Note: Descriptions are shown in the official language in which they were submitted.
BACKGROJND OF THE INVENTION
Field of the Invention
This invention relates to a process for remineralizing
dental enamel in which solutions containing calcium and
phosphate ions are mixed and applied to dental enamel, re-
sulting in remineralization of the dental enamel and efficacyagainst caries~
The Prior ~rt
It is well kno~n in the dental art that dental
caries begins as a subsurface demineralization ("white spots")
of the dental enamel and that remineralization or recalci-
fication may be of importancè in retarding or arresting dental
q~
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1060346
c~_ies. However, heretofore no method was known by which a
member of the general public could conveniently effect reminer-
alization of subsurface dental enamel. U. S. Patent 1,222,144,
April 10, 1917, to Ruthrauff, teaches acidic dentifrice compo-
sitions for remineralizing tooth enamel comprising a soluble
calcium salt, and an agent for more effectively causing the
solution to permeate and completely fill up the minute spaces in
the tooth surface. U. S. Patent 2,154,168, April 11, 1939, to
Klein et al, discloses denti ~ces ^ontaining calcium and phos-
phate ions and having a pH of from about ~ to about 10. U. S.
Patent 3,679,~360, July 25, 1972, to Rubin et al, discloses a
method, the purpose of which is to deposit calcium phosphate
from a gel medium onto the tooth surface. The surface on which
calcium phosphate growth is desired is prepared (as by
roughening) and the tooth and coatings are covered by a suitable
cap for several days while the remineralization takes place.
Although the prior art does not teach either compositions
or methods by which remineralization can be conveniently and
effectively accomplished, copending Canadian Application Ser. No.
20 183,295 of Robert John Grabenstetter and John Augustus Gray, III,
filed OctGber 12, 1973, said application being entitled "PROCESSES
AND COMPOSITIONS FOR REMINERALIZATION OF DENTAL ENAMEL" teaches a
method of remineralizing subsurface dental enamel in which two
compositions containing, respectively, a cation and an anion, such
as calcium ion and phosphate ion, are sequentially applied to the
dental enamel. This method, while successful, requires sequential
application of the respective solutions. The present invention,
on the other hand, provides a method by which subsurface dental
enamel may be remineralized by the application of one solution
to the tooth surface.
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`` 10~;0346
SUMMARY OF THE INVENTIONIn accordance with one aspect of the present invention,
demineralized tooth enamel is remineralized by:
(A) first, mixing a first solution containing a
soluble calcium salt yielding from about .005% to
about 5% of calcium ions with a second solution
containing a soluble phosphate salt yielding from
about .005% to about 5% phosphate ions, said
mixture having a pH of from about 2.0 to about 5.0
and a molar ratio of calcium ions to phosphate ions
of from about .01 to about 100; and
(B) second, within 5 minutes after forming said
mixture, applying a therapeutic amount of said
mixture to a tooth surface for a period of time
of from about 10 seconds to about 3 minutes.
The present invention, in another aspect, resides in a
composition for remineralizing dental enamel which takes the form
of a two-pack system wherein one pack contains a solution con-
taining a water-soluble calcium salt yielding from about 0.005%
to about 5~ by weight of calcium ions, and the other pack contains
a solution containing a water-soluble phosphate salt yielding from
about 0.005% to about 5% by weight of phosphate ions, said solu-
tion having individual pH's such that when mixed to form a
mixture having a molar ratio of calcium ions to phosphate ions
of from 0.01:1 to 100:1, said mixture has a pH of from about 2.0
to about 5.0; said system being adapted and arranges such
that the contents of the packs, when
~ - 3 -
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combined and admixed, provide a metastable solution of
calcium and phosphate ions having the aforesaid molar ratio
of calcium ions to phosphate ions of from 0.01:1 to 100:1
and a pH ranging from about 2.0 to about 5.0, which meta-
stable solution when applied to a tooth surface for a
period of time ranging from about 10 seconds to about 3
minutes, within five minutes after formation of said solution,
; effects remineralization of subsurface dental enamel.
In a further aspect, this invention resides in a
process for preparing a metastable solution for remineral-
izing tooth enamel, said process comprising: mixing a
first solution containing a water-soluble calcium salt
yielding from about 0.005% to about 5% by weight of calcium
ions with a second solution containing a water-soluble
phosphate salt yielding from about 0.005% to about 5% by
weight of phosphate ions, the proportions of said first and
second solutions being such as to provide a mixture having
a molar ratio of calcium ions to phosphate ions of from
` 0.01:1 to 100:1, and said first and second solutions having
individual pH's such that when they are mixed as aforesaid,
the metastable solution so formed has a pH of from about
2.0 to about 5Ø
In still another aspect, the present invention resides
in a metastable solution containing both calcium ions and
phosphate ions, in a molar ratio of said calcium ions to
said phosphate ions ranging from 0.01:1 to 100:1, and
having a pH ranging from about 2.0 to about 5.0, said
metastable solution being suitable for use in remineralizing
demineralized dental enamel when applied to a tooth surface
within 5 minutes after its formation.
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~`'1
1060346
In a preferred embodiment of the present invention,
the first solution additionally contains a soluble salt of
magnesium or a heavy metal yielding from about .005% to about
5%, preferably from .005~ to aboùt 0.1% of magnesium or heavy
metal cations and has a ^pH of less than about 5, and the second
solution additionally contains a soluble salt of an anion
capable of forming an insoluble precipitate with calcium,
magnesium or heavy metal cations, said soluble salt yielding
from about .005% to about 5%, preferably from about .005%
to about O.S~ of said anions. Preferred cations, in thè preferred
embodiment, are tin, aluminum, indium, and the rare earth
metals. Indium is most preferred. Preferred anions are
. ~ . .
..:
1~60346
fluoride, fluorophosphate, fatty acid radicals having from
8 to 18 carbon atoms and carbonate. Fluoride is most
preferred. Most preferably, the hea~y metal ion is indium,
the anion is fluoride, and the mixture has a pH of from
about 2~5 to about 4. If the remineralization contemplated
by this invention is carried out in accordance with this
preferred embodiment, an antisolubility effect results, i.e.,
the remineralized enamel is more resistant to demineralization
than was the original enamel.
DESC~I~TION OF THE INVENTION
The present invention lies in the discovery that
demineralized dental enamel may be remineralized by applying
to the teeth a metastable solution of calcium and phosphate
ions which will diffuse through the tooth surface to the de-
mineralized subsurface and precipitate, resulting in reminerali-
zation or recalcification of subsurface dental enamel. The
metastable solution is made by mixing a first solution, also
referred to herein as the cationic solution, containing a
water-soluble calcium salt yielding from about .005% to about
~0 5~ of calcium cations, with a second solùtion, also referred
to herein as the anionic solution, containing a water-soluble
phosphate salt yielding from about .005% to about 5% phosphate
anions, said mixture having a pH of from about 2.0 to about 5,
and a molar ratio of calcium cations to phosphate anions of
from about ~01 to 100 ~i.e., .01:1 to 100:1). Unless speci-
fied othe~ise, all percentages referred to herein are per-
centages by weight.
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The water-soluble calcium salts suitable for use
in the present invention can be any water-soluble calcium
salt which is safe for use in the oral cavity. ~he solu-
bility should preferably be at least about 0.07% in water
at 100C. Examp,les of suitable calcium salts are calcium
chloride, calcium acetate, calcium formate, calcium lactate
and calcium nitrate. Likewise, the phosphate salts suitable
for USQ can be any of the water-soluble phosphate salts which
are suitable for use in the oral cavity and having a solu-
bility of at least 0.07~ in water at 100C. Phosphoric acid
is also suitable for use, and for purposes of brevity, it
will be understood that when the term "phosphate salts" is
used herein, it is intended to also include phosphoric acid.
Examplès of suitable water-soluble phosphate salts are di-
sodium hydrogen phosphate, sodium dihydrogen phosphate,
potassium dihydrogen phosphate and trisodium phosphate.
It is preferred to remineralize the tooth strùcture
with a precipitate which has antisolubility characteristics,
i.e., with a precipitate which is more resistant to deminerali-
zation than was the original enamel. Thus, it is preferredth~t the first solution have a pH of less than about 5 and
~ontain a soluble salt of magnesium or a heavy metal yielding
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from about .005% to about 5~, preferably from about .005%
to about 0.1% of magnesium or heavy metal cations in addition
to the calcium salt, that the second solution additionall~
contain a soluble salt of an anion capable of forming an
insoluble precipitate with calcium, màgnesium or heavy metal
cation, said salt yielding from about .005% to about 5%,
preferably from about .005% to about 0.1~ of said anions,
and that the metasta~le mixture have a pH of from about 2.5
to aboùt 4.
While applicants do not wish the scope Or the present
invention to be limited by theory, it is believed that the
calcium and phosphate ions diffuse through the tooth surface
to the demineralized subsurface while the mixture is in the
metastable state and precipitate in the demineralized subsurface
where they remineralize the tooth structure. This is accom-
plished by employing à metastable solution in which the calciumand phosphate ions remain soluble for a period of time sufficient
to permit their diffusion into the demineralized subsurface of
the dental enamel. More specifically, this is accomplished by
combining the particular ions just prior to thèir application
~0 to the tooth in a solution having a pH of from about 2 to about
5, at which pH the calcium and phosphate ions remain soluble
~or the period of time re~uired. The calcium and phosphate
ions are stored separately to avoid the premature precipita-
tion of calcium phosphate.
` Chemically equiva'ent concentration~ of the first and
second solutions are not necessary so long as the molar ratio of
calcium and phosphate ions in the mixture is from .01 to 100.
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0346
It is preferred that the ratio is from about .2 to about 5
and it is most preferred that the ratio is about 1.67, the
ratio of calcium to phosphate in natural teeth enamel
(hydroxyapatite).
While completely aqueous solutions are preferred
in the present invention, non-aqueous solvents may be em-
ployed in combination with water. For example, suitable non-
a~ueous solvents include ethyi alcohol, glycerine and propylene
glycol. Solvent systems suitable for use in the present
invention are those which are capable of dissolving the
salts employed in the invention and which are safe for use
in the mouth.
~ n considering the period of time of exposure of
the metastable solution to the tooth, it is necessary that
the length of time be great enough to allow diffusion of the
ions into the demineralized subsurface. At least about ten
seconds are required for this diffusion. The solution is
preferably applied to the teeth for from about 10 seconds to
about 3 minutes. The pH of the solution will rise due to
natural factors after its introduction into the oral cavity.
Calcium phosphate prec;pitates during this rise in pH, but
after calcium ions and phosphate ions have diffused in~o the
demineralized tooth enamel. It is believed that the ability
of the metastable solution to provide ions for remineralization
2~ is greatest upon its first introduction into the oral cavity,
thereafter decreasing.
1~60346 .
The time period between the mixing of the first
and second solutions and the application of the mixture to
the teeth should not exceed 5 minutes, and preferably is less
than 1 minute. The essence of the present invention lies in
the creation of a metastable solution which will precipitate
calcium phosphate and, in the most preferred embodiment, also
indium phosphate and calcium fluoride, in the subsurface enamel
of the teeth~ Before such precipitation occurs, the solution
is applied to the teeth. The solution msut have a pH of about
5 or below to achieve this result. At a pH above about 5,
precipitation'occurs too rapidly. A pH below 2 is generally
undesirable from a safety standpoint and ad~s nothing
to the invention. Although one would expect an acidic solution
to demineralize the teeth, the use of the metastable solution
of the present invention, which is saturated or supersaturated
with respect to calcium phosphate, results in remineralization
instead o demineralization.
The pH of the solutions of the present invention
may be adjusted to the pH desired by methods well known in
~0 the art. The p~ may be lowered by the addition of any acid
which is safe for use in the oral cavity and which yields
t~e desired pH at the amount employed. Examples of suitable
acids are hydroEluoric acid, phosphoric acid, hydrochloric
acid, citric acid and malic acid. Should the pH be lower
~5 than desired, an appropriate amount of sodium hydroxide may
be added to raise it. The appropriate acid can be added
to the mixture of the first and second solutions immediately
upon mixing or, preferably, the acid can be incorporated into
one or both of the solutions before mixing in amount such
that the two solutions have the required pH after mixing.
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1060346
In order to effect remineralization of the dental
enamel, a therapeutic amount of a solution of calcium and
phosphate ions must be employed in the mouth. The amount of
solution placed in the mouth must contain at least .001 g.
of calcium phosphate, and preferably contains more than .1 g.
of calcium phosphate ~calculated as Ca3(PO4)2].
If the deminexalized subsurface dent::l enamel is
remineralized with a precipitate which is less soluble than-
the original enamel, the remineralized subsurface is more
resistant to demineralization than was the original enamel.
If the remineralization contemplated by this invention is
carried out in accordance with the preferred embodiments, the
remineralized enamel is more resistant to demineralization
than was the original enamel because magnesium or heavy metal
cations and/or certain anions such as fluoride ions, which are
capable of forming insoluble precipitates with calcium,
magnesium or heavy metal catio:~s (hereinafter also referred
to as secondary anions) are incorporated into the remineralized
tooth structure. If both types of ions are so incorporated,
the remineralized enamel is even more resistant to deminerali-
zation than if only one type of ion is incorporated. The
concentration of magnesium or heavy metal cation and s~condary
anion in the respective solutions may be from about .005%
to about 5~, and is preferably from about .005% to about 1%.
1060346
Examples of hea~-y ~,etal cations suitable for incor-
poration into the first, or cationic solution, herein include
soluble salts of mangan~se, tin, zinc, indium, zirconium,
iron, titanium, vanadium, rare earth metals such as lantl-anum
and ceriùm, and aluminum. Tin, indium, thè rare earth metals and
aluminum are preferred; indium is most preferrea. Suitable
soluble salts of these cations include the halide (e.g.,
chloride), nitrate, sulfate, acetate and gluconate salts of
the desired cation. For example, suita~le soluble indium
salts include indium chloride, indium sulfate, and indium nitrate.
Examples of anions which ~`ill react with cations to
give desirable insoluble preci~itates, and are therefore
suitable for incorporation into the second, or anionic solution
herein include fatty acid groups having from 8 to 18 carbon--
atoms, fluoride, fluorophosphate, silica fluoride, molybdate,sulfate, tungstate, tartrate, sorbate, alkyl sulfonates having
~rom 6 to 18 carbon atoms, carbonates, and ioaates. Fluoride,
iluorophosphate, fatty acids having from 8 to 18 carbon atoms,
e.g., laurate and stearate, and carbonates are preferred. Suitable
soluble salts of these secondary anions include the sodium,
rotassium, ammonium and substitutèd ammonium salts. The most
A~ lo-
1060346
preferred secondary anion is fluoride ion. Examples of soluble
fluoride salts which are suitable for use in the second solution
- of the present invention include sodium fluoride, ~.inc fluoride,
betaine fluoride, alanine stannous fluoride, and hexylamine
fluoride. Hydrofluoric acid can also be used.
It will be recognized by those skilled in the art
that many different precipitates can be formed by a solution
made in ac~ordance with the present invention. It is preferred
that the precipitate be white in color. Some of these
precipitates may be formed by first forming an original
precipitate which then further reacts to form the indicated
precipitate. For example, a hydroxide may form first and then
react further to form the corresponding oxide. It is most
preferred that the ingredients of the present invention are
selected so that most precipitates are calcium phosphate
compounds with small amounts of indium and fluoride incorporated
therein. This results in a remineralized tooth structure
which is similar to the natural tooth structure with small
amounts o~ indium and fluoride incorporated therein, resulting
in increased resistance to solubility. Thus, the reminerali~ed
tooth structure will be more resistant to dental caries than
was the ori~inal structure.
By employing suitable ions in the present composi-
tion, the following insoluble precipitates in addition to calcium
phosphate may be formed: CaF2, ZnN1~4PO4, InPO4, rare earth phos-
phates such as lanthanum, cerium, and samarium phosphate, rare
earth fluorides such as lanthanum, cerium, praseodymium,
10~0346
neodynium, and samarium fluorides, magnesium alkyl sulfonate
wherein the alkyl group has from 10 to 22 carbon atoms, magnesium
stearate, calcium stearate, zinc stearate, and aluminum
phosphate.
Other precipitates contemplated by this invention - -
are: Aluminum oxide; aluminum hydroxide; indium hydroxidej--
indium phosphate; lanthanum tartrate; lanthanum sorbate;
lanthanum oxalate; lanthanum oxide; lanthanum tungstate;
lanthanum phosphate; magnesium alkyl sulfonates such as
~0 magnesium n-decyl sulfonate, magnesium lauryl sulfonate,
magnesium myristyl sulfonate, magnesium cetyl sulfonate, and
magnesium n-octadecyl sulfonate; magnesium oleate; magnesium
myristate; magnesium palmitate; magnesium stearate; magnesium
laura'e; magnesium carbonate; magnesium fl~oride; magnesium
phosphates; magnesium hydroxide; magnesium ammonium phosphate;
manganese carbonate: manganess hydroxide; manganese ammonium
phosphate; nickel hydroxide; manganese laurate; manganese
myristate; manganese palmitate; manganese stearate;
stannous oxalate; zinc tartrate; zinc carbonate;
zinc oxalate; zinc hydroxide; zinc phosphate (usually complex
mixtures); zinc ammonium phosphate; zirconium hydroxide;
zirconium phosphate; calcium carbonate; calcium molybdate;
calcium silicate; calcium tunqstate; calcium lauryl sulfonate;
calcium m~ristyl sulfonate; ca.cium n-hexadecyl sulfonate;
calcium n-octadecyl sulfonate; calcium oleate; calcium
stearate; calcium tartrate; calcium aluminates; calcium
~ydroxide; calcium ammonium phosphate; tricalcium phosphate;
- 12 -
~`` ~` .
10~0346
dicalcium phosphate; calcium ~onofluorophosphate; Mg~PO4;
Mg3(PO4)2; MgNH4PO4; aluminum phosphates; aluminum ortho-
phosphate, calcium phosphates, zinc phosphates; strontium
phosphate; indium phosphate; tin phosphate; ceric phosphate;
MoO3; SiO2; SiO2 xH2O; Sn(OH)2; SnO ~ xH2O; Ti(oH)4; TiO2; V2O5;
and W03. These precipitates are formed by using the appropriate
cations ~n the first solution and the appropriate anions in
~he second solution as described above.`
For commercial exploitation of the present invention,
it is contemplated that "kits" will be made which will enable
the consumer to make a metastable solution and apply lt to the
teeth. Suitable kits can comprise two separately packaged
solutions of the respective cations and anions, but more
preferably, the kits are in the form of a two-part tooth-
paste or mouthwash composition. The two parts, a cationicportion and an anionic portion, should be packaged to
facilitate mixing the two parts and then applying the mixture
to the teeth~ The term "cationic part" refers to the solution
containin~ from ~005~ to 5% calcium cations, and the term
`'anionic part" refers to the solution containing from .005~
to 5~ phosphate anions. The solutions in the kit are compounds
with respect to acidity and ionic concentration such that
mixing of the solutions in proper proportions for use in the
process of the present invention will give a pH of from about
2.0 to abont 5.0 and a calcium to phosphate molar ratio of
from about 0~01 to 100.
- 13 -
10~0346
Both the cationic and anionic parts of mouthwashes
may be made in accordance with the following. Mouthwashes
generally comprise an aqueous solution of ethyl alcohol and
flavoxing materials. The alcohol provides an antibacterial
5 effect and also solubilizes the flavoring materials. Op-
tionally, mouthwashes also contain additional antibacterial
agents such as cetyl pyridinium chloride and domiphen bromide,
and humectants such as glycerine and sorbitol which give a
moist feeling to the mouth.
Typically, mouthwashes contain 3%-60% ethyl alcohol,
30~-90~ water, 5~-20~ glycerine or other humectant, 0.01~-0.1%
~ ~0~0346
of an antibacterial agent, 0.01~-0.5% of a sweetening agent,
0.01~-2.0% of a fLavoring agent, and from 0.1%-1% of an
emulsifier-surfactant such as polyoxyethylene (20) sorbitan
monoisostearate. Examples of suitable flavoring agents
include heliotropyl ni~rile, wi`ntergreen oil tmethyl salicylate)
oil of peppermint, oil of cassia, oil of anise, oil of cinnamon,
and mixtures thereof. Suitable sweetening agents include
sàccharin, g~ycerine, sorbitol, levulose, and 6-~trifluoro-
methyl)-tryptophane, aspartyl phenylalanine methyl ester~
The present invention may be embodied in a tooth-
paste composition and packaged in a codispensing toothpaste
tube such as tbat disclosed~in U.S. Patent 3,290,422, Dec. 6,
1966, t Kenneth George Michel, or Canadian Patent 1,016,131
of Charles R. Hood and Stephen F. Evans, granted August 23, 1977,
said patent being entitled "COLLAPSIBLE, LONGITUDINALLY
PARTITIONED TVBULAR DISPENSING CO~TAINER".
Suitable toothpastes may be made by employing
in both the anionic and cationic portions of the toothpaste,
~rom about 0.5~ to about 50~, preferably from 5% to 25%,
of an abrasive, from about 0.2% to about 5% of a sudsing
agent, from about 0.1~ to about 5~ of a binding a~ent, from
0~ to about 50~ of a humectant, and balance, water and minors.
The pH of the toothpaste containing the active cationic
ingredients has a pH of less than about 5. The mixture
of the t~o portions which is placed in the mouth must
have a pH of from about 2.0 to about 5. The pl~'s of the
cationic portion and the anionic portion may be adjusted
15 -
1060346
so long as the above parameters are not exceeded. Should the
anionic portion of the toothpaste contain fluoride ions and
have a pH of less than 5, the active f luoride might etch
the teeth should it be placed in the mouth alone.
' Suitable abrasives include silica xerogels such -
as those disclosed in U. S. Patent 3,538,230, dated Nov. 3, 1970,
to Pader et al. Other conventional toothpaste abrasives can
be used in the compositions of this invention, and include
~e~a-phase calcium pyrophosphate, zirconium silicate, the
thermosetting polymerized resins described by Cooley et al.
in U. S. Patent 3,070,510, dated Dec. 25, 1962. Silica
aerogels and the insoluble metaphosphates such as insoluble
sodium metaphosphatc. Mixtures of abrasives can also be used.
Silica xerogel abrasives are preferred.
.
Suitable sudsing agents are those which are rea-
sonably stable and form suds throughout an acidic pH range.
Preferably, non-soap anionic or nonionic oraanic synthetic
detergents. Examples of such agents are water-soluble salts
~0 o~ alkyl sulfate having from 10 to 18 carl~on atoms in the alkyl
radical, such as sodium lauryl sulfate, water-soluble salts
of sulfonated monoglycerides of fatty acids having from 10
to 18 carbon atoms, such as sodium monoglyceride sulfonate,
salts of ~10-C18 fatty acid amides of taurine, such as sodium
~-methyl,N-palmitoyl tauride, sodium N-coconut-acid-N-meth
taurate, salts of ClO-C18 fatty acid esters of isothionic
acid, and substantially saturated aliphatic acyl amides of
,, - 16 -
1~60346
saturated monoaminocarboxylic acids having 2 to 6 carbon atoms,
and in which the acyl radical contains 12 to 16 carbon atoms,
such as sodium-N-lauryl sarcoside. Mixtures of two or more
sudsing agents can be used.
~ binding material is added to thicken and provide
a desirable consistency for the present compositions. Suit-
able thickening agents are water-soluble salts of cellulose
ethers, such as sodium carboxymethyl cellulose, hydroxypropyl
cellulose, and hydroxyethyl cellulose. Natural gums such as
gum karaya! gum arabic, and gum tragacanth, can also be used.
Colloidal magnesium aluminum silicate, silica aerogels, silica
xerogels~ fumed silica, or other finely divided silica can be
used as part of the thickening agent for further improved
texture. A preferred thickening agent is xanthan gum, avail-
able from the Kelco Company.
It is also desirable to include scine humectantmaterial in a toothpaste to keep i~ from hardening. Suitable
humectants include glycerine, sorbitol, propylene glycol, and
other edLble polyhydric alcohols.
2~` Toothpaste compositions may also contain flavoring
agents such as oil of wintexgreen, oil of peppermint, oil of
spearmint, oil of sassafras r and oil of clove. Toothpaste
compositions may also contain sweetening agents such as
saccharin, dextrose, levulose, and sodium cyclamate. A
toothpaste and mouthwash illustrating the present invention are
set forth in the following examples, which are intended to
illustrate, but not to act as a limitation, upon the present
invention.
1~60346
EXAMPLE I
A s~__able two-part toothpaste for use in accordance
with the present invention was made of the following ingredients
and stored with the anionic and cationic portions separate.d:
`` ` . ' 1(~0346
~. ~
0~ ~o 1-- o o o o o o o u'l In o o
U Q~I I u~ ~ o o ~ O ~ O O I ~ ~ I ~ O
3I I ..... . ... I I
o ~ ~ ~ ~ ~ o o o ,1 o ~
R _~ ~ R
d~
,.
U ~3c~ o I ~ Oo o ~~ ~ ~ o
.~; o o ~ C5~ ~ O -i
i
a
s
~U o .~
s
o
B ~ ~ Z o . ~ --
o ^ 3 ^ ~ ~ ~ x ~ ~ ~ `
o ~ ~ S ~ ~o ~o
o3 ~ 3 n~ E~ 3 ~ n ~
~ r o n5
O ~ O ~ O ~ Q~
O O s~ s c~ a Qo) ~ 3 ~ ~ U O ~ O ~ ~ X X~ X
_I U h ~ ~ U h ~
D ¦ E `' ~3 V j C7 ~ ~' g o ~ h C V E C O h -- ~ h h
O 1:: - - H ~ 'I O C ~ O O ~ ~ 3 3 ,~
o "^, o U~ `
1060346
The anionic paste had a pH of about 5.2. The
cationic paste had a pH of about 3Ø One gram portions of
each of the above pastes were simultaneously placed in the
mouth whereupon the teeth were brushed in the usual manner
three times per day for four weeks. The pH of the mixture
was about 3.3. Observation indicatec~ that remineralization
of demineralized enamel had occurred. The remineralized
enamel was more resistant to demineralization than was the
original enamel.
EXAMPLE II
A suitable two-part mouthwash for use in accordance
with the present invention was made of the following ingre-
dients and stored with the anionic and cationic parts
separated:
1060346
h
~.C ~Uo~
~rl N ~D O O U) O ~ 1
- U ~ I I N O O 10 ~ N O ~i ~1 0 Id
N 0 01` 0 o O O O O 1~ --
O ~
P
~. ` ' ' .
~ ~ ~ . .
` al O
0 1`
~,1 ~ ~` O O O CO ~ 11'1 ' U~ ~ -
U ~ ~D O I I O In N I O ` O O O 115 N
~,~ æ . . I I ~ . . I . . . . .~
~ O O 1~ 0 O O O O
o ~ ~I
dP
o
o
N
rl O
O ~ O .t: o ` ~ rl O
,~ O ~1 U ,~
P~ rl O ~
~:: ~1 U ~ ~ t.) ~ U
~O .1 E ~ X U h
O ~ h u~
o .~ u ~ u ~ o a.)~
~ o r~ t~ ~ ~ O U O ~1 0 3 td, ~a
m ~ C~
- 21 ~
r~
1~60346
Ten ml. portions of each of the above solutions were
mixed and immed~ately (within ten seconds) placed in the mouth
whereupon the 20 ml. mixture was held in contact with the
teeth for from 15 to 30 seconds. The mixture had a pH of
about 2.7. This procedure was repeated twice a day for three
weeks. Observation indicated that remineralization of de-
mineralizèd enamel had occurred. The re:~ineralized enamel
was more resistant to demineralization than was the original
enamel.
lt~
