Polymerizable cement mixtures

The invention concerns polymerizable cement mixtures containing PA0 (a) polymerizable unsaturated monomers and/or oligomers and/or prepolymers containing acid groups and/or their reactive acid-derivative groups, PA0 (b) reactive fillers that can react with these acids or acid derivatives, and PA0 (c) curing agents that can be employed especially in dentistry as improved dental mixtures as well as in medicine.

The invention concerns polymerizable cement mixtures, especially those 
intended for dentistry and medicine. 
A number of cements are employed in dentistry for various purposes, 
especially for instance for securing crowns and inlays as well as 
orthodontic devices, as root-canal filling material, as underfilling 
material when introducing dental-restoration material to protect the tooth 
pulp, and even as the filling material itself. Some of these cements are 
employed in medicine as bone cements. 
Cements for dental and medicinal purposes consist as a rule of a mixture of 
finely divided metal oxides, metal hydroxides, silicate-cement glazes, or 
ion-leaching glasses, that is induced to react with a liquid medium that 
essentially contains phosphoric acid, polycarboxylic acid, or even 
salicylic-acid derivatives. 
Although cements based on phosphoric acid and silicate-cement glazes 
(silicate cements) or on metal oxides (phosphate cements) exhibit more 
(silicate cement) or less (phosphate cement) mechanical strength, they are 
very incompatible with the pulp, too brittle, and too water-soluble. 
Cements based on polycarboxylic acids and metal oxides (carboxylate 
cements) or on ion-leaching glasses (ionomer cements), however, although 
they are also only more (ionomer cements) or less (carboxylate cements) 
mechanically strong, are highly compatible with the tissues and exhibit 
satisfactory adhesion to the dental tissue. Still, they also are too 
brittle, also have the drawback of washing out too readily in an aqueous 
environment, and exhibit no chemical bond to acrylic-based filling 
materials, as well as not adhering to them. 
Cements based on salicylates and metal oxides or hydroxides, especially 
calcium hydroxide, are employed as pulp-capping materials and root-canal 
filling materials (U.S. Pat. No. 3,047,408). Cements of this type act, due 
to their high pH, as protective blocks against the acids and other toxic 
substances that can be included in some filling materials. They also 
occasion the formation of secondary dentin. The mechanical strength of the 
cured products, however, is not especially high, and its relatively high 
water-solubility makes the material dissolve more or less rapidly. 
Essential for cements is that they cure by means of ionic reactions like 
neutralization, salt formation, chelation, or crystallization, 
specifically in the presence of water. 
Different types of cement have turned out to be more or less practical for 
different applications in dentistry and medicine. 
Cements are employed mainly as underfilling materials, as fastening 
materials, and in exceptional cases, also as filling materials for lesions 
in the gingival region. 
The serious drawbacks of cements, their tendency to wash away and their low 
mechanical strength, have led to their being extensively replaced as 
filling materials by the longer-lasting, more stress-resistant, more 
edge-stable, insoluble, and cosmetically more satisfactory polymerizable 
acrylic-based filling materials called composites. 
Composites consist essentially of a polymerizable binder reinforced with 
organic or inorganic fillers. Appropriate polymerizable binders are 
compounds with olefinically unsaturated groups, especially, for dental and 
medicinal purposes, the esters of the (meth)acrylic acids of univalent and 
multivalent alcohols, mixed if necessary with other vinyl monomers. 
Employed as inorganic fillers are fine quartz powders, microfine silicic 
acid, aluminum oxide, barium glasses, and other particulate minerals that 
do not in themselves enter into chemical bonds with the polymerizable 
binders that surround them and are accordingly usually combined with a 
coupling agent in the form of a polymerizable silane to ensure 
satisfactory bonding to the binder. Essential to composites is that they 
cure via polymerization of the olefinically unsaturated groups in the 
binder, specifically by means of a radical reaction that does not require 
the presence of water. 
Although composites are what are mainly employed today (in addition to 
amalgams) as dental restoration materials, there are certain limits to 
their use. Composites have restricted applications, due to irritation of 
the tissues or for reasons of toxicity, in relation to deep cavities in 
the teeth and to restorations of the gingival border and dentin. 
Furthermore, they do not address to the dental tissue. Such cases usually 
required cements based on polycarboxylic acids and metal oxides 
(carboxylate cements) or on ion-leaching glasses (ionomer cements). 
Restoration materials of this type are less toxic and adhere well to the 
dental and osseous tissues. 
There has been no lack of attempts to improve not only the mechanical 
strength but also in particular the solubility behavior, miscibility 
behavior, and compatibility of cements to composites. 
To decrease water-solubility for example, polymers such as polystyrenes, 
polyvinyl acetates, and polyvinyl butyrals or even paraffin oil, linseed 
oil, colophony, and other natural resins have been added to 
calcium-hydroxide cements and carboxylate cements. Separation phenomena 
have been controlled by means of surface-active substances such as zinc 
stearate or ethyltoluene sulfonamide. 
Additives that contain olefinic double bonds, such as esters of 
5-methoxyconiferin--called syringates--have, in combination with the 
addition of radically reacting catalyst, provided cements with better 
mechanical strength, somewhat lower solubility, and a certain amount of 
bonding capacity to composites. 
The object of the invention is to provide new dental mixtures that not only 
exhibit essentially the advantages characteristic of cements based on 
polycarboxylic acid or salicylate, like good adhesion to the dental and 
osseous tissues, but also demonstrable those of composites, like lower 
solubility and increased mechanical strength, that can be copolymerized 
with composites, and that will have no outstanding separation phenomena. 
This object is attained in accordance with the invention by means of 
polymerizable cement mixtures that contain 
(a) polymerizable unsaturated monomers and/or oligomers and/or prepolymers 
containing acid groups and/or their salts and/or their reactive 
acid-derivative groups, 
(b) reactive fillers that can react with these acids or acid derivatives, 
and 
(c) curing agents. 
It turns out, surprisingly, that combining some of the polymerizable resin 
mixtures that have been developed for adhesion to the dental tissue with 
reactive fillers of this type, which are conventionally contained in 
cement for setting important constituents, will lead to mixtures that cure 
both radically and via ionic reactions. The result is a wide range of new 
composite cements with better properties and new application potentials. 
Examples of polymerizable unsaturated monomers with acid groups or reactive 
acid-derivative groups that are known as good bonding agents for oxidic 
materials and the dental tissue are unsaturated organic esters of 
phosphoric and phosphonic acids (German AS No. 2 711 234 & German OS No. 3 
150 285), unsaturated organic esters of monofluorophosphoric acid (U.S. 
Pat. No. 3,997,504), unsaturated organic esters of phosphoric acids that 
contain either chlorine or bromine bonded directly to the phosphorus (Eur. 
Pat. No. 0 058 483), unsaturated organic esters of phosphoric acid in the 
form of pyrophosphates (anhydrides) (German OS No. 3 048 410), and 
4-methacryloyloxyethyltrimellitic acid and its anhydride (M. Takeyama et 
al., I. Jap. Soc. f. Dent. App. a. Mat. 19, 170 [1978]), and 
bis-2-methacryloylethyl pyromellitate. 
Examples of powdered constituents commonly contained in cements because 
important for setting are specified for instance in German Patent No. 2 
061 513, Swiss Patent No. 588 863, German OS No. 2 751 069, German OS No. 
2 750 326, U.S. Pat. No. 4,250,277, European Patent No. 0 023 013, and 
U.S. Pat. No. 4,376,835. 
The polymerizable unsaturated monomers, oligomers, or prepolymers in the 
polymerizable cement mixtures in accordance with the invention can carry 
alkenyl, alkenoxy, cycloalkenyl, aralkenyl, or alkenaryl radicals, with 
acryl, methacryl, vinyl, or styryl radicals being practical and, of these, 
the acryl and methacryl radicals, which constitute the polymerizable 
groups in many monomers, being especially practical. 
Especially appropriate acid groups are all those that can react with 
oxidic, mineral, ceramic, vitreous, or metallic fillers. It is practical 
however for these acid groups to be carboxylic-acid radicals, the radicals 
##STR1## 
of phosphorus acids wherein R is alkyl, aryl, or vinyl for example, the 
radicals --SO.sub.2 H, SO.sub.3 H, or --O--SO.sub.3 H of sulfuric acids, 
and the radicals 
##STR2## 
of boron acids wherein R is alkyl, aryl, or vinyl. 
Cationic acid radicals like --NR.sub.2 H.sup.+ or --PR.sub.2 H.sup.+ 
(wherein R is H or alkyl) are also appropriate. 
The reactive acid derivatives can be substituted with acid halides, with 
acid anhydrides, and with acid amides, nitriles, and esters, that readily 
hydrolyze into acid, such can enter into ion-exchange, neutralization, 
salt formation, or chelation reactions with the reactive filler. 
Especially preferred are acid groups or reactive acid derivatives in the 
form of carboxylate, phosphate, phosphonate, sulfonate, or borate acid 
radicals or of their reactive derivatives. 
Especially appropriate are compounds that contain at least two 
polymerizable groups or at least two acid groups or acid-derivative 
groups. Examples are phosphoric-acid esters of glycerine dimethacrylate or 
1-methacryloxyethane-1,1-diphosphonic acid. 
Very especially preferred are compounds that contain at least two 
polymerizable groups and at least two acid groups, such as the chloro- or 
bromophosphoric-acid esters of bisphenol-A-glycidyl dimethacrylate 
(bis-GMA), which can easily be prepared by reacting bis-GMA with 
phosphoryl chloride and whereby the ratio of phosphorus to bis-GMA is 2:1. 
Examples of polymerizable unsaturated oligomers or prepolymers with acid 
groups or acid-derivative groups are compounds that contain not only 
polymerizable groups but also acid groups or acid-derivative groups bonded 
to chemically highly stable molecular backbones. 
It is practical for the polymerizable unsaturated oligomers or prepolymers 
to contain two unsaturated groups and/or two acid groups or two reactive 
acid-derivative groups and especially practical for them to contain three 
or more unsaturated groups and three or more acid groups or three or more 
reactive acid-derivative groups. 
Compounds of this type are very satisfactory as constituents of agents for 
bonding to an oiidic, mineral, ceramic, vitreous, metallic, or biological 
substrate, especially the dental tissue, and are especially appropriate as 
constituents of the cement mixtures in accordance with the invention. 
The molecular backbones of compounds of this type can be linear, branched, 
or cyclic. 
They can be polymers of ethylenically unsaturated monomers or they can be 
oligomeric or polymeric compounds, such as polyesters, polyamides, 
polyethers, polyphosphazenes, polysaccharides, etc. for instance, if their 
backbone is sufficiently hydrolysis-stable, if they can be supplied with 
the desired polymerizable groups, and if they include or can be supplied 
with the desired acid groups. 
The desired groups can be grafted if the backbone contains a number of 
bound functional groups, such as alcohol, halogen, acid halide, amino, 
epoxide, or isocyanate groups, that allow such a grafting reaction. 
This means that the aforesaid backbones can, no matter what components they 
are constructed of, usually polyalcohols, polyhalides, polyacid halides, 
polyamines, polyepoxides, polyisocyanates, or polyanhydrides, lead either 
alone or in mixtures to the oligomeric or polymeric compounds in the 
mixtures in accordance with the invention. Preferred backbones are 
polymers of ethylenically unsaturated monomers. 
The preferred oligomeric or prepolymeric backbone compounds that are 
preliminaries in the preparation of the preferred oligomeric or 
prepolymeric compounds can be prepared from polymerizable monomers by 
appropriate reactions that convert them into oligomers or polymers of 
various degrees of polymerization. 
A group of monomers that results in homo-oligomers or homopolymers is 
appropriate on the one hand, and, on the other, a group that results in 
co-oligomers or co-polymers by means of a combination of different 
monomers. Oligomers or polymers of unsaturated acids employed in the 
acid-chloride form, 
##STR3## 
are appropriate examples from the homopolymer group. They can be converted 
to a desired level with hydroxyethyl method is desired, with the 
acid-chloride radical being hydrolyzed in a second step. The statistical 
distribution of the grouped is for example 
##STR4## 
wherein MA is a methacryloyloxy radical 
##STR5## 
The second stage (hydrolysis) can, however, be replaced by means of 
alcoholysis with alcohols, such as a 1-hydroxy-ethane-1,1-diphosphonic 
acid, that contain acid groups to obtain products such as 
##STR6## 
Another good backbone for compounds in accordance with the invention is 
provided by homopolymers of unsaturated alcohols (D). Some of the hydroxy 
groups can be provided with polymerizable groups by for example 
esterification with an unsaturated acid or with an unsaturated acid 
chloride. Others can be converted into corresponding compounds (E) and (F) 
in accordance with the invention, by means of acids or acid chlorides such 
as boric acid or phosphoryl chloride for example. 
##STR7## 
wherein R and R.sup.1 are absent or are inert radicals. 
Especially preferred are oligomers or polymers of maleic acid anhydride: 
##STR8## 
which can be converted with a hydroxyalkyl methacrylate for instance in a 
ratio of 1:1 into products such as 
##STR9## 
A product with two different adhesive groups in accordance with the 
invention, 
##STR10## 
wherein S is absolutely any acid radical or acid-derivative radical and R 
is any radical, can be obtained by adding less hydroxymethacrylate and 
making up for it with more of the hydroxy-acid derivative. 
In another group of preferred fundamental compounds-specifically 
co-oligomers or co-polymers--vinyl, styrene, or (meth)acryl monomers such 
as vinyl phosphate, vinyl phosphonate, methacrylates of phosphoric acids 
or phosphonic acids, and styryl compounds with phosphoric, boric, and 
sulfuric acid groups, such as sulfonated styrene for example, that contain 
acid or an acid derivative can be copolymerized with unsaturated compounds 
such as vinyl chloroacetate or chloromethylated styrene into compounds 
such as for example 
##STR11## 
or, for example 
##STR12## 
Compounds of this type can then be converted with sodium methacrylate for 
example into a polymerizable compound 
##STR13## 
in accordance with the invention. 
Copolymers 
##STR14## 
of unsaturated alcohols and unsaturated acids also result subsequent to 
reaction with compounds such as methacrylic-acid chloride also result in 
products 
##STR15## 
in accordance with the invention. 
In constructing the backbone, units that do not have acid groups and that 
are not supplied with a polymerizable group can also be polymerized in. It 
can on the one hand be practical to do so in order to modify the 
solubility, as for example by inserting inert methyl-methacrylate units 
##STR16## 
The insertion of additional units with halotriazine, epoxide, isocyanate, 
or aldehyde groups 
##STR17## 
can on the other hand also be useful to induce an additional reaction with 
the collagen constituent of the dental or osseous tissue. The aldehyde 
groups may also be in the form of acetals or semi-acetals 
The insertion of units with groups that can be components of a 
polymerization-catalyst system can be of advantage. The groups do not 
absolutely have to be present as groups of that kind during the homo- or 
co-polymerization of the backbone, but can be grafted on subsequently by 
means for example of a halogen-, alcohol-, anhydride-, or amine-functional 
group. 
The reaction methods that result in the oligomeric or prepolymeric 
fundamental compounds can be determined by the choice of solvent, 
solubilities, concentration, temperatures, and polymerization catalysts 
and are known to one skilled in the art. 
It can be important for the polymerization catalysts to be destroyed by the 
reaction itself or for any residues to be removed before the polymerizable 
groups in accordance with the invention are introduced. 
It is practical for the oligomeric compounds to have a molecular weight of 
more than 500, and for the prepolymeric compounds to have one of greater 
than 1500, although preferably no greater than 100,000, and particularly 
preferably no greater than 20,000. 
The mixtures in accordance with the invention can also contain other 
polymerizable unsaturated monomers and/or oligomers and/or prepolymers 
that do not contain any acid groups and/or salts thereof and/or reactive 
readily hydrolyzing acid-derivative groups thereof. Particularly 
appropriate are monomers that are constituents of conventional composites 
such as for example bis-GMA or triethyleneglycol dimethacrylate. The 
mixtures can also if necessary contain other compounds that, although they 
contain acid groups and/or their salts and/or their reactive readily 
hydrolyzing derivative groups do not contain any groups that are 
unsaturated and polymerizable. Preferred in this case are multi-basic 
acids or their reactive, readily hydrolyzing derivatives. Especially 
preferred multibasic acids are hydroxy acids such as tartaric or citric 
acid, but also polyacids such as polycarboxylic, polyphosphoric, 
polyphosphonic, or polysulfonic acids. 
Compounds that have chelating groups but do not contain acid groups or 
readily hydrolyzing acid-derivative groups can be employed. Examples of 
this type are vanillates, syringates, and salicylates. 
The proportion of polymerizable compounds that contain acid groups or 
reactive acid-derivative groups in the overall content of the 
polymerizable compounds in especially preferred mixtures ranges from 20 to 
60% and in preferred mixtures from 5 to 100%, although mixtures with less 
than 5% also definitely exhibit the features peculiar to those in 
accordance with the invention. It can simultaneously be practical for 
example to allow the portion or some of the portion of the polymerizable 
compounds that contains the acid groups or acid-derivative groups to 
absorb onto the filler before the reactive fillers are worked in and 
sometimes to let it react (ionically) with the surface via traces of 
water, before, however, the polymerizable double bonds can react. The 
latter must not occur until the preliminarily treated fillers are mixed 
into the overal mix and while they themselves are polymerizing. 
Appropriate reactive fillers for the composite-cement mixtures in 
accordance with the invention that react with acid groups or 
acid-derivative groups in the polymerizable compounds are mainly metal 
compounds, glasses or ceramics that contain metal compounds, zeolites, 
oxidizable metals, and boron nitride, as well as the products derived from 
sintering these constituents. A prerequisite is that the fillers are 
present in a finely divided form, that they can react ionically with the 
acid groups in the polymerizable monomers accompanied by a certain amount 
of hardening or curing, and the reaction products are as insoluble as 
possible. It can be sufficient and may even by desirable for this reaction 
to occur only on the surface of the filler. 
Thus, sintering products of powders of the aforesaid metal compounds, 
glasses, ceramics, zeolites, or non-precious metals can also, in 
combination with powders of precious metals, other glasses and ceramics, 
SiO.sub.2, and aluminum oxides etc. that are generally common in 
composites in the capacity of inorganic fillers but that in themselves do 
not react or hardly react with polymerizable monomers that contain the 
acid groups, result in useful fillers. 
It can absolutely be sufficient or even practical for the stage or curing 
that accounts for the actual cement reaction and that occurs via ionic 
reactions not to occur until the material is in the mouth, as the result 
of moisture penetrating into the polymerized cement material. Practically 
appropriate for composite-cement mixtures in accordance with the invention 
are metal oxides and metal hydroxides, with the metals being calcium, 
magnesium, or zinc in particular. 
Also preferred are powder of silicate cements, powder of ionomer cements 
(ion-leaching glasses), or powder of ion-exchanging zeolites, whereby the 
release or exchange of calcium is especially preferred. Even mixing or 
sintering powder of silicate cement, ionomer cement, or zeolite with 
powdered silver or silver alloys and grinding the sintering products will 
lead to preferred embodiments. 
The reactive fillers do not absolutely have to be the only fillers in the 
mixtures in accordance with the invention. Other fillers of the type 
conventional in composites which are not reactive in the sense of ionic 
reactions or cement-setting reactions can be mixed in especially when 
silanized. This can be an advantage for example if the cured products are 
to exhibit high mechanical or chemical resistance. It can likewise be 
necessary to divide the mixtures in accordance with the invention into 
separate constituents for storage purposes, with one constituent 
containing the polymerizable monomers with the acid groups and the 
nonreactive filler and the other constituent containing the polymerizable 
monomers without the acid groups and the reactive filler. 
The proportion of reactive to total filler in preferred mixtures is higher 
than 5% by weight and is higher than 30% by weight in especially preferred 
mixtures. In some cases, however, even lower portions can have a definite 
effect, on alkalinity for example, which can be important for filling 
materials in the field of dentistry. The total filler content in the 
mixtures in accordance with the invention is in particular between 10 and 
95% and preferably between 30 and 85% (by weight) of the total. 
Appropriate polymerization catalysts in principle are all those systems 
that can trigger the radical polymerization of olefinic compounds. Whether 
the catalyst reaction is initiated by heating, by the introduction of an 
activator, or by photoirradiation is not essential. What is important, 
however, is for the catalyst system to dissolve satisfactorily in the 
mixture and essentially not be blocked or disintegrated by polymerizable 
compounds that contain acid groups or acid-derivative groups. 
Preferred for light-curing (photocuring) mixtures are curing systems 
consisting of .alpha.-diketones and tertiary amines such as those 
specified in French Patent No. 2 156 760 for instance or of combinations 
of sulfinic-acid salts and of xanthones or thioxanthones such as those 
specified in European Patent No. 0 132 318 for instance. 
Especially appropriate for bicomponent mixtures are combinations of one 
constituent that contains organic peroxides and of another constituent 
that contains a tertiary amine and a compound that exhibits sulfur in 
oxidation number +2 or +4. The constituent that does not contain the 
peroxide can preferably also contain bivalent metal ions, especially that 
of calcium, particularly when tertiary butyl permaleate is employed as the 
peroxide. Especially preferred are benzoyl peroxide for the organic 
peroxide and sodium para-toluene sulfinate as the sulfur compound. 
An especially practical mixture results when alcohols that contain one or 
more polymerizable olefinic unsaturated groups are added to the 
constituent that contains the sodium sulfinate to ensure adequate 
solubility of that salt. 
Appropriate for this purpose are for example hydroxyalkyl methacrylates 
such as hydroxyethyl methacrylate or vinyl compounds, such as allyl 
alcohol, that contain hydroxy groups, and especially dimethacrylate 
compounds, such as bisphenol-A-glycidyl methacrylate or glycerol 
dimethacrylate, that contain hydroxyl groups, and divinyl compounds, such 
as glycerinediallyl ether, that contain hydroxyl groups. It is generally 
necessary to add 10 to 20% PG,23 of these polymerizable monomers that 
contain hydroxyl groups. 
Curing agents that are typical for cements and that accelerate the ionic 
reactions, such as water or even tartaric acid or mellitic acid, can also 
be added. 
The composite cements in accordance with the invention can of course also 
contain conventional plastic additives, like pigments, UV stabilizers, 
antioxidants, etc., that have in a known way a beneficial effect on the 
appearance and stability of the still uncured pastes or of the cured 
products. Slight amounts of salts of heavy metals like iron, copper, 
manganese, cobalt, tin, chromium, nickel, and zinc can likewise be added 
to promote adhesion to the dental tissue for example. Curative 
constituents such as cortisone or corticoids, oleum pedum tauri (neatsfoot 
oil), etc. can also be added, not for purposes of physical chemistry but 
if indicated for strictly medicinal purposes. The function of the 
composite cement will then be not only that of a cement and in certain 
cases of a donor of calcium ions or contributor to the pH, but also of a 
pharmaceutical form. Compounds, such as sodium fluorophosphate or 
aminofluorides, that donate fluoride, can also be added for similar 
reasons. 
The composite cements in accordance with the invention to some extent 
exhibit the outstanding properties that have previously been ascribed only 
to composites or only to cements. They are in cost cases distinguished by 
good breaking strength and edge stability, satisfactory hardness, low 
brittleness, and good tissue compatibility, and even demonstrate the 
potential of highly alkaline-reacting plastic fillings. They are contain a 
comparable filler. Acrylic-based filling materials constructed on 
polymerizable unsaturated monomers can be copolymerized and provide a 
secure chemical bond. They also securely adhere chemically via ionic 
reactions to cements and to the dental tissue. 
It is also possible to obtain light-curing (photocuring) composite cements. 
Not of the least importance is that it is hardly necessary any longer to 
add paraffin oil, polymers, linseed oil, surface-active substances, etc. 
as in some type of cement for reasons of consistency or solubility. The 
polymerizable compounds that contain acid groups or acid-derivative groups 
wet the inorganic fillers admirably. 
One interesting property of the new composite cements is that, although 
polymerization shrinkage does occur during setting, the process is 
nullified or even overcompensated simultaneously or subsequently by water 
intake (e.g. hydration processes). This process can be controlled by the 
amount of water present in the unpolymerized mixture as well as by the 
humidity of the ambient medium subsequent to polymerization. 
The composite cements in accordance with the invention are appropriate, 
depending on composition, for root-canal fillings, pulp capping, 
underfilling, filled cavity liners, and filling materials, as well as as 
cements for crowns and inlays and orthodontic adhesives, as protective 
films for etched enamel, as adhesive opaques, and as adhesion-promoting 
intermediate layers between cements and composites. Not least important, 
polymerizable- hard, and very break-resistant dental plaster can be 
prepared. They also have a potential for employment as bone cements and as 
cements for general purposes. 
The composite cements in accordance with the invention are also appropriate 
for producing casts, in which case they can be employed directly and in 
conjunction with metal armatures. They are particularly appropriate as 
implants, especially when the casts include calcium compounds. 
The preparations that will now be specified are intended to illustrate the 
invention. Proportions are in terms of percent by weight unless otherwise 
specified. 
PREATION 1. A POLYMETHACRYLATED OLIGOMALEIC ACID 260 g of maleic-acid 
anhydride were refluxed with 2000 ml of toluene and 40 g of benzoyl 
peroxide for 6 days. A brownish-orange precipitate occurred. Upon 
termination of the residue washed with hexane. The yield was 200 g, which 
was treated with an equal volume of tetrahydrofuran. 
A mean molecular weight of 439 was determined, corresponding to an 
approximate oligomerization degree of 4 maleic-acid anhydride units. The 
IR spectrum exhibited the C.dbd.O band of anhydride groups (1790 
cm.sup.-1) but no acid-OH or double bonds. 100 g of the solution of 
oligomaleic-acid anhydride in tetrahydrofuran were treated with 10 g of 
powdered zinc, stirred, and filtered again. The solution was definitely 
light in color. 
60 g of hydroxyethyl methacrylate and catalytic volumes of orthophosphoric 
acid were added and the batch was allowed to stand for 2 weeks. The 
mixture was definitely viscous. Drawing off the volatile constituents in 
the vacuum and washing the batch in hexane resulted in a viscous oil that 
dissolved very well in acetone and in TEDMA and bis-GMA as well. 
The anhydride C.dbd.O band in the IR spectrum was almost invisible, 
although an acid-OH band and a double-bond band were definitely evident. 
PREATION. 2. A POLYMETHACRYLATED POLYCARBOXYLPOLYPHOSPHONIC ACID 
Powdered zinc was stirred into 100 g of the solution of oligomaleic-acid 
anhydride in tetrahydrofuran from Preparation 1, and the batch was treated 
with 30 g of hydroxyethyl methacrylate. 
The mixture was allowed to react for 2 weeks at room temperature. 40 g of 
hydroxyethane-1,1-diphosphonic acid was dissolved therein and the batch 
was allowed to stand for 2 more weeks. 
Extracting the tetrahydrofuran resulted in a rather viscous liquid, which 
was washed with hexane. The IR spectrum exhibited C.dbd.C bands at 1640 
cm.sup.-1 and P(O)OH bands at 1200 cm.sup.-1. The substance reacts like an 
acid and turns yellow when activator and peroxide are added. 
PREATION 3. A PREPOLYMERIC POLYMETHACRYLATED POLYMALEIC ACID 60 g of 
maleic-acid anhydride and 9 g of lauroyl peroxide were refluxed for 4 days 
in 150 ml of tetrahydrofuran. The tetrahydrofuran was extracted and the 
resulting viscous oil washed with hexane. 
The polymaleic-acid anhydride has a molecular weight of 1850, corresponding 
to approximately 17 units. The IR spectrum was identical with that of the 
oligomaleic-acid anhydride from Example 4. 
9.8 g of the oil were dissolved in 30 ml of THF and stirred with 2 g of 
hydroxy ethyl methacrylate for two weeks. The THF was extracted, leaving a 
viscous oil of polymethacrylated polymaleic acid with an IR spectrum 
identical to that of the polymethacrylated oligomaleic acid from 
Preparation 1. 
PREATION 4. PREPOLYMERIC POLYMETHACRYLATED POLYCHLOROPHOSPHORIC ACID 
42 g of hydroxyethyl methacrylate and 8 g of lauroyl peroxide were 
dissolved in 400 ml of toluene and allowed to stand for 1 hour at 
65.degree. C. The resulting powder was filtered out, washed with hexane, 
and dried. 
The yield was 40 g of polyhydroxyethyl methacrylate (polyHEMA). The 
molecular weight was 5700, approximately 44 monomer units. The IR spectrum 
was identical to that of the high-molecular poly-HEMA product manufactured 
by the firm of Aldrich. 
8 g of methacrylic-acid chloride and 8 g of triethylamine were stirred into 
13 g of the laboratory poly-HEMA over a period of 3 days. The precipitate 
was washed with water and dried. 
The yield was 15 g of partly methacrylated poly-HEMA. 
3.3 g of this powder were added along with 1.5 g of phosphoryl chloride to 
50 ml of tetrahydrofuran, and the batch was stirred over a period of 4 
days at room temperature. The precipitate was filtered out and washed with 
hexane, resulting in 3.8 g of a white powder. Its IR spectrum can be 
satisfactorily equated with that of a polymethacrylated product with 
--O--P(O)Cl.sub.2 groups. The powder hardly continues to exhibit any C--OH 
bands but still has the C.dbd.O (1730 cm.sup.-1) and C.dbd.C (1640 
cm.sup.-1) bands as well as revealing new bands in the P--O---alkyl range 
(1030 cm.sup.-1). 
PREATION 5. A POLYMETHACRYLATED POLYSULFONATE 
5.4 g of hydroxyethyl methacrylate, 10.1 g of potassium 
methacryloylpropylsulfate, and 1.6 g of lauroyl peroxide were heated in 80 
ml of methyl alcohol and 20 ml of toluene at 65.degree. C. until 
termination of precipitation. The batch was filtered and the filtrate 
washed with hexane and dried. 
The yield was 6.4 g of a water-soluble, powdery molecular weight of 7490, 
corresponding to approximately 20 units for each of the monomers employed. 
1.88 g of the copolymer was stirred along with 0.54 g of methacrylic-acid 
chloride and 0.50 g of triethylamine in 50 ml of tetrahydrofuran for 4 
days at room temperature. The precipitate was washed with hexane and 
dried. 
The yield was 1.92 g of a white, water-soluble, powdery polymethacrylic 
polypotassium sulfonate, continuing to exhibit a C.dbd.C band at 1640 
cm.sup.-1. The potassium content was 7.9% and the sulfur content 6.2%. 
PREATION 6. A POLYMETHACRYLATED POLIBORIC ACID 
3.3 g of the partly methacrylated poly-HEMA from Preparation 4 were heated 
with 3.1 g of boric acid and 4.1 g of phosphoric acid in dioxan at 
80.degree. C. until termination of precipitation. 
The batch was filtered, the filtrate washed free of phosphate and boric 
acid with water, and dried, yielding 3.45 g of a tannish polymethacrylated 
polyboric acid. 
The C.dbd.C and C.dbd.O bands in the IR spectrum are unchanged and new 
(B--OH) bands appear at 3220 cm.sup.-1. The boron content turns out to be 
2.4% by weight.

EXAMPLE 1. PREATION OF A BICOMPONENT COMPOSITE CEMENT BASED ON 
HALOPHOSPHORYLATED BIS-GMA AND POWDER OF PHOSPHATE CEMENT (ZnO/MgO) 
Different bicomponent mixtures were prepared and reacted. 
First component 
A resin mixture was prepared from 
10 parts bisphenol-A-glycidyl methacrylate (bis-GMA) 
10 parts triethyleneglycol dimethacrylate (TEDMA) 
1 part phosphoryl chloride. 
The mixture was allowed to stand for 5 days at room temperature (Resin 1, 
the polymerizable halophosphoric-acid compound specified in European 
Patent No. 0 058 483). 
Some of Resin 1 was catalyzed with 1% benzoyl peroxide (Resin 2). 
A catalyst paste was prepared by thoroughly mixing 22 parts of Resin 2 and 
78 parts of finely ground silanized barium glass (the non-reactive 
filler). This mixture was thick and pasty. 
Second component 
A resin mixture (Resin 3) was prepared from 
50 parts bis-GMA 
50 parts glycerin dimethacrylate 
(both being polymerizable compounds without acid groups) 
1 part N,N-bis-hydroxyethyl para-toluidine 
3 parts sodium benzene sulfonate 
1 part water 
0.002 parts iron oxalate. 
An activator paste was prepared by mixing 24 parts of Resin 3 and 76 parts 
of the powder components of Harvard Phosphate Cement (a phosphate cement 
manufactured on the basis of zinc oxide and magnesium oxide by the firm of 
Hoffman and Richter, Berlin: the reactive filler). 
The catalyst paste was mixed with the activator paste, and the material 
cured in 1 to 2 minutes. A Barcol hardness of 54 was measured 
approximately 30 minutes later. The compressive strength was 1800 
kg/cm.sup.2 subsequent to being kept wet for 24 hours at 37.degree. C. 
This cement in accordance with the invention proved to be highly 
tissue-compatible and was satisfactory as a bone cement. 
EXAMPLE 2. CONTROL FOR EXAMPLE 1 
The powder components of the Harvard cement were cured with the aqueous 
polyacrylic acid (Voco-Chemie, Cuxhaven, mfr.). Curing occurred within the 
interval of 5 to 8 minutes conventional for carboxylate cements. 
After 30 minutes it was hardly possible to establish a Barcol hardness. The 
indenter drove into the cast without meeting much resistance and fractured 
readily. A low level, below 5, was measured subsequent to 3 hours. The 
material was also very fragile. The compressive strength subsequent to 
being kept wet for 24 hours at 37.degree. C. was only 550 kg/cm.sup.2. 
This order of magnitude has also been demonstrated for other classic 
carboxylate cements. Even products improved by the addition of inert 
fillers such as powdered quartz, polymers, or chelating agents to the 
cement exhibited compressive strengths of only 800-900 kg/cm.sup.2. 
EXAMPLE 3. A CURING BICOMPONENT COMPOSITE CEMENT BASED ON 
HALOPHOSPHORYLATED BIS-GMA AND POWDER OF IONOMER CEMENT 
An activator paste was prepared by adding 7 parts of Fuji ionomer-cement 
powder (G-C Dental Corp., Japan, mfr.) to 3 parts of the Resin 3 from 
Example 1. This paste was mixed with equal amounts of the catalyst paste 
from Example 1. The material cured rapidly. A Barcol hardness of 57 was 
measured 30 minutes later. The compressive strength subsequent to being 
kept wet for 24 hours at 37.degree. C. was 2100 kg/cm.sup.2. No 
dissolution was demonstrable subsequent to being kept in water for 24 
hours at 37.degree. C. 
EXAMPLE 4. TWO MIX-CURING PASTES BASED ON POLYMETHACRYL-POLYCARBOXYLIC ACID 
AND POWDER OF PHOSPHATE CEMENT 
Two curing pastes were mixed. 
The first paste (Resin 4) was prepared from 
90 parts triethyleneglycol dimethacrylate 
7 parts polymethacrylpolycarboxylic acid (Prep. 1) 
2 parts benzoyl peroxide. 
This resin was filled to 68% with silanized amorphous sintered silicon 
dioxide and represented the catalyst paste. 
For the second paste a mixture of 
50 parts bis-GMA 
50 parts hydroxyethyl methacrylate 
1 part N,N-bis-hydroxyethyl para-toluidine 
3 parts sodium benzene sulfonate 
were kneaded with phosphate cement. The filler in this activator paste 
accounted for 75%. The activator and catalyst pastes were mixed to 
initiate curing. 
The cured composite cement has a compressive strength of 1500 kg/cm.sup.2. 
The Barcol hardness was 51. The material exhibited no fatigue subsequent 
to 4000 cycles of stress testing (immersions in water at temperatures 
alternating between 0.degree. and 60.degree. C.). The Barcol hardness in 
fact actually increased to 59, and the material was extremely edge-stable. 
It adhered very well to bovine dentin and enamel. 
EXAMPLE 5 
A highly alkaline cement mixture was obtained by mixing equal parts of an 
activator paste consisting of 
24 parts Resin 3 (Ex. 1) 
22 parts calcium hydroxide 
22 parts barium sulfate 
with the catalyst paste from Example 1 and allowing it to cure. 
The material was hard even a few minutes later, with a Barcol hardness of 
20 and a compressive strength of 2000 kg/cm.sup.2. The pH was over 11, and 
the product accordingly highly water-resistant. Given these properties and 
the fact that Ca(OH).sub.2 preparations stimulate secondary dentin 
formation, this X-ray opaque cement was extraordinarily effective as an 
underfilling material, as a root-canal filling material, and as a cement 
for securing metal pins in restoring stumps. Even improved Ca(OH).sub.2 
cements based on polycarboxylic acids or salicylates exhibited maximum 
compressive strengths of only 300 kg/cm.sup.2. Furthermore, they are known 
to fall apart in a few years, leaving hollow spaces. The latter cannot be 
expected of the composite cements in accordance with the invention, which 
are permeated by polymer networks. 
EXAMPLE 6 
Another polymerizable Ca(OH).sub.2 cement was obtained by mixing 
50 parts triethyleneglycol dimethacrylate 
50 parts polymethacrylpolycarboxylpolyphosphonic acid 
(Prep. 2) 
1 part butyl permaleinate 
and by mixing 6 parts of this mixture with 5 parts of calcium hydroxide and 
5 parts of barium sulfate. 
The mixture hardened in 5 to 7 minutes. 
EXAMPLE 7. 
A light-curing Ca(OH).sub.2 cement was obtained by mixing 
50 parts triethyleneglycol dimethacrylate 
50 parts polymethacryloligomaleic acid (Prep. 1) 
1 part camphor quinone 
1 part dimethylaminoethyl methacrylate 
50 parts calcium hydroxide 
50 parts barium sulfate. 
The mixture was light-cured in a Litema HL-150 halogen-lamp apparatus for 1 
minute. The surface hardened in 40 seconds, and another layer of 
light-curing Composite Merz could be polymerized onto it immediately. 
All of the polymerizable cement mixtures prepared as specified with 
reference to Examples 1 through 6 can also be copolymerized with 
polymerizable plastic filling material or resin materials based on 
unsaturated olefinic compounds. Thus, a secure bond can be obtained 
between composite cements in accordance with the invention and 
conventional composites. 
EXAMPLE 8. PREATION OF A LIGHT-CURING COMPOSITE IONOMER CEMENT. 
5 g of a mixture of 
50 parts bis-GMA 
50 parts triethyleneglycol dimethacrylate 
20 parts polymethacryl=ted polymaleic acid (Prep. 3) 
are absorbed onto 30 g of the powdered component of the ionomer cement 
Ceramfil Alpha (PSP Dental, Belvedere, Kent, UK, mfr.) with a solution of 
ethyl alcohol and dried. 
5 g of this powder are thoroughly mixed with 5 g of the polyacrylic-acid 
coated, powdered ionomer powder from the product Ceramfil Beta, Aqua Set 
(PSP Dental) to create a new ionomer-cement powder (I) for the 
light-curing ionomer cement. 
A liquid (II) is prepared from 
15 g H.sub.2 O 
10 g hydroxyethyl methacrylate 
0.15 g N,N-bis-hydroxyethll para-toluidine 
0.45 g sodium benzene sulfonate 
0.08 g camphor quinone. 
The powder (I) is mixed with the liquid (II) to the consistency of a paste 
(app. 4 parts powder to 1 part liquid). Some (A) of the mixture is kept in 
the dark and some (B) cured under a Litema HL-150 halogen lamp. 
Portion A begins to cure in 10 minutes and is finished in 20 minutes. A 
2-mm thick coating of portion A, however, is well cured in 40 seconds. 
Samples of Portions A and B are prepared in accordance with DIN Standard 13 
922 and their transverse strength measured 3 hours later. 
Samples were also prepared by mixing up the glass-and-ionomer cement 
Ceramfil Beta, Aqua Set (powder and water). Curing commenced in 5 minutes 
and they were well cured in 10 minutes. Their transverse strength was also 
measured 3 hours later. 
______________________________________ 
Transverse strengths 
Light-curing 
Light-curing 
ionomer cement 
ionomer cement 
Ceramfil Beta, Aqua Set 
(light-cured) 
(dark-cured) ionomer cement 
______________________________________ 
11.6 (3 h) 6.3 (3 h) 12.1 (3 h) 
43.0 (20 h) 
8.8 (20 h) 13.2 (20 h) 
______________________________________ 
EXAMPLE 9. A LIGHT-HARDENING IONOMER CEMENT 
A mixture of 1.50 g of polymethacrylated polychlorophosphoric acid (Prep. 
4) and 0.25 g of triethylene glycol dimethacrylate in ethyl alcohol is 
absorbed onto 1.75 g of the ionomer-cement powder from Ceramfil Beta, Aqua 
Set and dried (powder component). 
A reaction partner (liquid component) is prepared from a mixture of 
150 parts hydroxyethyl methacrylate 
50 parts water 
1 part camphor quinone 
2 parts N,N-bis-hydroxyethyl para-toluidine 
5 parts sodium benzene sulfonate. 
4 parts of the powder component and 1 part of the liquid component are 
mixed to the consistency of paste. Some is cured under a halogen lamp (20 
sec) and some left in the dark (until it cured, in about 50 min). 
3 hours later the sample cured under the halide lamp exhibited a transverse 
strength of 18.4 N/mm.sup.2 and, 20 hours later, one of 27.2 N/mm.sup.2. 
EXAMPLE 10. A ROOT-CANAL FILLING MATERIAL 
Equal parts of a paste consisting of 
12 parts hydroxyethyl methacrylate 
11 parts glycerin dimethacrylate 
1 part N,N-bis-hydroxyethyl para-toluidine 
76 parts Ceramfil Alpha ionomer powder 
and of a resin consisting of 
5 parts of polymethacrylated polyboric acid (Prep. 6) 
50 parts bis-GMA 
45 parts triethyleneglycol dimethacrylate 
3 parts benzoyl peroxide 
were mixed and employed to fill an excavated root canal. The mixture 
solidifies in 2 minutes. The tooth is left in a methylene-blue bath for 14 
days, sliced longitudinally, and polished. No penetration of the dye 
between the dental tissue and the filler material is demonstrable. 
EXAMPLE 11. AN ADHESIVE CEMENT 
A fraction with a particle size of less than 20 .mu.m was screened out of 
the silicate-cement powder from the product Omnifil (Jota, Germany, mfr.). 
100 parts were mixed into a paste (I) with 
0.3 parts sodium benzene sulfonate 
0.4 parts N,N-bis-hydroxyethyl para-toluidine 
7 parts bis-GMA 
8 parts triethyleneglycol dimethacrylate. 
5 parts of benzoyl peroxide are absorbed onto another 100 parts of the 
screened product and the results also mixed into a paste (II) with 
7 parts bis-GMA 
8 parts triethyleneglycol dimethacrylate. 
A liquid (III) was prepared from 
13 parts phosphoric acid 
15 parts hydroxyethyl methacrylate 
60 parts water 
12 parts polymethacrylated polysulfonate (Prep. 5). 
1 part each of Pastes I and II and of Liquid II were mixed and applied 
between etched tooth enamel and a metal plate of Resilloy (Renfert, 
Germany, mfr.). Light pressure was exerted of the plate. The adhesive 
mixture solidified in 2 minutes. 
5 minutes later the cemented sample was pulled apart with a 
tensile-strength testing apparatus at a load of 5.6 N/mm.sup.2. 
EXAMPLE 12. AN EXPANDING LIGHT-CURING CAVITY LINER 
A light-curing composite cement is prepared from 
50 parts bis-GMA 
50 parts triethyleneglycol dimethacrylate 
1 part camphor quinone 
1 part butyl dimethylaniline 
10 parts polymethacrylated polymaleic acid (Prep. 3) 
40 parts microfine silanized silicic acid 
240 parts Ceramfil Beta, Aqua Set ionomer-cement powder. 
The composite cement completely cures to a layer thickness of 3 mm in 20 
seconds of irradiation with the halogen lamp. The polymerization shrinkage 
in water is measured at 0.0% and, 30 minutes later the sample exhibits 
expansion of 0.24% and, in 16 hours, of 0.80%. The value hardly varies 
subsequently. Given these properties, this composite cement is preferable 
as a cavity liner below a tooth-filling material. Much of the 
polymerization shrinkage of the material can be compensated by its 
expansion properties. 
EXAMPLE 13. 
A polymerizable plaster was prepared by covering 90 parts of Moldano 
plaster (Bayer) with an alcoholic solution of 10 parts of the Resin 1 from 
Example 1 and withdrawing the solvent. 
The resulting plaster powder was mixed into a fluid pulp with a mixture of 
25 parts of water, to which had been added 1% N,N-bis-hydroxyethyl 
para-toluidine and 3% sodium benzene sulfonate, and 75 parts of 
hydroxyethyl methacrylate. 
The mixture was poured into a mold. It cured in approximately 2 minutes. 
The mold was removed, leaving an excellent cast that was hardly brittle at 
all and exhibited high resistance to scratching. 
EXAMPLE 14. CONTROL 
The procedure described with reference to Example 13 was followed, mixing, 
however, the untreated plaster into a fluid pulp with water. The mixture 
took 30 minutes to set and the resulting cast was very brittle and easy to 
scratch.