WO2004037038A1

WO2004037038A1 - Toothbrush bristle configuration and method of using same

Info

Publication number: WO2004037038A1
Application number: PCT/CA2003/001616
Authority: WO
Inventors: Guang Rong Liu; Li Hai Wang
Original assignee: Guang Rong Liu; Li Hai Wang
Priority date: 2002-10-24
Filing date: 2003-10-23
Publication date: 2004-05-06
Also published as: AU2003275836A1

Abstract

A toothbrush head having a base (14), the base having first and second side marginal edges (21, 23), a front marginal edge (30) and a rear marginal edge (28), with a plurality of tufts extending outwardly from a first side of the base, at least some the tufts being angled with respect to the perpendicular. The arrangement provides for the use of a new method of cleaning the teeth wherein the side, front and rear tufts each perform a different task for different portions of the teeth.

Description

TOOTHBRUSH BRISTLE CONFIGURATION AND METHOD OF USING SAME

FIELD OF THE INVENTION

The present invention relates to the general field of toothbrushes and more

specifically, relates to a novel bristle and tuft arrangement for the head of a toothbrush.

BACKGROUND OF THE INVENTION

As is well known, toothbrushes are used to clean teeth so as to prevent related dental

diseases. Manual toothbrushes are comprised of a toothbrush head and a toothbrush handle.

The head of a toothbrush usually comprises tufts of bristles and a base on which the bristles

are secured. Typically, each tuft of bristles has a proximal end held captive in and fixed to

the toothbrush base and an opposed distal or free end used for brushing. Conventional

bristles are generally of the same size, uniform height and are regularly arrayed on the head.

In conventional vertical tooth brushing methods, the cleaning of facial surfaces is

usually the main consideration. The users are required to clean tooth facial surfaces with the

top surfaces of the toothbrushes (the longitudinal axis of the bristles perpendicular to the

tooth surfaces to be cleaned), and move the toothbrushes along the direction of the crevice

between teeth (upward for lower teeth and downward for upper teeth).

Thus, the uniform cleaning surfaces of tufts can only touch the relatively flat

surfaces of the teeth, therefore, the cleaning effect is very limited even for teeth, facial

surface. In addition, the users usually will hurt their gums and cause abrasion to their teeth

when brushing with excessive force. Furthermore, under the conventional vertical brushing

method it is very difficult for a user to brush the lingual or tongue side of the teeth because

of the vertical movement constraint inherent within the confines of a human mouth. These are the inherent shortcomings of tooth brushing under the conventional vertical brushing

method.

In an attempt to circumvent the hereinabove mentioned disadvantages, the prior art

has proposed many different types of improvements, which are mainly divided into four

types of approaches.

In a first approach using the conventional vertical tooth brushing method, it has been

proposed that by varying the length of the toothbrush bristle and modifying the top surface

shape of the toothbrush, one could overcome the problem that uniform bristles and regular

array of bristles makes it hard for bristles to touch concave teeth surfaces.

The majority of these proposed measures have revolved around how to improve the

shape of the top cleaning surfaces of a toothbrush and array of the bristles so that the

improved top cleaning surfaces of the toothbrush can better correspond to the generally

hard-to-touch concave tooth surfaces compared to the conventional uniform bristle

configuration does.

For example, for the top concave surface of a molar, U.S. Publication Number

2001 0042 280 and U.S. Publication Number 2002 0138 931 show the front row of tufts of

bristle located away from the handle to protrude above and be narrower than other rows of

tufts. Some products on the market have longer tufts of bristles with a cone cleaning surface

positioned at the foremost end of the toothbrush head; these arrangements are alleged to

assist in the cleaning of the top concave surface of the molars.

For the other tooth surfaces to be cleaned, the improvement is limited since the

improvement is made based on the conventional vertical tooth cleaning method and this

does not get rid of the inherent shortcoming of the conventional vertical brushing method. Although the modified top cleaning surface of the toothbrush tufts can improve the

static match with the tooth surface to be cleaned, the outer tooth contour varies according to

each individual tooth and its relative position in the mouth. In fact, during the actual

cleaning process this relatively static match of irregular top surfaces of tufts of the

toothbrush cannot always match the changing curvature and irregularity of teeth facial

surfaces.

Furthermore, there is another disadvantage to these approaches in that they misguide

consumers into continuing to use the conventional vertical toothbrush method, instead of

trying to learn and master the ROLL METHOD promoted by the modern dental science.

The consequence is some of the consumers hurt their gums and teeth due to an inappropriate

tooth brushing method, especially when excessive force is applied.

A second type of proposal is illustrated by U.S. Patent 6,612,770 and U.S. Patent

6,505,373, wherein an elastic material is added to the base of the toothbrush head so that

when applied with force, the base can deform in order for the tufts of bristle to better match

the tooth surfaces to be cleaned and reduce the force on the gum so as to improve the

cleaning and thereby reduce the damage to the gums. However, since the base can only

deform when the force is strong enough, the improvement is still limited.

A third approach is illustrated by U.S. Patent 5,341,537 and U.S. Publication

Number 2003 0033 682 which suggest outwardly slanting bristles on the edges of

toothbrush heads which are taller than the other bristles. But the above invention still makes

use of the conventional brushing method, relying on that while other bristles clean the teeth

this special bristle can clean and massage gums.

In terms of tooth brushing methods, modern dental science recommends the BASS TECHNIQUE and the ROLL METHOD. The essence of the two brushing methods is to

clean teeth with a start point of the toothbrushes inclined towards the tooth surface at

45 degrees. But this method is hard to master. Therefore the patentee of U.S. Patent

5,305,489 designed a toothbrush handle angled at 45 degrees from the brush head in order to

overcome the difficulty of fulfilling the 45 degree cleaning requirement.

The above suggested 45 degree method improves three drawbacks of the

conventional vertical cleaning method, which are: first, during the cleaning, it is difficult for

the top cleaning surface of tufts to reach teeth concave surfaces (esp. the inter dental areas

between teeth.) to be cleaned. Secondly, the tougher top cleaning surface of tufts may hurt

the gums especially when excessive force is applied. Thirdly, during cleaning, some tufts

will bend and cause the cleaning surface of the tufts to stop moving along the tooth surface

to be cleaned and in this way these tufts lose the expected cleaning effect.

However, there is still room left for improvement. When cleaning the lingual

surfaces of teeth especially those of the incisor, the 45 degree method results in less

efficiency and is still difficult to apply due to the confines of the human mouth.

Furthermore, the 45 degree method has two other weaknesses if using the tufts of the bristle

configuration of existing toothbrushes. First, although the tufts of bristle may deform so

that its lateral part of free-end cleaning surface can touch the concave surfaces of the teeth to

be cleaned, the tufts of bristle may not provide enough strength such that the said lateral

working part of the tufts cannot remove the tartar on the teeth surface. Secondly, the touch

of the said lateral working surface of tufts on the teeth surface is an only line contacting,

thereby the working surface provides insufficient cleaning, and fails to fully utilize the

potential cleaning power. SUMMARY OF THE INVENTION

It is an object of the present invention to provide for a toothbrush head which will

overcome the above disadvantages.

According to one aspect of the present invention, there is provided a toothbrush head

having a base, the base having first and second side marginal edges, a front marginal edge

and a rear marginal edge, a plurality of tufts extending outwardly from a first side of the

base, characterised in that at least one of the tufts extends outwardly from the base at an

angle with respect to a line perpendicular to the base.

Initially, this invention will divide teeth surfaces into 4 categories by their different

characters such as shape, function and position in a human mouth:

category 1: top concave surfaces of molar

category 2: lingual surfaces of incisor

category 3: facial surfaces of teeth

category 4: lingual surfaces of teeth except for incisor

According to the four categories of tooth surface features, there will be described a

new tooth brushing method to cope with the four different categories of teeth.

For cleaning category 1 top molar concave surfaces, the brushing method is the same

as presently used, which is: during cleaning, the brushing method requires users to

horizontally (the base of a toothbrush head is horizontal) place the toothbrush (toothbrush

working surface downward for lower teeth, upward for upper teeth) so that the working

surface of tufts touches the category 1 top molar concave surfaces and then move the

toothbrush forward and backward along the longitudinal axis of teeth to finish the cleaning

process. For cleaning category 2 lingual surfaces of incisor, the proposed tooth brushing

method defines the backward outer lateral part of free-end of a tuft row of a toothbrush

positioned at the rear end of the brush head near the handle as the working surface instead of

its top flat surface of the said tufts of the toothbrush. During cleaning, the brushing method

requires users to place the toothbrush generally horizontally (toothbrush working surface

downward for lower teeth, upward for upper teeth) so that the lateral working surfaces can

touch the lingual surface of incisors at the root of the incisors (or the gum surface under the

incisors), then move the toothbrush forward and downward for the upper incisor teeth,

forward and upward for the lower incisor teeth to perform the cleaning. When cleaning,

users may close the mouth slightly to prevent the toothpaste foam from spilling out. In fact,

a user can use this cleaning method to clean the lingual surfaces of other teeth if the user

finds it an easier way to clean them since they are usually very difficult to reach by current

tooth brushing methods.

For cleaning the category 3 facial surfaces of teeth and the category 4 lingual

surfaces of teeth (except for incisors), the proposed tooth brushing method utilizes the outer

lateral part of free-end of two tuft columns of a toothbrush head positioned along the

longitudinal axis within the central part of the toothbrush head and adjacent the left and right

edges thereof as the working surface instead of the top flat surface of the tufts of the

toothbrush which is considered the working surface by current tooth brushing methods.

For cleaning category 3 facial surfaces of teeth, the brushing method requires users

to generally horizontally place the toothbrush (toothbrush working surface downward for

lower teeth, upward for upper teeth) so that the working surface of the tuft touches the

category 3 tooth facial surfaces at the root of the teeth (or the gum surface under the said teeth), and then the users can use one of three ways to clean the said teeth facial surface. A

first method involves moving the said toothbrush upward and inward for lower teeth or

downward and inward for upper teeth along the direction of crevice between the teeth.

Secondly, rotating the said toothbrush along the altitudinal axis so that the working surface

of the said tufts move past from the said gum surface, the bottom area of the said teeth

proximal to the gum, to the said teeth facial surface, and the lateral part of the crown surface

of the teeth. Thirdly, just moving the said toothbrush forward and backward along the

longitudinal axis of the teeth.

For cleaning category 4 lingual surfaces of teeth (except for incisors), the brushing

method requires users to generally horizontally place the toothbrush (toothbrush working

surface downward for lower teeth, upward for upper teeth) so that the working surface of the

tufts touches the lingual surfaces of teeth (except for incisors) at the root of the said teeth (or

the gum surface under the said teeth), and then the users can use one of two ways to clean

the teeth lingual surface: either moving the said toothbrush upward and outward for lower

teeth or downward and outward for upper teeth along the direction of crevice between the

teeth; or rotating the said toothbrush along the altitudinal axis so that the working surface of

the said tufts move past from the gum surface, the bottom area of the teeth proximal to the

gingival, to the teeth lingual surface, and the lateral part of the crown surface of the teeth.

For cleaning and massaging the gums, the proposed brushing method requires users

to place the toothbrush generally horizontally (toothbrush working surface downward for

lower teeth, upward for upper teeth) so that the working surface of the tufts touches the gum

surface, and then moving the said toothbrush forward and backward along the longitudinal

axis of the teeth. In preferred embodiments of the invention, there is provided one row of the first

special tuft grouping at the front end of the toothbrush head remote from the handle, which

is mainly used for cleaning category 1 molar tooth top concave surface and inter-proximal

area between teeth. This tuft grouping includes two tufts positioned generally proximal to

the front end of brush head remote from the handle in a generally symmetrical relationship

relative to the longitudinal axis of the brush head. The two tufts are of greater height than

the other tufts of bristle, and are slightly angled towards each other, and their cleaning

surfaces are bevelled with the peak leading to the direction of the center of the head board

with the tip of each tuft not touching each other. The cross-section of the tufts is generally

non-circular. Naturally more than two tufts may be utilised.

There may also be provided two columns of the second special tuft groupings along

the two outer edges of the toothbrush head in a generally symmetrical relationship relative to

the brush head longitudinal axis with the free-end of tufts of the second special tuft grouping

slanted outwardly in the direction of transverse axis of the toothbrush head base. They

would be mainly used for cleaning category 3 tooth facial surfaces and category 4 lingual

surfaces (except for incisors). The free-end of the tufts of bristles of the said second special

tuft groupings are slanted outwardly towards the side edges of the base so that the working

surfaces formed by the free-end of the tufts of bristle are generally not flat but curved and

inwardly bevelled with the peak or top leading to the direction of the center of the head base.

Each column is made up of several tufts of bristle and arranged along a generally convex or

concave circular line in the direction of the longitudinal axis of the brush head and the cross-

section of the tufts of bristle is preferably non-circular. To augment the resilience of the

cleaning surface, the cross-section of the lower part of the tufts is larger than that of the upper part of the tuft.

In a still further embodiment, one row of the third special tuft grouping, at the rear

end of the brush head near the handle, is mainly used for cleaning category 2 lingual

surfaces of incisors. The tufts of bristles of the said third special tuft grouping are slanted

backwardly towards the handle in a direction leading from the base to the free end of the

tufts and the working surfaces formed by the distal end of the tufts of bristle are generally

not flat but have a curvature and are forwardly bevelled with the peak away from the brush

handle. The third tuft grouping includes at least two tufts of bristle and the cross-section of

the tufts of bristle is preferably non-circular. To augment the resilience of the cleaning

surface, the cross-section of the lower part of the tufts is bigger than that of the upper part of

the tuft.

One group of toothbrush tufts of bristles consists of ordinary tufts of bristles among

the above mentioned tufts of bristles, with their main function of spreading toothpaste and

ordinary cleaning.

The four advantages and benefits of the toothbrushes manufactured in accordance

with the bristle configuration of the proposed invention are summarized as follows.

Firstly, according to study of tooth brushing, the efficiency of tooth cleaning is

mainly dependent on whether the users perform the correct tooth brushing method during

brushing. The three special tuft groupings proposed by the invention with obviously varying

shape and position will clearly guide users in easily understanding and mastering the correct

tooth brushing method.

Secondly, while cleaning the tooth surfaces to be cleaned, the above three special

tuft groupings can keep in close contact with the tooth surfaces since the tufts of the said three tuft groupings are resilient so that their working surfaces can deform according to the

varying surface contour of the said teeth and at the same time, these elastic and resilient

working surfaces of the toothbrush can provide sufficient cleaning power during the whole

process of cleaning.

Thirdly, the slanted resilient tufts of the second tuft groupings at the side edges of

the brush head can be directly used to clean and massage the gum by moving the toothbrush

forward and backward horizontally.

Fourthly, the bevelled working surface of the three special tuft groupings will

deform when contacting the tooth surface to be cleaned so that they touch the tooth surface

to be cleaned with a curved working surface and sweep the tooth surface more effectively.

To sum up, toothbrushes manufactured with the proposed toothbrush bristle

configuration, when used to clean teeth according to the proposed tooth brushing method,

can easily, completely and effectively clean all tooth surfaces, including crown, facial

surfaces of teeth, lingual surfaces, even inter-proximal areas, and can also massage gums.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus generally described the invention, reference will be made to the

accompanying drawings illustrating embodiments thereof, in which:

Figure 1 is a perspective view of one embodiment of the a toothbrush head;

Figure 2 is a perspective view of a modified embodiment of a toothbrush head;

Figure 3 is a perspective view of a further modified embodiment of a toothbrush

head;

Figure 4 is a perspective view of a still further modified embodiment of a toothbrush

head; Figure 5 is a side elevational view of the brush head of Figure 1;

Figure 6 is a top plan view of the brush head of Figure 5;

Figure 7 is a cross-sectional view taken along the lines A- A of Figure 6;

Figure 8 is an end elevational view of a tooth brush head illustrating the function of

a first group of tufts and their contact with the crown concave portion of a molar;

Figure 9 is an end elevational view of a brush head illustrating the function of a

third group of tufts and their contact with the lingual side surface of incisors;

Figure 10 is an end elevational view of a brush head illustrating the function of a

second group tufts and their contact with the facial and lingual surfaces of teeth except for

the incisors; and

Figure 11 is a top plan view of the brush head illustrating the function of the second

group of tufts and their contact with the facial and lingual surfaces of teeth except for the

incisors.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to Figure 1, there is shown a brush head (10) having a bristle

configuration (12) in accordance with one embodiment of the present invention mounted

thereon. The brush head (10) is typically part of a toothbrush including an elongated

member or handle (not shown) attached to the brush head (10). For applications such as

electric toothbrushes, the handle portion may include suitable attachment means (also not

shown) for securing the brush head (10) to a suitable driving means.

It should be understood that although the brush head (10) is shown as having a

generally trapezoidal configuration having base (14) with and a bottom wall (16), the

toothbrush head could have other configurations without departing from the scope of the present invention.

The brush head (10) is provided with individual bristles (18) extending therefrom

and grouped into bristle tufts, as is well known in the art. Each bristle (18) defines a bristle

proximal end (20) secured to a base surface (14) and a bristle second or distal end (22)

positioned generally away from the base surface (14).

The bristle tufts are arranged in tuft groupings defining specific bristle

configurations for enhancing the cleaning action of the toothbrush head. To better define a

positioning of the tuft groupings, the toothbrush base has a longitudinal axis (24) extending

generally in the direction of the handle of the toothbrush and a transverse axis (26); the

brush head (10) also has a brush head rear end (28) extending into the handle (not shown)

and a brush head front end (30) positioned away from the handle along with side edges (21)

and (23). Rows are in direction of the transverse axis (26) of the toothbrush head base (14),

while columns are in direction of the longitudinal axis (24) of the toothbrush head base (14).

In the drawings, the tufts are illustrated for reasons of clarity as being a single

bristle; it will be understood that each tuft is comprised of a plurality of bristles, at least

substantially all of a similar structure.

A first grouping of tufts (32) typically includes at least two distal tufts (34)

positioned generally proximal to the brush head front end (30) in a generally symmetrical

relationship relative to the brush head longitudinal axis (24).

The distal tufts (34) are typically configured and sized so as to extend over and

protrude from the brushing surface created by the other tufts such as the central grouping

(84) by a value generally in the range of 2 to 3 mm. It should however be understood that

the protruding distance could vary without departing from the scope of the present invention.

Preferably, the cross-section of the distal tufts (34) is non-circular.

Also, typically, each distal tuft (34) defines a corresponding generally angled

cleaning surface (36) relative to the geometrical plane of the brush base (14). Typically, the

angled cleaning surfaces (36) are angled relative to the geometrical plane of the brush base

(14) at an angle of between 30 and 60 degrees with a preferred angle being approximately

45 degrees. Typically, the angled cleaning surfaces (36) are bevelled in the direction of the

transverse axis (26) of the base with the tops of the two bevelled cleaning surfaces, being

adjacent to each other. The distance between the two tips of the tuft (34) is typically 0.5 to

2 mm so as to diverge away from each other in a direction leading towards the brush head

peripheral lateral section on the side edges of the toothbrush head.

As illustrated in Figure 7, the longitudinal axis (38) of the distal tufts (34) has an

angle (40) relative to a reference axis (42) extending perpendicularly from the brush head

first main surface (14), preferably between about 5 and 15 degrees. Typically, although by

no means exclusively, the cleaning surface (36) is angled by a cleaning angle (44) relative

to the reference axis (42) having a value of between 35 and 55 degrees and most preferably

in the range of 40 and 50 degrees.

It should however be understood that the angular values illustrated are only shown

by way of example and that the angular values and configuration of the distal tufts (34)

could vary without departing from the scope of the present invention.

As illustrated is Figure 8, the bevelled working surface (36) of tufts (34) are

particularly well suited for cleaning the crown concave surface (46) of molar tooth (48). Also, the tuft grouping (32) can be used for cleaning inter proximal areas.

The bevelled (angled) configuration of the cleaning surface (36),and the properly

sized non-circular cross-section feature of the tuft (34) allow a comprehensive cleaning

contact with the crown surface (46) while the longitudinal angle (40) of tufts (34) facilitates

further chances for the free-end (22) of the tuft (34) of bristles to enter the deeper concave

part of the crown concave surface (46) of molar tooth (48) by allowing the tuft (34) of

bristles to bend to an extent. The two distal tufts (34) are configured and sized such that the

peaks of each distal tuft of the two tufts (34) will touch each other and prevent each other

from further deforming after a certain deformation, so they provide enough force to remove

plaque on the deeper concave part of the crown concave surface (46) of molar tooth (48).

When the toothbrush head is horizontally placed with the tuft grouping (32)

mounted thereon, a forward and backward motion horizontally along the longitudinal axis of

the whole set of teeth will allow the working surface (36) of the tufts (34) to perform the

cleaning of crown concave surface of the single group of molar teeth. Repeating the

cleaning process for another group of molar teeth on the other side of the mouth will ensure

the crown concave surfaces of all molar teeth are cleaned.

As illustrated in Figure 1, the tuft configuration (12) typically also defines a pair of

second tuft groupings (50) positioned generally symmetrically about the brush head

longitudinal axis (24) and adjacent each brush head lateral edge (52). The tuft second

groupings (50) includes one or two tufts of second grouping tuft (54') and two or more tufts

of second grouping tuft (54) slanted or angled laterally generally outwardly in a direction

leading from the bristle first end (20) to bristle second ends (22). According to the definition of working surface which is used for cleaning facial

surfaces of teeth and lingual surfaces of the teeth except for the incisors by the new brushing

method, the second grouping working surface is the combination of the working surfaces

(64) and (64'). The working surface (64) or (64') consists of free-end (22) of bristles of tufts

(54 ) or (54') which is slanted outwardly towards the toothbrush lateral surface or edge (52).

Typically the working surface (64) or (64') is a bevelled configuration. It should be

understood that the working surface (64, 64') may assume numerous configurations without

departing from the scope of the present invention. For instance, the working surface (64) or

(64') can be a simple bevelled curvature as illustrated in Figures 1 and 3; or a combination of

bevelled curvature and straight top surface as illustrated in Figures 2 and 4; or a bevelled

straight surface.

As illustrated more specifically in Figure 7, each second type of tuft (54) typically

defines a second longitudinal axis (56) defining a second angle (58) relative to reference

axis (42) at a range of 10 to 30 degrees, and similarly, each second tuft (54') typically

defines a second longitudinal axis (56') defining a second angle (58') relative to reference

axis (42) being generally in the range of 10 to 30 degrees.

Also, the second tufts (54, 54') are typically aligned in a side-by-side relationship

relative to each other so as to define a second longitudinal topography. In the embodiments

shown in Figures 1, 5, 6 and 7, an isolated outwardly positioned second tuft (54') protrudes

from the toothbrush lateral surface or edge (52) relative to adjacent second tufts (54) so as to

define a generally convex longitudinal topography schematically illustrated by the reference

line (60). As illustrated in Figure 11, the more outwardly slanted second tufts (54') are

specifically adapted to be used for cleaning the inter proximal or interstices (62) between adjacent teeth (48):

In the embodiments shown in Figures 3 and 4, two outwardly positioned second

group tufts (54') are bigger and positioned more outwardly relative to adjacent smaller and

inwardly positioned second group tufts (54) so as to define a generally concave profile or

longitudinal topography. The use of an isolated protruding second grouping tuft (54') such

as shown in Figure 11 can facilitate positioning of second grouping tufts (54') in a given

interstice (62) while the use of a concave topography can facilitate the simultaneous contact

of the second grouping tuft (54) on the generally concave surface of the lingual and buccal

sections of a given tooth (48).

Still furthermore, the spacing (68) between the second grouping cleaning surface

(64') and the toothbrush lateral surface or edge (52) may vary depending on variants such as

the width of the brush head, the length of the second tufts (54') and the angular value of the

second longitudinal angle (58'). Also, the second cleaning surface (64') may be positioned

generally in registry or inward relative to the brush head lateral surface (52) without

departing from the scope of the present invention.

In addition, tufts (54') and (54) can have the same shape and size, and be arrayed

along a straight line adjacent the left and the right edges of brush head (14) in the direction

of longitudinal axis (24) .

Figures 10 and 11 illustrate how the second tuft (50) clean the facial or lingual

surfaces (70), (72) of tooth (48). When using second tuft groupings (50) to clean facial

surface (70) or lingual surface (72) , second tuft (54') are mainly used to clean the inter-

proximal area or interstice surface (62), while second grouping tufts (54) clean the facial

(70) or lingual surface (72) of the neighbouring teeth. During cleaning, one initially places the brush almost horizontal so that the cleaning

surface (64) of the second tufts (50) closely touch the gum surface (90) above the tooth root

(see Figure 10), and the second tufts (54') point to the interstice of the tooth to be cleaned

(see Figure 11). Then, along the longitudinal axis (42), one moves the brush upward and

inward for lower teeth or downward and inward for upper teeth, or rotate the toothbrush

head (10) along longitudinal axis (24) so that the cleaning surface (64) of the second tuft

grouping (50) moves past from the gum surface, the tooth surface (70) or (72), and to the

crown lateral surface of the tooth, one therefore can complete the whole process of cleaning

for facial (70) or lingual surface (72) of each tooth. The cleaning process is repeated until

all teeth's facial surfaces and the lingual surfaces of teeth other than incisors are cleaned.

Since the teeth and mouth size vary for each individual, during actual cleaning, the

individual user can freely choose the above-mentioned vertical cleaning method or the

rotation cleaning method.

The cleaning surface (64, 64') of the second tufts (50) can always keep in an

ultimate touch with the tooth to be cleaned since the tufts (54, 54') of bristle of the second

tuft grouping (50) can always deform flexibly according to the surface shape of the tooth to

be cleaned. On the other hand, the outwardly slanted arranged second grouping tufts

(54, 54') and its bigger lower cross-section of the tufts (54, 54') allow the cleaning surface

(64, 64') produce a strong brushing power to sweep the tooth surface to be cleaned. In

addition, when the tufts (54, 54') of bristle of the second tuft grouping (50) deform, the

contacting part of the cleaning surface (64, 64') on the tooth to be cleaned will be a curved

surface not a line, so this configuration of the cleaning surface (64, 64') of the second tuft

grouping (50) makes the cleaning more effective. Furthermore, because the bristle configuration (12) of the present invention is designed to clean one or two teeth at one time,

the user can easily and accurately locate and clean the facial or lingual surface of the tooth

to be cleaned, resulting in the effective way to completely clean each tooth.

Referring to Figure 1, the brush head (10) also includes a third special tuft grouping

(74), which is located at the rear end of the brush head and close to the brush rear end (28).

The grouping (74) includes at least one or more tufts (76) being illustrated.

The two working surfaces (82) of tufts (76) form a third working surface. The

working surface (82) consists of the distal end (22) of bristles of tufts (76) which are slanted

backwardly towards the brush rear end (28) in the direction of longitudinal axis (24).

Typically the working surface (82) is of a non-linear configuration. It should be understood

that the working surface (82) may assume numerous configurations without departing from

the scope of the present invention. For instance, the working surface (82) can be a simple

bevelled curvature as illustrated in Figures 1 and 3; or a combination of bevelled curvature

and straight top surface as illustrated in Figures 2 and 4; or a bevelled straight surface.

As illustrated in Figure 5, the tufts (76) define a longitudinal axis (78) at an angle

(80) of generally 15 to 30 degrees to the reference axis (42) . The distal ends (22) of tufts

(76) are located closer to the handle than the distal ends (22) of the distal ends (22) of any

other tufts. The cleaning surface (82) is mainly used for cleaning lingual surface (88) of

incisors. During cleaning, as illustrated in Figure 9, users can place the toothbrush head (14)

almost horizontally so that the cleaning surface (82) of the tufts (76) touches the lingual

surface (88) of the incisors. The user can then perform the cleaning by moving forward and

downward for the upper incisor or forward and upward for the lower incisor. The cleaning

process is repeated until all the lingual surfaces of incisors are cleaned. The third tufts (74) have generally the same characteristics as the second tufts (50);

that mean that the cleaning surface (82) of the third tufts (74) can always keep close touch

with the teeth surface to be cleaned and provide strong cleaning power to sweep the surface

to be cleaned with a curved contacting surface.

To fortify the resilience of working surface (64, 64') of the second tuft grouping (50)

and working surface (82) of the third tuft grouping (74), the present invention specially

designs several special tufts (54, 54', 76) .

As illustrated in Figure 1, the special tufts (54, 54', 76) are trapezoidal in the

direction of their longitudinal axis (56, 56', 78) (lower cross-section bigger than the upper

cross-section).

This structure not only facilitates augmenting the elasticity of working surfaces

(64, 64', 82), but also it simplifies the manufacturing of special tufts (54, 54', 76).

As illustrated in Figures 2, 3 and 4, the cross-sections of special tufts (54, 54', 76)

are bigger than those of (54, 54', 76) in Figure 1, also the cross-section of special tuft (54') is

bigger than the cross-section of the neighbouring special tuft (54).

Also, the respective angles (58, 58', 80) of special tufts (54, 54', 76) can be same or

different.

To restrict the deformation of the tufts of the second and the third tuft grouping, a

small platform with an inverted trapezoidal cross-section can be added to the generally flat

base (14), to ensure sufficient cleaning power of the cleaning surfaces of (64, 64', 82) of the

second and the third tufts. Typically, the distal end (22) of the second tuft (50), the third tufts (74) are in

registry with the distal end (22) of the central tufts 84, but are shorter than the distal end (22)

of the first tuft (32) .

The height of the tufts (76) of the third tufts (74) can be higher than that of the

fourth tufts (84) of (84) without departing from the scope of the present invention.

What's more, the cross-section and diameter of ordinary tufts (86) situated in the

center of base (14) can vary and the tufts can be flexibly arranged thereon: they may be

positioned in the center of the head, or some of them can be dotted among each of the two

groups of tufts (50); they may have one or two rows of tufts arranged between the second

group and the third group tufts at the proximal end of the brush head without departing from

the scope of the present invention.

Claims

WE CLAIM:

1. A toothbrush head (10) having a base (12), said base having first and second side

marginal edges (21, 23), a front marginal edge (30) and a rear marginal edge (28), a plurality

of tufts (32, 74, 54, 54', 84) extending outwardly from a first side of said base, characterised

in that at least one of said tufts (32, 74, 54, 54') is an angled tuft extending outwardly from

said base at an angle with respect to a line (42) perpendicular to said base.

2. The toothbrush head of Claim 1 including a plurality of angled tufts and wherein

said angled tufts (32) are located proximate said front marginal edge (30) of said base.

3. The toothbrush head of Claim 2 wherein opposing angled tufts (32) are angled

towards each other at an angle of between 10 and 30 degrees.

4. The toothbrush head of Claim 2 wherein said angled tufts (32) have a non circular

cross-sectional configuration.

5. The toothbrush head of Claim 4 wherein a distal end of said angled tufts (32) has a

bevelled top cleaning surface (36).

6. The toothbrush head of Claim 3 wherein two angled tufts (32) are angled towards,

each other, the distal ends of said angled tufts being separated by a distance of between 0.1

to 2 mm.

7. The toothbrush head of Claim 1 wherein said angled tufts are located proximate a

side marginal edge of said base, said angled tufts extending outwardly towards said side

marginal edge.

8. The toothbrush head of Claim 7 wherein said angled tufts (54, 54') extending

outwardly have distal ends which form a generally concave outline.

9. The toothbrush head of Claim 7 wherein said angled tufts (54, 54') extend outwardly

at an angle of between 5 and 20 degrees with respect to said line perpendicular to said base.

10. The toothbrush head of Claim 7 wherein distal ends of said angled tufts (54, 54')

have an inwardly bevelled upper surface (56).

11. The toothbrush head of Claim 7 wherein said angled tufts (54, 54') have a non-

circular cross sectional configuration.

12. The toothbrush head of Claim 11 wherein a cross-sectional area of said angled tufts

(54, 54') is larger proximate the base compared to a cross sectional area proximate said

distal ends.

13. The toothbrush head of Claim 1 wherein said angled tufts (74) are located proximate

said rear marginal edge (28) of said base, said tufts being angled outwardly towards said rear

marginal edge (28).

14. The toothbrush head of Claim 13 wherein said angled tufts (74) are angled at

between 5 and 30 degrees from said line perpendicular to said base.

15. The toothbrush head of Claim 13 wherein distal ends of said angled tufts (74) have

an arcuate surface (82).

16. The toothbrush head of Claim 13 wherein said angled tufts (74) have a larger cross-

sectional area proximate said base compared to a cross-sectional area proximate said distal

ends.

17. A toothbrush head having a base (14), said base (14) having first and second side

of tufts extending outwardly from a first side of said base, a first group of tufts (54, 54')

located proximate said first and second marginal edges (21, 23), said first group of tufts (54, 54') being angled outwardly from said base (14) at an angle with respect to a line (44)

perpendicular to said base, a second group of tufts (32) located proximate said front

marginal edge of said base, said second group of tufts being angled towards each other, a

third group of tufts (74) located adjacent a said rear marginal edge (28) of said base (14),

said third group of tufts (74) being angled outwardly towards said rear marginal edge, and a

fourth group of tufts (84) substantially peφendicular to said base, said fourth group of tufts

being located centrally of said base.