Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Patent
1990-03-21
1993-10-05
Michl, Paul R.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
523118, 524432, 524441, 524408, 524439, 524440, 524443, A61K 608, C08K 308
Patent
active
052505855
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a powder-form dental material according to the preamble of claim 1, its preparation and use.
Glass-ionomer cements which are the reaction product of a calcium-aluminum-fluorosilicate-glass powder and/or a strontium-aluminum-fluorosilicate glass, a water-soluble polycarboxylic acid and water, have the advantage compared with other dental materials used for filling purposes (e.g. composite-plastic fillings, amalgam) that they are physiologically very well tolerated and enter into a chemical compound with the tooth-substance which results in a perfect marginal seal.
Glass-ionomer cement powders containing metal are known from GB-A-2 028 855. This material, however, is a simple mixture of cement powder and metal powder which is not subjected to any thermal treatment.
A powder-form dental material is known from DE-A-32 48 357 which consists of a sintered mixture of calcium-aluminum-fluorosilicate-glass and the noble metals commonly used for dental purposes or their alloys with up to 40% by weight of base metals. This sintered dental material has a markedly higher wear resistance than the glass-ionomer cements of unsintered dental material.
The aim of the invention is the preparation of a sintered, metal-containing glass-ionomer cement powder which can be prepared without using expensive noble metals at a quality comparable with the material in DE-A-32 48 357.
This aim is achieved according to the invention by preparing a powder-form dental material according to the preamble of claim 1, which contains at least some of constituent (a) as a sintered mixture with constituent (b).
The new powder-form dental material is prepared according to the invention by the process in claim 2 or 3. The sintered product obtained can optionally be mixed with (1) unsintered aluminum fluorosilicate glass and/or (2) with dry polycarboxylic acid and/or (3) with a chelating agent, each in powder form.
For use, the powder-form dental material according to the invention is mixed in case (1) with aqueous polycarboxylic acid solution, which optionally contains a chelating agent, in case (2) with water, optionally containing a chelating agent, e.g. a tartaric acid solution, and in case (3) with aqueous polycarboxylic acid solution or with water, to form a tooth-filling material which is distinguished by its high wear resistance and which is therefore also suitable for modelling edges and corners in the molar region. The cement prepared from the dental material according to the invention adheres thereby to the tooth-substance and has good physiological tolerability.
In addition to the glass powders containing calcium, magnesium and lanthanum mentioned in DE-A-20 61 513 and DE-A-32 48 357 and the glass powders containing strontium in EP-A-241 277, glass powders with other cations can also be used. Calcium- and/or strontium-fluorosilicate-glasses are preferably used, and thus the aluminum-fluorosilicate-glass powder can have the following constituents in addition to oxygen:
______________________________________ Constituent Calculated as
% by wt.
______________________________________
Si SiO.sub.2 20-60
Al Al.sub.2 O.sub.3
10-50
Ca CaO 0-40
Sr SrO 0-40
F F 1-40
Na Na.sub.2 O 0-10
P P.sub.2 O.sub.5
0-10
______________________________________
total 0-20% by weight, calculated as oxides, of B, Bi, Zn, Mg, Sn, Ti, Zr,
La or other trivalent lanthanoids, K, W, Ge and further additives which do
not disadvantageously affect the properties and are physiologically
harmless. The glasses can be made x-ray visible by adding 10-20% by weight
of La.sub.2 O.sub.3.
The powder particles advantageously consist of:
______________________________________ Si as SiO.sub.2 25-50% by weight
Al as Al.sub.2 O.sub.3
10-40% by weight
Ca as CaO 0-35% by weight
Sr as SrO 0-35% by weight
F 5-30% by weight
Na as Na.sub.2 O 0-8% by weight
P as P.sub.2 O.sub.5
1-10% by weight
______________________________________
(calculated as SrO) must be contained and 0-10% by weight of B.sub.2
O.sub.3, Bi.sub.
REFERENCES:
patent: 3205566 (1965-09-01), Breton
patent: 4209434 (1980-06-01), Wilson et al.
patent: 4527979 (1985-07-01), McLean et al.
patent: 4569954 (1986-02-01), Wilson et al.
patent: 4814362 (1989-03-01), Billington et al.
patent: 4872936 (1989-10-01), Engelbrecht
Marxkors/Mieners, "Taschenbuch der zahnarztlichen Werkstoffkunde".
Pulvermetallurgie, p. 575.
Chem. Abs. 103, 1985.
Ellrich Klaus
Gasser Oswald
Guggenberger Rainer
Makinson Owen
McLean John W.
DeWitt LaVonda
ESPE Stiftung & Co. Produktions - und Vertriebs KG
Michl Paul R.
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