Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Patent
1985-09-27
1987-03-10
Anderson, Harold D.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
523117, A61K 606
Patent
active
046491651
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a new dental filling material containing a selected filler mixture.
Dental restoration materials on the basis of polymerizable compounds, so-called "composites", contain in addition to one or more polymerizable monomers, activators, polymerization catalysts, and other components compulsorily a mineral filler.
This filler determines according to type and amount the physical properties of the filling prepared by the composite. The higher the percentage of filler and its particle size, the better are the physical properties, but the worse is usually the polishability.
For this reason, it has been tried to improve the polishability of such materials by using fillers with smaller particle size of between approx. 10 and 300 nm; but this has diminished the mechanical properties.
These so-called "microfillers" are in particular mainly or almost exclusively used in the preparation of light-curing composites, i.e. dental restoration materials, which are present in one phase and which contain fillers, polymerizable compounds and a polymerization initiator which forms radicals under the influence of light.
This is particularly based on the fact that these materials must have a certain curing depth, which is not reached with most of the fillers with higher particle sizes, so-called "macrofillers".
Other macrofillers, which do not show this disadvantage cause discolorations during polymerization (=curing) of the filling. This applies particularly to different types of glass, which--when they are used by themselves--result in a greenish or greyish discoloration during curing of the filling and moreover are not polishable.
Moreover, also X-ray opacity of cured dental fillings is desirable, which cannot be achieved with microfillers on the basis of silica.
Therefore, there was a need to develop dental filling materials which do not show these disadvantages, which are well light-curable, if necessary even without polymerization catalysts, show no discoloration, but have good physical properties, particularly reduced water absorption and shrinkage, a coefficient of thermal expansion tending to zero and improved mechanical properties, particularly regarding hardness and diametrical tensile strength, and being also X-ray opaque.
Moreover, it is desirable to reach a polishability which is at least satisfactory.
According to the invention, it has been found now that a dental filling material having the described properties may be prepared by using as inorganic filling material in an amount of approx. 60 to approx. 90% by weight of the total composition a mixture of
(a) at least one optionally silanized X-ray opaque inorganic filler with a particle size distribution of between 0,5 and 40 .mu.m in an amount of approx. 5 to approx. 20, particularly approx. 10 to approx. 15% by weight of the filler mixture,
(b) at least one optionally silanized X-ray opaque inorganic filler with a particle size distribution of between 0,2 and 15 .mu.m in an amount of approx. 20 to approx. 40, particularly approx. 25 to approx. 35% by weight of the filler mixture, and
(c) an optionally silanized inorganic microfiller, particularly silica, with a particle size distribution from 5 to 150 nm in an amount of approx. 40 to approx. 75, particularly approx. 55 to approx. 65% by weight of the filler mixture.
The precise particle size distribution of the X-ray opaque filler with a higher medium particle diameter contained in an amount of 5 to 20, preferably 10 to 15, particularly approx. 10% by weight of the total filler usually is as following:
______________________________________ 5% 0,5-1 .mu.m
10% 1-2 .mu.m
20% 2-5 .mu.m
20% 5-10 .mu.m
30% 10-20 .mu.m
15% 20-40 .mu.m
______________________________________
smaller medium particle diameter contained in an amount of 20 to 40,
preferably 25 to 35, particularly approx. 30% by weight of the total
filler is shown in the following table:
______________________________________ 5% 0,2-0,5 .mu.m
10% 0,5-1 .mu.m
15% 1-2 .mu.m
45% 2-5 .mu.m
20%
REFERENCES:
patent: 4297266 (1981-10-01), Ibsen et al.
patent: 4388069 (1983-06-01), Orlowski
patent: 4389497 (1983-06-01), Schmitt et al.
patent: 4394465 (1983-07-01), Podszun et al.
patent: 4407984 (1983-10-01), Ratcliffe et al.
patent: 4427799 (1984-01-01), Orlowski et al.
patent: 4544359 (1985-10-01), Waknine
Anderson Harold D.
Blendax-Werke - R. Schneider GmbH & Co.
LandOfFree
Dental filling material comprising polymerizable (meth)acrylic c does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Dental filling material comprising polymerizable (meth)acrylic c, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dental filling material comprising polymerizable (meth)acrylic c will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1022119