Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
1999-08-12
2002-07-30
Szekely, Peter (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C523S115000, C433S037000, C433S040000, C433S048000, C433S202100, C433S228100, C522S027000, C522S028000, C522S030000, C522S064000, C522S065000, C522S068000, C522S096000, C522S102000, C522S103000, C522S908000, C526S318420, C526S318430, C526S318440
Reexamination Certificate
active
06426373
ABSTRACT:
The invention relates to a photopolymerizable one-component dental material, a dental kit, a method of making a prosthesis, the use of such dental material, a corresponding prosthesis, a fixing key, another dental kit, another method of making prostheses, the use of a specific material as fixing key and lastly an additional prosthesis.
The systems mainly used on the dental market for restoration are two-component systems on a powder-and-liquid basis, which can be worked by casting methods or by packing and pressing methods. Curing is performed by hardening in the water bath or in the microwave oven, and often pressure is applied to the restoration structures that are formed, especially prostheses, to prevent ebullition bubbles.
A disadvantage of this is the necessity of mixing so that, if too much material is mixed, it has to be discarded. Furthermore, these systems contain methyl methacrylate (MMA) and peroxides which have a high potential for irritation. Furthermore, the working time is as a rule very limited due to the swelling of the polymers and by the reaction start in autopolymerizates.
Far less widely used are the one-component systems, which heretofore have been used mainly for the full prosthesis market. These systems contain thermosetting, dough-like materials, with the result that casting them is not possible and—as is common practice with full prostheses—embedding in plaster must be performed.
Furthermore, the polymerization is very slow and the cooling phase that follows it is disproportionately long. The plastic dough contains as a rule, and in a disadvantageous manner, peroxide as the initiator which, as mentioned above, has a high irritation potential. The post-curing, especially in the case of glass-filled systems, is very time-consuming, and furthermore affinity for plaque accumulation is very great. Lastly, the materials' technical properties are unsatisfactory as a rule due to poor bonding of the fillers.
From what is set forth above, the problem arises of at least partially remedying the disadvantages named above by means of a new one-component dental material and, among other things, a new dental kit. The problem lies especially in devising a one-component dental material and a corresponding kit in which the production time is definitely shorter in comparison to the usual methods and materials, no free methyl methacrylate and virtually no peroxide is used, bonding to commercial polymethyl methacrylate (PMMA) materials is possible, and lastly the fettling that follows polymerization should be similar as regard difficulty to the systems of the prior art.
This problem is solved according to the invention by a one-component dental material comprising:
a) 80-10 weight-% of at least one polyfunctional urethane methacrylate and/or at least one polyfunctional urethane acrylate,
b) 10-30 weight-% of at least one polyfunctional acrylate resin,
c) 10-30 weight-% of at least one reactive thinner,
d) 0-20 weight-% of bis-GMA and/or at least one ethoxylated bisphenol-A dimethacrylate,
e) 0-10 weight-% of at least one filler,
f) 0-1 weight-% of at least one photoinitiator system, and
g) 0-1 weight-% of at least one color pigment.
The invention furthermore relates to a dental kit comprising the inventive one-component dental material; to a method for making a prosthesis, wherein the inventive one-component dental material is used; to a prosthesis comprising the inventive one-component dental material; to a fixing key comprising at least one transparent silicone or composite; to a dental kit comprising the inventive fixing key; to a method for making a prosthesis, wherein the inventive fixing key is used; and to a prosthesis comprising the inventive fixing key.
The one-component dental material according to the invention is one which has at least one polyfunctional urethane methacrylate and/or at least one polyfunctional urethane acrylate, at least one polyfunctional acrylate resin and at least one reactive thinner. The term, “reactive thinner,” as used in the context of the invention is to be understood as compounds which act more or less as “solvents and thinners” in their monomeric form, and thus reduce the viscosity of the one-component dental material, and furthermore which become copolymerized in the polymer matrix when it is set by exposure to light, i.e., when it is polymerized by wavelengths of light.
Furthermore, the material according to the invention can contain bis-GMA and/or at least one ethoxylated bisphenol A dimethacrylate which has positive influence on such material parameters as shrinkage, moisture absorption and mechanical properties. Bis-GMA is the common abbreviation of 2,2-bis(4-(2-hydroxy-3-methacryloyloxypropoxy)phenyl)propane and has the following structural formula:
Lastly, fillers, photoiniator systems and color pigments can be components of the material. The fillers can be hydrophobized—silanized for example, which improves wettability due to the lower polar character, which leads to easier copolymerizability into the matrix. Methacryloyloxypropyl-trimethoxy-silane is named as one example of many.
The photoinitiator system can consist, for example, of individual photoinitiators or else of systems which contain photoinitiators and co-initiators.
The color pigments can be of an organic nature, on a perylene basis for example, or of an inorganic nature, on a spinel basis for example.
Urethane methacrylate is the product of the reaction of a diisocyanate with an OH-functional methacrylate such as hydroxyethyl methacrylate for example. When a diisocyanate is used, the product is a urethane dimethacrylate; if an OH-functional acrylate is used, such as a hydroxyethyl acrylate,a difunctional acrylate is the result, similarly to the methacrylate.
Such a urethane methacrylate or urethane acrylate, especially a urethane dimethacrylate is advantageous, because among other things it offers superior material properties such as great stiffness or low moisture absorption.
Also possible is the use of a monomer prepared from the combination of triisocvanates or higher isocyanates with OH-functional acrylates or methacrylates, in which case these urethane methacrylates or urethane acrylates will have a functionality of 3 or more.
Advantageously, the urethane methacrylate is a urethane dimethacrylate or urethane trimethacrylate and the urethane acrylate is a urethane diacrylate or a urethane triacrylate.
It is furthermore advantageous if the urethane methacrylate and/or urethane acrylate has a viscosity of 10
3
to 5×10
4
mPas, especially 1×10
4
mPas, since when used in the one-component dental material as the main monomer, even without dilution, a good consistency for the dental plastic according to the invention is obtained. Advantageously, the urethane methacrylate and/or urethane acrylate has at T=+20° C. a viscosity of 10
3
to 5×10
4
mPas.
Advantageously, the urethane methacrylate and/or the urethane acrylate has a molar mass of 450 to 500 g/mol, since the shrinkage of the monomer is in the range of normal prosthesis materials. For example, the shrinkage of the monomer at a functionality of 2 (i.e., a urethane dimethacrylate or a urethane diacrylate) is less than 7%.
It is advantageous if the urethane methacrylate and/or the urethane acrylate is aliphatic, since such urethane methacrylates have a lower discoloration especially when irradiated with light containing UV than do aromatic urethane methacrylates and urethane acrylates.
The following urethane methacrylate of the following structural formula: has proven practical.
It is advantageous that the acrylate resin is a polyester triurethane acrylate, since due to a functionality of 3 a great stiffness results in spite of the high molar mass; and it is characterized by the elasticity modulus. Due to the long chains between the functional groups a high flexibility is simultaneously achieved, which leads to a decided improvement in impact toughness.
Advantageously, at T=+60° C., the acrylate resin has a viscosity of 5,000 to 15,000 mPas, since the high vi
Erdrich Albert
Puchalska Teresa
Savic Novica
Stange Frank
Heraeus Kulzer GmbH & Co. KG
Norris & McLaughlin & Marcus
Szekely Peter
LandOfFree
Photopolymerizable one-component dental material does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Photopolymerizable one-component dental material, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photopolymerizable one-component dental material will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2893350