The invention relates generally to the field of oral care,
and in particular to toothbrushes.
Tooth brushing and flossing are fundamental steps in achieving
good oral hygiene. The practice of flossing, unfortunately, has not met with widespread
acceptance among the general populace even though it is acknowledged by the general
populace that flossing is something that should be completed as part of good oral
hygiene. Furthermore, even people who floss oftentimes do not perform adequate flossing
in hard to reach areas of the mouth. Unfortunately, while most commercially available
toothbrushes clean the outer buccal face of teeth adequately, they fail to provide
improved cleaning of plaque and debris from the gingival margin, interproximal areas,
lingual surfaces and other hard to reach areas of the mouth.
One reason that such toothbrushes do not adequately clean
the interproximal region is that the tufts are not angled in a direction to optimize
interproximal and subgingival penetration. As such, these tufts cannot extend far
enough into the interproximal region. Another reason for poor interproximal penetration/cleaning
is that the bristle/tuft density is too high: having a large number of bristles/tufts
provides good surface cleaning but hinders the bristles from penetrating between
Some brushes have tufts of bristles which have angled tufts
which either appear to cross when viewed head-on (see for example
U.S. Patent No. 4,706,322
(the '322 patent), incorporated herein by reference) or from the side
(see for example
U.S. Patent No. 3,085,273
(the '273 patent), incorporated herein by reference) to provide better
interproximal penetration. The crossing tufts of the '322 patent will more effectively
penetrate between teeth when the brush is being moved up and down rather than back
and forth. Likewise, the crossing tufts of the '273 patent will more effectively
penetrate between teeth when the brush is being moved back and forth rather than
up and down.
Some current toothbrush designs involve filament tufts
angled away from the center line/long axis of the brush head (Figure
7) and some current toothbrush designs involve tuft filaments angled along
the center line of the brush (Figure 8).
When these toothbrushes are placed on or against the teeth, the filaments bend and
are deflected away from the gumline area.
discloses a toothbrush having bristle elements arranged in two banks.
The free ends of the bristle elements in the first bank extend convergingly with
the free ends of the bristle elements in the second bank to provide a V-shaped tooth
receiving channel having an acute included angle of from about 10 to 55 degrees.
The bristle elements in the banks which are closest together extend into contact
with one another at the bristle tips to define a doublet of mutually supported bristle
The present invention is directed to overcoming one or
more of the problems set forth above. Briefly summarized, according to one aspect
of the present invention, a toothbrush includes a head having bristle tufts implanted
therein. At least two of the tufts cross so as to permit at least some the bristles
to intermingle. One of the two tufts is located adjacent a long side of the head.
Another aspect of the present invention relates to a toothbrush
comprising a head having at least 2 bristle tufts which have a compound crossing
angle such that one of the tufts eclipses at least a portion of the bristles of
the other tuft when (a) viewed from a side of the toothbrush, and (b) viewed from
an end of the toothbrush.
Such a compound crossing angle allows the tufts to more
effectively penetrate in between teeth both when the brush is being moved up and
down, and, back and forth.
Another aspect of the present invention relates to a toothbrush
having a head with at least 2 bristle tufts. The head has two portions which define
an opening in an interior portion of the head such that water can flow through this
Allowing water to flow through an opening in a central
portion of the head facilitates removal of excess toothpaste and other debris, thus
enhancing the cleanliness of the brush over time.
A still further aspect of the invention relates to a toothbrush
having a head with bristle tufts implanted therein. At least two of the tufts cross
so as to permit at least some of the bristles to intermingle. At least some of the
intermingled bristles from one of the two tufts extends past the other tuft.
According to another aspect of the invention, a toothbrush
includes a handle, a head extending from the handle and having a top surface, and
a plurality of tufts of bristles projecting from the top surface of the head. The
cumulative cross-sectional area of each of the bristles defining a first area. A
plane intersects all of the bristles except the shortest bristle and is tangent
to or intersects at least a portion the free end of the shortest bristle. A perimeter
located in the plane connects an outer surface of all outer tufts, the area within
the perimeter defining a second area. The ratio of the first area to the second
area is between about 5% to about 20%.
The previous paragraph describes a brush having a relatively
low density of bristles/tufts. The density needs to be high enough so that it will
clean the exposed tooth surfaces and be acceptable to consumers, yet low enough
so that at least some of the bristles can penetrate and clean between teeth.
These and other aspects, objects, features and advantages
of the present invention will be more clearly understood and appreciated from a
review of the following detailed description of the preferred embodiments and appended
claims, and by reference to the accompanying drawings.
FIG. 1 is a perspective view of a preferred
(split head) brush of the present invention;
FIG. 2 is a bottom view of the brush of
FIG. 3 is a side view of the brush of
FIG. 4 is a top plan view of the brush
of FIG. 1;
FIG. 5 is an enlarged view of the crossing
tufts of the present invention depicting the intermingled bristles;
FIG. 6 is an end view of the brush of
FIG. 7 is a perspective view of a prior
art brush with tufts angled away from the centerline of the brush (Colgate Total);
FIG. 8 is a perspective view of a prior
art brush with tufts angled along the centerline of the brush (Oral-B CrossAction).
As used herein the term "intermingled tufts" means two
tufts which cross so as to force at least some of the individual filaments from
each tuft bundle to mingle with the filaments of the other.
As used herein the term "compound crossing angle" relates
to toothbrush filament tufts which are positioned on a toothbrush head at oblique
angles such that the tufts appear to cross (one tuft eclipses the other) when viewed
from a side of the toothbrush and when viewed from an end of the toothbrush.
Referring to Figure 1,
toothbrushes of the present invention are comprised of a handle 20 (shown partially
in the figures) connected to a relatively planar head region 1. Head 1 has a maximum
preferable width of about 0.45"-1.00", preferably 0.50"-0.80", and most preferably
0.51"-0.72". The head is comprised of two regions: a first region 2 and a
second region 3. In a preferred embodiment of the present invention, the
tufts are affixed to the first and second region as follows: The first region
2 is comprised of an outer row of tufts 4a-f which are inclined longitudinally
toward the distal end of the head 10. The region is further comprised of
two inner row of tufts 6 which are angled longitudinally toward the proximal
end of the head 11. This results in a first region which appears to have
tufts which cross when viewed from the side (see FIG.
Next, the second region 3 is comprised of outer
tufts 5 which are angled longitudinally toward the distal end of the head
10 and inner tufts 7 which are angled longitudinally towards the proximal
end of the head 11. As such, tufts 6 and 7 of the inner rows alternate with
each other along the length of the head. The result is a second region
3 which appears to have crossing tufts when viewed from the side. The free
ends of tufts 4a-f are spaced from the free ends of tufts 5 by about 0" (touching)-0.60",
preferably 0.05"-0.52", and most preferably 0.10"-0.42". The length of the tufts
is about 0.26"-0.75", preferably 0.325"-0.60", and most preferably 0.35"-0.50".
The angle A of the tufts along the length of the head (see Figure
3) is about 0-30 degrees, preferably 5-25 degrees, and most preferably
As shown in Figure 6,
the two regions of the head 2 and 3 are angled transversely (i.e. tilt inwardly).
As a result, the top surfaces of head portions 2 and 3 from which tufts project
tilt inwardly such that the tufts tilt inwardly. Tufts which appear to cross from
two directions can be on the same head region or on different head regions. The
angle B between the regions is about 140-178 degrees, preferably 150-175 degrees,
and most preferably 150-165 degrees. In this embodiment, the tufts appear perpendicular
to their respective head region when viewed end on. A maximum depth C from the top
of the "V" to the bottom of the "V" is about 0.03"-0.30", preferably 0.075"-0.25",
and most preferably 0.10"-0.225".
Alternatively, head 1 can be a conventional head with a
flat upper surface, and the tufts themselves can be tilted inward to give the same
appearance (not shown in figures). In this embodiment, the tufts would not be perpendicular
to the top surface of the head. Either embodiment results in tuft bundles which
intermingle (see Figures 4 and
Bottom plan view Figure
2 outlines a preferred configuration where the first region 2 and
second region 3 form a complimentary relationship as defined by the corrugated
space between the regions. Each region has alternating projections and spaces (recesses),
the projections of one region engaging at least partially into the spaces of the
other region. Regions (portions) 2 and 3 are movable independently of each other.
An opening 8 is created between regions 2 and 3 in an interior portion of the head,
and allows water to flow through the opening, thus facilitating rinsing of excess
toothpaste, saliva and debris from the head. The area of opening 8 at a top surface
of the head (see figure 4) is preferably
between about 2% to about 20% of the total area (including the area of opening 8)
of the top surface of the head, more preferably between about 4% to about 18%, even
more preferably between about 6% to about 16%, and most preferably between about
8% to about 14%. Each projection preferably has one or more tufts and is surrounded
on three sides by the other head portion.
However, the inventors also contemplate fabricating the
brush according to this invention from a solid head with no central opening which
is merely molded and tufted such that the bristles take on the geometric orientation
as described above. As a further alternative, the central opening in the head is
provided, but the two head portions are connected at the end of the head furthest
from the handle. As such, relative movement of the head portions will be minimized.
With reference to Figures
3 and 4, a cumulative cross-sectional
area of each of the bristles on the head defines a first area. An imaginary perimeter
22 is shown. Perimeter 22 lies in a plane. This plane intersects all of the bristles
except the shortest bristle and is tangent to or intersects at least a portion the
free end of the shortest bristle. Perimeter 22 connects an outer surface of all
outer tufts. The area within the perimeter defines a second area. The ratio of the
first area to the second area is preferably between about 5% to about 20%. The ratio
is more preferably between about 6% to about 18%, even more preferably between about
7% to about 16%, even more preferably between about 8% to about 14%, and most preferably
between about 9% to about 12%. This ratio defines a bristle density for the brush.
The tuft bundles 4, 5, 6 and
7 preferably have rectangular shaped cross-sections having a 1:2 to 1:6 length
to width aspect ratio. More preferably, this aspect ration is from about 1:3 to
1:4. The inventors also contemplate the use of round, rectangular, square or any
other shaped tuft bundles known to those skilled in the art. In the most preferred
embodiment, the free ends of the individual filaments 20 are rounded into a dome-like
shape. These are commonly referred to as end-rounded bristles.
Figure 5 is an enlarged perspective view
of two tufts which demonstrate the intermingled nature of these tufts. Region
30 is the region where the bristles are allowed to at least partially intermingle.
This region could be done merely at the tips of the bristles (ie. inverted "v",
not shown) or, as shown, forming a true crossing (i.e. "x") pattern (see
Fig. 3). Alternatively, region 30 could
take on the appearance of an inverted "y" with bristles from a first tuft extending
past a second tuft, but the bristles of the second tuft not extending past the first
tuft (not shown). As shown in Figure 4,
one of the two tufts 4b which intermingle is located adjacent a long side of head
The overlapping intermingled compound crossing angle pattern
of the present invention promotes better interproximal and subgingival penetration.
The tufts of the present invention are able to penetrate between the teeth, and
to penetrate under the sulcus, both proximally and along the buccal gingival margin.
In addition, it has been observed that the "3-dimensional" angling of tufts resulted
in multiple tufts penetrating from different angles simultaneously.
In a most preferred embodiment, the brush head is fabricated
from two parts relating to the first region 2 and the second region
3, which each have bristles angled in a pattern compound crossing angle.
The two sides consist of intermingled overlapping tufts (see Figure
5) which allow the two sides to be angled to come together in a unique
V-shaped configuration (see Figure 6).
The angled tufts allow for a spacing and relative tuft angle/height configuration
which is not manufacturable using current technology. The ability to have multiple
tufts come together at an inward angle, with appropriate spacing, allows multiple
tufts to engage interproximally and sub-gingivally simultaneously. Another added
benefit of the split handle design is rinsability.
It may be possible to achieve similar results by manufacturing
a first region and a second region on a brush head and subsequently bending the
two regions relative to each other. It is thus possible to create a similarly acting
tufting pattern on a single head with a bent head design, and possibly through the
use of staple tufting technology. Additionally, the toothbrush can be made with
a replaceable head feature.
A preferred manufacturing technique to produce the brushes
of the present invention is to individually mold right and left sides of the brush,
capturing the tufts of bristles in the head during molding (a hot tufting process).
These two sides are then placed relative to each other and secured together by melting