U.S. patent application number 16/833606 was filed with the patent office on 2021-03-04 for methods and compositions for whitening teeth.
This patent application is currently assigned to ORACEUTICAL LLC. The applicant listed for this patent is ORACEUTICAL LLC. Invention is credited to R. Eric Montgomery.
Application Number | 20210059802 16/833606 |
Document ID | / |
Family ID | 1000005211917 |
Filed Date | 2021-03-04 |
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United States Patent
Application |
20210059802 |
Kind Code |
A1 |
Montgomery; R. Eric |
March 4, 2021 |
METHODS AND COMPOSITIONS FOR WHITENING TEETH
Abstract
Compositions and methods for whitening the teeth of a patient or
subject include the application of at least one tooth whitening
composition to the surface of a stained tooth, accompanied by the
application of a sealant composition that forms a protective film
or coating on the tooth surface to resist moisture contamination of
the oxidizing composition. The whitening procedure can be further
enhanced by removal of acquired pellicle from the tooth surface
prior to application of oxidizing and sealant compositions. The
novel procedure allows for a high degree of tooth whitening by
protecting the oxidizing composition while it is in contact with
the tooth surface.
Inventors: |
Montgomery; R. Eric; (Lee,
MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ORACEUTICAL LLC |
Lee |
MA |
US |
|
|
Assignee: |
ORACEUTICAL LLC
Lee
MA
|
Family ID: |
1000005211917 |
Appl. No.: |
16/833606 |
Filed: |
March 29, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14664870 |
Mar 22, 2015 |
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16833606 |
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13656668 |
Oct 20, 2012 |
9101438 |
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14664870 |
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PCT/US2011/033464 |
Apr 21, 2011 |
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13656668 |
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61326484 |
Apr 21, 2010 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 8/22 20130101; A61C
17/22 20130101; A61C 17/005 20130101; A61M 2037/0007 20130101; A61C
19/066 20130101; A61K 2800/88 20130101; A61C 3/06 20130101; A61N
2/004 20130101; A61N 1/00 20130101; A61Q 11/00 20130101; A61K
8/8152 20130101; A61N 1/325 20130101; A61N 7/00 20130101; A61N
5/062 20130101; A61C 19/06 20130101; A61H 1/00 20130101; A61C 17/00
20130101; A61M 37/0092 20130101; A61N 2/02 20130101; A61K 8/8164
20130101 |
International
Class: |
A61C 19/06 20060101
A61C019/06; A61K 8/22 20060101 A61K008/22; A61K 8/81 20060101
A61K008/81; A61Q 11/00 20060101 A61Q011/00; A61C 3/06 20060101
A61C003/06; A61C 17/00 20060101 A61C017/00; A61C 17/22 20060101
A61C017/22; A61H 1/00 20060101 A61H001/00; A61N 1/00 20060101
A61N001/00; A61N 2/00 20060101 A61N002/00; A61N 2/02 20060101
A61N002/02; A61N 5/06 20060101 A61N005/06; A61N 7/00 20060101
A61N007/00; A61M 37/00 20060101 A61M037/00; A61N 1/32 20060101
A61N001/32 |
Claims
1. A method for simultaneously cleaning and whitening teeth
comprising the steps of: applying a conditioning composition to the
teeth surface; applying an oxidizing composition to said teeth
surface; applying a sealant composition to said teeth surface;
cleaning said teeth surface; polishing said teeth surface; and
removing said condition composition, said oxidizing composition and
said sealant composition.
2.-14. (canceled)
Description
BACKGROUND OF THE INVENTION
[0001] As the connections between healthy teeth and gums, and
general overall health, have become increasingly evident in the
past 100 years, oral care has become an important part of people's
daily health maintenance regimens. In the process, a healthy
looking smile has become representative of one's level of personal
grooming and even social status, with straight, white and well
shaped teeth being promoted in advertising and by cosmetic dentists
as an integral part of one's self-image. Over the past 20 years,
the availability of tooth whitening products and services has
exploded in the marketplace, ranging from low priced
over-the-counter (OTC) self-applied trays, strips, pens,
mouthwashes and toothpastes, to expensive professionally applied or
monitored products and procedures capable of effectively whitening
teeth in as little as 45 minutes. In general, professionally
applied products and services administered to a patient in a dental
office or other clinical setting are seen to achieve the best teeth
whitening results in the shortest amount of time. This is primarily
due to the concentration of active ingredient, usually hydrogen
peroxide or a hydrogen peroxide precursor, found in professionally
applied whitening compositions. Such high concentrations, typically
above 15% hydrogen peroxide by weight and often as high as 50%
hydrogen peroxide by weight, can only be safely administered in a
controlled setting where a professionally trained individual can
isolate soft tissues from contact with these highly oxidative
compositions. Frequent monitoring of a patient's progress over, for
instance, a one-hour period is also critical in maintaining a high
degree of safety when working with such high hydrogen peroxide
concentrations. Optionally, light or heat energy may be applied in
conjunction with these strong oxidizing compositions, in order to
accelerate the process beyond that which is possible using just the
compositions on their own. In general, these
professionally-monitored products and services applied in a dental
office or clinic will be referred to collectively as in-office or
chairside whitening procedures.
[0002] Chairside whitening procedures are generally performed
during a dental appointment scheduled specifically for the purpose
of whitening the patient's teeth, or as an adjunct following a
professional teeth cleaning, formally known as a dental prophylaxis
or "prophy". When tooth whitening is conducted immediately
following a prophy, the total amount of time that the patient must
remain in a dental chair can often exceed two hours.
[0003] A professional tooth cleaning is recommended by the American
Dental Association as a means to prevent gum disease. Gum disease,
or periodontitis, is the primary cause of tooth loss in adults over
the age of 40. Gum disease has also been linked to other health
problems, such as heart disease, osteoporosis, respiratory
diseases, and other more serious systemic diseases. According to
the Center for Disease Control and Prevention, approximately 68% of
adults in the United States have at least one professional tooth
cleaning annually (2008). There is speculation as to the reasons
why so many adults neglect the benefits obtainable from regular
tooth cleanings, ranging from lack of health insurance to the fear
of dental procedures. Lack of patient knowledge is a problem that
can be managed, however studies have shown that better education of
patients only leads to modest changes in behavior and attitudes
towards preventative dentistry.
[0004] In general, a typical teeth cleaning dental appointment
comprises the following procedural steps: [0005] (1) A dental
hygienist or dental assistant may or may not take x-rays of a
patient's teeth, [0006] (2) The dental hygienist or dental
assistant will generally take between 15 and 60 minutes to work on
the teeth and gums (the exact time depending upon both the amount
of accumulation present, as well as the teeth cleaning method
chosen), using a variety of tools, including manual or ultrasonic
scalers to remove the tartar and plaque from the patient's
teeth.
[0007] (3) The hygienist will then floss between the teeth and
generally complete the cleaning procedure by polishing the front
(buccal) and hack (lingual) surfaces of the teeth with an abrasive
composition known as a prophylaxis ("prophy") paste. Tooth
polishing leaves a smooth tooth surface that is more resistant to
the adhesion and buildup of dental plaque between dental cleaning
appointments.
[0008] Despite the apparent benefits of preventative teeth cleaning
as described above, nearly 80% of the population has some form of
gum disease ranging from early stage gingivitis to advanced
periodontitis. Symptoms of gum disease may include one or more of
the following: bleeding gums, halitosis (bad breath), had taste in
the mouth, tooth sensitivity, sore gums, loose adult teeth,
abscessed teeth or gums pulling away from the teeth, changes in the
way the teeth fit together or dentures fitting poorly, exudates
between the gums and teeth, sores in the mouth, and actual tooth
loss. Such a high rate of chronic or acute gum disease indicates a
low level of compliance when it comes to scheduling of a regular
dental cleaning, and any means of increasing such compliance would
clearly be beneficial to the patient's general oral health.
BRIEF DESCRIPTION OF THE INVENTION
[0009] The inventive tooth cleaning and Whitening method comprises
novel compositions and procedural steps that allow for the
simultaneous performance of a dental prophylaxis and tooth
whitening procedure. The procedure involves steps performed at
least partially in parallel or contemporaneously with a typical
dental prophylaxis procedure during which a significant amount of
plaque, tartar and, acquired pellicle are removed. In general,
these steps may include, but are not limited to, Chemical,
mechanical and/or chemomechanical tooth surface conditioning,
contact or impregnation of one or more teeth with a catalyst,
contact or impregnation of one or more teeth with an oxidizing
agent, exposure of one or more teeth to actinic energy comprising
heat, light, sound, ultrasound, air or mechanical pressure (and
combinations thereof), and contact or impregnation of one or more
teeth with a tooth remineralizing, opacifying or pigmenting
composition, Combinations of the above procedural steps have been
developed that accomplish significant whitening of stained teeth in
less than about 90 minutes when performed in conjunction with or
during a dental prophylaxis procedure.
[0010] The ability of the inventive compositions and methods to
simultaneously whiten teeth in parallel with a dental cleaning
procedure is highly dependent upon the ability of the oxidizing
agent to penetrate into tooth enamel and dentin. Roth tooth enamel
and dentin, are composite structures comprising both organic and
inorganic phases as well as interstitial spaces that are occupied
by fluid. These interstitial spaces can accommodate fluid movement,
which is generally in an outward direction, in other words from the
interior of the tooth towards the enamel surface, However. fluids
and other materials in contact with the enamel surface can
influence fluid movement through tooth enamel and dentin with
concentration gradients and/or capillary action, as well as in
conjunction with pressure, heat, light and other external physical
farces that can change the dynamic relationship between the tooth
and the fluid in contact with the tooth,
[0011] Mathematical models have been constructed to predict the
ability of fluids to penetrate into porous substrates. The
Lucas-Washburn equation is one such method of developing
comparative "Penetration Coefficient" for various fluids, based on
their viscosity, surface tension (with air) and contact angle (with
a porous substrate). The model assumes that the porous solid is a
bundle of open Capillaries, so in other words the Penetration
Coefficient is a comparative predictor of capillary flow rate. The
Lucas-Washburn equation
d 2 = ( .gamma. cos .theta. 2 .eta. ) r t ##EQU00001##
predicts the distance (d) traveled by a liquid in a porous
substrate, where the liquid has a surface tension (.gamma.) with
air, a contact angle (.theta.) with the porous substrate surface
and a dynamic viscosity CO, and where (r) is the capillary pore
radius and (t) is the penetration time. The bracketed component of
the Lucas-Washburn equation is the Penetration Coefficient,
expressed as centimeters second
PC = .gamma. cos .theta. 2 .eta. ##EQU00002##
[0012] The Lucas-Washburn equation predicts that the higher the PC,
the faster a liquid will penetrate into a given porous capillary
substrate, This means that, at least in theory, a high PC can be
achieved for liquids with low viscosities, particularly for
compositions also having low contact angle (which is often, but not
always, associated with a liquid having a low surface tension that
will lead to efficient wetting of the porous substrate.
[0013] Penetration coefficients have been used recently to design
improved dental materials, specifically sealants and low-viscosity
composites intended to arrest the progression of carious lesions
(Paris, et al, Penetration Coefficients of Commercially Available
and Experimental Composites Intended to Infiltrate Enamel Carious
Lesions, Denial Materials 23 (2007) 742-748). The authors show that
low viscosity materials with high Penetration Coefficients (>50
cm/s) are capable of penetrating enamel carious lesions better than
materials with low PCs (see corresponding patent application US
2006/0264532).
[0014] Prior an tooth whitening compositions have generally been
formulated to have high viscosities for better retention in dental
trays during the bleaching process, which prevents migration of the
whitening composition from the tray due to salivary dilution.
Moderate to high viscosities have also been the norm for chairside
whitening procedures, in order to prevent the whitening composition
from migrating away from the tooth enamel surface. According to the
Lucas-Washburn equation, moderate to high viscosity tooth whitening
compositions (greater than about 100 centipoise at 25 deg C.) will
have low Penetration Coefficients and thus be predicted to have
restricted movement into the whitening target, that is, the porous
enamel substrate. It would thus be advantageous to design a tooth
whitening carrier composition comprising an oxidizing agent with a
low viscosity (<100 cps) and a high Penetration Coefficient
(>50 cm/s) in order to achieve rapid penetration into tooth
enamel and dentin.
[0015] Other factors affecting the ability of a liquid penetrant to
infiltrate enamel and dentin are (1) surface charge effects (which
is related to pH of the micro environment within the tooth, as well
as the pH and counter ion content of the liquid penetrant), (2)
adhesion of the liquid penetrant to the tooth surface (which is
related to the surface tension and wetting ability of the liquid
penetrant), and (3) osmotic effects (which are related to the
direction of diffusion of the interstitial fluid in the tooth
structure in relation to the liquid penetrant in contact with the
tooth).
[0016] In general, the inventive simultaneous tooth cleaning and
whitening method comprises the following steps: [0017] 1)
Application of an oxidizing composition to the surfaces of the
teeth to be whitened; [0018] 2) Performing a dental cleaning or
hygiene procedure while the oxidizing composition is in contact
with the teeth to be whitened.
[0019] There is typically an extensive amount of scraping, scaling,
and other modes of plaque and tartar removal performed during a
dental cleaning or prophylaxis. During the cleaning procedure, the
patient's mouth is usually open for an extended period of time
during which excess saliva may accumulate in the oral cavity and
come in contact with the tooth surfaces. Also, the patient is
typically asked to rinse with water or a mouthwash at various times
during the cleaning procedure in order to clear debris (plaque,
tartar, blood, saliva, etc) from the oral cavity that accumulates
from the cleaning process. It has been found that in order to
achieve a desirable (that is, a noticeable) level of tooth
whitening during said dental cleaning or prophylaxis, it is
advantageous to prevent moisture from saliva or external sources
(such as the rinsing solutions referred. to above) from directly
contacting the tooth surfaces that have been previously contacted
with the oxidizing composition. By creating a barrier between
extraneous moisture and the oxidizing composition, said moisture is
prevented or limited in its ability to remove, dilute, neutralize
or otherwise decrease the effectiveness of the oxidizing
composition during the cleaning procedure.
[0020] One means of limiting the contact of external moisture with
the oxidizing composition is to utilize an oxidizing composition
having hydrophobic ("water-repelling") properties when in contact
with the tooth surface.
[0021] An alternative means of preventing moisture contamination of
the oxidizing composition on the tooth surface is to cover the
oxidizing composition with a film of water-insoluble or
water-resistance material. Such materials may include, but arc not
limited to, polymer films and water-resistant or water-insoluble
fluids, gels, creams, waxes and solids.
[0022] Yet another alternative means of preventing moisture
contamination of the oxidizing composition on the tooth surface is
to cover the oxidizing composition with a curable composition that
can be converted from a liquid or gel into a higher viscosity
liquid, gel or solid upon exposure to an external source of energy.
Said external energy source may be electromagnetic or light energy,
sound or ultrasound energy, mechanical or vibrational energy,
electrical energy, or combinations thereof.
[0023] A preferred tooth cleaning and whitening method comprises
the following steps [0024] 1) Placing a cheek and lip retraction
means into the oral cavity of a subject. Said means may include a
cheek retractor and/or cotton rolls placed in such a way as to
prevent the soft tissue of the inside of the lips and cheeks from
coming into contact with the tooth surfaces, [0025] 2) Conditioning
of the teeth surfaces to be whitened with a conditioning agent or
conditioning composition, using chemical, mechanical, or
chemo-mechanical means, [0026] 3) Contacting the conditioned tooth
surfaces with one or more compositions comprising an oxidizing
agent, [0027] 4) Contacting the tooth surfaces with a
water-resistant coating or film-forming composition to protect the
oxidizing agent from direct contact with external moisture during
the tooth cleaning process, [0028] 5) Cleaning and scaling of
subject's teeth in proximity to the gum line, gingival margins and
crevicular spaces while the compositions of steps (3) and (4) above
are in contact with the tooth surfaces, [0029] 6) Polishing the
teeth with prophylaxis or polishing paste following completion of
step (5), [0030] 7) Optionally repeating steps (3) and (4), and
[0031] 8) Cleaning and rinsing all residual materials from tooth
and gum surfaces that were applied or produced during the
performance of steps (1) through (7).
[0032] Modifications to the above procedure are possible and are
some cases preferable. For instance, the conditioning agent or
conditioning composition may be combined with the oxidizing
composition of step (3) in order to reduce the amount of time
required to perform the combined cleaning and whitening procedure.
Also, water-resistant properties may be imparted to the oxidizing
composition of step (3) in order to obviate the need for a separate
step (4). Therefore, it is contemplated, but not required, that the
compositions and/or agents of steps (2), (3) and (4) may be
combined into a single composition (a) prior to packaging, (b) just
prior to, use, or (c) on the tooth surface during, use. Optionally,
a tooth-desensitizing agent, such as potassium nitrate, may be
applied before, during, or after any of the steps outlined above.
Such tooth-desensitizing agent may be applied as a stand-alone
alone formulation or combined with the conditioning agent,
oxidizing agent, water-resistant or film-forming composition, or
any combination of these.
DETAILED DESCRIPTION OF THE INVENTION
[0033] The compositions of the present invention are designed to
provide a fast and effective means of whitening the teeth during
the performance of a dental cleaning or prophylaxis. Various
combinations of tooth conditioning compositions, oxidizing
compositions and sealant compositions are envisaged to have utility
in the practice of the inventive method, and the properties of
these individual compositions may be combined into a single
composition for ease of use and application. Alternatively, a tooth
conditioning function may be combined with an oxidizing function
into a single composition. Another alternative is to combine a
tooth sealing function with an oxidizing function to reduce the
number of application steps.
[0034] The tooth conditioning composition may comprise a fluid
carrier and one or more tooth conditioning ingredients. Fluid
carriers include water, ethanol, diethyl ether, methoxypropane
(methyl propyl ether), dimethyl isosorbide and combinations
thereof. The tooth conditioning function, that is the ingredient or
ingredients that remove the acquired pellicle and subsequently open
the enamel porosities for better penetration of the oxidizing
composition, may be provided by ingredients having an acidic and/or
calcium chelating capabilities Useful acidic compounds include both
inorganic and organic acids such as phosphoric acid, hydrochloric
acid, acetic acid, lactic acid, citric acid, and their salts.
Useful calcium chelating compounds include both inorganic and
organic chelating agents such as ethylenediaminetetraacetic acid
(EDTA), phytic acid, 1-hydroxyethylidene-1,1'-diphosphonic acid,
citric acid, and their salts. The tooth conditioning composition
may also comprise colorants and/or pigments to assist in the
placement and application of the tooth conditioning composition
onto the teeth during the combination whitening and cleaning
procedure.
[0035] The oxidizing composition, comprises a fluid carrier and an
oxidizing agent. Fluid carriers include water, ethanol, diethyl
ether, methoxypropane (methyl propyl ether), dimethyl isosorbide
and combinations thereof. Oxidizing agents include peroxides, metal
chlorites, percarbonates, perborates, peroxyacids, hypochlorites
and combinations thereof. Preferred oxidizing agents are hydrogen
peroxide, carbamide peroxide, poly (vinyl pyrrolidone)-hydrogen
peroxide complex (Peroxydone.RTM., ISP Corp, Wayne, N.J.),
peroxyacetic acid, and sodium chlorite. The oxidizing composition
preferably has a viscosity of less than about 100 centipoise and
most preferably less than about 10 centipoise. The oxidizing
composition may also comprise active components further related to
the tooth whitening function (such as stabilizers, a secondary
oxidizing agent, an oxidation catalyst, a pH-adjusting agent, and a
calcium chelating agent), or to a non-tooth whitening function
(such as remineralization of the tooth surface, prevention of tooth
decay, tooth-desensitization, prevention of gingivitis and/or
periodontal disease, and other diseases or conditions of the oral
cavity). In addition, the oxidizing composition may comprise one or
more colorants and/or pigments to assist in the placement and
application of the sealant onto the teeth during the combination
whitening and cleaning procedure. Such colorants and/or pigments
may also be present to provide a stain masking effect that changes
the appearance of the tooth while the oxidizing composition is in
contact with the tooth surface during the procedure.
[0036] Preferred oxidation catalysts are chelated metal complexes,
in particular complexes iron and manganese. Particularly preferred
chelated metal complexes are family of tetraamido-N-macrocyclic
ligand (TAML) iron catalysts described in U.S. Pat. Nos. 7,060,818,
6,241,779, 6,136,223, 6,100,394, 6,054,580, 6,099,586, 6,051,704,
6,011,152, 5,876,625, 5,853,428, and 5,847,120.
[0037] The oxidizing compositions of the present invention may also
contain a surface active agent in order to lower the surface
tension of the composition to provide for better wetting and
adhesion of the liquid to the surface of the tooth. Anionic,
cationic, non-ionic and zwitterionic surfactants are contemplated
to have utility in providing the oxidizing compositions with a low
surface tension. Preferred surfactants are sulfobetaines (such as
amidosulfobetaine 3-16 and Lonzaine CS) and fluorosurfactants (such
as Capstone 50 and Capstone FS-10).
[0038] Sealant compositions of the present invention may comprise a
water-resistant polymer, copolymer or crosspolymer. and a fluid
carrier. Hereinafter the term "polymer" and "polymers" shall be
used to denote polymer(s), copolymer(s) or crosspolymer(s).
Suitable water-resistant polymers include acrylate polymers,
inethaerylate polymers, modified cellulosic polymers, silicone
polymers, urethane polymers, polyamide polymers, vinyl polymers,
vinyl pyrrolidone polymers, maleic acid or itaconic acid polymers,
and others. The water-resistant polymer should be soluble or
dispersible in the fluid carrier. Particularly preferred polymers
are poly (butyl methacrylate-co-(2-dimethylaminoethyl)
methacrylate-co-methyl methacrylate), poly (ethyl
acrylate-co-methyl methacrylate-co-trimethylammonioethyl
methacrylate chloride), ethylcellulose, and esterified or
crosslinked poly (methyl vinyl ether-co-maleic anhydride). The
fluid carrier may be a volatile solvent which will evaporate after
contacting the sealant composition with the tooth surface, leaving
behind a liquid or solid coating or film. Said solvent should have
an evaporation rate equal to or greater than that of water, and
preferably equal to or greater than that of butyl acetate. Suitable
solvents include, but are not limited to, water, ethanol, diethyl
ether, methoxypropane (methyl propyl ether), acetone, ethyl
acetate, and other highly volatile solvents.
[0039] Alternatively, the sealant compositions may be curable
liquids or gels, which are placed on the tooth surface and
subsequently exposed to some form of activating energy which
converts the liquid or gel sealant composition to a solid coating
or film. Curable sealant compositions may also be chemically cured,
whereby two or more components are combined just prior to use and
placed on the tooth surface to cure, in other words, to change from
a liquid or gel into a solid coating or film.
[0040] The sealant composition may also comprise active components
related to a tooth whitening function (such as an, oxidizing agent,
an oxidation catalyst, a pH-adjusting agent, and a calcium
chelating agent), or to a non-tooth whitening function (such as
remineralization of the tooth surface, tooth-desensitization,
prevention of tooth decay, prevention of gingivitis and/or
periodontal disease, and other diseases or conditions of the oral
cavity). In addition, the sealant composition may comprise one or
more colorants and/or pigments to assist in the placement and
application of the sealant onto the teeth. during the combination
whitening and cleaning procedure. Such colorants and/or pigments
may also he present to provide a stain masking effect that changes
the appearance of the tooth while the sealant composition is
attached to the tooth surface, in the form of a coating or
film.
[0041] The combination whitening and cleaning method described
herein may also be practiced by employing an additional source of
energy to accelerate the oxidation process and further reduce the
time needed to complete the procedure. External energy sources such
as electromagnetic or light energy, sound or ultrasound energy,
mechanical or vibrational energy, electrical energy, or
combinations thereof may be advantageously employed at any point in
time during the combination whitening and cleaning procedure, to
accelerate the process.
EXAMPLES
[0042] In order to achieve a significant degree of tooth whitening
in an abbreviated time frame suitable for integration into the
tooth cleaning (dental prophylaxis) process, ideal conditions for
(1) oxidizer penetration into the tooth and (2) conversion of
initial oxidizer form into active whitening species must be
facilitated.
[0043] Time limitations are imposed on the additional steps
required to achieve whitening during the tooth cleaning process by
the realities of patient scheduling in the typical dental office,
and such additional steps should not exceed 30 minutes beyond or in
addition to the time required to perform a typical dental
prophylaxis. Optimal conditions for penetration of an active
whitening composition into tooth enamel must be present in order to
reduce the amount of time and oxidizer concentration required to
reach intrinsic stain depth. Important factors related to oxidizer
penetration into the tooth are (1) the viscosity of the oxidizing
composition, (2) the surface tension of the oxidizing composition
and (3) the surface free energy (also called the critical surface
tension) of the tooth surface.
[0044] The surface free energy of exposed tooth enamel is generally
in the range of about 50-55 dynes/cm, however the acquired.
pellicle can lower this number significantly. In fact, one of the
important functions of the acquired pellicle is to reduce the
critical surface tension of the tooth surface in order to reduce
the adhesion of bacteria. Liquid and gel compositions contacting
the tooth surface penetrate into the tooth structure in relation to
four primary factors: time, viscosity of the liquid or gel. surface
tension of the liquid or gel, and surface free energy of the tooth
at the point of contact.
[0045] The relationship of liquid surface tension to solid surface
free energy, low contact angle (the tangential angle formed by a
droplet deposited on a solid surface) and low viscosity, are all
directly related to the Penetration Coefficient (as derived from
the Lucas-Washburn equation) and must be optimized for the
whitening composition to (1) rapidly wet the surface of tooth
enamel and (2) penetrate the available porosities and channels
through enamel as quickly as physically possible.
Example 1
[0046] The ability of various oxidizing compositions to penetrate
intact enamel and dentin was determined as follows. Extracted molar
and pre-molar teeth were obtained from orthodontists with patient
consent and stored refrigerated in phosphate buffered saline (PBS)
solution at pH 6.8 until use. In order to assess the ability of
various liquid carrier fluids to penetrate tooth enamel, teeth were
sectioned to remove their roots and a 3 mm diameter chamber was
created in the center of the sectioned crown that was filled with
PBS solution. The crowns were partially immersed (chamber with PBS
solution facing up) in various liquid carrier fluids and a small (1
microliter) sample of the PBS solution was drawn every 60 seconds
and. placed on a peroxide test strip (EM Quinn Strips 10337, EMD
Chemicals, a division of Merck SA, Darmstadt, Germany) to determine
the amount of time required for hydrogen peroxide to penetrate the
tooth enamel and dentin from the outer surface of the crown to the
interior chamber containing PBS.
[0047] Oxidizing compositions in Table 1 below were prepared and
stored in 20 ml glass vials until use.
TABLE-US-00001 TABLE 1 Percent (w/w) Ingredient 1A 1B 1C 1D 1E 1F
1G 1H 1I 1J 1K 1L Water 75.0 65.0 75.0 65.0 85.0 75.0 65.0 75.0
65.0 75.0 65.0 100.0 Ethanol 200 10.0 20.0 5.0 15.0 5.0 15.0
Diethyl ether 5.0 5.0 Methoxypropane 5.0 5.0 Acetone 10.0 20.0
Dimethyl isosorbide 10.0 20.0 Hydrogen peroxide 15.0 15.0 15.0 15.0
15.0 15.0 15.0 15.0 15.0 15.0 15.0 0.0 Adjusted to pH 4.0 with
potassium hydroxide 0.1M Viscosity (cps @ 25 C.) <1 <1 <1
<1 1.3 <1 <1 <1 <1 1.5 1.5 1 Surface tension <40
<40 <40 <40 >50 <40 <40 <40 <40 <40
<40 >50 (dynes/cm) Contact angle (deg) <10 <10 <10
<10 30+ <10 <10 <10 <10 15 15 50+ PC (calculated)
>100 >100 >100 >100 <50 >100 >100 >100
>100 >100 >100 <30 H.sub.2O.sub.2 detection (min) 13 12
12 10 20 14 12 14 14 15 15 ND* *ND = Not detected
[0048] Oxidizing compositions in Table 1 trended towards faster
penetration of the tooth when both contact angle and viscosity of
the composition was low (Examples 1A, 1B, 1C, 1D, 1F, 1G, 1H, 1J,
and 1K). Oxidizing with high contact angles (greater than 30
decrees) did not seem to penetrate as well as those with contact
angles less than about 10 degrees.
Example 2
[0049] The following multi-step process was developed to provide
for rapid and effective whitening of the teeth during a dental
cleaning procedure.
[0050] Step 1--Acquired Pellicle Removal
[0051] Facilitating oxidizer penetration into the tooth requires a
thorough removal or modification of the acquired pellicle prior to
contact with the oxidizer formulation. Therefore, whether
integrated into a dental prophylaxis procedure or performed as a
stand-alone process, the first step in the abbreviated whitening
process (alter determining a starting tooth shade) must be the
removal of the acquired pellicle using chemical, mechanical or
(preferably) chemo-mechanical means. Once the acquired pellicle has
been removed, it is important that the "cleaned" tooth enamel
surface has limited contact with the patient's saliva prior to
application of the oxidizer composition (see Step 2) in order to
prevent reformation of the pellicle film on the exposed enamel
surface. Removal or modification of the acquired pellicle and
optional micro-roughening of the exposed enamel surface will
elevate the enamel surface free energy (preferably above about 60
dyne/cm), which promotes better wetting of the enamel surface by
the oxidizing composition. Surface wetting is a key factor related
to the speed at which a composition penetrates enamel, analogous to
the effects of viscosity and suffice tension on the penetration of
bonding adhesives into conditioned enamel and sealants into caries
lesions.
[0052] Step 1a Placement of cheek retractor or other means of
preventing contact of the lips and interior gum surfaces with the
teeth.
[0053] Step 1b Application of Conditioner for 30-60 seconds
[0054] Tooth Conditioner Composition
TABLE-US-00002 Ingredient Percent (w/w) Water 90.0 Poly (methyl
vinyl ether-co-maleic anhydride)* 10.0 *Gantrez S-95 (ISP Corp,
Wayne, NJ) (hydrolyzed, pH 2.0)
[0055] Step 2--Oxidizer Contact and Penetration
[0056] Once the acquired pellicle has been removed, the teeth
surfaces are contacted with a low viscosity oxidizer composition
with a surface tension significantly lower than that of the surface
free energy of the exposed enamel surface. A low viscosity
oxidizing composition that has a low surface tension will have a
very low contact angle when placed on the enamel surface and thus
be better suited to penetrate into the enamel porosities. The,
oxidizer composition should comprise hydrogen peroxide in an
aqueous form (or mixed with viscosity-reducing solvents) and at a
concentration between about 1% and 30% by weight (higher amounts
being contemplated in situations where precise control and
placement of the oxidizing composition is possible). The oxidizing
composition should also have a pH within a range similar to that
reported for the isoelectric point of tooth enamel, which is
between about 3.8 and 4.7, although higher pH levels are possible
with oxidizing compositions comprising ionized species capable of
counteracting the influence of charged components in tooth enamel.
The oxidizing composition is brushed repeatedly onto the tooth
surfaces to be whitened over the period of about 7-10 minutes to
provide as much full strength hydrogen peroxide at the interface
over the initial treatment phase.
[0057] Step 2a Application of oxidizing composition to buccal and
(optionally) lingual surfaces of teeth
[0058] Oxidizer Composition
Example 1D
[0059] Step 3--Scaling Enamel Surface Prior to Dental Prophylaxis
Procedure
[0060] In order to prevent dilution or removal of the oxidizing
composition in or from the tooth enamel treated in accordance with
Step 2 above, a water-resistant protective sealant is applied (and
if solvent-based, allowed sufficient time for the carrier solvent
to evaporate). The sealant composition may also comprise an
additional oxidizing agent to provide an additional reservoir of
whitening active, and/or an advanced oxidation catalyst in order to
promote active oxidizing species such as hydroxyl radicals (.OH)
and perhydroxyl anions (--OOH) and/or a desensitizing agent to
reduce or eliminate any tooth sensitivity associated with the
procedure.
[0061] Step 3a Application of Sealant to buccal and (optionally)
lingual surfaces of teeth
[0062] Sealant Composition
TABLE-US-00003 Ingredient Percent (w/w) Ethanol 200 proof 90.0 Poly
(butyl methacrylate-co-(2-dimethylaminoethyl) 10.0
methacrylate-co-methyl methacrylate)* *Eudragit E100 or EPO (Evonik
Rohm GmbH, Darmstadt, Germany)
[0063] The sealant composition is applied onto the surfaces of the
teeth previously contacted with the oxidizing composition and
allowed to fully dry before proceeding to Step 4.
[0064] Step 4--Performance of the Dental Prophylaxis Procedure
[0065] Following the sealing process, a dental prophylaxis is pert
armed using standard protocols and materials. Care should be taken
to avoid excessive disruption of the sealant on the buccal and
lingual (if coated) surfaces of the, teeth during the cleaning
procedure. The dental prophylaxis is otherwise performed in a
standard fashion, including polishing of the teeth with a standard
prophy paste (which will remove the Sealant applied in Step 3). A
final tooth shade may be taken at this time.
[0066] Step 5--Final Treatment
[0067] If time permits, Steps 2 and 3 are repeated after prophy
cleanup. No further intervention is required to remove the Sealant
if applied after completion of the dental prophylaxis and dismissal
of the patient. The Sealant may remain in place after the patient
leaves the office and will slowly erode over time. The patient may
also be supplied with a home-use version of the oxidizing
composition and the sealant as an option for continued improvement
in tooth color.
[0068] The above steps were performed on extracted molars and
premolars(n=25) obtained through orthodontists with patient consent
and stored refrigerated in phosphate buffered saline (PBS) solution
at pH 6.8 until use. Individual teeth were removed from the PBS
solution, allowed to air dry for 60 seconds and the roots inserted
up to the cementoenamel junction into a high viscosity aqueous gel
to keep the roots hydrated during the procedure. An initial tooth
shade was taken using a Minolta CM504i chromameter (Konica-Minolta)
and recorded. Steps 2 (total treatment time of 10 minutes) and 3
(total treatment time of 120 seconds) were performed on the
extracted teeth, and a 32 minute period was allowed to elapse
during which the teeth were rinsed with water every 8 minutes to
simulate the rinsing process that typically occurs during the
cleaning process. After the simulated cleaning process time had
elapsed, the teeth were polished with a medium grit prophy paste
using a slow speed handpiece and prophy cup. Teeth were rinsed with
water and a final tooth shade was taken using the method described
above and recorded in Table 2 below (L, a, b=Initial color
readings, L*, a*, b*=final color readings).
TABLE-US-00004 TABLE 2 Tooth L a b L* a* b* Delta L Delta a Delta b
Delta E 1 76.10 3.14 15.98 78.11 1.61 13.13 2.01 -1.53 -2.85 3.81 2
76.90 3.44 12.45 80.98 2.40 13.01 4.08 -1.04 0.56 4.25 3 74.23 3.32
16.05 78.33 1.98 12.77 4.10 -1.34 -3.28 5.42 4 74.25 2.00 16.21
77.21 1.74 12.12 2.96 -0.26 -4.09 5.06 5 78.21 3.24 14.76 80.43
1.99 11.26 2.22 -1.25 -3.50 4.33 6 75.21 3.01 15.90 77.77 2.45
14.01 2.56 -0.56 -1.89 3.23 7 74.79 1.82 13.88 78.23 1.43 13.20
3.44 -0.39 -0.68 3.53 8 72.24 3.32 16.43 75.20 2.99 13.95 2.96
-0.33 -2.48 3.88 9 73.19 3.87 15.81 78.81 2.33 10.32 5.62 -1.54
-5.49 8.01 10 77.31 3.66 14.73 77.60 1.84 9.99 0.29 -1.82 -4.74
5.09 11 71.89 3.97 17.68 76.39 2.77 14.02 4.50 -1.20 -3.66 5.92 12
74.54 3.58 14.32 78.40 2.87 13.13 3.86 -0.71 -1.19 4.10 13 73.29
3.82 14.65 78.41 2.02 13.03 5.12 -1.80 -1.62 5.66 14 74.03 3.92
16.33 76.75 2.36 14.56 2.72 -1.56 -1.77 3.60 15 71.99 2.98 15.03
77.90 1.75 11.82 5.91 -1.23 -3.21 6.84 16 73.98 3.92 15.57 78.02
1.99 11.08 4.04 -1.93 -4.49 6.34 17 73.12 3.22 16.23 76.19 1.56
13.84 3.07 -1.66 -2.39 4.23 18 76.00 3.42 15.48 78.88 1.98 10.63
2.88 -1.44 -4.85 5.82 19 73.94 3.73 14.14 78.58 2.02 10.73 4.64
-1.71 -3.41 6.01 20 74.74 3.46 15.02 77.33 2.38 13.05 2.59 -1.08
-1.97 3.43 21 70.95 3.98 17.43 75.02 2.97 12.83 4.07 -1.01 -4.60
6.22 22 73.49 4.03 16.55 77.91 3.13 13.43 4.42 -0.90 -3.12 5.48 23
76.03 3.10 18.30 78.73 1.57 13.22 2.70 -1.53 -5.08 5.95 24 73.83
3.28 17.43 77.00 1.22 10.15 3.17 -2.06 -7.28 8.20 25 74.17 2.98
15.12 78.36 2.09 11.03 4.19 -0.89 -4.09 5.92 Average 73.84 3.46
16.03 77.63 2.06 11.98 3.79 -1.40 -4.04 5.72
* * * * *