar were each exposed for 30 seconds. After opening the mold without the When the size and shape of the sample was damaged, each side was exposed for an additional 30 seconds. The total exposure time was therefore 2 min.

conditions was 1828 kg / cm.
Example 10

Example 9 was with a primary amine, namely n-butylamine, repeated. The strength after 2 minutes of exposure

ten with the Spectroline-B-100 lamp is 1125 kg / cm. It follows that the tertiary amine is the most suitable amine.

809 8 21/0840

Example 11

A different form of resin is used in this example. The glycidyl ether of bisphenol A is with Ice-acrylic acid implemented. The reaction product, namely bisphenol A bis (3-acrylato-2-hydroxypropyl) ether, is used to produce the mixed product.

Gew.-Ji

Bisphenol A bis (3-acrylato-2-hydroxypropyl) ether (including 100 ppm MEHQ; 1,6-hexanediol diacrylate (including 200 ppm HQ)

Benzil

Trihexylamine Barium aluminum lumensilcat Lithlumaluminum luminescent cat

This mixed product was examined in the same manner as above. After exposure to the Spectroline B 100 lamp For a total of 1 minute, a material was used with obtained a compressive or bursting strength of 2214 kg / cm.

Example 12

Weight-96

18th 08 3 2 O, 0, 72 23 55,

Bis-GMA resin (including 200 ppm MEHQ) 23.9

1,6-hexanediol diacrylate (including

200 ppm HQ) 3.9

Benzil 0.1

Trihexylamine 0.26 Silica 72.34

809821 / -0840

_1S 2751 Ab7

ao

The compressive strength of this composite product after exposure to the Spectroline-B-100 lamp over a ge

total duration of 1 min is 1898 kg / cm.

The most suitable formulation for a dental filling material is given below:

Wt%

Bis-GMA resin (including 200 ppm MRHQ) 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 to the Spectroline B-100 lamp for a total of 1 minute.

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

Since the dentist can use the composite product without any additions or mixing measures, Recoveries are possible, essentially from

809-82 1 / Π8Α0

- γα -

trapped air bubbles are free. This eliminates one large amount of mechanical defects and improves the final appearance of the restoration by providing a smoother solid surface is obtained. A smooth surface is against staining and bacterial accumulation less vulnerable and it gives a smoother feel to the tongue.

Radiation with a wavelength of 2970 to 3200 8 can induce cutaneous sunburn and carcinogenesis. This narrow bond is responsible for "phototoxic reactions". The polymerization reaction was repeated in full up to 3200% after filtering the radiation. No change in the strength of the polymer was observed.

By placing various optical filters between the lamp and the material, it was found that the most effective Polymerization with light from 4000 to 4500 Å, i.e. in the visible range, occurred.

The curing test was carried out with a tungsten halogen lamp, a Visible light source manufactured by General Electric Co. repeated. The light was shining on the material a 0.15 m long fiber bundle is focused. The material was found to be more effective with the tungsten halogen lamp hardened than with the mercury lamp.

In addition to the composite restorative material, the present invention results in the manufacture of single-phase (in contrast to the known two-phase systems) hole and crack sealants, binding agents, Lining agents for the cavities and restoration glazes, all under the collective name coating

09821/0840

2 7 5 1 over 7

- χι -2α

processing masses are summarized. All of these masses included mainly a photopolymerizable aromatic resin such as Bis-GMA, a diluent monomer such as Methacrylate, diine thacrylate, 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 fillers or have reduced filler contents. These masses polymerize in the oral environment by applying a actinic radiation.

The hole and crack sealant, the lining agent for cavities, the glaze material or the binder generally contain 70 to 80% by weight of Bis-GMA resin, 30 to 2.Q) ⁰ A 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 and crack sealant, binder, lining agent for cavities and Recovery enamel material may be used. Although any other methacrylate, acrylate, dimethacrylate, Diacrylate or triacrylate can be used as a diluent monomer for the above preparation, that preparation has with methyl methacrylate the best property as a thin film. The amount of methyl methacrylate could vary to adjust the viscosity of the mixture. This

809821/0840

One-component sealing system has a shelf life of 1 year in airtight and light-resistant bottles.

The formulas can be varied, with increasing the amount of diluent reducing the viscosity. Increasing the amount of filler increases the strength, but thickens the paste. Strength is also increased by increasing the amount of benzil. However, too much benzil should be avoided as it gives a yellow color and can cause polymerization when exposed to incident light. The described initiator and accelerator combination can be used for the photopolymerization of a large number of monomer resins.

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

809821/0840

Claims (32)

DIPL.-PHYS. F. FINALLY ο eos4 unterpfaffenhofen 15. Nov. 1977 PATENTANWALT postfach TELEFON PHONt (MUNICH) 84 36 38 2 ^ EiSZ MÖNCHEN DIPUPHYS FINALLY. D-ΘΟ34 UNTEHPFAFFENHOFEN. POSTF. . TELEX: 82I73O Sybron Corporation My File: S-4330 Claims 1. Photopolymerizable dental restoration material, characterized in that it a) a monomer resin b) a diluent monomer c) an initiator d) an accelerator and e) fillers contains. 2. Composition according to claim 1, characterized in that the monomer resin is bis-GMA. 3. Composition according to claim 1, characterized in that the diluent monomer is a monodi- or trifunctional acrylate or methacrylate. 4. Composition according to claim 3, characterized in that the diluent is 1,6-hexanediacrylate is. 5. Composition according to claim 1, characterized in that the diluent is an α-Dike ton or a derivative thereof. 6. Composition according to claim 5, characterized in that the α-dlketone is benzil. 809821/0840 27b tub '/ 7. Composition according to claim 1, characterized in that the accelerator is an amine. 8. Composition according to claim 7, characterized in that the accelerator is a tertiary amine is. 9. Composition according to claim 8, characterized in that g e k e η η - ζ ei c h η e t that the tertiary amine is trihexylamine. 10. Composition according to claim 1, characterized in that the filler for X-rays is impermeable. 11. Composition according to claim 10, characterized in that the opaque to X-rays The filler is barium aluminum silicate. 12. Composition according to claim 1, characterized in that the filler is lithium aluminum silicate is. 13. Composition according to claim 1, characterized in that the filler is a mixture of barium aluminum silicate and is lithium aluminum silicate. 14. Composition according to claim 1, characterized in that it contains the individual components in Contains the following amounts expressed as parts by weight: Monomer resin 10 to 25 Diluent monomer 2 to 5 Initiator 0.001 to 1 809821/0840 2751US7 Accelerator 0.01 to 2 Barium aluminum silicate 0 to 85 Lithlum aluminum silicate 0 to 85. 15. Composition according to claim 1, characterized in that it contains the individual components in Contains the following amounts expressed as parts by weight: Bis-GMA resin (200 ppm MEHQ) 18 1,6-hexanedioxydiacrylate (100 ppm MEHQ) 28 Benzil 0.08 Trihexylamine 0.2 Barium aluminum silicate 23 Lithium aluminum silicate 55.82. 16. Initiator-accelerator combination material for photopolymerization of monomer resins, characterized in that they are an α-diketone or its derivative and contains an amine. 17. Composition according to claim 16, characterized in that the a-diketone is benzil. 18. Composition according to claim 16, characterized in that the amine is a tertiary amine. 19. Composition according to claim 18, characterized in that the tertiary amine is trihexylamine. 20. Single-phase dental coating compound, characterized in that it a) a monomer resin 809821/0840 ₄ _ 2751ObV b) a diluent monomer c) an initiator and d) an accelerator contains. 21. Coating composition according to claim 20, characterized in that the monomer resin is bis-GMA. 22. Coating composition according to claim 20, characterized in that the diluent monomer is methyl methacrylate is. 23. Coating composition according to claim 20, characterized in that g e k e η η-draws, that the initiator is a cc-diketone or a derivative thereof. 24. A coating composition according to claim 23, characterized in that the oc-diketone is benzil. 25. Coating composition according to claim 20, characterized in that the accelerator is a tertiary amine is. 26. Coating composition according to claim 25, characterized in that the tertiary amine is trihexylamine. 27. Coating composition according to claim 20, characterized in that it contains the components in the following weight range contains: Monomer resin 70 to 80 parts Diluent monomer 20 to 30 parts 809821 / 08A0 Initiator 0.01 to 1 part Accelerator 0.01 to 1 part. 28. Coating composition according to claim 20, characterized in that g e k e η η indicates that it contains the following components: Bis-GMA resin 75 parts Methyl methacrylate 25 parts benzil 0.5 part Trihexylamine 0.5 part. 29. A method for filling tooth cavities, characterized in that the cavity with the composition of claim 1 and polymerizes it by exposure to a source of actinic radiation. 30. A method for coating teeth, characterized in that the teeth with the mass coated according to claim 20 and polymerized by exposure to a source of actinic radiation. 31. Photo-curable one-paste dental filling materials, thereby characterized by radiation having a wavelength in the range of 3600 to 4500 Å have been polymerized. 32. One phase photocurable coating composition, thereby characterized in that it polymerizes by irradiation with a wavelength of 3600 to 4500 8 has been. 809821/0840