Dental composition system and method

The invention provides dental composition system having curable liquid which is useful alone as a light curable composition and which is useful by mixing with a powder in preselected proportions to form dual cure compositions. The composition system is useful as bonding agent, cement, liner, base, restorative, pit and fissure sealants, and/or core build-up material, having improved adhesion to dentin. After storing the powder and the liquid in separate containers for at least two weeks and then mixing a portion of the powder and a portion of the liquid to form a mixture, the polymerizable compound polymerizes within 20 minutes of the mixing to form a first polymeric material having a flexural strength of at least 50 MPa, and an expansion in water at 37.degree. C. after 90 days of less than 1 percent by volume.

The invention relates to dental compositions. In particular the invention 
provides dental composition system which polymerizes in-situ by reaction 
between polymerizable monomers and/or prepolymers. Dental composition 
systems in accordance with the invention are useful as dental cement, 
liner, base, restorative, core build-up material and pit and fissure 
sealants. A liquid composition is useful alone as a sealant. The liquid is 
also useful by mixing the liquid in preselected proportions with a powder 
containing glass. 
It is the object of the invention to provide a method of using a dental 
composition system having a liquid composition and a powder composition. 
The liquid composition is enclosed by a first container and includes a 
polymerizable compound, a photoinitiator, and a first part of a redox 
polymerization catalyst system. The powder composition is enclosed by a 
second container and includes filler powder and a second part of the 
polymerization redox catalyst system. A first tooth surface is cleaned and 
then a first portion of the liquid is applied to the first tooth surface. 
A second portion of the liquid is mixed with a first portion of the powder 
to form a first mixture, which is applied to a second tooth surface. 
Huang et al in U.S. Pat. No. 5,367,002 disclose a light curable dental 
composition and method which includes a powder in combination with a 
liquid. Lu et al in U.S. Pat. No. 5,338,773 disclose dental composition 
and method which includes a powder in combination with a liquid. The prior 
art does not disclose a dual cure dental composition and method which 
includes a powder in combination with a liquid, which after storing the 
powder and liquid in separate containers for at least two weeks, 
polymerizes within 20 minutes of mixing the powder and liquid to form a 
polymeric material having a flexural strength of at least 50 MPa as is 
provided by the invention. 
The invention overcomes the problems of the prior art. 
Excavating carie dentin as used herein refers to the removal of dentin 
softened by decay by a hand held tool which does not have a motor. 
Peroxide decay and peroxide decomposing as used herein refer to break down 
of peroxide compounds which initiate or facilitate polymerization to 
compounds which do not initiate or facilitate polymerization. 
BRIEF DESCRIPTION OF THE INVENTION 
The invention provides dental composition system having curable liquid 
which is useful alone as a light curable composition and which is useful 
by mixing with a powder in preselected proportions to form dual cure 
compositions. The composition system is useful as cement, liner, base, 
restorative, pit and fissure sealants, and/or core build-up material, 
having improved adhesion to dentin. A dual cure dental composition 
includes a powder in combination with a liquid, which includes 
polymerizable compounds. After storing the powder and liquid in separate 
containers for at least two weeks, the polymerizable compounds polymerize 
within 20 minutes of mixing the powder and liquid to form a first 
polymeric material having a flexural strength of at least 50 MPa, and an 
expansion in water at 37.degree. C. after 90 days of less than 1 percent 
by volume. More preferably the polymerizable compounds polymerize within 
10 minutes of mixing the powder and liquid to form a polymeric material 
having a flexural strength of at least 50 MPa. The liquid is stored in a 
container for at least two weeks and a portion of the liquid is exposed to 
actinic light and polymerizes within 40 seconds to form a second polymeric 
material having an expansion in water at 37.degree. C. after 90 days of 
less than 1 percent by volume. More preferably the polymerizable compounds 
polymerize within 10 minutes of exposing the liquid to liquid to form a 
polymeric material having a flexural strength of at least 50 MPa, and an 
expansion in water at 37.degree. C. after 90 days of less than 1 percent 
by volume. 
A storage stable polymerizable liquid composition which includes a 
polymerizable phosphoric acid compound and a peroxide compound. 
Preferably, while in the liquid composition, the peroxide compound 
decomposes within one week at 23.degree. C. by less than or about equal to 
the percent of decomposition of TBPO within one week at 23.degree. C. The 
liquid polymerizes within 40 seconds from the moment of exposing the 
liquid to light (exposure to light is typically for about 2-10 seconds) to 
form a polymeric material having an expansion of less than 1 percent by 
volume after 90 days in water at 37.degree. C. 
DETAILED DESCRIPTION OF THE INVENTION 
In a preferred embodiment, the invention provides a curable liquid useful 
alone and useful with a powder in preselected proportions to form dental 
cement, liner, base, restorative, pit and fissure sealants, and core 
build-up material. For mixtures, the ratio preferably used is from 0.5 to 
6 parts by weight powder to 1 part by weight liquid. The liquid is cured 
by exposure to visible light. The liquid and powder mixtures self cure. 
A preferred embodiment of the invention provides a method of using a dental 
composition system having a liquid composition and a powder composition. 
The liquid composition is enclosed by a first container and includes a 
polymerizable compound, a photoinitiator, and a first part of a redox 
polymerization catalyst system. The powder composition is enclosed by a 
second container and includes filler powder and a second part of the 
polymerization redox catalyst system. A first tooth surface is cleaned and 
then a first portion of the liquid is applied to the first tooth surface. 
A second portion of the liquid is mixed with a first portion of the powder 
to form a first mixture, which is applied to a second tooth surface. 
Preferably the first tooth surface is exposed to light whereby the liquid 
composition is cured on the first tooth surface. 
In a preferred embodiment of the invention, the first tooth surface is in a 
first patient's mouth and the second tooth surface is in a second 
patient's mouth. The second tooth surface is preferably treated for 
example by etching the second tooth enamel surface, by excavating carie 
dentin or by drilling into the dentin thereof. Preferably the second 
portion of the liquid and the first portion of the powder are mixed in a 
weight ratio of between 1 to 5 and 4 to 1. More preferably the second 
portion of the liquid and the first portion of the powder are mixed in a 
weight ratio of between 1 to 3.4 and 1 to 4.5. 
In a preferred embodiment of the invention a bracket is applied to the 
second tooth. Preferably a third portion of the liquid is mixed with a 
second portion of the powder to form a second mixture, which is applied 
the second mixture to a third tooth surface. Preferably, the powder 
includes fluoride elutable glass. 
The compositions of the invention preferably contain powder elute fluoride 
ion to reduce the solubility of adjacent enamel and dentin and reduce the 
incidence of secondary caries. 
Compositions of the present invention which include powder may be light 
cured to provide filling materials especially useful in Class III and 
Class V restorations. They are also useful as core build-up materials at 
high filler solids concentrations with good strength values and 
insensitivity to trace interfacial water, the combination of which is an 
improvement in this invention. 
The liquid alone is useful as a light curable dental sealant. The liquid 
mixed with the powder is useful to provide consistencies suitable for use 
as dual cure pit and fissure sealants. Mixtures of the liquid and powder 
in ratios of powder to liquid of from about 3.5 to 1 to about 5 to 1 are 
useful as dual cure restoratives and as bases of low solubility and good 
strength under other filling materials including conventional composites 
and amalgams. The powder containing compositions polymerize rapidly and 
preferably elute fluoride ions which can react with hydroxyapatite of the 
tooth to form the less acid-soluble fluorapatite structure to reduce the 
risk of caries adjacent the filling. 
In accordance with an embodiment of the invention, intermediate solids 
concentrations having ratios of powder to liquid of from about 1.2 to 1 to 
about 1.8 to 1 are provided for dual curing adhesive dental cements used 
under light-transmitting glass-ceramic inlays, crowns, dental veneers, 
orthodontic, brackets, or to fill pits and fissures in teeth according to 
current dental practice. 
Dual cure compositions of the invention utilize two catalyst systems to 
cause them to harden promptly. Thus for example, for light curing the 
catalyst system includes 1) a light sensitizer, for example 
(2,4,6-trimethyl benzoyl) phosphine oxide, causes polymerization to be 
initiated upon exposure to activating wavelengths of light; and 2) a 
reducing compound. Accelerators for the polymerization, for example metal 
salts such as copper acetyl-acetonate, phosphinic acids and phosphinates, 
may also be used. 
A room temperature activating catalyst system comprised of a redox 
polymerization system is employed advantageously with the compositions of 
the invention by adding, for example, a peroxide capable of producing free 
radicals when activated by a reducing agent at such temperature. Peroxides 
useful in the invention include tert-Butyl peroxybenzoate (TBPO). Suitable 
promoters include the same reducing agents and accelerators used in light 
curing catalyst systems. Preferably dual curable dental compositions of 
the invention are comprised of 0.01 to 10 parts by weight, more preferably 
0.02 to 5 parts by weight, and most preferably 0.03 to 4 parts by weight, 
of a two catalyst system ingredients in the polymerizable powder and 
liquid composition. 
Preferably dual curable dental compositions of the invention include 1 to 
60 percent by weight, more preferably 2 to 50 percent by weight, most 
preferably 2 to 40 percent by weight, of an acid functional polymerizable 
organic compound in the cured composition. In accordance with a preferred 
embodiment of the invention, liquids contain polymerizable acid functional 
materials having ethylenic unsaturation include, among others, organic 
esters of one or more acids of phosphorus (hereinafter referred to as 
phosphorus acid esters), wherein the organic portion of the ester contains 
at least one polymerizable ethylenically unsaturated group. The organic 
portion of the ester may be alkenyl, alkenoxy, cycloalkenyl, aralkenyl, or 
alkenaryl, and preferably may have from 2 to 40 carbon atoms. The organic 
portion may be straight chain, branches, or cyclic, can contain skeletal 
hetero atoms, i.e., atoms other than carbon, and can be unsubstituted or 
substituted with moieties which do not interfere with the free radical 
polymerization of the phosphorus acid esters. Examples of unsaturated 
phosphorus containing acid esters which may be used include, but are not 
limited to, monomers containing phosphoric acid groups such as 
hydroxyethyl methacrylate monophosphate, 
2,2,-bis(.alpha.-meth-acryloxy-.beta.-hydroxy-propoxyphenyl) propane 
diphosphonate (BIS-GMA diphosphonate), BIS-GMA diphosphate, 
methacryloxyethyl phosphate, and glyceryl dimethacrylate phosphate. Other 
suitable polymerizable acid esters are disclosed, for example, in U.S. 
Pat. No. 4,499,251 to Omura et al, U.S. Pat. No. 4,222,780 to Shibantani 
et al, U.S. Pat. No. No. 4,235,633 to Tomioka, U.S. Pat. No. 4,259,117 to 
Yamauchi et al, U.S. Pat. No. 4,368,043 to Yamauchi et al, and Sakashita 
in U.S. Pat. No. 4,920,188. 
In accordance with a preferred embodiment of this invention, the liquid 
contains polymerizable phosphate acid ester monomers which are reactive 
with cations eluted from the reactive fillers. Upon polymerization, alone 
or in combination with other polymerizable components, these form 
polyacids which are also reactive with cations. Polymerizable phosphates 
preferred for use with this invention are adhesive to tooth structure and 
improve the adhesion of the compositions. 
In accordance with an embodiment of the invention the liquid composition 
preferably includes phosphoric acid esters: 
##STR1## 
wherein R.sub.1 is hydrogen, lower alkyl of from 1 to 5 carbons, halogen 
or CN radical; n and m are independently integers of 1 or greater, Z is an 
aliphatic, cycloaliphatic or aryl radical having a carbon chain comprising 
at least 2 carbon atoms and 0 or more oxygen or sulfur atoms and having a 
valency of m+n. In a preferred embodiment of the invention, the phosphoric 
acid esters used are those compositions of Formula I wherein m is 1. 
In accordance with a further embodiment of the invention, acid esters 
within the scope of Formula I are partially neutralized to form phosphoric 
acid esters of the general Formula II and III as follows: 
##STR2## 
wherein M, M.sub.1 and M.sub.2 each is independently a cation, such as K, 
Li, Na, NH.sub.4 or an amine. Preferably 20-40 equivalent weight percent 
of the phosphoric acid ester is neutralized by reaction with base. 
Preferably the polymerizable liquid composition includes a polymerizable 
carboxylic acid compound, such as OEMA to adhere the polymeric material 
formed to metal containing substrates for example brackets and crowns. 
Liquid compositions of the invention preferably include polymerizable 
unsaturated substituted aromatic compounds containing at least one acid 
moiety. These aromatic compounds are preferably within the scope of the 
general formula (I): 
##STR3## 
wherein R.sub.1 and R.sub.2 each independently is a polymerizable 
unsaturated moiety having from 2 to 13 carbon atoms, 
R.sub.3, R.sub.4, R.sub.5, and R.sub.6 each independently is hydrogen, 
halogen, alkyl having from 1 to 10 carbon atoms or halogenated alkyl of 
from 1 to 10 carbon atoms, 
R.sub.9, R.sub.10, R.sub.11, R.sub.12, R.sub.13 and R.sub.14 each 
independently is hydrogen, alkyl having from 1 to 10 carbon atoms or aryl 
having from 6 to 10 carbon atoms. 
Z.sub.1 and Z.sub.2 each independently is a moiety including an acid group 
or a reactive acid derivative, 
a, m and n each independently is 0 or 1, 
b and p each independently is an integer from 1 to 10. 
In accordance with a preferred embodiment of the invention R.sub.1 and 
R.sub.2 each independently is: 
##STR4## 
wherein R.sub.7 a divalent carbon containing radical and 
R.sub.8 is hydrogen, halogen or alkyl having from to 10 carbon atoms. 
In a preferred embodiment of the invention compounds are provided within 
the scope of general formula I wherein n and m are zero, X is oxygen, 
sulfonyl or ditrifluoromethyl; Z.sub.1 and Z.sub.2 are --COO(M) wherein M 
is hydrogen or an alkali metal, alkaline-earth metal, amine or amine salt; 
and R.sub.1 and R.sub.2 are 
##STR5## 
Most preferably compounds within the scope of general formula I are those 
wherein X is oxygen, and M is hydrogen, Li, Na or K. Appropriate 
polymerizable unsaturated groups R.sub.1 and R.sub.2 independently are 
alkenyl, alkenoxy, cycloalkenyl, arylalkenyl, and alkenaryl moieties; with 
vinyl, and styryl moieties being preferred, and acryl and methacryl 
moieties that constitute the polymerizable groups of many monomers in 
dental materials being especially preferred. 
In accordance with an embodiment of the composite composition, phosphoric 
acid esters useful in the composition include: 
##STR6## 
wherein R.sub.1 is hydrogen, lower alkyl of from 1 to 5 carbons, halogen 
or CN radical; n and m are independently integers of 1 or greater, Z is an 
aliphatic, cycloaliphatic or aryl radical having a carbon chain comprising 
at least 2 carbon atoms and 0 or more oxygen or sulfur atoms and having a 
valency of m+n. In a preferred embodiment of the invention, the phosphoric 
acid esters used are those compositions of Formula I wherein m is 1. 
Polymerizable liquid compositions include monomers and/or prepolymers 
selected to form, in combination with the other ingredients of the liquid 
composition of the invention, a balance of properties in the liquid prior 
to polymerization, as well as in the polymerized product. These include 
mutual solubility, stability, viscosity, mechanical strength and physical 
integrity of the cured materials, biotolerance, and the like. Monomers 
useful as polymerizable monomer in accordance with the invention include 
those disclosed in Dentsply's U.S. Pat. Nos. 3,825,518, 3709,866, 
4,553,940, 4,514,342, and 4,657,941. Including ethylene glycol 
dimethacrylate, triethylene glycol dimethacrylate, dipropylene glycol 
dimethacrylate, BIS-GMA, 1,1,6 trimethyl hexamethylene urethane 
dimethacrylate, cyclohexyl methacrylate, hydroxyethyl methacrylate, 
glycerol mono-, di- and trimethacrylates. Prepolymers useful in accordance 
with the invention include adducts formed by the reaction of BIS-GMA and 
1,1,6 trimethyl hexamethylene diisocyanate, the adducts formed between 
polyethers and diisocyanates end capped with hydroxyethyl methacrylate, 
the adducts formed by polyethers or polyalcohols with an isocyanato 
methacrylate such as isocyanatoethyl methacrylate. By substituting the 
methacrylate function of these monomers and prepolymers with the 
corresponding acrylate, fluoroacrylate, or cyanoacrylate function, 
additional, polymerizable moieties are provided for use as monomers or 
prepolymers in accordance with the invention. Preferably curable dental 
compositions of the invention include 1 to 60 parts by weight, more 
preferably 2 to 50 percent by weight, most preferably 5 to 40 percent by 
weight, of polymerizable monomer and/or prepolymer in the cured 
composition. 
Preferred reactive fillers for use in accordance with the invention 
preferably include elutable cations having a valence of 2 or more, for 
example, strontium, calcium, zinc, aluminum, iron, zirconium. Elutable 
glasses also preferably contain elutable fluoride ion, for example, finely 
ground aluminosilicate and silicate glasses including, for example without 
limitation, calcium fluoroaluminosilicate glasses, strontium 
fluoroalumino-silicates, strontium-calcium fluoroaluminosilicates and the 
like. Preferably curable dental powder compositions of the invention 
include 10 to 90 percent by weight, more preferably 20 to 90 percent by 
weight, most preferably 30 to 90 percent by weight, reactive glass in the 
cured composition. 
As used herein, non-reactive fillers are characterized as those which do 
not form hardened coherent products within 10 hours by reaction between 
the glass filler and a 50% aqueous solution of the polyacid after being 
mixed at a ratio of 2g powder to 1 gram polyacid solution. Non-reactive 
fillers are optionally included in compositions of the invention to 
include beneficial properties. For example, fumed silica is a non-reactive 
filler which is included to provide viscosity control, and barium 
aluminosilicate is a non-reactive filler included to extend the 
composition, and increase its strength and radiopacity. Curable dental 
compositions in accordance with one embodiment of the invention include 
preferably 1 to 60 percent by weight, more preferably 4 to 40 percent by 
weight, most preferably 4 to 30 percent by weight, of the non-reactive 
filler in the cured composition. 
In accordance with a preferred embodiment of the invention is provided a 
storage stable polymerizable liquid composition which includes a 
polymerizable phosphoric acid compound and a peroxide compound which 
decomposes by less than 50 percent within one week at 23.degree. C. A 
preferred peroxide is TBPO. Such compositions are stable for at least 2 
weeks and more preferably at least one month and less preferably at least 
6 months. Such liquid compositions in accordance with the invention 
preferably polymerize within 20 minutes and more preferably within 10 
minutes of exposure to actinic light. 
Preferably, both reactive and non-reactive fillers are included having a 
coating such as an organic phosphate for compatibility with the organic 
components of the compositions. A suitable organic phosphate is 
pentaerythritol trimethacrylate phosphate. Alternative coatings, 
especially for the non-reactive fillers, include organic silane, such as 
gamma methacryloxy propyl trimethoxy silane applied by procedures well 
known in the art. 
Preferably, compositions in accordance with the invention are water 
tolerant to reduce the effects of surface contamination by water which may 
affect adhesion between tooth and restorative. Preferably, compositions in 
accordance with the invention more nearly match the coefficient of thermal 
expansion than do conventional composites to permit greater longevity to 
the adhesive bond formed. Preferably, compositions in accordance with the 
invention are radiopaque through the use of an radiopaque non-reactive 
fillers.

EXAMPLE 1 
Powder for use with liquids in accordance with the invention is formed by 
adding 96.83 parts by weight strontium aluminofluorosilicate glass; 1.0 
parts by weight benzoyl peroxide; 0.15 parts by weight ascorbyl palmitate 
FCC concentrate, 0.02 parts by weight cupric acetylacetonate and 2.0 parts 
by weight sodium fluoride. 
EXAMPLE 2 
Powder for use with liquids in accordance with the invention is formed by 
adding 95.66 parts by weight strontium aluminofluorosilicate glass; 2.0 
parts by weight benzoyl peroxide; 0.3 parts by weight ascorbyl palmitate 
FCC concentrate, 0.04 parts by weight cupric acetylacetonate and 2.0 parts 
by weight sodium fluoride. 
EXAMPLE 3 
Polymerizable liquid prepared by mixing 17.0 parts by weight of 
4,4'-oxydiphenylether-1,1,6,6"-tetracarboxylic acid 1,1'-(methacryloxy) 
dimethacrylate (OEMA), 1.0 parts by weight of water, 42.6 parts by weight 
of bisphenol-A glycidyl dimethacrylate (Bis GMA); 28.4 parts by weight 
triethyleneglycol dimethacrylate; 10.0 parts by weight dipentaerythritol 
pentacrylate phosphoric acid ester (PENTA); 0.5 parts by weight of 
tert-Butyl peroxybenzoate (TBPO) and 0.5 parts by weight diphenyl 
(2,4,6-trimethyl benzoyl) phosphine oxide (L-TPO). 
EXAMPLE 4 
Polymerizable liquid prepared by mixing 17.0 parts by weight of 
4,4'-oxydiphenylether-1,1,6,6"-tetracarboxylic acid 1,1'-(methacryloxy) 
dimethacrylate (OEMA), 1.0 parts by weight of water, 40 parts by weight of 
bisphenol-A glycidyl dimethacrylate (Bis GMA); 30.5 parts by weight 
triethyleneglycol dimethacrylate; 10.0 parts by weight dipentaerythritol 
pentacrylate phosphoric acid ester (PENTA); 1.0 parts by weight of 
tert-Butyl peroxybenzoate (TBPO) and 0.5 parts by weight diphenyl 
(2,4,6-trimethyl benzoyl) phosphine oxide (L-TPO). 
EXAMPLE 4A 
The polymerizable liquid prepared in Example 4 is brushed onto a cleaned 
tooth and then exposed to light to from a sealant coating on the tooth. 
EXAMPLE 4B 
The polymerizable liquid prepared in Example 3 is brushed onto a cleaned 
tooth and then exposed to light to from a sealant coating on the tooth. 
EXAMPLE 5 
A mixture suitable as a dental cement is prepared by mixing 2.5 parts by 
weight of the powder formed as in Example 2 with 1 part by weight of the 
polymerizable liquid formed as in Example 4. Samples are applied to a 
tooth surface in a patient's mouth and self polymerizes within 10 minutes 
to form a cured polymeric material. 
EXAMPLE 6 
A mixture suitable as a dental liner is prepared by mixing 2.5 parts by 
weight of the powder formed as in Example 2 with 1 part by weight of the 
polymerizable liquid formed as in Example 4. Samples are applied to a 
tooth surface in a patient's mouth and polymerized by exposing to actinic 
light using a Caulk MAX curing light. 
EXAMPLE 7 
A mixture suitable as a dental base is prepared by mixing 5.0 parts by 
weight of the powder formed as in Example 2 with 1 part by weight of the 
polymerizable liquid formed as in Example 4. Samples are applied to a 
tooth surface in a patient's mouth and polymerized by exposing to actinic 
light using a Caulk MAX curing light. 
EXAMPLE 8 
A mixture useful as a dental restorative is prepared by mixing 5.0 parts by 
weight of the powder formed as in Example 2 with 1 part by weight of the 
polymerizable liquid of Example 4. The mixture is applied to a tooth 
surface in a human patient's mouth and self polymerizes. 
EXAMPLE 9 
A mixture useful as a dental restorative is prepared by mixing 5.0 parts by 
weight of the powder formed as in Example 1 with 1 part by weight of the 
polymerizable liquid of Example 3. The mixture is applied to a tooth 
surface in a human patient's mouth and self polymerizes. 
EXAMPLE 10 
A mixture useful as a dental restorative is prepared by mixing 5.0 parts by 
weight of the powder formed as in Example 1 with 1 part by weight of the 
polymerizable liquid of Example 3. The mixture is applied to a tooth 
surface in a human patient's mouth, and is polymerized using light to form 
a cured polymeric material. 
The ratios of powder and liquid used in Examples 4A and 5 through 8 are 
shown in Table 1. 
TABLE 1 
______________________________________ 
CE- RESTORATIVE/ 
SEAL- 
MENT LINER BASE CORE BUILD-UP 
ANT 
Example 5 6 7 8 4A 
______________________________________ 
POWDER/ 2.5/1 2.5/1 5.0/1 5.0/1 
LIQUID 
RATIO 
LIQUID 100% 
______________________________________ 
EXAMPLE C1 
This is a comparative example and corresponds exactly with Example 5 of 
U.S. Pat. No. 5,367,002 (Case 1627). 
EXAMPLE C2 
This is a comparative example and corresponds exactly with Example 15A of 
U.S. Pat. No. 5,338,773. 
The polymerizable composition of Examples 4A and C1 are light cured to form 
polymeric material having the physical properties shown in TABLE 2. The 
polymerizable compositions of Examples 8, 9 and C2 are self cured to form 
polymeric material having the physical properties shown in TABLE 2. 
Flexural strength (MPa) is measured by ISO 4049. Bond strength to dentin 
(psi) is measured by the Haang method of Example 4 (column 9, lines 61-68 
through column 10, lines 1-22) in U.S. Pat. No. 5,367,002. Extracted human 
teeth used for the bond strength testing are treated in 1% sodium 
hypochlorite for 18 to 24 hours, washed with water, mechanically sanded 
with 120/320/600 grit carborundum paper until the dentin is exposed. The 
prepared teeth are stored in distilled water in a refrigerator at about 
4.degree. C. until needed. Each tooth is blow dried with compressed dry 
air to ensure the dentin surface is free from noticeable moisture. Using a 
ball tipped applicator, the test compositions are placed on prepared tooth 
structure. In Examples 6 and 7 the bond strengths are obtained by applying 
primer (Prisma Universal Bond.RTM. 3 Primer described in U.S. Pat. No. 
4,996,934) with a brush to a prepared tooth surface, letting the primer 
stand for 30 seconds, and then blowing the primer dry with compressed air. 
A small plastic straw with 3.68 mm inner-diameter and 2 to 3 mm in length 
is filled with uncured dental composite of the invention and seated on the 
dentin so as to form a post. The upper open end of the straw is covered 
with a thin film of cellophane. Gentle pressure (about 1-5 psi) is applied 
to the post through the cellophane with the tip of the handpiece of a 
MAX.RTM. light curing unit (sold by L.D. Caulk Division of DENTSPLY 
International Inc). The unit is activated and the composite is cured for 
40 seconds. The specimens are stored in distilled water at 37.degree. C. 
for 1 to 3 days and their posts are sheared on an INSTRON with 50 kg load 
and 5 mm/min. head speed. The shear bond strengths are calculated. Linear 
expansion (percent) is measured after 7 days in water at 37.degree. C. 
TABLE 2 
______________________________________ 
Example 4A 9 8 C1 C2 
______________________________________ 
Flexural 61 71 70 31 31 
Strength 
(MPa) 
Bond 1695 839 1631 1097 1522 
Strength 
to Dentin 
(psi) 
Compressive 
335 175 206 184 149 
Strength 
(MPa) 
Linear 0.9 0.16 -- 1.7 1.5 
expansion 
in water 
at 37.degree. C. 
after 
7 days 
(percent) 
Linear -- 0.5 -- -- 3.3 
expansion 
in water 
at 37.degree. C. 
after 
90 days 
(percent) 
Cure Depth 
more N.A. N.A. 0 N.A. 
at 2 months 
than 
at 50.degree. C. (mm) 
15 
______________________________________ 
*In Table 2 N.A. means Not Applicable 
Preferably the liquid composition includes a polymerizable compounding 
having a carboxylic acid containing moiety. An example of a preferred 
compound is OEMA. 
Preferably mixtures of powder and liquid form polymerizable material which 
polymerizes an adheres to dentin with an adhesion of at least 700 psi and 
adheres to metal containing substrates such as crowns and brackets with an 
adhesion of at least 500 psi. Preferably, the powder comprises about 70-99 
percent by weight strontium fluoroaluminosilicate glass. Preferably, the 
powder comprises about 5 to 0.1 percent by weight benzoyl peroxide. 
Preferably, the powder comprises about 5 to 0.1 percent by weight ascorbyl 
palmitate. Preferably, the liquid comprises about 90 to 10 percent by 
weight alkylacrylate. Preferably, the powder comprises about 30 to 0.1 
percent by weight dipentaerythritol pentacrylate phosphoric acid. 
Preferably, the powder includes about 25 to 0.1 percent by weight 
(2,4,6-trimethyl benzoyl) phosphine oxide. Preferably, the powder includes 
about 5 to 0.1 percent by weight tert-butyl peroxybenzoate. Preferably, 
the liquid and the powder are in a ratio between 2.0:1 to 6.0:1 in the 
mixture. 
Various alteration and modifications of this invention will be apparent to 
those skilled in the art without departing from the scope and spirit of 
this invention, and it should be understood that this invention is not 
limited to the illustrative embodiments set forth herein.