Note: Descriptions are shown in the official language in which they were submitted.
- 1 -
toss ~~2 ;
A Primer Composition
The present invention relates to a primer
composition. More particularly, the present invention
relates to a primer composition which, when dental
adhesive restorative materials such as dental resin
cements, composite resins, PMMA resins and the like are
made to adhere directly or through bonding agents to
substrates such as vital hard tissues, especially enamel
or dentin of natural teeth, glass ionomer cements and the
like, is able to impart a strong and durable adhesive
property between both without treating said substrates
with an acid and the like.
Dental restorative resins, in general, have
insufficient adhesive properties to teeth such that
restorative materials may fall off or that there may
occur secondary caries, pulpal irritation, marginal
fracture or marginal discoloration due to invasion or
leakage of bacteria at the margin of restoration, causing
clinical problems.
To solve these clinical problems, techniques to
improve the adhesive property between the restorative
materials and teeth have been proposed and will be
described in detail below.
2 - ~nss~7z.
A proposal of the so-called acid etching
technique is now being evaluated clinically as a
technique for adhesion to enamel [Journal of Dental
Research, Vol. 34(6), pp. 849 - 853, (1955)]. Adhesion
by this technique is based not on the chemical bonding
between the teeth and adhesive resins but on a mechanical
anchor effect caused by curing and anchoring of the
resins that have penetrated into a honeycomb structure
mainly formed by demineralization of enamel prisms.
However, this honeycomb structure is not formed on any
enamel surface which has not been subjected to the acid
etching treatment and adhesive property in this case
remains insufficient.
Recently much interest has been focused on
adhesion to the dentin and, increasingly, many proposals
have been made with some improvements. These proposals
are, however, concerned with a method wherein the dentin
is pretreated, or reformed and reinforced in some cases,
by using inorganic acids, organic acids, organic acids
and some kinds of metal chlorides, or EDTA or their
salts. Apart from the case of the enamel, clinical
problems are pointed out in these methods when they are
applied to the dentin. Etching treatment of the dentin
especially by using phosphoric acid has caused many
discussions in Japan as well as in Europe and United
States, and the American Dental Association has
- 3 - ~,~ ~5 ~ ~ 2
recommended against the phosphoric acid treatment of
dentin. However, citric acid and oxalic acid are still
considered as an acid treatment agent of dentin since
they are considered to have less etching effect than
phosphoric acid [see AIDR/AADR Abstracts No. 915, p. 276
(1985) or U.S. Patent Specifications No. 4,521,550 and
No. 4,538,990]. Treatment methods using EDTA are also
proposed [see U.S. Patent Specifications No. 4,553,941
and No. 4,593,054]. However, dental societies and
dentists strongly desire a method of yielding a strong
and durable adhesion to dentin without subjecting it to
any acid treatment.
Meanwhile, adhesion to dentin has
remarkably progressed in recent years. It is reported
that an adhesive strength of 100 kgf/cm2 or more was
reached by using a conventional bonding material and a
composite resin, wherein the dentin was treated with a
mixed solution of glutaraldehyde, water and 2-
hydroxyethyl methacrylate (named as Gluma*) after a pre-
treatment with a solution of EDTA~Na salt solution
[Journal of Dental Research, Vol. 63(8), pp. 1087 - 1089
(1984); Scand. J. Dent. Res., Vol. 93, pp. 463 - 466
(1985); and International Dental Journal, Vol. 35, pp.
160 - 165 (1985)]. It is proved, however, that when the
dentin is not subjected to the EDTA~Na treatment, a value
of about 30.9 kgf/cm2 is actually shown, indicating that
the value still remains low.
f
*~Trade Mark
.:
~~ ~ ~ 2 .:~
- 4 - -
In Proceedings of the 7th Meeting of Japan
Society for Adhesive Dentistry, pp. 121.- 122 and pp. 123
- 124 (1989), or in Proceedings of the 1st International
Congress on Dental Materials, pp. 236 - 237 (1989) and
Dental Engineering, pp. 31 - 38 (1987), it is reported
that high adhesive strength is maintained by MMA/TBB-O
resin even after 2000 times of thermal cycles using
cool water (4°C) and hot water (55°C), wherein the dentin
has been subjected to a primer treatment using a mixed
solution of solution A [70$ of 2-HEMA + 6~ of o-
methacryloxytyrosinamide (MTYA)] and solution B (2~ of
glutaraldehyde), which is the above-described Gluma
type of treatment solution, after an acid treatment of
the dentin. For example, it is reported that an adhesive
strength of 164 kgf/cm2 is obtained by a mixed primer
treatment of the above-described solution A and solution
B after a treatment with 40~ of phosphoric acid. On the
other hand, an adhesive strength of 48 kgf/cm2 to the
dentin without acid treatment is shown even at 0th cycle,
which is indicative that not only the power is
insufficient in a sense of the intrinsic adhesive
strength but also durable adhesive property to the dentin
without acid treatment is hardly obtained. Although
adhesive strength is improved by this method, it is still
low against the dentin without acid treatment in a strict
sense. The proposer of the above-described technique has
recognized in the disclosures that the intrinsic adhesive
9, ~ ~.
A 6 ~ ~ ~' 2 .a~
- 5 -
strength to the dentin has not been reached yet.
More recently, a primer composition which does
not require any pre-treatment such as acid treatment,
i.e. a primer composition for hard tissues comprising
water, a water soluble film-forming agent and salts of
acids, has been proposed (see Japanese Patent KOKAI No.
113057/1989).
When the primer composition is used for making
a composite resin adhere to the dentin of teeth, however,
the adhesive strength is largely influenced by the kinds
and blending amounts of acid salts, thereby causing
difficulties that not only the resulting adhesive
strength may be inferior to that obtained by using no
primer composition, but also durable adhesive property is
not obtained.
The present invention has been achieved to
provide a primer composition which can solve the above-
described problems and which, when dental adhesive
restorative materials such as dental resin cements,
composite resins, PMMA resins and the like are made to
adhere directly or through bonding agents to substrates
such as vital hard tissues, especially enamel or
dentin of natural teeth, glass ionomer cements and the
like, is able to impart a strong and durable adhesive
property between both without treating said
CA 02065472 2003-11-27
- 6 -
substrates with an acid and the like.
The inventors of the present invention have
found that, through concentrated studies on primers to
impart the durable adhesive property, certain primer
compositions are able to solve the above problems in the
prior art and that, when dental adhesive restorative
materials such as dental resin cements, composite resins,
PMMA resins and the like are made to adhere directly or
through bonding agents to substrates such as vital hard
tissues, especially enamel or dentin of natural teeth,
glass ionomer cements and the like, the primer
composition is able to give a strong and durable adhesive
property between both without treating said substrates
with an acid and the like. The present invention was
completed based on the findings described above.
In one embodiment the present invention is
directed to a primer composition comprising: (i) 10 -
55$ by weight of water; (ii) 20 - 60~ by weight of a
polymerizable monomer having a polymerizable unsaturated
group and a hydroxyl group; (iii) 2.5 - 60$ by weight of
a polymerizable monomer having a polymerizable
unsaturated group and an acidic group; and (iv) 0.3 -
10$ by weight of a curing agent.
In another embodiment the present invention is
directed to a primer composition comprising: (i) 10 -
55~ by weight of water; (ii) 20 - 60o by weight of a
polymerizable monomer having a polymerizable unsaturated
group selected from the group consisting of acryloyl
group, methacryloyl group, vinyl group and acrylic group,
and a hydroxyl group; (iii) 2.5 - 60~ by weight of a
polymerizable monomer having a polymerizable unsaturated
CA 02065472 2003-11-27
- 6a -
group selected from the group consisting of acryloyl
group. methacryloyl group, vinyl group and acrylic group,
and an acidic group selected from the group consisting of
carboxyl group, phosphoric acid group, acid anhydride
residue and acid amide group; and (iv) 0.3 - 10a by
weight of a curing .agent.
Water which is stable on storage and acceptable
as an ingredient for medical use, and does not
intrinsically contain any harmful impurities to the
components and adhesive effect of the composition is
preferably used in this invention. Distilled water (or
- , _ ~~ ~a5 ~ ~ ~.
purified water) or ion-exchange water (or deionized
water) is suitable. The blending amounts of water are in
general in the range of 0.5 - 90~ by weight, preferably 5
- 80~ by weight and more preferably 10 - 50~ by weight.
An amount of less than 0.5~ by weight causes a
deterioration in adhesive property while amounts of
more than 90~ by weight also causes a decrease in
adhesive property.
The polymerizable compounds having hydroxy
groups which are used in this invention are polymerizable
monomers, oligomers or polymers having polymerizable
unsaturated groups such as acryloyl group, methacryloyl
group, vinyl group, acrylic group and the like together
with hydroxy groups, the monomers being particularly
preferable.
Examples of these kinds of compounds are 2-
hydroxyethyl(meth)acrylate (this abbreviation means 2-
hydroxyethylacrylate or 2-hydroxyethylmethacrylate, and
similar denotations are used hereinafter), 2- or 3-
hydroxypropyl(meth)acrylate,
4-hydroxybutyl(meth)acrylate,
5-hydroxypentyl(meth)acrylate,
6-hydroxyhexyl(meth)acrylate,
10-hydroxydecyl(meth)acrylate;
dialkyleneglycolmono(meth)acrylates such as
diethyleneglycolmono(meth)acrylate,
triethyleneglycolmono(meth)acrylate,
.'_.
- g -
tetraethyleneglycolmono(meth)acrylate,
polyethyleneglycolmono(meth)acrylate,
dipropyleneglycolmono(meth)acrylate, polypropylene-
glycolmono(meth)acrylate; 1,2- or 1,3- or 2,3-
dihydroxypropyl(meth)acrylate, 2-hydroxypropyl-1,3-
di(meth)acrylate, 3-hydroxypropyl-1,2-di(meth)acrylate,
N-(meth)acryloyl-1,2-dihydroxypropylamine, N-
(meth)acryloyl-1,3-dihydroxypropylamine; and addition
products of phenols with glycidyl(meth)acrylate such as
1-phenoxy-2-hydroxy-propyl(meth)acrylate, 1-naphthoxy-2-
hydroxypropyl-(meth}acrylate and bisphenol-A-
diglycidyl(meth)acrylate. 2-Hydroxyethyl(meth)acrylate
and 2-hydroxypropyl(meth)acrylate are particularly
suitable among them.
Two or more types of these compounds having
hydroxy groups can be used together, if desired.
The blending amounts of above-described
compounds having hydroxy groups are generally in the
range of 5 - 90~ by weight, preferably 10 - 70~ by weight
and more preferably 20 - 60~ by weight, and the amounts
of less than 5~ by weight or more than 90~ by weight
cause a deterioration in adhesive property.
The polymerizable compounds to be used in this
invention are monomers, oligomers or polymers having
polymerizable unsaturated groups such as acryloyl group,
methacryloyl group, vinyl group, allyl group and the like
together with acidic groups such as carboxyl group,
~~F.~f:... ; ~. . ..
-9- ~0~~~~2:
phosphoric acid group, acid anhydride residues, acid-
amide groups and the like, the monomers being
particularly preferred among them.
Examples of polymerizable monomers having
carboxy groups are monocarboxylic acids, dicarboxylic
acids, tricarboxylic acids or tetracarboxylic acids and
their derivatives such as acrylic acid, methacrylic acid,
1,4-di(meth)acryloxyethyl-pyromellitic acid, 6-
(meth)acryloxyethylnaphthalene-1,2,6-tricarboxylic acid,
N,0-di(meth)acryloxy-tyrosine, O-(meth)acryloxytyrosine,
N-methacryloxytyrosine, N-(meth)acryloxyphenylalanine, N-
(meth)acryloyl-p-aminobenzoic acid, N-(meth)acryloyl-o-
aminobenzoic acid, N-(meth)acryloyl-5-aminosalicylic
acid, N-(meth)acryloyl-4-aminosalicylic acid,
4-(meth)acryloxyethyl trimellitic acid,
4-(meth)acryloxybutyl trimellitic acid,
4-(meth)acryloxyhexyl trimellitic acid,
4-(meth)acryloxydecyl trimellitic acid, 4-acryloxybutyl
trimellitic acid, 2-(meth)acryloyloxybenzoic acid, 3-
(meth)acryloyloxybenzoic acid, 4-(meth)acryloyloxybenzoic
acid, addition product of 2-hydroxyethyl(meth)acrylate
with malefic anhydride, p-vinylbenzoic acid, o-
methacryloxy-tyrosinamide, N-phenylglycine-
glycidyl(meth)acrylate, N-(p-methylphenyl)glycine-
glycidyl-(meth)acrylate, 11-methacryloxy-1,1-undecane
dicarboxylic acid, 4-[(2-hydroxy-3-
methacryloyloxypropyl)aminoJphthalic acid, 5-[(2-hydroxy-
;,.
- 10 -
3-methacryloyloxypropyl)amino]isophthalic acid, 3-[N-
methyl-N-(2-hydroxy-3-methacryloyloxypropyl)-
amino]phthalic acid, 4-[N-methyl-N-(2-hydroxy-3-
methacryloyl-oxypropyl)amino]phthalic acid, a reaction
product of pyromellitic acid dianhydride and 2-
hydroxyethyl(meth)acrylate in 1 . 2 molar ratio, malefic
acid and the like. 4-Acryloxy-ethyltrimellitic acid, 4-
methacryloxyethyltrimellitic acid and a reaction product
of pyromellitic acid dianhydride and 2-
hydroxyethyl(meth)acrylate in 1 . 2 molar ratio are
particularly preferred among them.
Radically polymerizable monomers having
hydroxyl groups and carboxylic groups in one molecule are
also included in the polymerizable monomers containing
acidic groups, especially carboxylic groups, as described
in the above examples.
Polymerizable monomers containing phosphoric
acid or phosphonic acid groups are suitable for the
polymerizable monomers containing phosphoric groups,
examples of them being bis[2-
(meth)acryloxyethyl]phosphoric acid, [2-
(meth)acryloxyethylphenyl]phosphoric acid, 10-
(meth)acryloyloxydecyl dihydrogen phosphate, 6-
(meth)acryloyloxyhexyl dihydrogen phosphate,
vinylphosphonic acid and p-vinylbenzylphosphonic acid.
The other examples are polymerizable monomers having
thiophosphoric acid group.
:... ~ ..i:.; y :.:
.y~
.;
- 11 -
Examples of the polymerizable monomers having
acid anhydride residues are as follows; 4-(meth)acryloxy-
ethyltrimellitic acid anhydride, 6-(meth)acryloxyethyl-
naphthalene-1,2,6-tricarboxylic acid anhydride, 6-
(meth)acryloxyethylnaphthalene-2,3,6-tricarboxylic acid
anhydride, 4-(meth)acryloxyethylcarbonylpropionoyl-1,8-
naphthalic acid anhydride and 4-(meth)acryloxyethyl-
naphthalene-1,8-tricarboxylic acid anhydride.
Two or more types of the above described
polymerizable compounds having acidic groups can be used
together, if desired. -
The blending amounts of the polymerizable
compounds having acidic groups are generally in the range
of 1 - 90~ by weight, preferably 0.5 - 60~ by weight, and
an amount of less than 0.1~ by weight causes
deterioration in adhesive property while amounts of
more than 90~ by weight bring about difficulty in
solubility or decreases in adhesive property.
The curing agents conventionally used for
initiators and accelerators for polymerization or photo-
polymerization are also suited for the curing agents to
be used in this invention.
Examples of initiators for polymerization,
accelerators for polymerization and the other curing
agents are organic peroxides, amines and barbituric acid
or derivatives thereof, respectively.
Trialkylborones or their oxides are also
~Y~h
- 12 -
included in the examples.
Initiators for photopolymerization are
initiators for ultraviolet light curing or visible light-
curing, and examples of them are organic nitrogen
compounds, particularly amines.
The following compounds are examples of
organic peroxides: benzoyl peroxide, 4,4'-dichlorobenzoyl
peroxide, 2,4-dichlorobenzoyl peroxide, dilauryl
peroxide, methylethylketone peroxide, t-butylperoxymaleic
acid and succinic acid peroxide. t-Butylperoxymaleic
acid, succinic acid peroxide, benzoyl peroxide and 4,4'-
dichlorobenzoyl peroxide are particularly suitable
examples among them.
The compounds represented by the following
general formula are examples of the amines;
Rz
Rl N I
2 0 R3
[wherein R1 - R3 denote independently hydrogen atom,
alkyl groups having 1 - 10 carbon atoms or cycloalkyl
groups having 6 - 12 carbon atoms which may have
substituents (hydroxyl group, (meth)acryloyl groups and
the like, for example), or phenyl groups which may have
substituents (halogens, alkyl groups having 1 - 10 carbon
atoms, hydroxyl group, (meth)acryloyl group and the like,
for example) provided that the groups R1 - R3 do not all
denote hydrogen atoms at the same time].
,~~
,~~~~2~~
- 13 -
Other amines such as cyclic amines or
multivalent amines such as diamines may be used.
Examples of these kinds of amines are n-
butylamine, propylamine, pentylamine, hexylamine,
dimethylamine, diethylamine, dipropylamine, di-n-
butylamine, dipentylamine, trimethylamine, triethylamine,
tripropylamine, tri-n-butylamine, tripentylamine,
trihexylamine, phenylethylamine, ethyleneamine,
tetramethyleneamine, N,N-dimethylaminoethylmethacrylate,
N,N-diethylaminoethylmethacrylate, monoethanolamine, N-
methyldiethanolamine, triethanolamine, aniline,
methylaniline, dimethylaniline, diphenylamine, toluidine,
anilidine, N,N-dimethyl-m-anilidine, N,N-dimethyl-p-
anilidine, N,N-dimethyl-m-aminophenol, N,N-diethyl-m-
aminophenol, N,N-diethyl-p-anilidine, p-propoxy-N,N-
dimethylaniline, p-hexyloxy-N,N-dimethylaniline, p-
butoxy-N,N-dimethylaniline, chloroaniline, bromoaniline,
dimethyl-p-toluidine, N,N-di(2-hydroxyethyl)-p-toluidine,
p-aminophenylmethacrylate, N,N-dimethylaminophenyl
methacrylate, N,N-di(2-hydroxyethyl)phenylmethacrylate,
p-(J3-hydroxy-y-methacryloxypropoxy)phenylamine, N,N-di(2-
hydroxyethyl)-phenylglycidyl(meth)acrylate, N-
methylmorpholine, imidazole, 1-methylimidazole, 2-
methylimidazole, 2-methyl-4-methylimidazole,
ethylenediamine, methylenedianiline, phenylenediamine,
N,N-bis(hydroxyethyl)diethylenetriamine, N,N-bis-
(hydroxyethyl)triethylenetetramine, 3-amino-1,2-
,~ .;~.
I
- 14 -
propanediol, D,L-1-amino-2-propanol, 2-amino-4-
phenylphenol, 2-amino-2-phenylethanol, L-2-amino-1-
propanol, 3-amino-1-propanol, 2-anilinoethanol, N,N-
dihydroxy-ethylaniline, o- or p-aminophenethyl alcohol,
5-amino-1-pentanol, 5-amino-2-methylphenol, 2-amino-5-
methylphenol; aminobenzoic acid esters such as methyl p-
aminobenzoate, ethyl p-aminobenzoate, butyl p-
aminobenzoate, propyl p-aminobenzoate, isopropyl p-
aminobenzoate, ethyl p-(N,N-dimethylamino)benzoate and
isopropyl p-(N,N-dimethylamino)benzoate. N,N-di(2-
hydroxydiethyl)-p-toluidine,- N,N-dimethylaminoethyl-
methacrylate, p-aminophenylmethacrylate, p-(J3-hydroxy-y-
methacryloxypropoxy)phenylamine, triethanolamine,
monoethanolamine, isopropyl p-(N,N-dimethylamino)benzoate
and ethyl p-aminobenzoate are the suitable examples among
them.
The compounds represented by the following
formula are the examples of barbituric acid or
derivatives thereof:
R1
i
,
N~R2
R' 0
(wherein R1 and RZ may be the same or different
and denote hydrogen atom or aliphatic, aromatic,
alicyclic or heterocyclic residues which may have
. -.
- 15 -
substituents such as halogen atoms, alkyl groups, alkoxy
groups, allyl groups or cyclohexyl group).
The following compounds are examples of
these compounds: barbituric acid, 1,3-dimethylbarbituric
acid, 1-methylbarbituric acid, 1,3-diphenylbarbituric
acid, 5-butylbarbituric acid, 1,5-dimethylbarbituric
acid, 5-ethylbarbituric acid, 5-isopropylbarbituric acid,
5-cyclohexylbarbituric acid, 1,3,5-trimethylbarbituric
acid, 1,3-dimethyl-5-ethylbarbituric acid, 1,3-dimethyl-
5-n-butylbarbituric acid, 1,3-dimethyl-5-sec-
butylbarbituric acid, 1,3-dimethyl-5-isobutylbarbituric
acid, 1,3-dimethyl-5-tert-butylbarbituric acid, 1,3-
dimethyl-5-cyclopentylbarbituric acid, 1,3-dimethyl-5-
cyclohexyl-barbituric acid, 1,3-dimethyl-5-
phenylbarbituric acid, 1-benzyl-5-phenylbarbituric acid,
1-cyclohexyl-5-ethyl-barbituric acid and their salts
(particularly salts of alkali metals or alkaline earth
metals).
The other examples of barbituric acid
derivatives are 5-aminobarbituric acid, 2-
chlorobarbituric acid, thiobarbituric acid derivatives
such as 1,3,5-trimethyl-2-thiobarbituric acid, 5-butyl-2-
thiobarbituric acid and their salts (particularly salts
of alkali metals or alkaline earth metals).
Particularly suitable barbituric acid
derivatives are 5-butylbarbituric acid, 1,3,5-
trimethylbarbituric acid, 1,3-dimethyl-5-
- 16 -
isobutylbarbituric acid, 1-benzyl-5-phenylbarbituric
acid, 1-cyclohexyl-5-ethylbarbituric acid and 1,3,5-
trimethyl-2-thiobarbituric acid.
Examples of trialkylborone or their oxides are
tri-n-butylborone, tri-n-amylborone, triisoamylborone,
tri-sec-amylborone, triethylborone, tripropylborone,
triisopropyl-borone or their derivatives which are
partially oxidized.
Sensitizers for ultraviolet or visible light
such as benzoin methylether, benzoin ethylether, benzoin
isopropylether, benzoin, benzophenone, 2-
chlorothioxanthone, 2-hydroxy-3-(3,4-dimethyl-9H-
thioxanthene-2-yloxy)-N,N,N-trimethyl-1-propane ammonium
chloride, 9,10-anthraquinone, camphorquinone, benzyl,
4,4'-dicyclo-benzyl and diacetyl are examples of
photopolymerization initiators.
Examples of photopolymerization accelerators
are N,N-dimethyl-p-toluidine, N,N-
di(2-hydroxyethyl)-p-toluidine, triethylamine,
trihexylamine, 2-dimethylamino-ethanol, N-
methylethanol~mine, N,N-dimethylaminoethyl-methacrylate
and N,N-diethylaminomethacrylate.
Two or more kinds of the above described curing
agents may be used, if necessary.
The blending amounts of the curing agent are in
the range of 0.01 - 30~ by weight, preferably 0.05 - 10~
by weight and more preferably 0.1 - 5~ by weight. When
~S
- 1~ -
the amounts are less than 0.01 by weight, adhesive
property tends to decrease while it is also decreased
when the amounts are more than 30~ by weight.
Besides the components described above,
appropriate amounts of polymerizable compounds without
hydroxyl groups and acidic groups, i.e., urethane
(meth)acrylates such as an adduct of 1,1,3-
trimethylhexamethylene diisocyanate and 2-
hydroxyethylmethacrylate in 1 . 2 molar ratio, an adduct
of isophorone diisocyanate and 2-hydroxyethylmethacrylate
in 1 . 2 molar ratio, and bisphenol A-dimethacrylate,
ethyleneglycoldimethacrylate, triethyleneglycoldimeth-
acrylate, polyethyleneglycoldimethacrylate, N-vinyl-
pyrrolidone and methoxypolyethyleneglycolmonomethacrylate
may be blended, if desired. The blending amounts of the
polymerizable compounds without hydroxyl groups and
acidic groups are in the ranges of 0 - 90% by weight.
Besides the components described above,
appropriate amounts of organic solvents, i.e. alcohols
such as ethyl alcohol, isopropyl alcohol, propylalcohol
and the like, ketones such as acetone and the like,
aldehydes such as glutaraldehyde, formaldehyde and the
like, or tetrahydrofuran may be blended, if desired, to
the primer composition according to the present invention
in order to adjust the viscosity of the composition or
solubility of the components of the composition. The
.;,; i :: ~.,Y
. ..
. .u;
v.
.,
1
- 18 -
blending amounts of the organic solvents are in the range
of 0 - 90~ by weight. Hydroquinone, hydroquinone
monomethylether, hydroxymethoxybenzophenone or butylated
hydroxytoluene may be blended appropriately as a
stabilizer for the shelf life of the composition.
The composition according to the present
invention can be used by dividing the components of the
composition into two or more portions. When the
components of a curing agent are composed of initiators
and accelerators, for example, they can be divided into
two or more portions so that they can be subjected to use
after mixing. Even when the component of the curing
agent is composed of one type of agent, it can be divided
into two portions for use. Methods for mixing the
portions can be appropriately selected. The
method for mixing the portions in a small plate by the
dentist immediately before use, and the method for mixing
the portions in cavities of the patient's teeth for
adhesion are exemplified. These component dividing
methods can be selected appropriately from their
combinations. For the primer composition comprising (i)
water, (ii) a polymerizable compound having a hydroxyl
group, (iii) a polymerizable compound having an acidic group
and (iv) a curing agent, the following combinations are
exemplified; (i) and (ii) for solution A and (iii) and
(iv) for solution B; (i) and (ii) for solution A and
(ii), (iii) and (iv) for solution B; (i), (ii) and (iv)
- 19 -
for solution A and (ii) and (iii) for solution B; (i) for
solution A and (ii), (iii) and (iv) for solution B; (i)
and (iii) for solution A and (ii) and (iv) for solution
B; (i), (ii) and (iii) for solution A and (iv) for
solution B; or (i), (ii) and (iv) for solution A and
(ii), (iii) and (iv) for solution B (one component can be
amine and another component can be a curing agent in
(iv) in some cases).
The present invention will be illustrated by
the following examples, but it is not restricted to these
examples. _
Examples 1 - 5 and Comparative Examples 1 - 6
Eleven primers were prepared from ion-exchange
water, 2-hydroxyethylmethacrylate (2-HEMA), 4-
acryloxyethyl trimellitic acid (4-AET), 4-acryloxyethyl
trimellitic acid anhydride (4-AETAA), bis(2-
methacryloxyethyl)phosphoric acid (BMEPA), N,N-
di(hydroxyethyl)-p-toluidine (N,N-DEPT), 4,4'-
dichlorobenzoylperoxide (p-C1-BPO) and glutaraldehyde
according to the formulation listed in Table 1.
A powder component of a resin cement was
prepared by mixing silane-treated silica (75 parts by
weight); silane-treated barium sulfate (25 parts by
weight), N,N-di-(2-hydroxyethyl)-p-toluidine (0.1 part by
weight) and 1-benzyl-5-phenyl-barbituric acid (1.0 part
by weight). A liquid component of the resin cement was
prepared by mixing a reaction product of 1,1,3-
~:._, . ; ,
- 20 -
trimethylhexamethylene diisocyanate and 2-
hydroxyethylmethacrylate in 1:2 molar ratio (60 parts by
weight), triethyleneglycol dimethacrylate (28 parts by
weight), 2-hydroxyethylmethacrylate ('1 parts by weight),
4-acryloxyethyl trimellitic acid (5 parts by weight),
benzoyl peroxide (0.3 part by weight) and butylated
hydroxytoluene (0.05 part by weight). The resin cement
was prepared immediately before use by mixing both
components in a powder/liquid ratio of 3.5/1Ø
Silane treatment of the filler (silica and
barium sulfate) was carried-out using y-
methacryloxypropyltrimethoxysilane according to the
following conventional acetic acid method. One hundred
parts by weight of the filler was added to 100 parts by
weight of a solution which was prepared by dissolving y-
methacryloxypropyltrimethoxysilane into 0.1~ of aqueous
acetic acid solution to form 2.0~ by weight in
concentration. After air-drying this slurry, surface
treatment of the filler was carried out by subjecting the
silane-treated filler to a heat treatment at 80°C for 2
hours, followed by an additional heat treatment at 120°C
for 30 minutes.
Adhesive strength was determined by a shear
bond test between a bovine dentin and the resin cement.
Freshly extracted bovine anterior teeth were freeze-stored in
distilled water and defrosted immediately before use.
The bovine teeth were mounted in epoxy resin and
C
- 21 - -
the surface of the dentin was polished using a water-
proof abrasive paper (#600) to make the surface smooth.
After polishing the bovine dentin, the surface of the
dentin was treated by respective primers listed in Table
1 in a rubbing manner for 60 seconds. After drying the
teeth, the mixed slurry of the resin cement was cured and
made to adhere onto the surface of the dentin using a
separable plastic mould of 4mm in inner diameter and 2mm
in height. Thirty minutes after curing of the
cement, the adhered test samples were immersed in
distilled water at 37°C for-24 hours and then adhesive
strength under a compressive shearing force was measured
by using a Shimadzu* autograph AG-5000B at a cross-head
speed of lmm/min. All the tests described above and
hereinafter were carried out at room temperature of 23 ~
2°C. The results are shown in Table 1.
*Trade Mark
y .:~~r"ro,)
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:.
- 23 -
As is apparent from Table 1, in the case of
Example 1 in which a primer comprising ion-exchange
water, 2-HEMA, 4-AET and N,N-DEPT, which are the
components constituting the present invention, was used,
a value of 127.6 kgf/cmZ was obtained for adhesive
strength under compressive shearing force between the
bovine dentin without being subjected to an acid etching
(hereinafter, abbreviated as a dentin without acid
etching) and the resin cement prepared by way of test.
In Comparative Examples 1 - 7 wherein the
compositions which are out of the range of this invention
were used, on the other hand, the results showed very low
values. In Comparative Example 7 in which no primer
was used, the value was 33.5 kgf/cm2 while a four times
higher value of the adhesive strength was obtained in the
case in which the bovine dentin was subjected to a primer
treatment according to this invention. In the
Comparative Example 6 in which a conventional composition
comprising ion-exchange water, 2-HEMA and glutaraldehyde
was used, a value of 30.9 kgf/cmz was obtained for the
dentin without acid treatment, showing that the value was
significantly lower compared with that obtained by the
composition according to this invention. No primer
effect was observed in Comparative Example 6 in
comparison with the results in Comparative Example 7.'
It is apparent from the results in Comparative
Examples 1 - 5 (13.4 to 34.7 kgf/cm2) that any lack of
"~ x o~ r-e
.,~~i
- 24 _ 2065472 ~
the components of the primer composition according to the
present invention results in a remarkable decrease in the
adhesive strength. It was made clear from these results
that an excellent adhesive strength against the dentin
without acid treatment can be obtained by an interaction
among ion-exchange water, 2-HEMA, 4-AET and N,N-DEPT
which are the basic constituents of this invention.
When 4-AETA having an acid anhydride group
(Example 2) or BMEPA having phosphoric acid group
(Example 3) was used as a polymerizable monomer having an
acidic group instead of 4-AHT in which the acidic group
is a carboxyl group, or when a peroxide was used for the
curing agent (Example 4), and when the blending amounts
of the components constituting this invention were varied
(Example 5), the values of 70.9 - 90.8 kgf/cm2 were
obtained which are significantly higher than the values
obtained in Comparative Examples 1 - 7.
Adhesive strength under shearing force between
the bovine enamel without acid etching treatment and the
resin cement prepared by way of test was measured after
immersing the test sample in distilled water at 37°C for
one day, wherein the compositions obtained in the
Examples 1 and 2 were used as a primer. The value
obtained using the composition according to
Example 1 was 187.7 kgf/cm2. When the bovine enamel was
subjected to an etching treatment with phosphoric acid
instead of the primer treatment of this invention,
_~:;.
2os5~a2_~
- 25 -
adhesive strength of 208.0 kgf/cm2 was obtained. These
results indicate that substantially the same adhesive
strength as that obtained by the etching treatment with
phosphoric acid can be obtained using the primer
according to this invention. The adhesive strength of
the resin cement to the bovine enamel which was not
subjected to primer or acid treatment was 56 kgf/cm2.
From the results described above, it was made clear that
the primer compositions according to this invention are
also effective to increase the adhesive property to
the enamel which was not subjected to an etching
treatment with an acid.
Examples 6 and 7 and Comparative Examples 8 and 9
Adhesive primers were prepared according to the
formulations shown in Table 2 and adhesive strength under
shearing force between the dentin without acid treatment
and resin cements which were prepared by way of test in
Examples 1 - 5 and Comparative Examples 1 - 7)
was measured according to the same manner as that
described in the aformentioned Examples. The results are
shown in Table 2.
_z
- 26 - ~~~54a2 -~
Table 2
Example Comparative
Components) & Adhesive Exam
)e
strength
6 7 8 9
Ion-exchange water 40 40 40 40
2-HEMA
60 60 60 60
4-AET
7 _ _ 7
MEPPZ
_ 7 _ _
N,N-DEPT
0.6 0.6 - -
BBA3
0.4 - - -
NaCl -
- - 0.6 0.6
Adhesive strength to dentin
(kgf/cm2) 95.2 112.7 42.3 65.7
(Note) 1. Unit of the blending amounts of the
components is parts) by weight.
2. MEPP . Methacryloxyethylphenyl phosphoric
acid
3. BBA . 5-Butylbarbituric acid
":. ~ ~, y,
~, a
- 27 -
As is apparent from Table 2, significantly higher
adhesive strength to the dentin was obtained when the
primer composition according to this invention was used
(Examples 6 and 7) than that in Comparative Examples
8 and 9 wherein salt of a mineral acid is blended with
a mixture of water and 2-hydroxyethylmethacrylate or
a mixture of water, 2-hydroxyethylmethacrylate and 4-
acryloxyethyl trimellitic acid.
Example 8
A primer was prepared by mixing 35 parts by
weight of distilled water, 60 parts by weight of 2-
hydroxyethylmethacrylate, 5 parts by weight of 4-
methacryloxyethyl trimellitic acid, 0.6 part by weight of
dl-camphorquinone and 0.8 part by weight of N,N-
dimethylaminoethylmethacrylate.
A powder component of a chemically and
photochemically curable resin cement was prepared by
mixing 75 parts by weight of silane-treated silica, 25
parts by weight of silane-treated barium sulfate, 5 parts
by weight of 4-acryloxyethyl trimellitic acid and 0.3
part by weight of benzoyl peroxide. A liquid component
of said resin cement was prepared by mixing 40 parts by
weight of a reaction product of isophorone diisocyanate
and 2-hydroxyethyl-methacrylate in 1:2 molar ratio, 10
parts by weight of bisphenol A-diglycidyl-methacrylate,
parts by weight of triethyleneglycoldimethacrylate, 10
parts by weight of ethyleneglycoldimethacrylate, 10 parts
r_ 1 ~
- 28 -
by weight of 2-hydroxyethylmethacrylate, 0.6 part by
weight of dl-camphorquinone, 0.5 part by weight of N,N-
dimethylaminoethylmethacrylate and 0.5 part by weight of
N,N-dimethyl-p-toluidine. The curable resin cement was
prepared immediately before use by mixing both
components in a powder/liquid ratio of 3.2/1Ø
For measuring the adhesive strength under
shearing force between the dentin without acid treatment
and resin cement, a test sample was prepared according to
the method described in Example l and a visible light
beam was irradiated for 30 seconds over the surface of
the applied resin cement using the Shofu Daylight Lamp
II (Shofu Inc.). The measurement was carried out under
the same conditions as that used in Example 1. _.
The adhesive strength under shearing force
between the dentin without acid treatment and the resin
cement was 110.2 kgf/cmz, said value being significantly
higher than the value of 10.7 kgf/cm2 obtained using
no primer described above.
These results indicate that a light-cure agent
is also effective as a curing agent to increase the
adhesive strength.
Example 9
One solution (Solution A)of a two liquid type
primer was prepared by mixing 80 parts by weight of ion-
exchange water, 20 parts by weight of 2-
hydroxyethylmethacrylate and 0.8 part by weight of N,N-
~~~ :.~:
,'.;.~~
- 29 - ,
di(2-hydroxyethyl)-p-toluidine. The other solution
(Solution B) was prepared by mixing 100 parts by weight
of 2-hydroxyethylmethacrylate, 15 parts by weight of 4-
methacryloxyhexyl trimellitic acid, 0.5 part by weight of
benzoyl peroxide and 0.08 part by weight of butylated
hydroxytoluene. The primer was prepared immediately
before use by mixing equal amounts of solutions A and B.
Adhesive strengths under shearing force to a dentin, an
enamel or a glass ionomer cement [Shofu* Base Cement
(Shofu Inc.) which was used 1 hour after curing] without
acid treatment were determined using the resin cement
used in Example 1 in the manner described in Example 1.
The results are listed in Table 3.
Table 3
Dentin Enamel Glass ionomer
without acid without acid cement
treatment treatment without acid
treatment
Adhesive
strengths 83.3 158.8 140.7
under kgf /cm2 kgf /cm2 kgf /cm2
shearing
force
(Note) 1. The adhesive strength shows the results after
the test sample was immersed in water at 37°C
for 24 hours.
*Trade Mark
- 30 -
Example 10
Adhesive strength between the dental light-cure
composite resin [Shofu LITE-FIL P*(Shofu Inc.)) and the
dentin or glass ionomer cement without acid treatment was
evaluated using the composition according to this
invention as a primer. A one liquid type light-cure
bonding agent was prepared by mixing 60 parts by weight
of a reaction product between isophorone diisocyanate and
2-hydroxyethylmethacrylate in 1:2 molar ratio (IPDI-2-
HEMA), 30 parts by weight of
triethyleneglycoldimethacrylate, 5 parts by weight of 2-
hydroxyethylmethacrylate, 5 parts by weight of
ethyleneglycoldimethacrylate, 0.8 part by weight of dl-
camphorquinone, 1.0 part by weight of N,N-
dimethylaminoethylmethacrylate and 0.05 part by weight of
butylated hydroxytoluene.
Solution A prepared in Example 9 was used
as one solution of a two liquid type primer for the dentin
or the glass ionomer cement without acid treatment, and
the other solution (solution B) was prepared by mixing
100 parts by weight of 2-hydroxyethylmethacrylate, 14
parts by weight of 4-acryloxyethyl trimellitic acid and
0.01 part by weight of butylated hydroxytoluene. Equal
amounts of solution A and B were mixed to prepare the
primer. The dentin or the glass ionomer cement was
treated with the primer in a rubbing manner and was dried
after 60 seconds. After drying, the one liquid type
*Trade Mark
.~~ ,-
- 31 -
light-cure bonding agent was applied to the dentin or the
glass ionomer cement using a small paint brush and
visible light was irradiated on the surface thereof by
means of Shofu Daylight Lamp-II (Shofu Inc.) for 30
seconds. A plastic mould (inner diameter: 4 mm, height:
2 mm) was fixed to the dentin or the glass ionomer
cement. The plastic mould was filled with Shofu LITE-
FIL-P (Shofu Inc.) and visible light was irradiated for 30
seconds on the surface thereof by the same method as
described above. The obtained test samples were immersed
in water at 37°C for 1 day Both cycle) and then Thermal
Cycling Tests (1 cycle: immersed in water at 4°C for 1
minute ~ immersed in water at 60°C for 1 minute) in order
to evaluate a durability concerning the adhesive
strength. The test samples were subjected to 0, 2000,
and 5000 times of the Thermal Cycling Tests and the
adhesive strength under shearing force after each cycle
was measured. The results are shown in Table 4.
'1
- 32 -
Table 4 Adhesive strength (kgf/cmz) under shearing force
Test Adhering 0th cycle 2000th 5000th
sam 1e a ent c cle c cle I
Dentin
without Composite 176.6 *D 163.8 *D 157.5 *D
acid resin
treatment
Glass
ionomer Composite 187.5 *G 194.4 *G 188.2 *G
cement resin
without
acid
treatment
(Note) *D . Cohesive failure in dentin
*G . Cohesive failure in glass ionomer cement
No adhesive strength (0 kgf/cm2) was observed
for the dentin without acid treatment using the one -
liquid type light-cure bonding agent and Shofu LITE-FIL-P
instead of using the composition according to this
invention prepared by mixing the solutions A and B. On
the contrary, when the primer prepared by mixing the
solutions A and B, the results listed in Table 4 were
obtained and cohesive failure in the dentin or glass
ionomer cement was observed. These results show that the
primer composition according to this invention brings
about an extremely high and durable adhesive effect
against the substrate to be adhered.
Examples 11 - 17
Adhesive property between a dental light-cure
composite resin of Shofu LITE-FIL-P (Shofu Inc.) and a
~i
- 33 -
dentin without acid treatment was evaluated using the
composition according to this invention as a primer. A
one liquid type light-cure bonding agent was prepared by
mixing 50 parts by weight of a reaction product of 1,3,5-
trimethylhexamethylene dimethacrylate and 2-
hydroxyethylmethacrylate in 1:2 molar ratio, 35 parts by
weight of triethylemeglycoldimethacrylate, 10 parts by
weight of ethyleneglycoldimethacrylate, 5 parts by weight
of 2-hydroxyethylmethacrylate, 0.8 part by weight of dl-
camphorquinone, 1.0 part by weight of N,N-
dimethylaminoethylmethacrylate and 0.05 part by weight of
butylated hydroxytoluene.
A bovine dentin polished by water-proof
abrasive paper (#600) was treated with the primer in a
rubbing manner for 60 seconds, then air-dried for 20
seconds. The dentin was then coated with the above-
described one liquid type light-cure bonding agent
using a small paint brush, and visible light was
irradiated for 30 seconds by means of Shofu Daylight Lamp
II (Shofu Inc.). A plastic mould (inner diameter: 4 mm,
height: 2 mm) was fixed to the dentin. The mould was -
filled with Shofu LITE-FIL-P and visible light was
irradiated for 30 seconds from the top face of the mould.
Adhesive strength under compressive shearing force of the
adhered test sample was measured after immersing the test
sample in water at 37°C for 24 hours. A primer was
prepared by blending 7 parts by weight of 4-acryloxyethyl
a : ~ ..'.
- 34 -
trimellitic acid and 0.6 part by weight of N,N-di(2-
hydroxyethyl)-p-toluidir_A with water/2-
hydroxyethylmethacrylate (2-HEMA) in an amount shown in
Table 5. The results of the measured adhesive strength
under compressive shearing force of the adhered test
samples when respective primers were used are shown in
Table 5.
>: ~ ra
.,
_35_ ~~~~~ '..3
Table 5
Adhesive
Water 2-HEMA strength under
(parts by (parts by shearing forte
weight weight) (kgf/cm )
Comparative
Example 10 100 0 29.4 #D
Example 11 80 20 79.6
Example 12 70 30 82.8
Example 13 60 40 132.9 *D
Example 14 50 50 216.3 *D
Example 15 40 60 247.0 *D
Example 16 30 70 98.7
Example 17 20 80 115.4 *D
Comparative 0 100 33.8 #D
Example 11
Comparative No primer is 0
used
Example 12
(Note) *D . Cohesive failure in dentin
#D . Adhesive failure in dentin
-_ ~ , .,,
1;
- 36 -
Examples 18 - 31
Adhesive strength under shearing force t~ the
dentin without acid treatment was evaluated using a
similar method as described in Examples 11 - 17,
wherein Shofu LITE-FIL-P (Shofu Inc.), the one liquid-
type light-cure bonding agent used Examples 11 -
17 and a primer composition was prepared by blending 4-
acryloxyethyl trimellitic acid (4-AET) with 40 parts by
weight of ion-exchange water and 60 parts by weight of 2-
hydroxyethylmethacrylate in an amount listed in Table 6
were employed. N,N-Di(2-hydroxyethyl)-p-toluidine was
added to the primer composition in an amount of 0.6 part by
weight based on the total amount of said three
components. The result of the measured adhesive strength
under compressive shearing force of the adhered test
samples when respective primers were used are shown in
Table 6.
:..,
_ 37 _
Table 6
4-AET Adhesive strength
(part(s) by weight) under sheariig force
( kgf /cm )
Comparative 0 57.3 #D
Example 13
Example 18 0.5 100.6
Example 19 1.0 104.3
Example 20 2.5 199.5 *D
Example 21 5.0 200.3 *D
Example 22 7.0 247.0 *D
Example 23 10.0 165.5 *D
Example 24 15.0 133.8 *D
Example 25 20.0 145.7 *D
Example 26 30.0 186.7 *D
Example 27 60.0 258.1 *D
Example 28 90.0 251.5 *D
Example 29 100.0 216.6 *D
Example 30 120.0 303.0 *D
Example 31 130.0 175.1 *D
(Note) #D . Adhesive failure in dentin
*D . Cohesive failure in dentin
- 38 -
As is apparent from Table 6, about 2 - 6 times
higher adhesive strength for the dentin was obtained
using the primers according to Examples 18 - 31, in which
the primers comprise the monomer having an acidic group
(4-AET), than that obtained using the primer which does
not comprise this monomer (Comparative Example 13).
A particularly high adhesive strength of 303 kgf/cmZ was
obtained in Example 30. In Example 30, there was the
adhered test sample which shows adhesive strength of
472.8 kfg/cmz (failure in dentin), said value being an
amazingly high adhesive strength exceeding the tensile
strength of the natural dentin [420 kgf/cmz: Dental
Engineering, Vol. 70, p. 42 (1984)].
Examples 32 - 40
Adhesive strength under shearing force of a
dental light-cure composite resin to the dentin without
acid treatment was evaluated according to the method
described in Examples 11 - 17, wherein the composition
according to this invention as a primer, and Shofu LITE
FIL-P (Shofu Inc.), the one liquid type light-cure
bonding agent which used in Examples 11 - 17 and a
primer composition prepared by blending 40 parts by
weight of ion-exchange water, 60 parts by weight of 2-
hydroxyethylmethacrylate and 7 parts by weight of 4-
acryloxyethyl trimellitic acid with N,N-di(2-
hydroxyethyl)-p-toluidine (N,N-DEPT) in an amount listed
in Table 6 were employed. The results of the measured
- 39 -
adhesive strength under shearing force of the adhered
test samples when respective primers were used are shown
in Table 7.
Table 7
Adhesive strength
N,N-DEPT under sheariig force
part s by (kgf/cm )
weight)
Comparative
Example 14 0.0 (0.00 mold) 75.2
Example 32 0.3 (0.154 mold) 218.1 *D
Example 33 0.6 (0.307 mold) 247.0 *D
Example 34 0.9 (0.462 mobs) 116.4 *D
Example 35 1.2 (0.616 mold) 117.8 *D
Example 36 1.5 (0.770 mold) 147.3 *D
Example 37 3.0 (1.540 mold) 117.5 *D
Example 38 6.0 (3.080 mold) 126.2 *D
'~ Example39 10.0 (5.130 mold) 135.3 *D
Example 40 30.3 (15.4 mold) 96.5
(Note) The numerals in parentheses in the table denote
mole ~ relative to the mixture of water (40
parts by weight)/4-AET (60 parts by weight).
*D . Cohesive failure in dentin
- 40 - ~~
Example 41
A primer was prepared by mixing 40 parts by
weight of ion-exchange water, 60 parts by weight of 2-
hydroxyethylmethacrylate, 10 parts by weight of ethyl
alcohol, 1.0 part by weight of N-phenylglycine-
glycidylmethacrylate and 0.6 part by weight of N,N-di(2-
hydroxyethyl)-p-toluidine. Adhesive strength under
shearing force to the dentin without acid treatment was
evaluated according to the method described in
Examples 11 - 17, wherein said primer, Shofu LITE FIL-P
(Shofu Inc.) and a liquid type light-cure bonding agent
used in Examples 11 - 17 were employed. Adhesive
strength of 102 kgf/cmz was obtained.
Examples 42 - 47
Adhesive strength under shearing force of a
dental light-cure composite resin to the dentin without
acid treatment was evaluated according to the methods
described in Examples 11 - 17, wherein Shofu LITE
FIL-P (Shofu Inc.), a one liquid type light-cure bonding
agent used in Examples 11 - 17 and a primer
composition prepared by blending 40 parts by weight of
ion-exchange water, 60 parts by weight of 2-
hydroxyethylmethacrylate and 7 parts by weight of 4-
acryloxyethyl trimellitic acid with various types of
amines in an amount listed in Table 8 were employed. The
results of the measured adhesive strength under shearing
force of the adhered test samples when respective primers
- 41 -
were used are shown in Table 8. The amines were blended
in an amount of 0.307 mol% relative to the water mixture
(40 parts by weight)/2-HEMA (60 parts by weight).
Table 8
i
Adhesive
I
strength
Parts ) by under
Amines weight (mold) shearing
force
( kgf /cm2
)
Example 42 Monoethanolamine 0.19 (0.307) 133.9 *D
Example 43 Triethanolamine 0.46 (0.307) 199.3 *D
Example 44 DMMA1 0.48 (0.307) 141.1 *D
Example 45 PABEZ 0.51 (0.307) 177.9 *D
Example 46 ~pg3 1.02 (0.307) 126.7 *D
Example 47 plpM4 0.67 (0.307) 204.6 *D
(Note) 1. N,N-dimethylaminoethylmethacrylate
2. Ethyl p-aminobenzoate
3. p-(J3-Hydroxy-y-methacryloxypropoxy)
phenylamine
4. p-Aminophenylmethacrylate
5. *D . Cohesive failure in dentin
t. ,
y f ~;
n. .~.~
- 42 - ~ ~ ~ .
Example 48
A primer was prepared by mixing distilled water
(40 parts by weight), 2-hydroxyethylmethacrylate (60
parts by weight), 4-acryloxyethyl trimellitic acid (7
parts by weight), triethyleneglycol dimethacrylate (3
parts by weight), dl-camphorquinone (0.6 part by weight),
N,N-dimethylaminoethylmethacrylate (0.8 part by weight).
A one liquid type light-cure bonding agent was
prepared by mixing an adduct of 2,2,4-
trimethylhexamethylene diisocyana-te and 2-
hydroxyethylmethacrylate in 1:2 molar ratio (50 parts by
weight), triethyleneglycoldimethacrylate (30 parts by
weight), ethyleneglycoldimethacrylate (5 parts by
weight), 2-hydroxyethylmethacrylate (10 parts by weight),
4-acryloxyethyl trimellitic acid (5 parts by weight), dl-
camphorquinone (0.8 part by weight) and N,N-
dimethylaminoethylmethacrylate (1.0 part by weight).
A bovine dentin mounted in epoxy resin was
polished using a water-proof abrasive paper (#600),;
washed with water and dried. The surface of the bovine
dentin was rubbed for one minute with a piece of
sponge impregnated with the primer and then air dried.
air. The light-cure bonding agent was applied to the
surface of the bovine dentin and then visible light was
irradiated on said surface for 30 seconds with a
Shofu Daylight Lamp II (Shofu Inc.). A plastic mould
(inner diameter: 4mm, height: 2 mm) was fixed to the
- 43 -
bovine dentin and the plastic mould was filled with a
light-cure composite resin [Shofu LITE-FIL A (Shofu
Inc.)] and then light-cured to form an adhere test
sample. The adhered test sample was immersed in
distilled water at 37°C for 24 hours and then subjected
to a shear bond test. The adhesive strength of said
sample was 210 kgf/cmz.
Example 49
An adhered test sample was prepared according
to the same manner as that described in Example 48 except
that 1,2-dihydroxypropylmethacrylate was employed in
place of 2-hydroxethylmethacrylate as an ingredient of a
primer. The adhered test sample was subjected to a shear
bond test. The adhesive strength of said sample was
225 kgf/cm2.
y~, i :~.
44 y
Examples 50 and 51
In order to evaluate the adhesive strength of a
PMMA type dental restorative resin "ADFA" (Shofu Inc.) to
the dentin, a primer was prepared by mixing 40 parts by
weight of distilled water, 50 parts by weight of 2-
hydroxyethylmethacrylate, 10 parts by weight of 1,2-
dihydroxypropylmethacrylate, 5 parts by weight of 4-
methacryloxyethyl trimellitic acid and 0.6 part by weight
of N,N-(2-hydroxyethyl)-p-toluidine. The MMA type
bonding liner "ACRYL BOND"" (Shofu Inc.) in accordance
with the instructions and the one liquid type light-cure
bonding agent used in Example 48 were used. The
adhesive strength under shearing force between the dentin
without acid treatment and "ADFA" was measured according
to the method described in Example 48. The results
of the measured adhesive strength of the adhered test
samples are shown in Table 9.
*Trade Mark
- 45 -
Table 9
Adhesive
strength
under
Primer Bonding shearing
agent PMMA resin force
( kgf /cmz
)
Example 50 Primer of Acryl ADFA 124.2
this bond
invention
Example 51 Primer of One ADFA 123.4
this liquid
invention type
bonding
a ent
Comparative - Acryl ADFA 23.6
Exam 1e 15 bond
Comparative - - ADFA 9.6
Example 16
Example 52
The dentin without acid treatment was treated
with the primer and the one liquid type light-cure
bonding agent used in Example 48 and then the resin
cement used in Example 1 was made to adhere in place
of LITE-FIL to the dentin according to the method
described in Example 48. The adhesive strength under
shearing force between the dentin and the resin cement
measured by the method of Example 48 was 227 kgf/cm2.
Example 53
A composite resin was prepared by mixing
silane-treated silica obtained by the method of
Example 1 (50 parts by weight), a reaction product of
- 46 -
2,2,4-trimethylhexamethylene diisocyanate and 2-
hydroxyethylmethacrylate in 1 . 2 molar ratio (27.0 parts
by weight), triethyleneglycoldimethacrylate (13 parts by
weight), 2-hydroxyethylmethacrylate (5 parts by weight),
4-acryloxyethyl trimellitic acid (4 parts by weight), dl-
camphorquinone (0.4 part by weight) and N,N-
dimethylaminoethylmethacrylate (0.6 part by weight).
According to the method described in
Example 48, the primer used in Example 48 was applied
on the surface of the dentin and the composite resin was
made to adhere directly to the dentin and then the shear
bond test was carried out. The adhesive strength under
shearing force between the dentin and the composite resin
was 140 kgf/cm2.
The same shear bond test as that described
above was carried out except that the primer was not
applied on the surface of the dentin. The adhesive
strength under shearing force between the dentin and the
composite resin was 35 kgf/cm2.
Example 54
An adhesive PMMA resin consisting of a powder
component and a liquid component was prepared. The
powder component was prepared by mixing
polymethylmethacrylate powder (100 parts by weight), N,N-
bis(hydroxyethyl)-p-toluidine (0.5 part by weight) and 5-
butyl barbituric acid (1.5 parts by weight). The liquid
component was prepared by mixing methylmethacrylate (80
~os~4~z~
- 47 -
parts by weight), triethyleneglycoldimethacrylate (6
parts by weight), 4-acryloxyethylmethacrylate (8 parts by
weight), benzyl peroxide (0.3 part by weight) and
butylated hydroxy toluene (0.08 part by weight).
According to the method described in
Example 48, the primer used in Example 49 was applied
on the surface of the dentin and the PMMA resin was made
to adhere directly to the dentin and then the shear bond
test was carried out. The adhesive strength under
shearing force between the dentin and the PMMA resin was
178 kgf/cmz. _
The primer composition according to this
invention is in general a suitable composition as an
undercoating for adhering the bonding restorations to the
substrates. For example, when dental adhesive
restorative materials such as dental resin cements,
composite resins, PMMA resins and the like are made to
adhere directly or through bonding agents to substrates
such as vital hard tissues, especially enamel or dentin
of natural teeth, glass ionomer cements and the like, the
primer composition imparts a strong and durable adhesive
property between both.
Although the object of this invention is
focused on the field of dental medicine, the primer
composition according to this invention has a wide
variety of applications in other fields such as surgery,
orthopaedic surgery, anaplastic surgery and the like.
