[0001] This invention relates to a toothbrush, and more particularly to a toothbrush capable
of exhibiting a high cleaning function sufficient to effectively remove hard to remove
dental plaque which tends to readily accumulate at areas such as recesses between
teeth, boundaries between teeth and gingivae and the like and capable of feeling soft
to the gingivae to a degree sufficient to exhibit excellent usability.
[0002] In order to protect teeth and gingivae from periodontal diseases and dental caries,
which are called the two major dental diseases, it is essential to remove dental plaque
by means of a toothbrush. For this purpose, it has been recently recognized that cleaning
of teeth which is carried out by using tips of the fillings of a toothbrush is effective
for removing dental plaque, such a way of brushing being called scrubbing, the Bass
technique or the like.
[0003] In a toothbrush using fillings made of a synthetic filament material, the fillings
are each formed of a soft material into a thin shape in order to prevent tips of the
fillings from damaging gingivae during cleaning by brushing such as the Bass technique
or the like. Such fillings feel soft to a user, however, they fail to exhibit rigidity
and/or stiffness sufficient to permit dental plaque to be effectively removed, as
well as satisfactory durability.
[0004] Also, a toothbrush of another type is proposed, which is constructed in such a manner
that tips at both ends of each of the fillings are each formed into a tapered shape
so as to permit the tips of the fillings to enter or reach areas such as recesses
between teeth, boundaries between teeth and gingivae, and the like. Unfortunately,
a length of the tapered tips of the fillings thus provided is as small as about 1mm,
so that the toothbrush fails to significantly improve both a cleaning function and
a soft feeling exhibited to a user thereof. Thus, the tapered tips of the fillings
fail to exhibit advantages over conventional fillings of which the tips are rounded.
[0005] Further, it is known that fillings each having tips formed into a pointed tapered
shape of an increased length by chemical treatment are used for various kinds of brushes
such as painting brushes, cosmetic brushes, face washing brushes and the like, as
taught in Japanese Utility Model Application Laid-Open Publications Nos. 12934/1982
and 65632/1982. In various kinds of brushes disclosed in each of the above Japanese
publications, fillings of which the tips are each formed into a pointed tapered shape
are used in place of conventional fillings exclusively made of natural animal hairs,
to thereby improve feeling properties of the brush, its durability, its sanitary properties
and the like. However, the toothbrush including the pointed tapered fillings is substantially
inferior in cleaning performance to a conventional toothbrush having non-tapered fillings
set thereon, because the tapered fillings are excessively soft or flexible owing to
a improper tapered shape. In order to solve the problem, it is required to provide
the fillings with suitable hardness by increasing a maximum diameter of the fillings.
Unfortunately, this causes the pointed tapered tips of the fillings to be so hard
to damage gingivae.
[0006] The present invention has been made in view of the foregoing disadvantage of the
prior art.
[0007] Accordingly, it is an object of the present invention to provide a toothbrush which
is capable of exhibiting a significantly improved tooth cleaning effect.
[0008] It is another object of the present invention to provide a toothbrush which is capable
of preventing damage to teeth and gingivae during cleaning thereof.
[0009] It is a further object of the present invention to provide a toothbrush which is
capable of effectively cleaning areas such as recesses between teeth, boundaries between
teeth and gingivae, and the like.
[0010] It is still another object of the present invention to provide a toothbrush including
fillings made of a synthetic filament material which are capable of permitting the
toothbrush to accomplish the above-described objects while exhibiting a soft feeling
and excellent usability to a user thereof.
[0011] In accordance with a first aspect of the present invention, a toothbrush is provided.
The toothbrush includes fillings made of a synthetic filament material and a handle
provided at a distal end thereof with a filling setting base. Each of the fillings
is formed at a tip thereof into a pointed tapered shape and the fillings are tied
up into a plurality of bundles. The filling setting base is formed with filling setting
holes in which the bundles of the fillings are set so as to permit the pointed tapered
tip of each of the fillings to be outwardly projected therefrom. The filling setting
holes are arranged in a plurality of rows in parallel to a longitudinal direction
of the handle.
[0012] In the toothbrush of the present invention generally constructed as described above,
the pointed tapered tip of each of the fillings is formed with a length of 4 to 8mm,
a non-tapered section of each of the fillings is formed with a maximum diameter of
0.16 to 0.20mm and each of the filling setting holes is formed with a diameter of
1.5 to 2.0mm and spaced from other holes at an interval of 1.0 to 1.2mm in the longitudinal
direction of the handle.
[0013] In a preferred embodiment of the present invention, the pointed tapered tip of each
of the fillings may be formed with a length of 4 to 7mm, the non-tapered section of
each of the fillings is formed with a maximum diameter of 0.17 to 0.18mm, and each
of the filling setting holes may be formed with a diameter of 1.5 to 1.9mm and spaced
from other holes at an interval of 1.0 to 1.2mm in the longitudinal direction of the
handle.
[0014] In accordance with a further aspect of the present invention, a toothbrush is provided.
The toothbrush includes fillings made of a synthetic filament material and handle
provided at a distal end thereof with a filling setting base. Each of the fillings
is formed at a tip thereof into a tapered shape and the fillings are tied up into
a plurality bundles. The filling setting base is formed with filling setting holes
in which the bundles of the fillings are set so as to permit the tapered tip of each
of the fillings to be outwardly projected therefrom. The filling setting holes are
arranged in at least one row parallel to a longitudinal direction of the handle. In
the toothbrush, the tapered tip of each of the fillings is formed into a shape defined
by diameters of the tapered tip of the filling at distances of 1mm, 3mm, 5mm and 8mm
from a tip end of the filling, the diameters being set in the ranges of 25 to 35%,
55 to 70%, 80 to 90% and 90 to 100% of a diameter of a proximal section of the filling,
respectively.
[0015] In a preferred embodiment of the present invention, the fillings may have a stiffness
represented by calculated values from deflection forces at distances of 1mm, 3mm,
5mm and 8mm from the tip ends of said fillings, the calculated values being 0.5 to
2.0N/mm², 2.5 to 4.5N/mm², 3.5 to 5.5N/mm² and 6 to 15N/mm², respectively, as measured
and calculated according to the International Standard ISO 8627.
[0016] These and other objects and many of the attendant advantages of the present invention
will be readily appreciated as the same becomes better understood by reference to
the following detailed description when considered in connection with the accompanying
drawings in which like reference numerals designate like or corresponding parts throughout;
wherein:
Fig. 1 is a plan view showing an embodiment of a toothbrush according to the present
invention;
Fig. 2 is a side elevation view showing an example of one of fillings incorporated
in a toothbrush according to the present invention;
Fig. 3 is a fragmentary enlarged plan view showing a filling setting base of the toothbrush
shown in Fig. 1 on which the fillings are set;
Fig. 4 is a fragmentary enlarged side elevation view showing the fillings set on the
filling setting base of Fig. 3;
Fig. 5 is a side elevation view showing another example of one of fillings according
to the present invention; and
Fig. 6 is a graphical representation showing the relation between diameters of a tapered
tip and distances from a tapered tip end in each of fillings having tips of different
tapered shapes.
[0017] Now, a toothbrush according to the present invention will be described hereinafter
with reference to the accompanying drawings.
[0018] Referring to Figs. 1 to 4, an embodiment of a toothbrush according to the present
invention is illustrated. A toothbrush of the illustrated embodiment generally designated
at reference numeral 10 in Fig. 1 includes fillings 12. The fillings 12 are made of
a synthetic filament material such as polyester, polyamide, polypropylene, other polyolefins,
or the like. The fillings 12, as shown in Fig. 2, are each formed at both tips thereof
into a pointed tapered shape as indicated at reference numeral 14. Each of the pointed
tapered tips 14 has a length of 4 to 8mm, and preferably 4 to 7mm. Also, each of the
fillings 12 includes a non-tapered intermediate section or proximal section 16 interposedly
arranged between both pointed tapered tips 14. The non-tapered intermediate section
16 is formed into a maximum diameter of 0.16 to 0.20mm, and preferably 0.17 to 0.18mm.
The toothbrush also includes a handle 18 made of a suitable synthetic resin material
such as polypropylene, AS resin or the like. The handle 18 is provided at a distal
end thereof with a filling handle 18 is provided at a distal end thereof with a filling
setting base 20 as shown in Figs. 1 and 3. The filling setting base 20 is formed thereon
with a plurality of filling setting holes 22.
[0019] A plurality of the fillings 12 formed as described above are tied up into a plurality
of bundles and then each bundle is formed into a U-shape by bending a central portion
thereof. The bent central portions of the respective filling bundles are set in the
corresponding filling setting holes 22, resulting in the toothbrush being fabricated
as shown in Fig. 4.
[0020] The filling setting holes 22 are each formed into a diameter of 1.5 to 2.0mm, and
preferably 1.5 to 1.9mm. Also, the holes 22 are arranged in a plurality of rows in
parallel to a longitudinal direction of the handle 18 in such a manner that intervals
X between the holes 22 in the longitudinal direction of the handle 18 are set to be
1.0 to 1.2mm. The fillings 12 bundled and bent as described above are set in the holes
22 so that the length Y of each of the fillings 12 is 10 to 12mm as in the conventional
toothbrush (Fig. 4).
[0021] The above-described construction of the present invention was achieved after a number
of experiments performed by the inventors. If the pointed tapered tips 14 have a length
exceeding 8mm, the rigidity and/or stiffness of the fillings 12 will be reduced to
a degree sufficient to cause the cleaning performance of the fillings 12 to be significantly
deteriorated, whereas a length less than 4mm causes the fillings 12 to feel unsoft
to the gingivae and makes it difficult for the tips 14 of the fillings 12 to enter
or reach areas such as recesses formed between teeth, boundaries between teeth and
gingivae, and the like, resulting in the fillings 12 failing to exhibit a satisfactory
cleaning action. When the non-tapered intermediate sections 16 of the fillings 12
have a maximum diameter exceeding 0.20mm, the tips 14 of the fillings stimulate the
gingivae, leading to a possibility, depending on the manner of cleaning with the toothbrush,
that the gingivae will be damaged; whereas a maximum diameter less than 0.16mm causes
the fillings 12 to fail to exhibit rigidity and/or stiffness sufficient to permit
the pointed tapered tips 14 of the fillings to exhibit a satisfactory cleaning function.
[0022] If the filling setting holes 22 have a diameter exceeding 2.0mm, the bundles of the
fillings will have to be excessively increased in diameter, resulting in it being
difficult for the tips 14 of the fillings to reach or enter areas such as recesses
between teeth, boundaries between teeth and gingivae, and the like. Also, such a diameter
of the holes 22 causes the fillings 12 to feel unsoft to the gingivae. On the other
hand, a diameter less than 1.5mm causes a cleaning action of the fillings to deteriorate
and the tips 14 of the fillings 12 to be readily deformed or bent into a tulip-like
shape, leading to the tips losing their utility.
[0023] When the intervals X between filling setting holes 22 in the longitudinal direction
of the handle 18 are more than 1.2mm, the bundles of the fillings are decreased in
density, so that the cleaning action of the toothbrush is significantly deteriorated.
On the other hand, intervals below 1.0mm cause the density of the bundles to be excessively
increased, to thereby make it difficult for the tips 14 of the fillings 12 to reach
or enter areas such as recesses between teeth, boundaries between teeth and gingivae,
and the like and deteriorate the productivity and utility of the toothbrush. Intervals
between the filling setting holes 22 in directions other than the longitudinal direction
of the handle 18 may be suitable set as in the prior art.
[0024] The length of the pointed tapered tips 14 of the fillings 12, the maximum diameter
of the non-tapered intermediate section 16 of the fillings 12, the diameter of the
filling setting holes 22, and the intervals X between the filling setting holes 22
in the longitudinal direction of the handle 18 in the toothbrush of the present invention
which are set as described above permit the fillings 12 to exhibit a softness similar
to the softness of the hair of such animals as a horse, a goat and the like. Also,
the above-described maximum diameter of the non-tapered intermediate section 16 of
the fillings 12 which are to be set in each of the filling setting holes 22 permits
the fillings set in the holes 22 to exhibit satisfactory rigidity and/or stiffness.
Further, in the illustrated embodiment, the fillings 12 are bundled to have a thickness
sufficient to permit the fillings to readily enter areas such as recesses between
teeth, boundaries between teeth and gingivae, and the like. Thus, it will be noted
that the toothbrush of the illustrated embodiment permits dental plaque, which the
conventional toothbrush failed to remove, to be effectively removed while also preventing
gingivae from being damaged.
[0025] Referring to Fig. 5 and 6, another embodiment of fillings of a toothbrush according
to the present invention is illustrated. The fillings 12 are made of a synthetic monofilament
such as polyester, polyamide, other polyolefins, or the like. The fillings 12, as
shown in Fig. 5, are each formed at both tips thereof into a predetermined pointed
tapered shape as indicated by reference numeral 14. Each of the pointed tapered tips
14 is formed into a shape defined by diameters of the tapered tip 14 of the filling
12 at distances of 1mm, 3mm, 5mm and 8mm from a tip end of the filling 12, which diameters
are set in the ranges of 25 to 35%, 55 to 70%, 80 to 90% and 90 to 100% of a diameter
of the proximal section 16 of the filling 12, respectively. Each of the pointed tapered
tips 14 has a length of 8 to 15mm, and preferably 8 to 10mm. A central proximal section
16 of each of the fillings 12 is formed into a maximum diameter of 0.15 to 0.25mm,
and preferably 0.17 to 0.20mm.
[0026] A plurality of the fillings 12 formed as described above are tied up into a plurality
of bundles and then each bundle is doubled over at a central portion thereof. The
central portions of the respective fillings bundles are set in the corresponding filling
setting holes 22, resulting in the toothbrush being fabricated as shown in Fig. 4.
[0027] In this embodiment, the fillings setting holes 22 are each formed into a diameter
of 1.5 to 2.2mm, and preferably 1.5 to 1.9mm. The holes 22 are arranged in a plurality
of rows, for example 2 to 4 rows, parallel to a longitudinal direction of the handle
18. The intervals X between the holes in the longitudinal direction of the handle
18 are set to be 1.0 to 1.4mm. The length Y of each of the fillings 12 set in the
holes 22 as described above is 10 to 13mm as in the conventional toothbrush.
[0028] The present invention will be understood more readily with reference to the following
examples; however, these examples are intended to merely illustrate the invention
and are not to be construed as limiting the scope of the invention.
Example 1
[0029] Toothbrush specimens shown in Table 1 were prepared for a comparative test of cleaning
capability. The toothbrush specimens were made in such a manner that the filling setting
holes 22 wherein the fillings with tapered tips are set of the filling setting base
20 provided at the distal end of the handle 18 made of polypropylene each had a diameter
of 1.5mm and the intervals X between the filling setting holes 22 in a longitudinal
direction of the handle 18 were set to be 1.0mm.
Table 1
Toothbrush Specimens Used for Evaluation of Cleaning Capability |
Toothbrush |
Filling Material |
Maximum Diameter (mm) |
Length (Y) of Filling (mm) |
Processing of Tip of Filling |
A |
Thermoplastic |
0.18 |
11 |
Alkali-Treated |
|
Polyester |
|
|
Taper |
|
Filament |
|
|
Taper Length: 5mm |
B |
Thermoplastic |
0.18 |
11 |
Alkali-Treated |
|
Polyester |
|
|
Taper |
|
Filament |
|
|
Taper Length: 11mm |
C |
Nylon |
0.20 |
11 |
Rounded by Filing |
|
Filament |
|
|
|
D |
Nylon |
0.20 |
11 |
Formation of Taper by Filing |
|
Filament |
|
|
Taper Length: 1mm |
E |
Nylon |
0.13 |
11 |
Formation of Taper by Filing |
|
Filament |
|
|
Taper Length: 1mm |
F |
Hair (Horse) |
<0.13 |
11 |
Formation of Taper by Filing |
|
|
|
|
Taper Length: 1mm |
[0030] The cleaning capability of each of the toothbrush specimens tested was evaluated
according to the following procedure.
[0031] Fifteen persons were selected as subjects. The toothbrush specimens were tested by
the subjects over a total period of time of six weeks, each of the specimens being
respectively tested, in an order from specimen A to specimen F, for one week. Also,
the degree of removal of dental plaque resulting from use of each of the toothbrush
specimens was measured each week.
[0032] The degree of removal of dental plaque due to use of each of the toothbrush specimens
was measured according to the following procedure.
[0033] On the first day, the tartar and dental plaque were fully removed from the tooth
of each of the subjects and then use of the toothbrush specimens was commenced. On
the sixth day, the cleaning was interrupted to allow dental plaque to accumulate on
the teeth of the subjects. On the seventh day, the amount of dental plaque accumulated
was measured and then brushing by the toothbrush specimen was carried out to measure
the amount of dental plaque remaining on the teeth after brushing again. Then, the
difference between the amount of dental plaque before the cleaning on the seventh
day and that after the cleaning was divided by the amount of dental plaque obtained
before the cleaning, resulting in obtaining degrees of removal of dental plaque by
use of each of the toothbrush specimens in the form of percentages.
[0034] In the example, six teeth of which positions are shown in Table 2 were chosen as
the object for the test from a set of teeth. The six teeth of each of the subjects
selected were found to be healthy. The results were as shown in Table 3.
[0035] As can be seen from Table 3, the tooth specimen A achieved a cleaning performance
superior to those of the toothbrush specimens E and F wherein fillings were made of
a fine filament material, the toothbrush specimens C and D having a conventional "normal"
hardness, and the toothbrush B wherein the fillings were tapered along the whole length
thereof.
Example 2
[0036] This example was carried out to determine at which degree of thickness of the fillings
having pointed tapered tips and at which length of the tapered tips gingivae were
stimulated (pricked).
[0037] Toothbrush specimens which included a filling setting base provided at a distal end
of a handle as in Example 1 described above and fillings of thermoplastic polyester
filament, having tapered tips of different lengths and maximum diameter sections of
different thicknesses set in the filling setting base, were prepared and applied to
fifteen persons selected as subjects of this experiment for determining at which degree
of thickness of the fillings having pointed tapered tips and at which length of the
tapered tips gingivae were stimulated. The results were as shown in Table 4.
[0038] As indicated in Table 4, when the thickness of the maximum diameter section of the
fillings was 0.22mm or less, the effect of the thickness of the maximum diameter section
of the fillings on stimulus to gingivae was partially or fully prevented, depending
on the lengths of the tapered tip, while thicknesses of 0.14mm or less fully prevented
the fillings from stimulating gingivae irrespective of lengths of the tapered tips.
[0039] In addition, a cleaning test was carried out using toothbrush specimens having fillings
with tapered tips of different lengths and maximum diameter sections of different
thickness and conventional toothbrush specimens with fillings having non-tapered tips.
[0040] The test was carried out using model jaws of a standard size on which teeth were
detachably mounted. In the test, the teeth were coated with model dental plaque made
by dissolving a water-soluble polymer red coloring matter in water in such a manner
that the model dental plaque reached the root of each of the teeth. Then, the coated
teeth were mounted on the model jaws and each of the teeth in the same positions as
in Table 2 were cleaned ten times by brushing according to the Bass technique using
the toothbrush specimens. Thereafter, a position of a gingival edge of the model jaws
to which each of the teeth positionally corresponds was marked and then the teeth
were removed from the model jaws to evaluate a depth to which the model dental plaque
submarginal relating to the gingival edge of each of the teeth was removed. The results
were as shown in Table 5.
[0041] As indicated in Table 5, the effect of lengths of the tapered tips on the cleaning
capability of the toothbrush varied depending on the thicknesses of the maximum diameter
sections. More particularly, when the thickness of the maximum diameter section was
0.20mm, which was most typical, the tapered tips having a length of between 4mm and
8mm had good cleaning capability, while the tapered tips having a length of 10mm or
more failed to exhibit good cleaning capability. This is because an excessive decrease
in the lengths of the tapered tips causes the fillings to fail to exhibit flexibility,
resulting in it being difficult for the tips of the fillings to enter narrow recesses
submarginal relating to an edge of gingivae, whereas an excessive increase in the
length of the tapered tips causes rigidity and/or stiffness of the fillings to deteriorate,
so that the fillings fail to satisfactorily exhibit a function for cleaning the above
recesses.
[0042] Thus, the results shown in Tables 4 and 5 indicate that a combination of a thickness
of the maximum diameter section between 0.16mm and 0.20mm and a length of the tapered
tips between 4mm and 8mm prevents the fillings from stimulating gingivae and permits
the fillings to exhibit a satisfactory cleaning effect.
Example 3
[0043] This example was carried out to observe the effects of the diameter of the filling
setting holes and intervals between the filling setting holes in a longitudinal direction
of a handle in a toothbrush including fillings having pointed tapered tips, on a cleaning
action of the fillings.
[0044] For this purpose, toothbrush specimens were prepared which included fillings formed
with pointed tapered tips, and filling setting holes provided in four rows in such
a manner as shown in Fig. 3, the diameters of the holes and intervals between the
holes being different. The fillings were made of a thermoplastic polyester filament
material and each one had a length of 11mm, a thickness of a maximum diameter section
of 0.18mm, and a tapered tip having a length of 5mm. Also, in the example, the same
model jaws as used in Example 2 were used and the same procedure as in Example 2 was
repeated to evaluate the degree to which model dental plaque submarginal relating
to an edge of gingivae was removed. The results were as shown in Table 6.
[0045] As indicated in Table 6, the toothbrush specimens having filling setting holes with
diameters of 1.5 to 2.0mm and intervals of 1.0 to 1.2mm arranged between exhibited
an excellent cleaning effect so that model dental plaque submarginal relating to an
edge of gingivae was effectively removed, the conventional non-taper toothbrush having,
by contrast, failed to remove such plaque. However, intervals between the filling
setting holes which were 1.4mm or more or 0.8mm or less failed to permit the fillings
to exhibit a satisfactory cleaning effect. The reason why is that when the intervals
are 1.4mm or more, density of the bundled fillings is reduced to such a degree that
removal of the plaque becomes difficult; whereas the intervals of 0.8mm or less cause
the density of the bundled fillings to be excessively increased to substantially prevent
the tips of the fillings from entering submarginal recesses.
[0046] In connection with an effect of a diameter of the filling setting holes on a cleaning
action of the fillings, the diameter of 1.4mm or less and 2.1mm or more failed to
permit the fillings to exhibit a satisfactory cleaning function. The reason why is
that the diameter of 1.4mm or less causes the bundled fillings to be excessively reduced
in rigidity and/or stiffness so they lose the capability of removing the plaque, whereas
the diameter of 2.1mm or more causes a diameter of the bundled fillings to be excessively
increased to prevent the tips of the fillings from entering the submarginal recesses.
Example 4
[0047] Toothbrush specimens shown in Table 7 were prepared for a comparative test of cleaning
capability. The toothbrush specimens were made in such manner that the filling setting
holes 22 arranged in four rows had a diameter of 1.6mm and the intervals X between
the filling setting holes 22 in a longitudinal direction of the handle 18 were set
to be 1.2mm. In the toothbrush specimens, the fillings 12 made of a synthetic monofilament
material each included a proximal section 16 having a diameter of 200 µ m and a length
Y of the fillings was 11mm.
[0048] The cleaning capability of each of the toothbrush specimens tested was evaluated
according to the same procedure as in Example 1 described above. The results were
as shown in Table 8.
[0049] As can be seen from Table 8, the tooth specimen I achieved a cleaning performance
superior to those of the toothbrush specimens G and H wherein fillings were formed
with thicker tapered tips, the toothbrush specimens J and K wherein fillings were
formed with thinner tapered tips, and the toothbrush specimen L having fillings with
conventional rounded tips.
[0050] Also, the same toothbrush specimens as in the table 8 were prepared and applied to
fifteen persons selected as subjects for determining by what shape of the pointed
tapered tips gingivae were stimulated (pricked). The results were as shown in Table
9.
[0051] In addition, a durability test was carried out using the toothbrush specimens according
to the following procedure.
[0052] The toothbrush specimens each were moved 20000 cycles with a stroke of 3cm in warm
water at a temperature of 35 °C while the fillings thereof being kept in contact with
an rough surface of a plate with a load of 500gf. After this operation, the evaluation
of the durability of the fillings was carried out by observing the degree of spread
of the fillings. The results were as shown in Table 10.
[0053] As can been seen from Tables 8 to 10, the shape of the tapered tips of fillings like
that of the toothbrush specimen I is practical and useful.
Example 5
[0054] This example was carried out to determine which degree of stiffness of the fillings
at predetermined points, which fillings had pointed tapered tips, was practical and
useful. Stiffnesses of the fillings at the predetermined points were obtained by measuring
deflection forces at the predetermined points on the tapered tips and calculating
them according to the International Standard ISO 8627. The results were as shown in
Table 11. In this case, experimental points on the tapered tips of the filling were
set to be at distances of 1mm, 3mm, 5mm and 8mm from the tip ends of the fillings.
The toothbrush specimens were each fixed so that the experimental points might be
flush with a plane formed by parallel wires in a measuring apparatus. Then, horizontal
deflection forces or reaction forces caused by the deflection of the fillings were
measured when the filling setting base was moved across the wires. The measurement
was carried out under the following conditions and the mean value of the stiffness
was calculated:
- --- dry:
- the toothbrush specimens were each tested within five (5) minutes after being kept
at a temperature of 20± 1 °C and a relative humidity of 65± 2% for 24 hours;
- --- wet:
- the toothbrush specimens were each tested within five (5) minutes after being immersed
in water at 20 ± 1 °C for 24 hours.
Table 11
Deflection Forces at Positions on Fillings of Toothbrush Specimens Having Filling with Tips of Different Tapered Shapes ( N/mm²) |
Experimental Positions on Fillings |
Toothbrush |
Distance from Tip End |
|
1mm |
3mm |
5mm |
8mm |
M |
3.0-4.0 |
5.5-7.0 |
7.5-8.0 |
14.0-15.0 |
N |
2.0-3.0 |
4.5-5.5 |
5.5-7.0 |
6.0-15.0 |
O |
0.5-2.0 |
2.5-4.5 |
3.5-5.5 |
6.0-15.0 |
P |
0.3-0.5 |
1.5-2.5 |
2.5-3.5 |
6.0-15.0 |
Q |
0-0.3 |
0.5-1.5 |
1.5-2.5 |
4.0-6.0 |
[0055] In this example, the toothbrush specimens having fillings made of a polyester resin
monofilament material were tested to observe the cleaning capability, stimulus to
gingivae and durability of the toothbrush specimens, likewise respectively. The results
were as shown in Tables 12, 13 and 14.
[0056] The criteria for evaluation were the same as described.
Table 13
Effects of Stiffness of Tapered Tips of Fillings on Stimulus to Gingivae |
Toothbrush |
M |
N |
O |
P |
Q |
Evaluation |
× |
Δ |
○ |
○ |
○ |
[0057] The criteria for evaluation were the same as described.
Table 14
Effects of Stiffness of Tapered Tips of Fillings on Durability |
Toothbrush |
M |
N |
O |
P |
Q |
Evaluation |
○ |
○ |
○ |
Δ |
× |
[0058] The procedure of testing was the same as described.
[0059] Tables 12 to 14 indicate that the toothbrush specimen O is more practical and useful
than others.
[0060] Though 100 percent of the fillings in each bundle have the same shape as specified
in the examples described above, each bundle may include substantially 90% ore more
of the specified fillings in combination with other fillings of different shapes.
The toothbrush having such combination of fillings can achieve or exhibit a considerable
cleaning capability and a soft feeling to gingivae. Also, the toothbrush having one
or two rows of the filling setting holes arranged in the filling setting base can
be effectively used for brushing boundaries between teeth and gingivae according to
the Bass technique.
[0061] As can be seen from the foregoing, the toothbrush of the present invention includes
the fillings which are made of a synthetic filament material and of which a length
of the pointed tapered ends or tips, a maximum diameter of the non-tapered section,
a diameter of the filling setting holes, and intervals between the filling setting
holes are defined within specified ranges, respectively. Alternatively, the toothbrush
of the present invention includes the fillings of which diameters of the pointed tapered
tips at predetermined positions are defined within specified ranges. Such construction
of the present invention permits the tips of the fillings to enter or reach areas
such as recesses between teeth, boundaries between teeth and gingivae, and the like
to effectively remove food debris, dental plaque and the like therefrom. Also, such
construction results in the tips exhibiting a soft feeling sufficient to permit the
toothbrush to be suitable for cleaning a periodontal pocket formed by a weakened gingiva.
Thus, it will be noted that the toothbrush of the present invention effectively prevents
periodontal diseases, as well as tooth decay.
[0062] While a preferred embodiment of the invention has been described with a certain degree
of particularity with reference to the drawings, obvious modifications and variations
are possible in light of the above teachings. It is therefore to be understood that
within the scope of the appended claims, the invention may be practiced otherwise
than as specifically described.
1. A toothbrush comprising:
fillings (12) made of a synthetic filament material, each of said fillings being
formed at a tip (14) thereof into a pointed tapered shape, said fillings being tied
up into a plurality of bundles; and
a handle (18) provided at a distal end thereof with a filling setting base (20),
said filling setting base being formed with filling setting holes (22) in which said
bundles of said fillings are set so as to permit the pointed tapered tip of each of
said fillings to be outwardly projected therefrom, said filling setting holes being
arranged in a plurality of rows in parallel to a longitudinal direction of said handle,
characterized in that:
the pointed tapered tip (14) of each of said fillings is formed with a length of
4 to 8mm, a non-tapered section (16) of each of the fillings being formed with a maximum
diameter of 0.16 to 0.20mm; and
each of said filling setting holes (22) is formed with a diameter of 1.5 to 2.0mm
and spaced from other holes at an interval (X) of 1.0 to 1.2mm in the longitudinal
direction of said handle.
2. A toothbrush as defined in Claim 1, wherein the pointed tapered tip (14) of each of
said fillings is formed with a length of 4 to 7mm,
said non-tapered section (16) of each of the fillings is formed with a maximum
diameter of 0.17 to 0.18mm and
each of said filling setting holes (22) is formed with a diameter of 1.5 to 1.9mm
and spaced from other holes at an interval (X) of 1.0 to 1.2mm in the longitudinal
direction of said handle.
3. A toothbrush as defined in Claims 1 or 2, wherein said fillings are each formed at
both tips (14) thereof into a pointed tapered shape, and each of said bundles of said
fillings is doubled over at a central portion (16) thereof, said central portion being
set in a corresponding one of said filling setting holes.
4. A toothbrush comprising:
fillings (12) made of a synthetic filament material, each of said fillings being
formed at a tip (14) thereof into a tapered shape, said fillings being tied up into
a plurality of bundles; and
a handle (18) provided at a distal end thereof with a filling setting base (20),
said filling setting base being formed with filling setting holes (22) in which said
bundles of said fillings are set so as to permit the tapered tip of each of said fillings
to be outwardly projected therefrom, said filling setting holes being arranged in
at least one row parallel to a longitudinal direction of said handle,
characterized in that:
the tapered tip (14) of each of said fillings is formed into a shape defined by
diameters of the tapered tip of the filling at distances of 1mm, 3mm, 5mm and 8mm
from a tip end of the filling, said diameters being set in the ranges of 25 to 35%,
55 to 70%, 80 to 90% and 90 to 100% of a diameter of a proximal section (16) of the
filling, respectively.
5. A toothbrush as defined in Claim 4, wherein said fillings have a stiffness represented
by calculated values from deflection forces at distances of 1mm, 3mm, 5mm and 8mm
from the tip ends of said fillings, said calculated values being 0.5 to 2.0N/mm²,
2.5 to 4.5N/mm², 3.5 to 5.5N/mm² and 6 to 15N/mm², respectively, as measured and calculated
according to the International Standard ISO 8627.
6. A toothbrush as defined in Claim 5, wherein the tapered tip (14) of each of said fillings
is formed with a length of 8 to 15mm, said proximal section of the filling being formed
with a maximum diameter of 0.15 to 0.25mm, and
each of said filling setting holes (22) is formed with a diameter of 1.5 to 2.2mm
and spaced from other holes at an interval (X) of 1.0 to 1.4mm in the longitudinal
direction of said handle.