U.S. patent application number 09/874792 was filed with the patent office on 2001-09-27 for apparatus and method for photothermal destruction of oral bacteria.
Invention is credited to Azar, Zion, Shalev, Pinchas.
Application Number | 20010024777 09/874792 |
Document ID | / |
Family ID | 11071266 |
Filed Date | 2001-09-27 |
United States Patent
Application |
20010024777 |
Kind Code |
A1 |
Azar, Zion ; et al. |
September 27, 2001 |
Apparatus and method for photothermal destruction of oral
bacteria
Abstract
Oral hygiene apparatus for destroying sensitized oral bacteria,
comprising: an incoherent light source; and a light directing
member, adapted for directing light from said light source onto at
least part of a surface of at least one tooth within an oral
cavity.
Inventors: |
Azar, Zion; (Shoham, IL)
; Shalev, Pinchas; (Kfar-Saba, IL) |
Correspondence
Address: |
William Dippert
c/o Cowan, Liebowitz & Latman
1133 Avenue of the Americas
New York
NY
10036-6799
US
|
Family ID: |
11071266 |
Appl. No.: |
09/874792 |
Filed: |
June 5, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09874792 |
Jun 5, 2001 |
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09255273 |
Feb 23, 1999 |
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09255273 |
Feb 23, 1999 |
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PCT/IL99/00030 |
Jan 17, 1999 |
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Current U.S.
Class: |
433/29 |
Current CPC
Class: |
A46B 15/003 20130101;
A61N 5/0603 20130101; A61N 2005/0606 20130101; Y10S 362/804
20130101; A46B 15/0036 20130101; A46B 15/0002 20130101 |
Class at
Publication: |
433/29 |
International
Class: |
A61C 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 24, 1998 |
IL |
123437 |
Claims
1. Oral hygiene apparatus for destroying sensitized oral bacteria,
comprising: an incoherent light source, comprising a flash lamp;
and a light directing member, adapted for directing light from said
light source onto at least part of a surface of at least one tooth
within an oral cavity, said light being in an amount and at a
wavelength effective to destroy bacteria but not to cause
coagulation of blood vessels in the mouth.
2. Apparatus according to claim 1 wherein the light directing
member comprises a light guide removably coupled to a housing
containing the light source.
3. Apparatus according to claim 1 wherein said light directing
member comprises a reflective layer coated light passage.
4. Apparatus according to claim 3 wherein said reflective layer
coated light passage comprises a hollow passage whose radial extent
is defined by a light reflecting surface.
5. Apparatus according to claim 2 wherein said light guide
comprises an elongated member, having at least one peripheral
surface uncoated by a reflecting material, said light guide
directing light entering it at one end by internal reflection from
said at least one peripheral surface to a second end.
6. Apparatus according to claim 1 wherein said incoherent light
source includes a reflector which directs at least part of the
light produced by said lamp to said light directing member.
7. Apparatus according to claim 6 wherein said reflector is a
parabolic reflector, a spherical reflector, a quasi-spherical
reflector or an ellipsoidal reflector.
8. The device according to claim 6 wherein said light source
further includes at least one lens disposed between said flash lamp
and said light directing member for directing light onto said light
directing member.
9. Apparatus according to claim 1 including at least one filter
which passes light to which said bacteria has been sensitized.
10. Apparatus according to claim 9 wherein the at least one filter
substantially blocks light at wavelengths at which oxyhemoglobin
absorbs substantial energy.
11. Apparatus according to claim 1 wherein said light is directed
to said tooth surface from an exit port of the light directing
member.
12. Apparatus according to claim 1 and including a power source
that powers the incoherent light source and a controller that
controls said light source.
13. Apparatus according to claim 12 wherein said power source is a
battery and wherein said incoherent light source, said battery and
said controller are mounted within a common housing.
14. Apparatus according to claim 1 wherein said light directing
member is easily separated from the light source and wherein the
light directing member is disposable.
15. Apparatus according to claim 1 wherein the light is band
limited to exclude a substantial portion of the light having
wavelength which are substantially absorbed by oxyhemoglobin.
16. Apparatus according to claim 1 wherein the light is filtered
such that it is band limited to a wavelength range of between
450-500 nanometers.
17. Apparatus according to claim 1 wherein the light is filtered to
substantially exclude light having a wavelength of between 388
nanometers and 448 nanometers.
18. Apparatus according to claim 17 wherein the light is filtered
to substantially exclude light having a wavelength of between 500
nanometers and 600 nanometers.
19. Apparatus according to claim 1 wherein the light is filtered to
substantially exclude light having a wavelength of between 500
nanometers and 600 nanometers.
20. Oral Hygiene apparatus for destroying oral bacteria,
comprising: an incoherent light source; a light directing member,
adapted for directing light from the light source onto at least
part of a surface of at least one tooth within an oral cavity,
wherein the light is band limited to exclude a substantial portion
of the light having wavelength which are substantially absorbed by
oxyhemoglobin.
21. Oral Hygiene apparatus for destroying oral bacteria,
comprising: an incoherent light source; a light directing member,
adapted for directing light from the light source onto at least
part of a surface of at least one tooth within an oral cavity,
wherein the light is filtered such that it is band limited to a
wavelength range of between 450-500 nanometers.
22. Oral Hygiene apparatus for destroying oral bacteria,
comprising: an incoherent light source; a light directing member,
adapted for directing light from the light source onto at least
part of a surface of at least one tooth within an oral cavity,
wherein the light is filtered to substantially exclude light having
a wavelength of between 388 nanometers and 448 nanometers.
23. Apparatus according to claim 22 wherein the light is filtered
to substantially exclude light having a wavelength of between 500
nanometers and 600 nanometers.
24. Oral Hygiene apparatus for destroying oral bacteria,
comprising: an incoherent light source; a light directing member,
adapted for directing light from the light source onto at least
part of a surface of at least one tooth within an oral cavity,
wherein the light is filtered to substantially exclude light having
a wavelength of between 500 nanometers and 600 nanometers.
Description
RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 09/255,273, filed Feb. 23, 1999 which is a
continuation of PCT Application No. PCT/IL99/00030, filed Jan. 17,
1999, which designates the US.
FIELD OF THE INVENTION
[0002] The present invention relates generally to the field of oral
hygiene and more particularly to devices and methods for selective
photo-thermal destruction of oral bacteria.
BACKGROUND OF THE INVENTION
[0003] Various forms of periodontal disease in humans are caused by
oral bacteria. Oral bacteria create plaque, a sticky, colorless
film of bacteria that constantly forms on the surface of teeth and
may lead to periodontal diseases. Plaque, if allowed to stay on the
tooth's surface will eventually lead to gingival irritation also
known as gingivitis, which may be accompanied by gum swelling,
bleeding and by fibrous enlargement of the gingiva.
[0004] The plaque forming bacteria create toxins which irritate the
gums and result in breakdown of the attachment of gum tissues to
teeth. Over time, these toxins can destroy gum tissues, allowing
the infection to progress to bone loss.
[0005] Plaque that is not timely removed can combine with other
materials and harden into a rough, porous deposit called calculus
or scale. If the plaque and scale builds up and are not removed by
professional cleaning, the gums will start to move away from the
teeth. This is the start of periodontal gum disease. Pockets form
between the teeth and gums. If the gums are allowed deteriorate
further, the gums recede and the bone and other supporting tissues
around the teeth start deteriorating and the teeth may eventually
become loose.
[0006] Calculus on the tooth's surface, above the gum-line, does
not contribute to periodontal diseases. However, calculus on the
root surface, below the gums, makes removal of new plaque and
bacteria more difficult. Unlike plaque, which can be removed by
tooth brushing, calculus must be removed by a dentist or dental
hygienist.
[0007] Prevention and treatment of periodontal gum disease must be
based to a large extent on the control of bacterial plaque. This
requires a considerable effort on the patient's part. In addition,
routine professional oral hygiene requires a considerable effort on
the part of the dental health professionals which have to provide
the patient with renewed motivation and instruction on careful
daily oral hygiene techniques, thorough professional cleaning of
the teeth and frequent reassessment of the patient's periodontal
tissues to provide early detection and treatment of new or
reoccurring abnormalities or of destruction of supporting
periodontal tissues.
[0008] By far the most important aspect of controlling periodontal
diseases is the practicing of daily oral hygiene techniques that
needs to be initiated at pre-adolescence and carried on for the
rest of the patient's life. Daily maintenance schedules ideally
require full patient's compliance with instructions and an ideal
tooth cleaning technique. Far too often, token attempts at dental
bacterial plaque control are inadequate and unsuccessful in one or
more sites of the dentition leading to inflammatory changes at
these sites and further loss of periodontal attachment.
[0009] Products sold for the prevention of periodontal diseases
include toothpaste, mouth rinsing solutions, Manual toothbrushes,
dental floss and powered toothbrushes and oral irrigators.
[0010] Chemical antibacterial agents are increasingly being used in
prophylactic and therapeutic regimes for plaque-related diseases.
As these agents can be rendered ineffective by the development of
resistance in the target organisms there is a need to develop
alternative anti-microbial treatments. Light from high-power lasers
is known to be bactericidal and investigations have shown that it
is effective against organisms implicated in carries and
inflammatory periodontal diseases. However, the adverse effects of
such light on dental hard tissues argues against its use solely as
an antibacterial agent.
[0011] U.S. Pat. No. 4,784,135 to Blum et al. discloses a method
for treating tooth decay, by far UV radiation generated by an argon
fluoride (ArF) laser, which is based on ablative
photo-decomposition of organic biological material. No staining of
the material is disclosed.
[0012] U.S. Pat. No. 5,658,148 to Neuberger et al. discloses a
method and a device for cleaning teeth by a low power diode laser
applying the principle of photodynamic therapy. This method is
based on using a photosensitizer compound. The photosensitizer
compound produces singlet oxygen upon irradiation by the laser
light. The singlet oxygen thus produced destroys oral bacteria.
[0013] U.S. Pat. No. 5,611,793 to Wilson discloses a method of
disinfecting or sterilizing tissues, wounds or lesions of the oral
cavity. The method comprises applying a photosensitizing compound
to the tissues and irradiating the tissues with laser light at a
wavelength absorbed by the photosensitizing compound. The
helium-neon laser or the gallium aluminum arsenide diode laser used
by Wilson are expensive and may not be suitable for home use.
[0014] There is a widely recognized need for a simple, inexpensive
and selective method for killing oral bacteria which is suitable
for home use.
SUMMARY OF THE INVENTION
[0015] It is therefore an object of some preferred embodiments of
the present invention to provide a device and a method for
destroying oral bacteria.
[0016] An aspect of some preferred embodiments of the present
invention involves the pre-staining of the bacteria using bacterial
selective dyes or stains.
[0017] An aspect of some preferred embodiments of the present
invention involves the use of incoherent broad band light for
irradiating the preferably pre-stained bacteria.
[0018] As aspect of some preferred embodiments of the invention
involves a dentifrice containing a bacterial stain. This dentifrice
is preferably used to stain the bacteria during normal brushing so
that they can be destroyed.
[0019] There is thus provided, in accordance with a preferred
embodiment of the invention, oral hygiene apparatus for destroying
sensitized oral bacteria, comprising:
[0020] an incoherent light source; and
[0021] a light directing member, adapted for directing light from
said light source onto at least part of a surface of at least one
tooth within an oral cavity.
[0022] Preferably, the light directing member comprises a light
guide removably coupled to a housing containing the light
source.
[0023] Preferably, the light directing member comprises a
reflective layer coated light passage. Preferably, the reflective
layer coated light passage comprises a hollow passage whose radial
extent is defined by a light reflecting surface.
[0024] In a preferred embodiment of the invention, the light guide
comprises an elongated member, having at least one peripheral
surface uncoated by a reflecting material, said light guide
directing light entering it at one end by internal reflection from
said at least one peripheral surface to a second end.
[0025] In a preferred embodiment of the invention, the incoherent
light source includes a lamp, a reflector which directs at least
part of the light produced by said lamp to said light directing
member. Preferably, the lamp is a an arc discharge lamp or a flash
lamp. Preferably, reflector is a parabolic reflector, a spherical
reflector, a quasi-spherical reflector or an ellipsoidal
reflector.
[0026] In a preferred embodiment of the invention the light source
further includes at least one lens disposed between said flash lamp
and said light directing member for directing light onto said light
directing member.
[0027] Preferably, the apparatus includes at least one filter which
passes light to which said bacteria has been sensitized.
Preferably, the at least one filter substantially blocks light at
wavelengths at which oxyhemoglobin absorbs substantial energy.
[0028] In a preferred embodiment of the invention, the light is
directed to said tooth surface from an exit port of the light
directing member.
[0029] In a preferred embodiment of the invention, the apparatus a
tooth brush like member adjacent to or surrounding said exit port.
Preferably, the tooth brush like member comprises a plurality of
bristle like members arranged peripherally around said exit port to
enable said light exiting said port to reach said at least part of
a surface of at least one tooth within said oral cavity while teeth
are being brushed by said tooth brush like member.
[0030] In a preferred embodiment of the invention the apparatus
includes a plurality of bristles coupled to said light directing
member such that a first end of each of said plurality of bristles
is optically coupled to said second end of said light guide and a
second end of each of said plurality of bristles extends out of
said terminal part for directing at least part of said light onto
said at least part of said surface of said at least one tooth
within said oral cavity.
[0031] In a preferred embodiment of the invention the apparatus
includes a dental floss like member optically coupled to said
incoherent light source which member emits said light along its
length.
[0032] In a preferred embodiment of the invention the apparatus
includes a power source that powers the incoherent light source and
a controller that controls said light source. Preferably, the power
source is a battery and said incoherent light source, said battery
and said controller are mounted within a common housing.
[0033] In a preferred embodiment of the invention, the light
directing member is easily separated from the light source and
wherein the light directing member is disposable.
[0034] In a preferred embodiment of the invention, the light source
is a pulsed light source.
[0035] There is further provided, in accordance with a preferred
embodiment of the invention, a method for selective photothermal
destruction of bacteria, the method comprising:
[0036] selectively staining at least some bacteria by application
of a suitable selective bacterial stain; and
[0037] exposing at least some of said stained bacteria after said
step of selectively staining to incoherent light, to photothermally
coagulate said bacteria.
[0038] Preferably the incoherent light is band limited to exclude a
portion of said light having wavelengths which are substantially
absorbed by oxyhemoglobin. Preferably, the incoherent broad band
light is pulsed.
[0039] In a preferred embodiment of the invention, the pulsed
incoherent broad band light has a frequency of pulsing in the range
of 0.5-50 pulses per second, a pulse duration in the range of
0.1-10 milliseconds and an energy density in the range of 0.1-10
joule/cm.sup.2.
[0040] Preferably, the selective bacterial stain has at least one
substantial light absorption peak which has no substantial overlap
with the major peaks of light absorption of oxyhemoglobin.
[0041] Preferably, exposing comprises:
[0042] generating at least one pulse of incoherent broad band light
from a pulsed light source including a gas discharge lamp or a
flash lamp;
[0043] modifying said at least one pulse of light to exclude a
substantial portion of said at least one pulse of light, said
portion having wavelengths which are substantially absorbed by
oxyhemoglobin, to convert said at least one pulse of light into at
least one band-limited light pulse; and
[0044] directing said at least one band-limited light pulse onto
said bacteria to photothermally coagulate said bacteria.
[0045] In a preferred embodiment of the invention, the bacteria are
oral bacteria. Preferably, the bacteria are situated in the oral
cavity.
[0046] There is further provided, in accordance with a preferred
embodiment of the invention, a dentifrice including a stain for
bacteria in a concentration sufficient to stain at least some
bacteria remaining in the mouth after tooth brushing with the
dentifrice. Preferably, bacteria stained with said stain have a
substantial absorption peak at a wavelength for which oxyhemoglobin
does not have such an absorption peak. Preferably, the stain
comprises E-127 (Erythrosin-B), preferably in a weight percentage
of 0.1%-1%.
[0047] There is further provided, in accordance with a preferred
embodiment of the invention, an oral hygiene kit comprising:
[0048] a dentifrice according to the invention; and
[0049] an oral hygiene apparatus comprising:
[0050] an light source which generates radiation which is absorbed
by the stain; and
[0051] a light directing member, adapted for directing light from
said light source onto at least part of a surface of at least one
tooth within an oral cavity.
[0052] Preferably, the oral hygiene apparatus is constructed
according to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] The invention will be more clearly understood by the
following description of preferred embodiments thereof, herein
described, by way of example only, with reference to the
accompanying drawings, in which like components are designated by
like reference numerals wherein:
[0054] FIG. 1 is a schematic graph illustrating the absorption
spectrum of an aqueous solution erythrosin B;
[0055] FIG. 2 is a schematic graph illustrating the absorption
spectrum of the commercially available stain PLAK CHEK.TM.;
[0056] FIG. 3 is a schematic part block diagram part cross
sectional view of a device for selective photothermal destruction
of oral bacteria, in accordance with a preferred embodiment of the
present invention;
[0057] FIG. 4 is a schematic cross sectional view of a hand held
part of a device for selective photothermal destruction of oral
bacteria, in accordance with another preferred embodiment of the
present invention;
[0058] FIG. 5A is a schematic part block diagram part cross
sectional view of a device for selective photothermal destruction
of oral bacteria having a light source optically coupled to a hand
held part by an optical fiber bundle, in accordance with yet
another preferred embodiment of the present invention;
[0059] FIG. 5B is an isometric view of a system for selective
photothermal destruction of oral bacteria including the device of
FIG. 5A and a plurality of the light directing members of the type
illustrated in FIG. 3;
[0060] FIG. 6 is an isometric view of a light directing member
attachable to the handle of the devices of FIGS. 3, 4 and
5A-5B;
[0061] FIG. 7 is a cross sectional view of the light directing
member of FIG. 6 taken along the lines VII-VII;
[0062] FIG. 8 is a side view of a toothbrush like light delivery
member attachable to the handle of the devices of FIGS. 3, 4 and 5,
in accordance with another preferred embodiment of the present
invention;
[0063] FIG. 9 is a schematic cross sectional view of a toothbrush
like light directing member attachable to the handle of the devices
of FIGS. 3, 4 and 5, and having transparent bristles optically
coupled to a light guide included within the light directing
member; and
[0064] FIG. 10 is a schematic cross sectional view of a light
directing member attachable to the handle of the devices of FIGS.
3, 4 and 5, and having a light scattering dental floss member
optically coupled to a light guide included within the light
directing member.
DETAILED DESCRIPTION OF THE INVENTION
[0065] Preferred embodiments of the present invention are based on
the use of incoherent broad band light for the selective
photothermal destruction of selectively stained oral bacteria
within dental plaque. The bacteria are stained preferably by
applying a liquid or paste like formulation containing a bacterial
selective dye within the oral cavity preferably followed by rinsing
the oral cavity to wash out the excess dye. The bacteria within the
dental plaque are thus selectively stained by the dye.
[0066] The inventors of the present invention have noticed that
when irradiated with broad band incoherent light, the stained
bacteria within the plaque absorb more light than nearby non
stained tissues, leading to a temperature increase of the stained
bacteria and to their destruction by coagulation. However, broad
band light including light having wavelengths in the range
substantially absorbable by oxyhemoglobin may be absorbed by the
oxyhemoglobin contained within red blood cells of the blood
included in blood vessels. This may lead to undesired photothermal
coagulation of blood vessels within the oral cavity. To prevent
such undesired blood vessel coagulation the broad band light is
preferably filtered to exclude a substantial portion of the light
having wavelengths which are substantially absorbed by
oxyhemoglobin. Thus the filtered light is band limited. The main
absorption peak of oxyhemoglobin is at a wavelength of 418 nm with
an absorption bandwidth of approximately 60 nm around this main
peak. Oxyhemoglobin also has secondary absorption peaks at 542 nm
and 577 nm with an overall bandwidth of approximately 100 nm around
these peaks.
[0067] Optimally, band limiting of the broad band light is coupled
with the selection of specifically selected stains or dyes which
selectively stain bacteria within dental plaque and which have at
least one major absorption peak at least a portion of which has no
substantial overlap with the major peaks of light absorption of
oxyhemoglobin. When the broadband irradiation is filtered to
exclude the absorption peaks of the oxyhemoglobin, the stains or
dyes absorb enough light energy from the band limited light
irradiating them to ensure efficient photothermal destruction of
the stained bacteria, without damage to the oxyhemoglobin.
[0068] An example of such a dye suitable for selective photothermal
destruction of oral plaque forming bacteria is the topical solution
of erythrosin B, commercially available from TRISA AG, Switzerland.
The oral bacteria may be stained by putting 3-5 drops of the
topical solution of erythrosin B under the tongue and rinsing the
teeth with the dye solution for approximately 30 seconds, followed
by washing the mouth. The surfaces of the teeth that have bacterial
plaque on them are thus stained red.
[0069] Reference is now made to FIG. 1 which is a schematic graph
illustrating the absorption spectrum of an aqueous solution of
erythrosin B. The horizontal axis represents the wavelength in
nanometers and the vertical axis represents the absorbance in
arbitrary units. The curve labeled 1 represents the absorption
spectrum of erythrosin B. The curve has a main absorption peak 2 at
a wavelength of approximately 542 nm and a secondary absorbance
peak 3 at a wavelength of approximately 638 nm.
[0070] It is noted that the main absorption peak 2 is within the
absorption region of oxyhemoglobin. However, peak 3 is outside the
absorbance peaks of oxyhemoglobin.
[0071] Another example of a dye suitable for selective photothermal
destruction of oral plaque forming bacteria is PLAK-CHEK.TM.,
commercially available from Clairol Inc., CT, USA The staining
method is similar to the method described for erythrosin B
hereinabove.
[0072] Reference is now made to FIG. 2 which is a schematic graph
illustrating the absorption spectrum of the commercially available
stain PLAK-CHEK.TM..
[0073] The horizontal axis represents the wavelength in nanometers
and the vertical axis represents the absorbance in arbitrary units.
The curve labeled 4 represents the absorption spectrum of the
PLAK-CHEK.TM. solution. The curve has a main absorbance peak 5 at a
wavelength of approximately 494 nm. The main absorbance peak 5 has
a bandwidth of approximately 40 nm. Thus, PLAK-CHEK.TM. may be a
better stain than erythrosin B since its main absorption peak 5
does not substantially overlap the absorption peaks of
oxyhemoglobin.
[0074] It is noted that, since both of the staining dyes disclosed
hereinabove have a relatively broad bandwidth of absorption, using
a non coherent light source having a suitably broad bandwidth
corresponding to the full bandwidth of the main absorption peak of
the dye is preferable to using a narrow bandwidth laser. Thus, such
a narrow bandwidth laser will be less efficient for photothermal
heating of these dyes than a non coherent light source.
[0075] Reference is now made to FIG. 3 which is a schematic part
block diagram part cross sectional view of a device for selective
photothermal destruction of oral bacteria, in accordance with a
preferred embodiment of the present invention. Device 10 includes a
handle 11 having a housing 12. Housing 12 is preferably formed of a
thermally and electrically insulating material such as plastic or
the like. Device 10 also includes an incoherent light source 14 and
a controller unit 16 preferably disposed within housing 12 and
attached thereto. Incoherent light source 14 preferably includes a
reflector 15 and a lamp 20 disposed within the reflector. Reflector
15 is preferably reflective and is made from a reflective metal
shell such as aluminum or any other suitable highly reflective
metal. Alternatively, reflector 15 is formed of plastic or any
other suitable material coated, on its internal surface, by a light
reflecting coating. The reflector or reflecting surface faces lamp
20 and reflects light produced by the lamp. Lamp 20 is preferably
electrically connected to controller unit 16 by suitable isolated
electrically conductive wires 27. Device 10 further preferably
includes a power supply 18 that supplies electrical power to lamp
20 and to the controller unit 16. Power supply 18 is preferably
suitably connected to controller unit 16 by a power cable 37
entering housing 12. Alternatively power supply may be attached to
the housing.
[0076] Power supply 18 may be a direct current (DC) source such as
a disposable or a rechargeable battery or any other suitable type
of battery. Alternatively, power supply 18 can be an alternating
current (AC) operated power supply suitably connected to the
mains.
[0077] Reflector 15 is preferably shaped as an ellipsoidal
reflector and has an opening 17 at it's end which is attached to
housing 12. Ellipsoidal reflector 15 has two focal points. Lamp 20
is preferably disposed in the region of the focal point which is
distal from opening 17. However, lamp 20 may also be disposed at
other regions within reflector 15. Alternatively, opening 17 may be
centered about the right focus of the ellipsoid to improve the
coupling of the light into the opening. Alternatively or
additionally, the reflector may have a different shape that couples
the light generated by the lamp into the opening. Alternatively,
the reflector may have other shapes such as parabolic,
quasi-parabolic, spherical, quasi spherical, quasi-ellipsoidal
reflectors or any other suitable shape.
[0078] Light source 14 further preferably includes one or more
filters 21 and 23 situated between lamp 20 and opening 17 which
filters the light produced by the lamp 20 to produce band limited
light.
[0079] In a preferred embodiment of the invention lamp 20 is an arc
discharge lamp such as a flash lamp or any other lamp suitable for
producing incoherent broad band light having an energy density
sufficient for performing photothermolysis of dye stained bacteria.
Preferably, lamp 20 is a xenon flash lamp that has a peak of light
emission in the visible part of the spectrum at around 500
nanometers. One suitable lamp is xenon flash lamp model G5109
commercially available from The Electronic Goldmine, Ariz.,
USA.
[0080] When a xenon flash lamp is used and system 10 is designed
for use in conjunction with the PLACK CHEK.TM. stain, filter 21
preferably transmits all wavelengths above 450 nm and blocks all
wavelengths below 450 nm and filter 23 preferably transmits all
wavelengths below 500 nm and blocks all wavelengths above 500 nm.
For example, filters 21 and 23 can be the filters having catalog
numbers 450FH-90-25 and 500FL07-25, respectively, commercially
available from Andover Corporation, N.H., USA.
[0081] Filters 21 and 23 filter the broad band light produced by
the xenon lamp to produce incoherent light which is band limited
with a bandwidth of approximately 50 nm including the approximate
wavelength range of 450-500 nm. This band of wavelengths is outside
the absorption bands of oxyhemoglobin and within the main
absorption band of the stain.
[0082] It is noted that, while the non-limiting examples of filters
21 and 23 disclosed hereinabove are suitable for use in a device
designed for being used in conjunction with PLACK CHEK.TM., other
different types of filters having similar absorbance ranges can
also be used.
[0083] It is further noted that, if other selective bacterial
stains or dyes which are different from the stain PLACK CHEK.TM.
are used, filters 21 and 23 are preferably chosen to pass
wavelengths which match the absorbance of the particular stain or
dye.
[0084] It is still further noted that, while the filtering of the
light of lamp 20 is disclosed as being performed by two distinct
filters 21 and 23, it is also possible to use a single optical
filter having appropriate band limiting characteristics.
[0085] In another example, if the device 10 is used with the dye
erythrosin B, a single filter can be used to replace filters 21 and
23. The single filter preferably absorbs all the wavelengths below
600 nm and transmit all wavelength above 600 nm. A suitable filter
for use with erythrosin B is the filter having a catalog number
600FH90-25 commercially available from Andover Corporation, NH,
USA.
[0086] Controller unit 16 controls the energizing of flash lamp 20.
Controller unit 16 includes standard electronic circuitry needed to
operate the flash lamp 20 such as a triggering unit, a capacitor
unit and electronic timing circuitry for timing the frequency of
flashing of the lamp 20. A suitable electronic circuit that can be
used to construct as the controller unit 16 is the Personal Safety
Strobe, Catalogue Number 61-2506, commercially available from Radio
Shack, a division of Tandy Corporation, TX, USA The Personal Safety
Strobe circuitry is preferably modified by electrically connecting
an electrolytic capacitor having a capacitance of 120 microfarad
(rated at 330 volts) in parallel with the capacitor already
included in the Personal Safety Probe. The flashing frequency of
the modified Personal Safety Strobe is approximately 1 Hz.
[0087] It is noted that, The particular circuitry disclosed
hereinabove is given by way of example only and that many other
types of circuitry known in the art can be used to implement
controller unit 16.
[0088] Device 10 preferably includes an on-off switch 19 attached
to the housing 12 and suitably connected to the controller 16 for
starting and stopping the operation of the controller 16. The
switch 19 can be any suitable type of switch. It is noted that,
while the switch 19 of FIG. 3 is attached to the housing 12, the
switch may be attached to the housing 12 or to the power supply or
to any other suitable part of the device.
[0089] Device 10 further preferably includes a light directing
member 22 attached to handle 11 for directing light from the
incoherent light source 14 into the oral cavity of a user. In a
preferred embodiment of the invention, light directing member 22 of
the device 10 is an elongated member made of a thermally insulating
material such as plastic or the like. Light directing member 22 has
a proximal end 24 preferably detachably attached to housing 12 and
a distal end 26 extending distally of the housing 12.
[0090] In one preferred embodiment of the invention, light
directing member 22 has a hollow passage 30 passing therethrough.
Hollow passage 30 has an opening 17 at proximal end 24 of member 22
to receive light from light source 14 and a second opening 25 at
distal end 26 of member 22. Opening 25 is preferably closed by an
optical window 34 which seals opening 25. Optical window 34 is
preferably made from a material which is substantially transparent
to the band limited light which passes through filters 21 and 23.
For example optical window 34 can be made from a suitable glass or
a suitable plastic material or the like. Alternatively, one or both
of filters 21 and 23 can be omitted from the light source and
placed within the light guide or as a replacement for or as part of
window 34.
[0091] Optical window 34 prevents any material such as saliva or
other liquids or solid materials present in the oral cavity from
entering and accumulating in passage 30 and partially or fully
blocking the path of the light produced by light source 14 from
entering the oral cavity.
[0092] It is noted that, while the light directing member
preferably includes optical window 34, other embodiments of the
present invention are possible which do not include an optical
window and opening 25 is uncovered.
[0093] Light directing member 22 preferably further includes a
layer 32 of light reflecting material attached to the internal
surface of passage 30. Layer 32 is preferably made of a light
reflecting material such as aluminum or any other metal or material
having suitable light reflecting properties. Layer 32 may be formed
by deposition thereof on the internal surface of passage 30 or by
any other suitable forming or attaching method such as, for example
vapor deposition or electroplating methods may be used.
[0094] Light reflecting layer 32 forms a light guide which guides
the light produced by light source 14 and directs it onto the
surfaces of teeth 36 within the oral cavity of the user.
[0095] In other preferred embodiments of the invention, the light
guide may be any other type of suitable light guide as known in the
art. For example, it may be a solid plastic rod coated on its
outside with a light reflective coating or cladding. Alternatively,
the light may be reflected from the outer surface of the guide by
total internal reflection. Other suitable light guides will occur
to persons of skill in the art.
[0096] Preferably, passage 30 has a circular cross-section.
However, the passage 30 may also have an oval cross-section or any
other cross section suitable for use in a light guide.
[0097] Light directing member 22 further preferably includes a
tooth brush member 28 extending from end 26 of light directing
member 22. Tooth brush member 28 preferably includes a plurality of
bristles 29 for brushing teeth.
[0098] It is noted that, while the tooth brush like member 28 is a
physical extension of the end 26 of the light directing member 22,
it can also be formed as a separate part (not shown) which can be
attached to the end 26 by gluing or fusing or by any other suitable
attachment method.
[0099] When device 10 is used for photothermal destruction of oral
bacteria, a user first selectively stains plaque bacteria by using
a bacterial selective stain or dye such as PLAK-CHECK.TM. as
described above. The user then holds housing 12 in his hand,
switches switch 19 to the "on" position to commence the flashing of
flash lamp 20 of light source 14. and inserts brush member 28 into
his oral cavity. The user then brushes his teeth using brush member
28. Preferably, flash lamp 20, is flashed at a flashing rate of
approximately 1 Hz to 10 Hz, but flashing rates in the range of
approximately 0.5-50 Hz may be used. Typically, each light flash
has a duration of 0.1 to 10 msec and irradiates the teeth 36 with
incoherent band limited light having an energy density of
approximately 0.1-10 Joule/cm.sup.2, thereby heating stained
bacteria to the temperature of coagulation. Using energy densities
within this range, even a single flash can effectively cause
photothermal heating and coagulation of selectively stained plaque
bacteria.
[0100] Light rays produced by flash lamp 20 such as light ray 13
are reflected by reflector 15, directed towards filters 21 and 23
to be filtered thereby. The filtered light rays are directed within
the light guide by multiple reflections from the reflecting layer
32 to exit from the exit 25. The filtered light rays are directed
towards the surface of teeth 36 for coagulating stained plaque
bacteria by photothermal heating.
[0101] The frequency of flashing of the lamp 20 by the electronic
timer circuitry may be factory preset so as to take into account
the typical parameters of the movements of brush member 28 over the
teeth during the brushing of teeth by the user and to provide a
sufficient irradiation of the surfaces of the teeth within the oral
cavity of the user for efficient photothermal destruction of dental
plaque bacteria.
[0102] After the user finishes the photothermal coagulation
procedure, the user switches off the flashing of the flash lamp 20
by switching the switch 19 to the "off" position. If desired, the
user may then apply a tooth paste to the bristles 29 of the tooth
brush like member 28 and proceed to brush his teeth normally.
[0103] Alternatively, the person first brushes his teeth normally,
using ordinary toothpaste or other dentifrice. The bacteria is then
stained and the above irradiation procedure is performed.
[0104] Alternatively, a toothpaste incorporating a stain as
described herein is used for ordinary brushing with the brush
member. This brushing will be operative to clean the teeth and to
stain any remaining bacteria. The mouth and the toothbrush are then
preferably rinsed and the irradiation procedure, as described
herein, is performed. In a preferred embodiment of the invention,
E-127 red food coloring (Erythrosin-B) in a concentration of
0.1%-1% can be used as the stain. Other suitable stains can also be
used.
[0105] As may be noted, light directing member 22 and brush member
28 are preferably detachable from handle 11. Thus, a separate
directing member may be used for each person using the device.
Furthermore, the brush may be replaced from time to time as it
becomes used.
[0106] Reference is now made to FIG. 4 which is a schematic cross
sectional view of a handle 41 of a device for selective
photothermal destruction of oral bacteria, in accordance with
another preferred embodiment of the present invention. Handle 41
includes a housing 42 having a recessed opening 58 therein. Handle
41 further includes a controller unit 16 attached to a power supply
(not shown) by a suitable power cable 57. Handle 41 also includes
switch 19 suitably connected to the controller 16 as disclosed with
respect to FIG. 3. Switch 19 is used to turn controller 16 on and
off as disclosed for device 10 of FIG. 3. Handle 41 further
includes a reflector 44 to reflect light from a lamp 50 to an
opening 58. Handle 41 further preferably includes two filters 21
and 23 disposed between the lamp and the opening. Handle 41
preferably also includes a lens 55 situated between filter 23 and
opening 58.
[0107] Lamp 50 is similar to lamp 20 of FIG. 3 and is electrically
connected to the controller 16 by a conducting wires (not shown for
the sake of clarity of illustration). Reflector 44 is made of a
light reflecting material such as polished aluminum or any other
suitable reflecting material. Alternatively, the reflector 44 may
be made of a preferably thermally insulating material such as
plastic or the like which is plated or coated by a light reflecting
layer made of a suitable reflecting metal such as aluminum, silver
or the like. Reflector 44 is preferably a parabolic reflector but
can also have a quasi-parabolic, spherical or quasi-spherical shape
or any other suitable shape. Light rays 56 produced by the lamp 50
are reflected by the reflector 44, filtered by the filters 21 and
23 as disclosed above and focused by the lens 55 at a point 59
within opening 58.
[0108] Handle 41 can be attached to light directing member 22 of
FIG. 3 by inserting end 24 of member 22 into opening 58 of handle
41. When switch 19 is switched on, the light produced by lamp 50
and focused at point 59 enters into passage 30 and is directed by
the light guide formed from the reflecting layer 32 to exit from
the optical window 34 as disclosed above.
[0109] Reference is now made to FIG. 5A which is a schematic part
block diagram/part cross sectional view of a device 71 for
selective photothermal destruction of oral bacteria. Device 71 has
a light source optically coupled to a hand held part by an optical
fiber bundle 67, in accordance with yet another preferred
embodiment of the present invention.
[0110] Device 71 includes a handle 61 and a base 77. Handle 61
includes a housing 62 having a recessed opening 68 therein. Handle
61 and the base 77 are optically coupled by flexible optical fiber
bundle 67 passing through housing 62 of handle 61 and attached
thereto. Base 77 preferably includes a housing 72, a light source
74, a power supply 18 and controller 16 electrically connected to
light source 74 to control the energizing of light source 74 by
power supply 18. Base 77 also may include a control panel (not
shown in FIG. 5A) suitably connected to controller 16 for
activation of the controller.
[0111] Light source 74 preferably includes a lamp 70 similar to
lamp 20 of FIG. 2. and electrically connected to controller 16.
Light source 74 preferably also includes a reflector 75 which
includes filters 21 and 23 attached thereto as disclosed above.
Reflector 75 is made of a light reflective material or is
constructed from a thermally insulating material coated with a
light reflecting layer as disclosed above. The reflector 75 may be
ellipsoidal but may also have other shapes as disclosed above.
Optical fiber bundle 67 has a first end 67A and a second end 67B.
Light source 74 is optically coupled to first end 67A, by the
structure shown or by other suitable means known in the art.
Optical fiber bundle 67 passes within housing 62 of handle 61 and
end 67B of optical fiber bundle 67 is attached to housing 62 at
recessed opening 68 in such a way that it can be optically coupled
to the light guide of light directing member 22 of FIG. 3. Thus,
light produced by light source 74 enters first end 67A and is
directed by the individual optical fibers within optical fiber
bundle 67 to exit at second end 67B.
[0112] It is noted that end 67B of optical fiber bundle 67 can also
be optically coupled to various types of light directing members
which are constructed differently from light directing member 22 of
FIG. 3 some of which are disclosed below.
[0113] Reference is now made to FIG. 5B which is an isometric view
of a system 80 for selective photothermal destruction of oral
bacteria including the device of FIG. 5A and a plurality of the
light directing members of the type illustrated in FIG. 3.
[0114] FIG. 5B illustrates base 77 which includes a control panel
73 for activation of controller unit 16 by the user. Base 77 is
suitably formed to house handle 61 while it is not being used. Base
77 is also suitably formed to house a plurality of light directing
members 22 each of which may be attached to handle 61 for use by a
different individual for his own personal use. Optical fiber bundle
67 may be conveniently wound around a member 67 for storage.
[0115] Reference is now made to FIGS. 6 and 7. FIG. 6 is an
isometric view of a light directing member 82, in accordance with a
preferred embodiment of the invention, attachable to the handle of
the devices of FIGS. 3, 4 and 5A-5B. FIG. 7 is a cross sectional
view of the light directing member of FIG. 6 taken along the lines
VII-VII.
[0116] Light directing member 82 is an elongated member having a
proximal end 84 and a distal end 86. Proximal end 84 can preferably
be detachably attached to any of handles 11, 41 and 61 of FIGS. 3,
4 and 5, respectively. Distal end 86 is insertable into the oral
cavity of the user (not shown).
[0117] Turning to FIG. 7, the light directing member 82 includes a
hollow member 83 preferably made from a thermally insulating and
light opaque material such as opaque plastic or the like. Light
directing member 82 further includes a light guide 85 having a
first end 85A and a second end 85B. First end 85A of light guide 85
is attached to hollow member 83 at proximal end 84 of light
directing member 82 and second end 85B of light guide 85 is
attached to hollow member 83 at distal end 86 of light directing
member 82. Light guide 85 is preferably separated from hollow
member 83 by an air gap 87. Preferably, first end 85A of light
guide 85 terminates in a flat surface 89A which is suitable for
being optically coupled to a light source such as light source 14
of FIG. 3 or to second end 67B of optical fiber bundle 67 of FIG.
5A. Second end 85B of light guide 85 terminates in a flat surface
89B which is suitable for directing the light entering light guide
85 onto the oral cavity of a user.
[0118] Light guide 85 is optimally made from a material which is
transparent to the bandwidth of the band limited light which is
being used for photothermally coagulating the oral bacteria. The
transparent material forming light guide 85 has an index of
refraction which is higher than the index of refraction of air. A
light ray 81 which enters light guide 85 at surface 89A is guided
by multiple reflections along light guide 85 towards end 85B of
light guide 85 where it exits through surface 89B.
[0119] Preferably, light guide 85 is shaped as a rod having a
generally circular cross-section, and is made from clear
polymethylmetacrylate (PMMA), glass or any other optically suitable
transparent material. However, light guide 85 may have other
different shapes and cross-sections which are suitable for
implementing a light guide.
[0120] Reference is now made to FIG. 8 which is a side view of a
toothbrush like light delivery member 92 attachable to the handle
of the devices of FIGS. 3, 4 and 5, in accordance with another
preferred embodiment of the present invention. Light directing
member 92 is similar to light directing member 82 of FIG. 6 and
includes a light guide 83.
[0121] However, in contrast to hollow member 83 of FIG. 6, hollow
member 93 of light directing member 92 includes a lip 94 extending
therefrom and surrounding surface 89B. A plurality of bristles 95
are attached to lip 94 and extend from lip 94 in a direction which
is generally perpendicular to the surface of the 94 forming a tooth
brush like member 97 at the end of light directing member 92. When
light directing member 92 is attached to a handle such as, for
example, handle 11 or 41 or 61 of FIGS. 3, 4 and 5A, respectively,
and teeth within the oral cavity of a user are brushed by tooth
brush like member 97, the light which exits from surface 89B is not
blocked by bristles 95 and illuminates part of the surface of the
teeth which lie underneath tooth brush like member 97.
[0122] It is noted that, while light can be directed onto the
surfaces of teeth as disclosed hereinabove for the light directing
members 22, 82 and 92, other methods for directing light can be
used.
[0123] For example, FIG. 9, to which reference is now made, is a
schematic cross sectional view of a toothbrush like light directing
member 102 attachable to the handle of the devices of FIGS. 3, 4
and 5. Member 102 has transparent bristles 109 optically coupled to
a light guide included within the light directing member. Light
directing member 102 is an elongated member having a proximal end
104 and a distal end 106. Proximal end 104 can be detachably
attached to any of Handles 11, 41 and 61 of FIGS. 3, 4 and 5,
respectively. Distal end 106 is insertable into the oral cavity of
a user.
[0124] Light directing member 102 preferably includes a hollow
member 103 preferably made from a thermally insulating and light
opaque material such as opaque plastic or the like. Light directing
member 102 further includes a light guide 85 as described above.
Light directing member 102 further preferably includes a terminal
part 109. Terminal part 109 preferably includes a plate 107 made of
a thermally insulating and preferably light opaque material such as
plastic or the like. Terminal part 109 preferably has a plurality
of holes 108 passing therethrough.
[0125] Terminal part 109 further includes a plurality of
transparent bristles 105. Each of the bristles 105 has a first end
105A and a second end 105B. Bristles 105 are attached to plate 107.
First end 105A of each of the bristles 105 is inserted into a hole
108 and glued to or frictionally held within the hole. First end
105A of each of bristles 105 is optically coupled to light guide 85
at surface 89B thereof by abutting surface 89B or by being glued to
surface 89B using a suitable optically transparent glue.
[0126] Second end 105B of each of bristles 105 extends distally
from plate 107 in a direction generally perpendicular to a surface
107A thereof. Bristles 105 are preferably made from a flexible
material which is transparent to the bandwidth of the band limited
light which is being used for photothermally coagulating the oral
bacteria. For example, bristles 105 can be made from nylon or from
any other suitably transparent flexible plastic. Light from surface
89B enters first end 105A and is guided within each bristle 105 to
exit from second end 105b of each of bristle. When teeth are
brushed by bristles 105, light exiting ends 105B of bristles 105
irradiates the surfaces of the teeth and may photothermally
coagulate selectively stained bacteria within plaque covering the
surfaces of teeth.
[0127] While all the preferred embodiments of the present invention
disclosed hereinabove are useful in photothermally coagulating
bacteria within plaque deposited on the more accessible surfaces of
teeth, plaque on tooth surfaces which are less accessible to
irradiation may need a treatment using another technique of
irradiation.
[0128] For example, FIG. 10 to which reference is now made is a
schematic cross sectional view of a light directing member 112 in
accordance with a preferred embodiment of the invention. It is
preferably attachable to the hand held part of the devices of FIGS.
3, 4 and 5. and has a light scattering dental floss like member 120
optically coupled to a light guide 115 included within a hollow
cavity member 113 within the light directing member. Light
directing member 112 has a proximal end 114 and a distal end 116.
Light guide 115 has a first end 115A at proximal end 114 of light
directing member 112 and a second narrowing end 115B at distal
end.
[0129] Light directing member 112 includes a terminal part 119
extending from distal end 116. Terminal part 119 includes a floss
holding member 117 holding light scattering dental floss like
member 120 having a first part 120A and a second part 120B. Floss
like member 120 is preferably made from a flexible transparent
material such as nylon or any other type of suitably transparent
flexible plastic. First part 120A is attached to and optically
coupled to the second end 115B of the light guide 115. The optical
coupling may be performed by a glue having suitable optical
properties or, alternatively, floss like member 120 can be an
extension of narrowing end 115B of light guide 115. Second part
120B of floss like member 120 is attached to floss holding member
117 such that floss like member is suitably held for flossing.
[0130] Floss like member 120 is constructed to scatter light which
enters it from light guide 115. The scattering of light may be
caused by small light reflecting particles which are embedded in
the transparent plastic material forming the floss like member 120.
However, other methods of inducing light scattering may also be
used such as, for example, forming a plurality of closely spaced
grooves or indentations on the outer surface of the floss like
member.
[0131] After selective staining of plaque bacteria as disclosed
above, a user inserts the floss like member 120 between the teeth
as he would with ordinary floss. The light scattered from floss
like member 120 irradiates the plaque on the surfaces of the teeth
that are not accessible by regular brushing and performs
photothermal coagulation of selectively stained plaque bacteria
positioned at these inaccessible surfaces, while normal flossing is
performed.
[0132] It is noted that each of the handles 11, 41 and 61 can be
attached to any of the light directing members 22, 82, 92, 102 and
112 of FIGS. 3, 7, 8, 9 and 10, respectively.
[0133] It is further noted that, while any of the light directing
members 22, 82, 92, 102 and 112 of FIGS. 3, 7, 8, 9 and 10,
respectively, may be made for extended use, they may also be made
to be disposable. Furthermore, while various features and forms of
features have been shown in the various preferred embodiments, many
of these features and variations may be present in other preferred
embodiments of the invention. Furthermore, some preferred
embodiments of the invention may omit some features shown in the
preferred embodiments.
[0134] It will be appreciated by those skilled in the art that many
variations of the preferred embodiments of the present inventions
can be made which are within the scope and spirit of the present
invention. As used herein, the words "comprise" or "include" or
their conjugates mean "including but not necessarily limited
to."
* * * * *