Dental hygiene appliance

A dental hygiene appliance for brushing teeth composed of a handle; a brushing head connected to the handle and a set of tooth brushing bristles projecting in a given direction from the head; a source of monochromatic radiation having a given wavelength; and elements for directing the radiation from the head in a direction having at least a component in the given direction; wherein the elements for directing radiation are structurally separate from the bristles.

BACKGROUND OF THE INVENTION 
The present invention relates to dental hygiene appliances, and 
particularly toothbrushes equipped to apply radiation to tooth surfaces. 
It has been proposed in the art to equip a toothbrush with a light source 
which can illuminate the region being brushed. The purpose of such devices 
is to aid the brushing operation by better illuminating the portion of the 
teeth being brushed. A device of this type is disclosed in U.S. Pat. No. 
4,779,173, where the toothbrush bristles are plastic filaments which 
conduct radiation from a light source in the handle of the brush. This 
patent also discloses earlier prior art including a dental cleaning 
apparatus in which the head portion or bristle holding portion is 
eliminated. 
It is also known in the art that laser radiation can have a variety of 
beneficial effects on teeth. 
U.S. Pat. No. 5,030,090 discloses a tooth brush having a bundle of bristles 
constituted by optical fibers which are coupled to a semiconductor laser. 
The fibers constitute the bristles of the toothbrush. This patent 
discloses that the radiation produced by a semiconductor laser can be used 
for treating or preventing gingivitis and other oral diseases, and 
specifically can serve to reduce pain and inflammation and to improve 
blood circulation. 
One of the characteristics of the device as disclosed in the above-cited 
patents is that they employ filaments which are capable of functioning as 
both optical fibers and brushing bristles. One problem with devices of 
this type is that filaments which are capable of functioning as optical 
fibers can not be given the mechanical characteristics required to permit 
them to function in an optimum manner as brushing bristles. In particular, 
if the filaments must be fabricated to function as optical fibers, it will 
prove difficult to give them the durability desired for brushing bristles. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a novel dental hygiene 
appliance which applies radiation having a selected wavelength to tooth 
surfaces while those surfaces are being brushed. 
Another object of the invention is to provide an appliance of this type in 
which the toothbrush bristles are employed only for brushing, and may 
therefore be selected solely on the basis of the characteristics required 
for performing that function. 
Another object of the invention is to employ such an appliance in a manner 
to enhance the effectiveness of the brushing action, possibly with the aid 
of a chemical product which facilitates observation and/or removal of one 
or more substances of the type which form deposits on teeth. 
The above and other objects are achieved, according to the present 
invention, by a dental hygiene appliance for brushing teeth comprising: a 
handle; a brushing head connected to the handle and a set of tooth 
brushing bristles projecting in a given direction from the head; a source 
of monochromatic radiation having a given wavelength; and means for 
directing the radiation from the head in a direction having at least a 
component in the direction; given wherein the means for directing 
radiation are structurally separate from the bristles. 
Objects according to the invention are further achieved by supplying with 
the appliance a chemical product which is capable and/or facilitating 
removal, of a substance which forms deposits on teeth and when that 
substance is irradiated by the radiation having a given wavelength. Then, 
since the brushing action is performed on, and the radiation is being 
applied to, substantially the same tooth areas, the brushing action in the 
presence of that chemical product will facilitate thorough cleaning of the 
teeth.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The basic components of an appliance according to the present invention 
include, as shown in FIGS. 1 and 2, a handle 4 and a brushing head 5. 
Brushing head 5 is constituted by a body 6 having a base surface 7 from 
which a set of tooth brushing bristles 8 project. The composition and form 
of bristles 8, and the manner in which bristles 8 are secured to body 6, 
conform to conventional practice in the toothbrush art. 
Appliances according to the present invention are further provided with 
means for directing monochromatic radiation of a selected type from body 6 
in the direction of arrow 10, which is generally parallel to the direction 
in which bristles 8 project from body 6. However, in appliances according 
to the invention, the radiation is not guided by the bristles themselves, 
but is emitted generally via base surface 7 of body 6. 
In the embodiment illustrated in FIGS. 1 and 2, handle 4 is provided with a 
laser device 14, for example a semiconductor laser, and brushing head 5 is 
provided with a lens 18, one or more semitransparent mirrors 20 and a 
fully reflecting mirror 22. Radiation produced by laser 14 may be in the 
form of a small diameter collimated beam extended along an axis 
corresponding to the longitudinal axis of handle 4 and head 5. Mirrors 20 
and 22 may be oriented at an angle of 45.degree. to the beam axis and lens 
18 is constructed and arranged to give the laser radiation beam a slightly 
diverging form such that the beam will diverge to an area essentially 
coextensive with the area occupied by mirror 22. 
Body 6 may itself be made of a plastic which is transparent to the laser 
radiation so that portions of the radiation will be reflected in the 
direction 10 by mirrors 20, and the remaining radiation will be reflected 
by mirror 22. The optical system constituted by lens 18 and mirrors 20, 22 
is arranged to cause radiation to traverse an area at least approximately 
coextensive with the area covered by the tips of bristles 8. However, the 
radiation area may, depending on the particular operations to be 
performed, extend over a smaller or larger area. 
In the embodiment illustrated in FIGS. 1 and 2, handle 4 includes a power 
cord 30 which may be plugged into a wall outlet in order to supply 
operating power to laser 14. Alternatively, handle 4 could be constructed 
as a holder for a replaceable or rechargeable battery which supplies the 
necessary operating power. In addition, in the embodiment illustrated in 
FIGS. 1 and 2, brushing head 5 is readily detachable from handle 4. This 
allows a plurality of brushing heads 5, each used by a different 
individual, to be mounted on head 4 for use. In addition, as shown in 
FIGS. 1 and 2, lens 18 may form a unit with head 2, so that each of the 
brushing heads 5 need not be provided with its own lens. This would reduce 
the cost of manufacturing each head 5. 
FIG. 3 shows an alternative embodiment of the brushing head, which can be 
constituted by two plastic pieces 34 and 36 joined together along a plane 
40 having a series of surfaces which are inclined at an angle of 
45.degree. to the axis of the radiation emitted by laser 14. Plane 40 is 
made to be a reflecting surface by an appropriate coating or finishing 
process. In FIG. 3, the bristles 8 are not shown, for the sake of 
simplicity. 
The radiation provided in an appliance according to the present invention 
has a wavelength as well as an intensity, selected to have a desired 
effect on one or more substance which may become deposited on tooth 
surfaces and which it is desired to remove. Typical substances of this 
type include bacteria, tartar and calculus, all of which contribute or are 
precursors, to tooth decay. In addition, when certain chemical products 
are brought into contact with one or another of these substances, the 
application of radiation having an appropriate wavelength and energy 
content can render the substance or substances visible and/or can help to 
remove those substances from tooth surfaces. 
Thus, in accordance with the invention, an appliance of the type described 
above is used in cooperation with such a chemical product, which may be 
incorporated into a toothpaste, tooth gel or tooth powder, formulated and 
marketed for use specifically with the appliance. 
By way of example, one of the purposes of tooth brushing is to remove 
bacteria which have collected on tooth surfaces, frequently in pits and 
fissures in the tooth enamel. It is known that regardless of the care 
exercised and time spent in a brushing session, some of the bacteria 
deposits may not be dislodged and removed from the tooth surfaces. It is 
also known that there are chemical products, known as disclosing 
solutions, which can make any deposited bacteria visible. There are other 
chemical products, which may be preferable to the conventional disclosing 
solutions, which will react with bacteria in such a manner as to render 
the bacteria visible in the presence of radiation having a certain 
wavelength. Such product can be provided as an ingredient of a special 
toothpaste, tooth gel or tooth powder supplied with the appliance 
according to the invention. 
When such a tooth cleaning preparation is employed, the chemical product 
will render any existing bacteria visible under the radiation produced by 
source 14, so that brushing can be continued until the user can observe 
that all bacteria have been removed from all visible tooth surfaces. While 
it would be more difficult to carry out this procedure on lingual tooth 
surfaces, this would be possible, if brushing were carried out while 
viewing those surfaces with a mirror. 
In further accordance with the invention, the chemical product may be 
selected to render tartar or calculus visible, while the appliance is then 
utilized to remove those materials. Possibly, special brush heads with 
appropriate bristles could be provided for this purpose. 
In further accordance with the invention, use may be made of a product 
which reacts with bacteria, tartar or calculus in such a manner that 
radiation of an appropriate wavelength will have the effect of removing 
the bacteria, tartar or calculus, or of altering the nature of the 
bacteria, tartar, or calculus, as by softening it, in a manner to 
facilitate complete removal by the brushing action. 
According to one exemplary embodiment of the invention, the chemical 
product consists of or contains nigrosin and the radiation source produces 
radiation at a wavelength of between 1.mu. and 6.mu.. The radiation source 
may be, for example, an Nd:YAG laser. The source will be adjusted to emit 
radiation at an energy level selected on the basis of the expected 
concentration of nigrosin in the material to be treated. 
Nigrosin will stain, for example, cariogenic bacteria or streptococcus 
faecalis black so that this bacteria, or any other substance absorbing 
nigrosin, will readily absorb the laser radiation. 
According to another possibility, the chemical product can be sudan red as 
a vital stain when the radiation source is an argon laser. 
In both cases, the radiation energy density could be made sufficiently high 
to directly vaporize the stained substance. For example, in the case where 
streptococcus faecalis is stained with nigrosin and irradiated by an 
Nd:YAG laser, this effect can be achieved with an energy density of the 
order of 10 J/cm.sup.2. 
While the description above refers to particular embodiments of the present 
invention, it will be understood that many modifications may be made 
without departing from the spirit thereof. The accompanying claims are 
intended to cover such modifications as would fall within the true scope 
and spirit of the present invention. 
The presently disclosed embodiments are therefore to be considered in all 
respects as illustrative and not restrictive, the scope of the invention 
being indicated by the appended claims, rather than the foregoing 
description, and all changes which come within the meaning and range of 
equivalency of the claims are therefore intended to be embraced therein.