U.S. patent application number 09/850355 was filed with the patent office on 2001-11-22 for methods for accelerated desensitization of teeth.
Invention is credited to Lindquist, Sherrill F..
Application Number | 20010044096 09/850355 |
Document ID | / |
Family ID | 24259945 |
Filed Date | 2001-11-22 |
United States Patent
Application |
20010044096 |
Kind Code |
A1 |
Lindquist, Sherrill F. |
November 22, 2001 |
Methods for accelerated desensitization of teeth
Abstract
Apparatus and methods for providing accelerated desensitization
of a person's teeth. The apparatus and methods involve the use of a
heating apparatus, such as a dental curing lamp, laser, or dental
impression tray that includes a patient dentition impression formed
from a dental impression material such as an alginate. The
impression tray advantageously includes heating means for heating
and maintaining the formed patient dentition impression at a
temperature greater than about 105.degree. F. A dental office
procedure for treating teeth involves the basic steps of: (1)
coating a specially-prepared dentition impression with a
desensitizing dental composition; (2) placing the coated patient
dentition impression into the person's mouth; (3) heating the
dentition impression and dental composition to a temperature of at
least about 105.degree. F.; and (4) retaining the patient dentition
impression in position for period of time in a range of about 1
minute to about 60 minutes so as to desensitize the person's teeth.
The procedure can be adapted to microwave heating, electrical
resistance heating, or hot fluid heating of the patient dentition
impression.
Inventors: |
Lindquist, Sherrill F.;
(Dublin, OH) |
Correspondence
Address: |
Rick D. Nydegger
WORKMAN, NYDEGGER & SEELEY
1000 Eagle Gate Tower
60 East South Temple
Salt Lake City
UT
84111
US
|
Family ID: |
24259945 |
Appl. No.: |
09/850355 |
Filed: |
May 7, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09850355 |
May 7, 2001 |
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09565752 |
May 8, 2000 |
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Current U.S.
Class: |
433/215 |
Current CPC
Class: |
A61C 9/0006 20130101;
A61C 19/063 20130101 |
Class at
Publication: |
433/215 |
International
Class: |
A61C 005/00 |
Claims
What is claimed and desired to be secured by United States Letters
Patent is:
1. A method for accelerated desensitization of a person's teeth
comprising: contacting a person's teeth with a dental composition
that includes a desensitizing agent; and heating the dental
composition to a temperature of at least about 105.degree. F. for a
time period effective for reducing tooth sensitivity.
2. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the dental composition is heated to a
temperature in a range of about 110.degree. F. to about 150.degree.
F.
3. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the dental composition is heated to a
temperature in a range of about 120.degree. F. to about 140.degree.
F.
4. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the desensitizing agent includes a
potassium salt.
5. A method for accelerated desensitization of a person's teeth as
defined in claim 4, wherein the potassium salt is potassium
nitrate.
6. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the desensitizing agent is selected
from the group consisting of potassium citrate, citric acid, citric
acid salts, strontium chloride, fluoride salts, and mixtures
thereof.
7. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the desensitizing agent is included in
a an amount in a range of about 0.01% to about 50% by weight of the
dental composition.
8. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the desensitizing agent is included in
an amount in a range of about 0.05% to about 10% by weight of the
dental composition.
9. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the desensitizing agent is included in
a an amount in a range of about 0.1% to about 5% by weight of the
dental composition.
10. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the desensitizing agent includes a
fluoride salt.
11. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the dental composition is heated by
means of a dental impression tray that includes a heated impression
material.
12. A method for accelerated desensitization of a person's teeth as
defined in claim 11, wherein the impression material is heated by
means of a resistive heating element associated with the impression
tray.
13. A method for accelerated desensitization of a person's teeth as
defined in claim 11, wherein the impression material includes a
formed dentition impression of the person's teeth and wherein the
dental composition is first placed within the formed dentition
impression and then contacted with the person's teeth by inserting
the dental impression tray into the person's mouth.
14. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the dental composition is heated by
means of radiant energy emitted by a curing light.
15. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the dental composition is heated by
means of radiant energy emitted by laser.
16. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the dental composition is maintained in
contact with the person's teeth for a time period in a range of
about 1 minute to about 60 minutes.
17. A method for accelerated desensitization of a person's teeth as
defined in claim 1, wherein the dental composition is maintained in
contact with the person's teeth for a time period a range of about
5 minutes to about 30 minutes.
18. A method for accelerated desensitization of a person's teeth
comprising: providing a dental impression tray that includes a
formed impression at least approximately corresponding to a
person's teeth and means for heating the formed impression;
introducing a dental composition that includes a desensitizing
agent into the formed impression; inserting the impression tray
into the person's mouth in order to contact at least a portion of
the person's teeth with the dental composition; and maintaining the
dental composition in contact with the person's teeth at a
temperature of at least about 105.degree. F. for a time period
effective for reducing tooth sensitivity.
19. A method for accelerated desensitization of a person's teeth as
defined in claim 18, wherein the dental composition is maintained
in contact with the person's teeth at temperature in a range of
about 110.degree. F. to about 150.degree. F. for a time period in a
range of about 1 minute to about 60 minutes.
20. A method for accelerated desensitization of a person's teeth as
defined in claim 18, wherein the dental composition is maintained
in contact with the person's teeth at temperature in a range of
about 120.degree. F. to about 140.degree. F. for a time period in a
range of about 5 minutes to about 30 minutes.
21. A method for accelerated desensitization of a person's teeth
comprising: contacting a person's teeth with a dental composition
that includes potassium nitrate in an amount effect for
desensitizing teeth; and heating the dental composition to a
temperature in a range of about 110.degree. F. to about 150.degree.
F. for a time period in a range of about 1 minute to about 60
minutes.
22. A method for accelerated desensitization of a person's teeth as
defined in claim 21, wherein the dental composition is maintained
at a temperature in a range of about 120.degree. F. to about
140.degree. F. for a time period of about 5 minutes to about 30
minutes.
Description
RELATED APPLICATION
[0001] This application is a continuation-in-part of copending U.S.
application Ser. No. 09/565,752, filed May 8, 2000. For purposes of
disclosure, the foregoing application is incorporated herein by
specific reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention is in the field of apparatus and methods for
use in desensitizing teeth. More particularly, the invention is in
the field of apparatus and methods for accelerating the activity of
desensitizing dental compositions by means of the application of
heat. A laser, curing lamp or heated dental impression material may
advantageously be employed to impart the necessary heat to the
desensitizing composition.
[0004] 2. Review of the Relevant Technology
[0005] In the last decade there has been a proliferation of
compositions and methods for bleaching teeth. Compositions for both
in-office or at-home use typically include a peroxide bleaching
agent, such as carbamide peroxide, hydrogen peroxide or sodium
perborate. Carbamide peroxide is a complex of urea and hydrogen
peroxide. Sodium perborate is a complex of sodium borate and
hydrogen peroxide. On the other hand, hydrogen peroxide by itself
only exists in aqueous form and is generally unstable except at
relatively low pH.
[0006] One of the drawbacks of the use of dental bleaching agents
is their tendency to irritate or sensitize the patient's teeth. It
is believed that the dental bleaching agent, or at least the active
oxidizing agents released therefrom, are able to penetrate into the
teeth through microscopic holes or passages normally found in
teeth. Because dental bleaching agents work by oxidizing stains or
other coloration by penetrating into the afore-mentioned dental
pores, it is not surprising that such oxidizing agents, because
they are caustic, are often found to cause irritation of the teeth.
By penetrating into the patient's teeth, the irritating oxidizing
agents are sometimes able to reach nerve endings found within the
pulp, which can cause acute pain or generally increased sensitivity
of the teeth.
[0007] Teeth can also become irritated or sensitized for other
reasons as well, including a wide variety of common dental
ailments. These include, for example, tooth decay, cracks or
fissures in the enamel, tiny gaps or pores between filling
materials and dental tissue, heat, cold, jarring of the teeth, and
the like.
[0008] Tooth sensitivity and pain can be treated by means of a
topical application of a desensitizing composition. There are
presently numerous over-the-counter toothpastes that incorporate a
desensitizing agent for application to a person's teeth during
regular brushing and general daily hygiene. A common desensitizing
agent found within toothpastes is potassium nitrate. One of the
drawbacks of desensitizing toothpaste compositions is that the
duration of contact between the desensitizing agent and a person's
teeth during daily brushing is sometimes insufficiently long to
adequately treat tooth sensitivity. Most people brush for less than
60 seconds, which is usually not long enough to adequately treat
overly sensitized teeth. Nevertheless, the use of desensitizing
toothpaste compositions over a prolonged period of time may have a
beneficial effect due to the frequency with which it is applied to
the teeth.
[0009] In order to obtain faster results, there are a number of
specially formulated desensitizing dental compositions that are
formulated so as to remain in contact with a person's teeth for a
prolonged period of time, typically from 30 minutes to 8 hours.
Examples of desensitizing compositions that may be applied to a
person's teeth by means of a dental tray are set forth in U.S. Pat.
No. 5,855,870 and U.S. Pat. No. 5,851,512. Examples of other
desensitizing compositions that include potassium nitrate are set
forth in U.S. Pat. No. 5,153,006.
[0010] The advantage of using compositions that can remain in
contact with a patient's teeth for longer periods of time is that
it allows more time for the potassium nitrate or other
desensitizing agent to penetrate through the enamel and into the
dental pulp where it can impart its anesthetizing effect. The
downside is that the patient must maintain the desensitizing
composition in contact with the sensitive teeth being treated for a
prolonged period of time, thus potentially causing discomfort or
inconvenience to the patient.
[0011] In view of the foregoing, it would be an improvement in the
art to provide apparatus and methods for desensitizing teeth in a
manner that would significantly reduce the time it takes for
potassium nitrate or other suitable desensitizing agents to impart
their desired desensitizing effect.
[0012] It would further be an improvement in the art if such
apparatus and methods significantly reduced the time it took to
desensitize the teeth, while utilizing conventional desensitizing
compositions presently available on the market.
[0013] Such apparatus and methods for accelerating desensitization
of a patient's teeth are disclosed and claimed herein.
SUMMARY AND OBJECTS OF THE INVENTION
[0014] The present invention relates to apparatus and methods used
to accelerate desensitization of a person's teeth through the
application of heat together with a desensitizing composition. The
heat may be imparted to the desensitizing composition by means of
any heating apparatus known in the art, such as a dental curing
lamp or a laser. In a preferred embodiment, acceleration of
desensitization may advantageously be carried out by means of
conventional or specially adapted dental impression trays in
conjunction with a heated impression material. The use of an
impression material provides the dentist with the ability to
manufacture what is, in essence, a customized tray that can be
loaded with a desensitizing dental composition and heated before or
after placement of the tray into the patient's mouth. The formed
impression material can be heated by, e.g., microwave energy,
resistive heating devices, or a heated fluid in order to accelerate
the rate at which the desensitizing dental composition is able to
carry out its intended desensitization of a person's teeth.
[0015] The dental impression trays may advantageously be sold or
provided to a dentist in the form of a kit that includes at least a
portion of the means necessary to form and then heat a dentition
impression of the patient's teeth, followed by treatment of a
patient's teeth using a dental desensitizing composition. Such kits
will preferably include, at a minimum, a dental impression tray
capable of receiving sufficient impression material so as to make
an impression of at least a portion of the patient's teeth, means
for heating the impression during the treatment process, and one or
more dental compositions, including a composition which includes a
desensitizing agent (e.g., a potassium salt such as potassium
nitrate or a fluoride salt such as sodium fluoride). The kits may
optionally include an impression material, such as a standard
alginate impression material known in the art. Nevertheless,
because most dentists already have standard impression materials on
site for other purposes, it is typically not necessary for the kits
to include an impression material.
[0016] An exemplary embodiment of utilizing a formed dentition
impression to provide heat includes the following steps: (1)
filling at least a portion of a dental impression tray with an
unset dental impression material; (2) placing the filled dental
impression tray into the patient's mouth in order to take an
impression of at least a portion of the patient's teeth; (3)
maintaining the impression tray in place for a sufficient length of
time for the dental impression material to at least partially cure
to thereby form a patient dentition impression; (4) removing the
dental impression tray and included formed patient dentition
impression from the patient's mouth; (5) placing an appropriate
quantity of a dental desensitizing composition within the formed
patient dentition impression; (6) introducing the dental impression
tray and included formed patient dentition impression with the
desensitizing composition into the patient's mouth so as to at
least approximately register the patient's teeth and the
corresponding formed patient dentition impression; (7) heating
and/or maintaining the temperature of the formed patient dentition
impression at a temperature of at least about 105.degree. F.; and
(8) removing the dental impression try and included dentition
impression from the patient's mouth and thoroughly rinsing the
patient's mouth prior to release of the patient.
[0017] In a preferred embodiment, the formed patient dentition
impression will be heated to and maintained at the desired
temperature by means of an electrical resistance heating element
located within, or otherwise associated with, the dental impression
tray. The dentition impression may alternatively be heated by means
of microwave energy or by the use of a heated fluid. The
temperature of the dentition impression is preferably maintained in
a range of about 110.degree. F. to about 150.degree. F., more
preferably in a range of about 120.degree. F. to about 140.degree.
F.
[0018] In the case where an electrical resistance heating element
is used, the dental impression tray will be electronically
connected to a power supply, such as a DC power supply that
supplies a desired amount of power. In a preferred embodiment, the
patient may be given a control device that interacts with the power
supply so as to heat and maintain the dentition impression at an
elevated, yet comfortable, temperature so as to optimize patient
comfort and dental composition activity. In order to further
maximize patient comfort, it may be advantageous to trim away a
portion of the patient dentition impression that would otherwise
contact or overlap the patient's gingival tissue. In this way the
heat can be concentrated or focused on the teeth and kept away from
the much more sensitive gingival tissue surrounding the teeth.
[0019] The treatment times according to the present invention
typically range of about 1 minute to about 60 minutes, more
preferably in a range of about 5 minutes to about 30 minutes,
depending on the dental composition being used, as well as the time
necessary for carrying out the desired desensitization treatment.
Where it has heretofore been known that heat is able to destabilize
peroxide-based dental bleaching agents so as to accelerate the
liberation of oxygen radicals used in bleaching teeth, it has
heretofore not been known that heat can also accelerate the
beneficial effects of other dental agents, such as desensitizing
agents based on potassium nitrate or remineralizing agents based on
fluoride salts. This is a surprising result since neither potassium
nitrate nor fluoride salts decompose when heated to the
temperatures described herein.
[0020] Accordingly, it is an object of the invention to provide
apparatus and methods for desensitizing teeth in a manner that
significantly reduces the time it takes for potassium nitrate or
other suitable desensitizing agents to impart their desired
desensitizing effect.
[0021] It is a further object to provide apparatus and methods that
significantly reduce the time it takes to desensitize the teeth,
while utilizing conventional desensitizing compositions presently
available on the market.
[0022] These and other objects and features of the present
invention will become more fully apparent from the following
description and appended claims, or may be learned by the practice
of the invention as set forth hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] In order that the manner in which the above-recited and
other advantages and objects of the invention are obtained, a more
particular description of the invention briefly described above
will be rendered by reference to a specific embodiment thereof
which is illustrated in the appended drawings. Understanding that
these drawings depict only a typical embodiment of the invention
and are not therefore to be considered to be limiting of its scope,
the invention will be described and explained with additional
specificity and detail through the use of the accompanying drawings
in which:
[0024] FIG. 1 depicts a preliminary procedural step of coating the
principal cavity of an alginate dental impression tray with a
conventional adhesive;
[0025] FIG. 2 depicts a preliminary step of applying a dental wax
overlay to the surfaces of the patient's teeth that are to be
whitened;
[0026] FIG. 3 illustrates the step of placing an unset conventional
dental impression material in the principal cavity of the dental
impression tray of FIG. 1;
[0027] FIG. 4 is a cross-section view taken at line 4-4 of FIG. 3
and extending transversely through the filled dental impression
tray of FIG. 3;
[0028] FIG. 5 depicts the act of inserting the compound-filled
dental impression tray of FIGS. 3 and 4 into a patient's mouth for
impression-setting purposes;
[0029] FIG. 6 is a plan view of the completed dental impression
prior to wax overlay removal;
[0030] FIG. 7 is a cross-section view taken at line 7-7 of FIG.
6;
[0031] FIG. 8 is a cross-section view similar to FIG. 7 but after
accomplishing wax overlay removal;
[0032] FIG. 9 is a cross-section view taken at line 9-9 of FIG.
6;
[0033] FIG. 10 is a cross-section view taken at line 9-9 of FIG. 8
but with an alternative dental impression material having a
particulate filler dispersed therein;
[0034] FIG. 11 depicts the step of placing a desensitizing dental
composition into the formed dental impression cavity preparatory to
treating the patient's teeth;
[0035] FIG. 12 depicts the placement of the tray of FIG. 11 into
the patient's mouth in order to effect bleaching;
[0036] FIG. 13 schematically depicts an alternate embodiment of a
dental impression material and impression tray in which resistive
heat is employed to heat and maintain the proper temperature of the
set dental impression material;
[0037] FIG. 14 is a cross-section view taken at line 14-14 of FIG.
13;
[0038] FIG. 15 schematically depicts another alternative embodiment
of a dental impression material and impression tray in which a
heated fluid is used to heat and maintain the proper temperature of
the set dental impression material;
[0039] FIG. 16 is a cross-section view taken at line 16-6 of FIG.
15;
[0040] FIG. 17 is a perspective view of an alternative dental
impression tray equipped with resistive heating elements;
[0041] FIG. 18 is a perspective view of the dental impression tray
of FIG. 17 into which a dental impression material has been placed
into the upper half of the impression tray.
[0042] FIG. 19 is a cross-section view taken at line 19-19 of FIG.
18;
[0043] FIG. 20 is a perspective view of a heating element used in a
dental impression tray according to the invention; and
[0044] FIG. 21 schematically depicts an integrated system employing
the impression tray of FIG. 17 together with a power supply and a
controller.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0045] I. INTRODUCTION.
[0046] The present invention encompasses apparatus and methods for
accelerated desensitization of a patient's teeth, typically in an
in-office procedure, utilizing heat and a desensitizing dental
composition applied to a person's teeth. The heat may be imparted
to the desensitizing composition by means of any heating apparatus
known in the art, such as dental curing lamp or a laser. In a
preferred embodiment, the heat used for accelerating
desensitization of a person's teeth may be provided by a
conventional or specially adapted dental impression tray that
includes a heated dental impression material. The impression
material may be heated, e.g., by means of microwave energy, a
resistive heating device, or a heated fluid so as to accelerate the
rate at which the dental desensitizing composition is able to
desensitize a person's teeth. Other optional steps may be
performed, as desired.
[0047] The use of an impression material to make what is in essence
a customized dental tray into which an appropriate dental
composition can be loaded eliminates the time-consuming practice of
manufacturing a customized dental tray. Moreover, the heated
impression materials of the present invention are far less
expensive than expensive lasers, or even relatively inexpensive
curing lamps, but provide similar or even superior results. Because
dental impression trays and impression materials are so
inexpensive, they may be used once and then discarded.
[0048] Of course, it is certainly within the scope of the invention
to use a heated custom dental tray, such as those disclosed in U.S.
Pat. No. 6,102,705. For purposes of disclosing heating apparatus
for use in carrying out the inventive tooth desensitization
methods, the foregoing patent is incorporated herein by
reference.
[0049] Examples of lasers that may be used, or adapted for use, in
desensitizing teeth according to the present invention are
disclosed in U.S. Pat. No. 5,645,428, U.S. Pat. No. 5,611,733, U.S.
Pat. No. 6,086,367, U.S. Pat. No. 6,083,218, U.S. Pat. No.
5,928,220 and U.S. Pat. No. 5,713,738. For purposes of disclosing
lasers for use in carrying out the inventive tooth desensitization
methods, the foregoing patents are incorporated herein by
reference.
[0050] Examples of dental curing lamps for use in desensitizing
teeth according to the present invention are disclosed in U.S. Pat.
No. 6,171,105, U.S. Pat. No. 6,168,431, U.S. Pat. No. 6,123,545 and
U.S. Pat. No. 5,749,724. For purposes of disclosing dental curing
lamps for use in carrying out the inventive tooth desensitization
methods, the foregoing patents are incorporated herein by
reference.
[0051] II. APPARATUS FOR FORMING AND HEATING A PATIENT DENTITION
IMPRESSION.
[0052] In a preferred embodiment, the apparatus and methods
according to the invention utilize a dental impressing tray. One of
the purposes of the dental impression tray is receive and retain a
dental impression material during the formation of a patient
dentition impression and also during subsequent treatment of the
patient's teeth. The impression tray will advantageously include
means for heating the formed patient dentition impression during
the treatment process. Nevertheless, virtually any dental
impression tray, both conventional or specialized, may be used
within the scope of the present invention, in combination with an
impression material, to form a dentition impression of a patient's
teeth to be treated.
[0053] Examples of suitable dental trays that include means for
heating a formed dentition impression are illustrated more
particularly in FIGS. 13-21. More preferred are dental impression
trays that incorporate, or otherwise have associated therewith, a
resistive heating element, such as the trays illustrated in FIGS.
13-14 and 17-21, which shall be discussed first.
[0054] FIGS. 13 and 14 illustrate a dental impression tray 10
according to the present invention that includes a resistive
heating element or wire. Impression tray 10 includes one or more
heating wires 34 that are looped around within an interior cavity
12 of the tray 10 prior to filling tray cavity 12 with an unset or
uncured dental impression material 16. During use, the one or more
heating wires 34 are connected to a power supply 32. Together, the
impression tray 10 and power supply 32 form a system 30 that is
capable of heating the impression material 16 disposed within the
interior trough of the tray 10. Because the impression tray 10 is
advantageously disposable, or at least in order to separately store
the tray 10 and power supply 32, the one or more heating wires 34
are advantageously coupled to the power supply 30 by means of
conventional or specialized electrical connectors 36.
[0055] Although FIG. 14 depicts an arrangement wherein the heating
wires 34 are embedded within the impression material 16, any
arrangement whereby impression tray 10 is able to heat and maintain
the impression material 16 within a desired temperature range is
within the scope of the invention. In an experimental embodiment of
apparatus 30, approximately 40 to 50 inches of No. 24 insulated
audio speaker wire were used as resistance heating wire 34. Power
supply 32 comprised a conventional 120/30 volt alternating current
step-down transformer with a 2.5 ampere output current, an
alternating current-to-direct current rectifier, an electronic
intermittent switch having 30-40 second on times alternated with
30-40 second off times, and a system on-off timer switch mechanism.
The power supply timer functioned to activate power supply 32 for
periods of time in a range of from 1 to 15 minutes.
[0056] FIGS. 17-21 depicts an alternative dental impression tray 50
configured so as to be able to treat the upper and lower teeth of a
person of the same time. As shown in FIG. 17, dental impression
tray 50 includes a generally arcuate structure 52, which defines an
interior region for receipt of a dental impression material 64
(FIG. 18). Arcuate structure 52 is attached to a handle 62, which
serves the dual purpose of facilitating gripping by the dental
practitioner as well as providing a protective housing for wires 60
used to supply an electric current used to heat a formed dentition
impression of the person's teeth (not shown) within dental
impression tray 50.
[0057] Tray 50 further includes a substantially planar divider or
barrier 54, which provides opposing surfaces for placement of an
impression material 64 on either side of divider 54. Divider 54 may
comprise any appropriate material, examples of which include a
solid metal or plastic sheet, or a wire or nylon fabric or mesh. A
generally curved wall 56 assists in retaining the alginate or other
impression material within the space between arcuate structure 52
and wall 56. FIG. 17 further depicts a pair of heating elements 58a
and 58b disposed on an interior surface of arcuate structure 52,
which are used to heat an impression material.
[0058] FIG. 18 depicts tray 50 into which an unset impression
material 64 has been placed within the space defined by wall 56 and
arcuate structure 52 on an upper surface of divider 54. In the case
where it will be desired to bleach both the upper and lower teeth,
a layer of impression material 64 may also be placed on the
underside of divider 54. The use of a mesh or other porous material
as the divider 54 promotes adhesion of the impression material 64
onto the surface of the divider 54, even on the underside. Of
course, glue or other adhesion aids may be used as desired to
retain the impression material 64 within the tray 50.
[0059] It will be appreciated that a person's gums or gingiva are
typically more sensitive to heat than teeth. Accordingly, it may be
desirable to trim back a portion of the cured impression material
of the formed dentition impression in the area of the gingival
interface. In this way the cured impression material advantageously
touches or is adjacent to only the person's teeth being treated
rather than the more sensitive gingival tissue.
[0060] In order to heat the formed patient dentition during
treatment, heating elements 58a and 58b heat up as an electrical
current is passed therethrough. As more particularly shown in FIG.
19, wires 60 deliver an appropriate electrical current to heating
elements 58a and 58b. In the case where the heating elements 58a
and 58b are relied on to generate heat, they should comprise an
appropriate high resistance metal or other poorly conductive
material capable of generating heat when a current is passed
therethrough.
[0061] In the alternative, heating elements 58a and 58b may
passively act as heat sinks that assist in distributing heat
generated by adjacent heating element wires in contact with
elements 58a and 58b. In this way, elements 58a and 58b may not
themselves generate heat but will act to better disperse heat over
a wider area compared to heating element wires in contact with
heating elements 58a and 58b. In such a case, the heating elements
58a and 58b may advantageously comprise a metal or other material
that readily conducts heat, such as aluminum.
[0062] As more fully depicted in FIG. 20, heating element 58
includes a channel 59 into which one or more electrical wires 60
are placed so as to deliver an appropriate current to the heating
element 58 in order to cause heating element 58 to generate heat.
In the alternative, the one or more wires 60 may include a length
of a heating wire, such as a Ni-Cad wire, disposed within channel
59. In this embodiment, the Ni-Cad wire, rather than the metallic
heating element 58, will be primarily responsible for generating
the heat used to heat up the patient dentition impression (not
shown) formed from the impression material 64 in order to
accelerate activity of the dental agent. In this case, metallic
heating element 58 will act primarily as a heat sink used to
transfer heat energy from the Ni-Cad wire to the impression
material 64.
[0063] It should be understood that any appropriate power supply
may be used so long as it is able to provide a desired quantity of
electrical energy in order to heat the impression material to
within a desired temperature range. As shown in FIG. 21, a
preferred system 70 according to the invention includes a dental
impression tray 50 as described in FIGS. 17-19, together with a
power supply 72 and a controller 74. In one embodiment, the power
supply will provide between 5 and 10 volts of DC current at 1.2
amperes to each of heating elements 58a and 58b. The controller 74
may be operated by either the patient or a dental practitioner as
desired. Allowing the patient to control the temperature of the
dental tray and associated patient dentition within the patient's
mouth will allow for optimization between patient comfort and
treatment time. The optimum temperature may vary from patient to
patient depending on how sensitive a patient is to heat. In
general, the optimum temperature in terms of minimizing treatment
time, while being sensitive to patient comfort, will be the maximum
temperature at which the patient still feels comfortable and is not
experiencing excessive pain or discomfort.
[0064] In a preferred embodiment, the temperature within the
impression material may be measured by means of a diode (not
shown), which is an extremely inexpensive device for measuring
temperature but which is preferred where impression tray 50 is
intended to be disposable. While diodes are not necessarily as
accurate as other devices for measuring temperature, such as
thermocouples, they have adequate accuracy within the narrow
temperature ranges involved in the present invention (e.g.,
preferably about 110-150.degree. F., more preferably about
120-140.degree. F.).
[0065] FIGS. 15 and 16 depict an alternative system 40 for
continuously heating a patient dentition impression tray 10 during
a desired dental treatment regimen. System 40 includes a hot fluid
supply 42 in fluid communication with a looped tubular fluid
conduit 44 disposed within the principal cavity 12 of the
impression tray 10. The fluid conduit 44 may be selectively
connected to and disconnected from the hot fluid supply 42 by means
of conventional fluid connectors 46. In this embodiment, the dental
impression tray 10 is provided with the looped fluid conduit 44
disposed in the bottom of principal cavity 12 prior to filling the
cavity 12 with unset or uncured dental impression material 16. In
an experimental embodiment of apparatus 40, 1/8 inch rigid plastic
fluid conduit was used as fluid conduit 44 connected to a supply 42
of water heated to approximately 130.degree. F. Satisfactory
results were obtained where the apparatus was retained in a
patient's mouth for a period of time in a range of about 5 minutes
to about 20 minutes.
[0066] The afore-mentioned resistive heating elements or wires and
the heated fluid constitute different examples of heating means for
heating a formed patient dentition impression. Another example of a
resistive heating device is an etched resistive circuit. For
purposes of this disclosure and the appended claims, the term
"heating means" generally includes any heating apparatus known in
the art that is or can be adapted for use with a dental impression
tray to heat a formed patient dentition impression. Outside the
context of a heated dental impression material, the term "heating
means" shall broadly encompass any known or conventional device
that may be used to heat up the desensitizing dental compositions
according to the inventive methods, i.e., within the temperature
ranges and time durations disclosed herein. The term "fluid" shall
be understood to broadly include substances in a gaseous, liquid or
supercritical fluid state.
[0067] Other dental impression trays may alternatively be used in
connection with the present invention, including those illustrated
in FIGS. 1-12. FIGS. 1-12 depict one possible method sequence using
a conventional dental impression tray 10 that includes a principal
cavity 12. Even though FIGS. 1-12 depict a method of using a
conventional dental impression tray 10, the general method steps
illustrated therein may be generalized as having applicability to
methods that employ the dental trays depicted in FIGS. 13-21,
keeping in mind that some of the steps depicted in FIGS. 1-12 are
merely optional. While certainly within the scope of the invention,
the use of a conventional dental impression tray that is not
adapted with heat generating means will typically require the use
of an external heat source, such as a heater or microwave capable
of temporarily imparting heat energy to the dental tray and/or
included patient dentition impression.
[0068] III. METHODS OF TREATMENT.
[0069] In general, any method that employs the use of heat to
accelerate the desensitization of a person's teeth using a dental
composition is within the scope of the invention. The term
"dentition impression" should be broadly interpreted to include any
depression or void space formed within an impression material
regardless of whether or not the depression closely or only very
roughly approximates the person's teeth. Preformed, non-custom
depressions or void spaces formed within an impression material are
within the scope of the term "dentition impression".
[0070] It has been found that heating a desensitizing dental
composition significantly reduces the time necessary to desensitize
a person's teeth. Even though potassium nitrate, fluoride salts or
other desensitizing agents are within the temperature ranges of the
inventive methods, for reasons and mechanisms not entirely
understood, it has been found that heating a desensitizing
composition increases the rate by which the desensitizing agent is
able to impart its beneficial desensitizing properties. Perhaps the
increased temperature increases the rate at which the desensitizing
agent is able to penetrate into the pulp. Although the present
invention contemplates the use of any appropriate heat source, the
use of a heated dentition impression greatly reduces the time and
hassle, and increases patient comfort, compared to treatments that
utilize conventional heat sources, such as lasers or dental curing
lamps.
[0071] In an exemplary method for utilizing a heated dentition
impression to carry out accelerated desensitization of a patient's
teeth, the following steps are employed: (1) filling at least a
portion of a dental impression tray with a dental impression
material, preferably an unset dental impression material; (2)
placing the filled dental impression tray into the patient's mouth
in order to take an impression of at least a portion of the
patient's teeth; (3) maintaining the impression place for a
sufficient length of time for the dental impression material to at
least partially cure to thereby form a patient dentition
impression; (4) removing the dental impression tray and included
formed patient dentition impression from the patient's mouth; (5)
placing an appropriate quantity of a desensitizing dental
composition within the formed patient dentition impression; (6)
introducing the dental impression tray including the formed patient
dentition impression and dental composition into the patient's
mouth so as to at least approximately register the patient's teeth
with the formed patient dentition impression; (7) heating and/or
maintaining the temperature of the formed patient dentition
impression at a temperature of at least about 105.degree. F.
(preferably in a range of about 110.degree. F. to about 150.degree.
F., more preferably in a range of about 120.degree. F. to about
140.degree. F.); and (8) removing the dental impression try and
included dentition impression from the patient's mouth and
thoroughly rinsing the patient's mouth.
[0072] In order to illustrate one exemplary method for treating a
patient's teeth using a heated impression material according to the
invention, reference is now made to FIGS. 1-12. FIG. 1 depicts an
optional preliminary step of brushing or otherwise applying a
dental impression adhesive onto the surface of the principal cavity
12 of a conventional, disposable alginate dental impression tray
10. In one embodiment, one such tray 10 is required for the
mandibular (or lower) teeth that are to be whitened, and a separate
but like tray 10 may be used for treating the patient's maxillary
(or upper) teeth. It will be appreciated, however, that it is
within the scope of the invention to utilize a two-sided impression
tray capable of receiving impression material sufficient for both
the top and bottom teeth.
[0073] FIG. 2 depicts an optional step of applying a sheet-like
dental wax overlay 14 onto those surfaces of the patient's teeth
that are to be whitened--usually just to the facial aspects of the
teeth. The purpose of the wax sheet is to create more space between
the formed dental impression and the patient's teeth so as to hold
an additional quantity of the dental composition, if desired. It
should be understood, however, that treatment of the patient's
teeth is possible with or without this extra space formed as a
result of the wax overlay 14. Other blockout materials may be used,
such as curable liquids, coatings or pliable materials,
collectively referred to as "amorphous blockout materials".
[0074] FIG. 3 depicts the step of filling the principal cavity 12
of an impression tray 10 with a suitable quantity of an impression
material 16, typically an unset alginate dental impression material
or catalyzed dental impression compound. FIG. 4 is a
cross-sectional view of a tray 10 according to FIG. 3 that has been
filled with impression material 16 prior to insertion of the tray
10 into the patient's mouth.
[0075] FIG. 5 depicts the step of inserting the impression tray 10
and impression material 16 into a patient's mouth. Thereafter, the
patient is asked to gently bite down into the impression material
16 so as to conform the impression material 16 to the shape of the
patient's teeth and thereby form a patient dentition impression 18
(see FIG. 6). In a preferred embodiment, the impression material 16
will comprise a curable impression material, and the tray 10 will
be held in place within the patient's mouth for a sufficient length
of time for the dental impression material 16 to at least partially
set or cure in order to yield a formed dentition impression 18 that
will maintain its shape when removed from the patient's mouth.
[0076] Following removal of dental impression tray 10 with its
included formed patient dental impression 18 from within the
patient's mouth, any wax overlay or other blockout material 14 that
is retained on the surfaces of patient dentition impression 18 is
manually removed from the impression 18 by appropriate manual
scraping or the like. In addition, some of the impression material
defining the dentition impression 18 may be trimmed away in order
to reduce or eliminate subsequent contact of the heated impression
material with sensitive gingival tissues. FIGS. 6 and 7 depict the
set patient dentition impression 18 with wax overlay material 14 in
place. FIG. 8 is similar to FIG. 7 but illustrates the formed
patient dental impression 18 with the wax overlay material 14
having been removed.
[0077] FIGS. 9 and 10 are alternative cross-sectional views of the
tray 10 of FIG. 6 depicting the use of different types of
impression materials. FIG. 9 depicts a patient dentition impression
18 formed from a conventional impression material, e.g., alginate.
FIG. 10 alternatively depicts an impression tray 10 and set patient
dentition impression 22 formed from an impression material that
includes a particulate filler material. The particulate filler
material is included in order to increase the specific heat of the
patient dentition impression 22 so that it is capable of absorbing
and transferring a greater quantity of heat energy per unit of
time.
[0078] FIG. 11 depicts the step of loading the patient dentition
impression 18 (or 22) with a desensitizing dental composition by
means of a syringe 20. An exemplary desensitizing composition
includes 3% potassium nitrate by weight. Because the act of placing
the dental tray 10 into the patient's mouth will typically cause
the dental composition to spread out and coat the tooth surfaces,
there is no specifically required method of loading the dentition
impression 18 (or 22). In one embodiment, it may be desirable to
coat the interior labial surfaces of the set patient dentition
impression 18 (or 22) corresponding to the patient tooth surfaces
to be treated with approximately 0.5 to 1 cc. of the dental
composition. The tray is then inserted into the patient's mouth in
a manner so as at least approximately register the formed patient
dentition impression 18 (or 22) with the patient's teeth to be
treated.
[0079] FIG. 12 depicts the step of treating the patient's teeth.
The tray 10 and set patient dentition impression 18 (or 22) are
typically heated before or after insertion of the tray into the
patient's mouth, depending on the type of heat source that is
employed. In the case where the dental tray includes a heating
means, such as a resistive heating element or a heated fluid, the
tray is typically heated after insertion into the patient's mouth,
although it may optionally be preheated prior to insertion into the
patient's mouth. On the other hand, in the case where the tray is
heated using a completely external heat source, such as a heater or
microwave, the tray will typically be heated before insertion into
the patient's mouth, with stored heat providing the desired energy
for heating the dental composition.
[0080] Regardless of the method used to heat the formed dentition
impression, the formed dentition impression and/or the dental
composition should be maintained at a temperature of at least about
105.degree. F. in order to accelerate the desensitizing activity of
the desensitizing agent. The dental composition and/or formed
dentition impression are preferably heated and maintained at a
temperature in a range of about 110.degree. F. to about 150.degree.
F., more preferably in a range of about 120.degree. F. to about
140.degree. F., during treatment.
[0081] In addition, the dental tray will typically remain in the
patient's mouth for a period of time in a range of about 1 minute
to about 60 minutes, more preferably in a range of about 5 minutes
to about 30 minutes, depending on the strength or concentration of
the desensitizing agent, the operating temperature(s), and the
like. Although not a precise measurement, it has been found that,
for every 10 degree increase in the operating temperature, the time
period for desensitizing teeth is cut approximately in half. In the
case where a tray is heated externally, such as by means of
microwave energy, it may be necessary to reheat the tray
periodically as it cools off in the patient's mouth, optionally
with the additional step of replenishing the desensitizing dental
composition.
[0082] IV. COMPOSITIONS USED IN CONJUNCTION WITH THE INVENTIVE
APPARATUS AND METHODS.
[0083] In general, there are two different types or classes of
compositions that will be used together with the inventive
apparatus--an impression material used to form a dentition
impression and a dental composition that includes at least one
desensitizing agent. The present invention contemplates the use of
both conventional impression materials and dental compositions, as
well as impression materials and dental compositions that may be
specially formulated for use in conjunction with the inventive
apparatus.
[0084] A. Impression Materials.
[0085] Any plastic and deformable material known in the art that is
capable of making an impression of a person's teeth may be used in
combination with an impression tray according to the present
invention. In order for the dentition impression to be easily
formed and then maintain its shape once formed, it will be
preferable to use a material that can set or cure in a relatively
short period of time, such as in a matter of minutes or even
seconds, after being placed into a patient's mouth.
[0086] Alginate impression materials are presently preferred.
Alginate impression materials are a common feature in most dental
offices and are regularly used to make impressions of a patient's
teeth for a variety of reasons. Therefore, dentists are familiar
with how alginates are mixed, utilized and set to form a reliable
and resilient dentition impression. Alginate materials are also
non-toxic and are set or cured by hydration with water. They are
relatively inexpensive and readily available. Because they are
initially water soluble, a wide range of flavorants may be used to
enhance the taste and decrease the tendency of patients to gag
while taking an impression.
[0087] Notwithstanding the foregoing, virtually any settable
impression material may be used. Examples of alternative impression
materials include silicone rubbers, polyethers, and epoxies.
[0088] In order to increase the heat capacity of dental impression
materials, particularly materials such as silicone, polyethers or
epoxies that do not absorb or transfer heat as well as alginate
materials, it may be desirable to mix a heat-retention material
into the impression material, such as a particulate or fibrous
filler. Examples of suitable materials that may be used to increase
the heat capacity and/or the heat transference properties of the
impression materials include metal fibers or powders, ceramic
fibers or powders, or mineral fibers or powders.
[0089] By way of example, polished 2 mm-3 mm. size, stone chips may
be added and uniformly mixed into an unset alginate dental
impression composition in the ratio of approximately 121/2 parts by
weight of polished dental stone chips to approximately 871/2 parts
by weight of unset alginate dental impression material. Inclusion
of the aggregate in the composition extends the length of time
during which the patient dental impression, following heating by
microwave oven equipment or other heating means, will remain above
the minimum temperature of about 105.degree. F. while being held in
the patient's mouth.
[0090] On the other hand, the heat transferability qualities of
impression materials such as silicone and polyethers, which do not
readily transfer heat, may be increased through the use of more
conductive fillers such as those based on metals or more conductive
ceramics materials.
[0091] B. Dental Compositions.
[0092] It is within the scope of the invention to utilize any
dental composition that includes a desensitizing agent, and
optionally one or more additional active agents for providing other
treatments. Examples include dental bleaching compositions,
desensitizing compositions, and remineralizing compositions. Dental
bleaching compositions are characterized by the inclusion of a
dental bleaching agent, e.g., carbamide peroxide, aqueous hydrogen
peroxide, sodium perborate, and the like. Desensitizing
compositions are characterized by the inclusion of a desensitizing
agent, e.g., potassium nitrate, other potassium nitrate salts like
potassium citrate, citric acid, citric acid salts, strontium
chloride, fluoride salts, and the like. Remineralizing compounds
are characterized as including a fluoride salt such as sodium
fluoride, stannous fluoride, sodium monofluorophosphate, and the
like.
[0093] It will be readily understood that the dental compositions
according to the present invention may include a plurality of
active agents, such as two or more of a bleaching agent, a
desensitizing agent, a remineralizing agent, or some other active
dental agent (whether or not activated by heat so long as the
composition includes at least one active agent that is activated by
heat).
[0094] Exemplary desensitizing compositions that may be used in the
inventive methods are available from Ultradent Products, Inc.,
located in South Jordan, Utah. For example, Ultradent sells a
desensitizing composition under the name of UltraEZ.RTM., which
includes 3% by weight potassium nitrate and 0.11% by weight
fluoride ion within a sticky, viscous gel formulation. A duel
desensitizing/remineralizing composition that includes 1.1% by
weight sodium fluoride is sold under the name of Flor-Opal.RTM.. In
addition, a variety of blended compositions that include various
concentrations of carbamide peroxide (10%, 15% or 20%), together
with 3% potassium nitrate and 0.11% fluoride ion, are sold under
the name of Opalecence.RTM. PF. Finally, blended compositions that
include various concentrations of carbamide peroxide (15% or 20%),
together with 0.11% fluoride, are available under the name of
Opalecence.RTM. F.
[0095] Compositions and methods for manufacturing a wide range of
desensitizing compositions, such as those exemplified by
UltraEZ.RTM., or blended bleaching compositions such as
Opalecence.RTM. PF, are generally described in U.S. Pat. No.
5,855,870 and U.S. Pat. No. 5,851,512. Compositions and methods for
manufacturing dental compositions that include a fluoride salt are
generally described in U.S. Pat. No. 5,376,006. For purposes of
disclosing dental compositions suitable for use in conjunction with
the apparatus and methods of the present invention, the foregoing
patents are incorporated herein by reference.
[0096] The desensitizing agent may be included in an amount in a
range of about 0.01% to about 50% by weight, more preferably in a
range of about 0.05% to about 10% by weight, and most preferably in
a range from about 0.1% to about 5% by weight.
[0097] V. KITS.
[0098] It is within the scope of the invention to sell, or
otherwise provide, one or more of the foregoing heating apparatus
and compositions in the form of a kit. For example, a kit may
advantageously include a disposable dental impression tray and one
or more dental compositions. In a preferred embodiment, a kit may
advantageously include a dental impression tray having means for
heating a formed patient dentition impression, such as a resistive
heating element, and one or more dental compositions that include a
desensitizing agent, e.g., a composition that includes potassium
nitrate and/or a blended composition that includes more than one
active dental agent. The kit may include multiple dental impression
trays together with multiple doses of one or more dental
compositions. For simplicity of storage and delivery, the dental
compositions may advantageously be loaded into and delivered from a
syringe, such as a syringe that includes a unit dose of the dental
composition.
[0099] Although the kit may also include an impression material,
this may not be necessary in many cases in view of the fact that
many dentists typically keep ample alginate impression material on
hand to take dental impressions for a variety of different reasons.
Virtually any material capable of taking a dentition impression may
be used within the kits of the present invention. Alginate
impression materials are presently preferred due to their low cost,
ready availability and ease and familiarity of use.
[0100] A particulate or fibrous filler for increasing the heat
capacity and/or heat transferability may be included within the
kits, either alone, in combination with but separate from an
impression material, or premixed within an impression material.
[0101] The kits may also include a suitable power supply designed
to provide a desired amount or range of power in order to heat and
maintain the dental impression tray and accompanying impression
material at a desired temperature or within a desired temperature
range. In the case where the impression trays are disposable, i.e.,
are to be used and then disposed of after each use, it will
generally only be necessary to purchase one power supply (or
optionally one power supply per dental chair in the case of
multiple-chair offices) that may be used with a series of trays
purchased at the same time as the power supply or thereafter.
[0102] The kits may include one or more wax overlay sheets in order
to act as a blockout material on the surface of the patient's teeth
(see FIG. 2). Alternatively, the blockout may be an amorphous
material that can be brushed, sprayed or other pressed onto the
tooth surfaces. The term "amorphous blockout material" shall
broadly include any material other than a sheet that can be applied
to a person's teeth in order to temporarily increase the apparent
thickness of the teeth during formation of the patient dentition
impression. One purpose for doing this is to increase the size of
the dentition impression, particularly at the interface between the
impression material and the labial tooth surfaces to be treated, in
order to create a reservoir for the inclusion of additional dental
composition during treatment.
[0103] VI. SUMMARY.
[0104] The invention provides apparatus and methods for
desensitizing teeth in a manner that significantly reduces the time
it takes for potassium nitrate or other suitable desensitizing
agents to impart the desired desensitizing effect.
[0105] The invention further provides apparatus and methods that
significantly reduce the time it takes to desensitize the teeth,
while utilizing conventional desensitizing compositions presently
available on the market.
[0106] The present invention may be embodied in other specific
forms without departing from its spirit or essential
characteristics. The described embodiments are to be considered in
all respects only as illustrative and not restrictive. The scope of
the invention is, therefore, indicated by the appended claims
rather than by the foregoing description. All changes which come
within the meaning and range of equivalency of the claims are to be
embraced within their scope.
* * * * *