CA1273171A - Toothbrush - Google Patents

Toothbrush

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Publication number
CA1273171A
CA1273171A CA000510433A CA510433A CA1273171A CA 1273171 A CA1273171 A CA 1273171A CA 000510433 A CA000510433 A CA 000510433A CA 510433 A CA510433 A CA 510433A CA 1273171 A CA1273171 A CA 1273171A
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CA
Canada
Prior art keywords
bristles
toothbrush
lengths
bristle
diameter
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
CA000510433A
Other languages
French (fr)
Inventor
Yasuteru Eguchi
Satoshi Tsujita
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kao Corp
Original Assignee
Kao Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kao Corp filed Critical Kao Corp
Priority to CA000510433A priority Critical patent/CA1273171A/en
Application granted granted Critical
Publication of CA1273171A publication Critical patent/CA1273171A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Abstract

Abstract of the Disclosure A toothbrush capable of removing plaque from the teeth, and massaging the gums effectively without hurting the same. The toothbrush has a handle, and bristles implanted into the handle, and is characterized in that all of the bristles have spherical portions formed at the free ends thereof, these bristles con-sisting of bristles of not less than two lengths, the difference between the length of the longest bristles and that of the shortest bristles being within the range of 1-4 mm, the bristles being arranged in such an implantation pattern that the bristles of an equal length do not gather locally so as to prevent the spherical portions thereof from contacting one another, whereby these bristles are not bent outward.

Description

12~317~ 5702 241 TOOTHBRUSH

Field of the Invention The inven~ion relates to a ~oothbrush. The toothbrush of the invention is effective in removing dental plaque, and massaging the gums and not hurting them.
Description of the Prior Art:
In toothbrushes used in our daily lives, the material for, and the thickness, length and implantation pattern, of the bristles, and the material for and the shape of the handle are determined selectively so that mainly the dirt on the surfaces of the teeth, i.e. plaque or sordes can be efficiently removed.
It is known that a toothbrush has a gum massaging effect in addition to the plaque removing effect. Komori et al (Bulletin of Japan Society of Dental Pathology, 20, 246-259, 1974) proved by making experiments using monkeys that if the gums are massaged with a toothbrush, gingivitis can be prevented.
In spite of the fact that a toothbrush has such a gum massaging effect, regular toothbrushes commercially available at present are rarely designed so as to improve their gum massaging effect. There are no other toothbrushes designed with the intention, if any, of improving the gum massaging effects thereof than a toothbrush the ends of the bristles of which are rounded to prevent the gums from being hurt when the ends of the bristles contact the same while the teeth are cleaned.
There are commercially-available toothbrushes for the gum massaging purpose only, though the number of them in use is -- 1 -- ~ ,~

1~73171 small. However, in these toothbrushes, very soft bristles are implanted into the handle thereof so that the gums do not hurt when the bristles are applied thereto. Rubber tips instead of bristles are sometimes attached to the handle. Therefore, it is impossible to expect such toothbrushes to have a sufficiently large plaque removing effect. In view of the fact that plaque directly causes not only caries but also gingivitis and alveolar pyorrhea to occur, it can be said that these gum massaging tooth-brushes are too ineffective to be used for the prevention of gin-givitis.
Japanese Utility Model Laid-open No. 7676~/1976 dis-closes a toothbrush in which bristles of an equal length having small balls at the free end portions thereof are implanted into the handle. In this type of toothbrush, the level of the force required to insert the free end portions of the bristles into the space between two adjacent teeth, in which it is the most diffi-cult to remove the plaque, is substantially equal to that of the force required to insert the free end portions of the bristles of a conventional toothbrush into a similar space. Hence, the tooth-brush disclosed in this publication has no special advantages inthis respect. Moreover, since the toothbrush has bristles of equal length, the end of each bristle contacts a tooth in a simple pattern. Accordingly, when a person, who moves a toothbrush in a peculiar way while he cleans his teeth, uses this toothbrush, the free ends of the bristles thereof would not contact some parts of the teeth.

~X73171 Summarv of the Invention The present invention provides a toothbrush comprising a handle, bores and bristle~ implanted into the bores, the bristles having a diameter of from 6/1000 to 15/1000 of an inch and having a free spherical end portion with a diameter of from 1.1 to 2.5 times the bristle diameter, the bristles being a mixture of longer and shorter bristles wherein the length difference between the longer and sh~rter bristles is withln the ~ange of fro~ 1 to 4 mm, and wherein the lengths of 50~ or greater of the brlstles which are ad~acent to any one arbitrary bri~tle are of a different length to the arbitrary bristle.
Advantageous features of the inventlon will become apparent from the following description of the preferred embodiments taken in conjunction with ~he accompanying drawings.
Brief DescriPtion of the Drawinas Figure 1 is a schematic side elevation of an embodiment of the toothbrush according to the present invention; and Figure 2 shows a bristle implantation pattern.
DescriPtion of the Preferred Embodiments The toothbrush according to the present invention is formed by implanting bristles which have spherical portions at ~he free ends thereof, and which are made in not less than two different length~, into a handle. The upper limit of the number ~''J

~7317~

of lengths of the bristles is not specially determined. If the number of lengths of the bristles is increased so that the distri-bution of the vario~s lengths thereof becomes as uniform as possible, i.e., not one-sided, the possibility of partial abrasion of the free ends of the bristles decreases.
Concerning the lengths of the adjacent bristles on the same handle, it is preferable that the lengths of not less than 50% of a plurality of bristles which are adjacent to one arbitrary bristle be different from that of the single bristle. If this single bristle has a plurality of adjacent bristles of a length equal to that thereof, the spherical portions of the bristles contact one another, and the free end portions of the bristles are inclined outward, so that the external appearance of the bristles is spoiled.
The toothbrush according to the present invention has a characteristic mode of arrangement of bristles, and spherical portions are formed at the free ends of all of the bristles. The difference between the length of the longest bristles and that of the shortest bristles is in the range of 1-4 mm. It is necessary that the number of lengths of these bristles be not less than two or three.
Since the spherical portions formed at the free ends of all of the bristles have the plaque rernoving effect, the tooth-brush according to the present invention has a larger plaque removing effect than a regular type of toothbrush. Since the bristles in the toothbrush according to the present invention are formed to various lengths the differences among which are within the range of 1-4 mm, the free end portions thereof easily enter a ~7~17~
space between two adjacent teeth, in which it is difficult -to remove the plaque from the teeth, so that the plaque removing effect of this toothbrush in such a s;pace is far greater than that of a regular toothbrush. According to the present invention, the free end of any one of the bristles always contact a tooth during cleaning of the teeth irrespective of the magnitude of the force applied to the bristles in motion, the kind of tooth (molar tooth, premolar tooth, canine and incisor), and the position of the tooth. Therefore, the plaque can be removed completely, so that a uncleaned part of a tooth is not left.
The gum massaging effect of toothbrushes will now be discussed. The bristles in a toothbrush, which have spherical portions at the free ends thereof, and which are formed to an equal length, contact the gums more softly than those of a regular type of toothbrush, which are rounded at the free ends thereof and formed to an equal length, but the former bristles hurt the gums in some cases. It is considered that the reason why these bristles hurt the gums is that the free ends of all the bristles contact the gums. If spherical portions are formed at the free ends of all the bristles with the bristles set to various lengths as in the toothbrush according to the present invention, the free ends of the bristles contact the gums with moderate pressure.
Therefore, even if the teeth are cleaned with a large force, the gums do not hurt.
As described above, in the toothbrush according to the present invention, it is necessary that the difference between the length of the longest bristles and that of the shortest bristles be within the range of 1-4 mm. When this difference is less than 1;~73171 1 mm, the bris~les extend substantially in the same manner as those in a toothbrush, which are formed of an equal length. Such bristles have neither a sufficient plaque removing effect nor a sufficient gum massaging effect. When this difference exceeds 4 mm, the shortest bristles do not contact the teeth and gums.
Hence the bristles including such shortest bristles are substan-tially identical with the implanted bristles of a reduced density.
Such bristles also have insufficient plaque removing and gum massaging effects.
The present invention will further be described with reference to the diameter of the bristles. The diameter of the portion of a bristle which excludes its free end portion, i.e. a non-spherical portion of a bristle is suitably around 6/1000-15/1000 inch. When the diameter of the bristles is less than 6/1000 inch, the firmness of the bristles is lost, and the force applied thereto during the cleaning of the teeth would not effec-tively work as a plaque removing and gum massaging force. If the tooth-cleaning force is then increased, the bristles would be bent or the gums would be hurt. When the diameter of the bristles exceeds 15/1000 inch, the firmness of the bristles becomes too high, so that they contact the gums so as to cause discomfort. A
preferable diameter of the bristles is 6/1000-11/1000 inch.
On the other hand, the diameter (maximum diameter) of a spherical portion at the free end of a bristle is suitably about 1.1-2.5 times the other portion thereof, and preferably about 1.2-2.0 times as large as the same. When the diameter of the spherical portions of the bristles is less than 1.1 times that of the other portions thereof, these bristles are substantially iden ~X73~7~

tical with the bristles having no spherical portions in a regular type toothbrush, and do not have a sufficient practical effect.
When the diameter of the spherical portions exceeds 2.5 times that of the other portions of the bristles, the free end portions of the bristles are inclined outward to spoil the external appearance thereof, and cause the commercial value of the toothbrush to decrease greatly.
The spherical portion formed at the free end of the bristle may also be made elliptical, nail-shaped, rectangularly-shaped with the four corners rounded, square and trapezoidal. Thepattern of implanting bristles of not less than two or three lengths is not specially li~ited. The bristles are preferably implanted according to a pattern in which bristles of different lengths are suitably distributed, i.e. a pattern in which the bristles of the same or substantially the same length do not locally gather.
The number of the bores into which the bristles are implanted is generally 20-30, and the number of the bristles implanted into one bore 30-60. These numbers do not constitute the characteristics of the present invention. In addition, the material for the bristles is not specially limited. The materials of which the bristles in the conventional toothbrushes are made can be used. The Nylon (TM) which is now widely used can also be employed.
EMBODIMENT:
The toothbrush according to the present invention will now be described with reference to its embodiment. The toothbrush to be now described is only an example of the present invention.

~7~

The lengths of the bristles, the diEference between the length of the longest bristles and that of the shortest bristles, the dis-tribution of the bristles of differen-t lengths and the implanta-tion pattern of the bristles are not limited to those in the embodiment which will now be described.
A toothbrush according to the present invention is shown in schematic side elevation in Figure 1. Referring to Figure 1, reference numeral 1 denotes a handle, 2 the bristles, and 3 the spherical portions at the free ends of the bristles. As shown in Figure 1, the bristles consist of bristles of larger and smaller lengths. The distribution of the lengths of the bristles was as follows.
Distribution of the lengths of the bristles:
Length of the bristlesDistribution (%) g.o _ 9.9 10.1 10.0 - 10.9 58.3 11.0 - 11.9 30.3 12.0 - 12.4 1.3 Total: 100.0 20Length of the longest bristles: 12.4 mm Length of the shortest bristles:9.0 mm Difference between the lengths of the longest and shortest bristles: 3.4 mm The diameter of the portion of each bristle which is other than the free end portion thereof was 8/1000 inch, and the diameter of the spherical portion at the free end of each bristle 1.3-1.8 times that of the non-spherical portion thereof.
The implantation pattern of these bristles was as shown in Figure 2. Referring to this drawing, reference numeral 4 317~
denotes bores into which the bristles are implanted, and the unit of the measurements shown by smaller numerals is in millimeters.
The diarneter of each bore ~ was 1.~ mm, and forty bristles were implanted into each bore. The distribution of the lengths of the bristles, which is shown above, was determined with respect to all of the bristles implanted into a total of thirty-two bores.
Embodiment and Comparative Examples:
In accordance with the bristle implantation pattern of Figure 2, the following four types of toothbrushes were prepared, and a test was conducted, in which the magnitude of the force applied to the teeth or gums was measured with respect to each type of brush. The results are shown in Table 1.
Toothbrush A: The length of the bristles was set equal.
The corners of the free ends of the bristles were rounded. The bristles had a diameter of 8/1000 inch.
Toothbrush B: Bristles of larger and smaller lengths were implanted. The corners of the free ends of the bristles were rounded. The bristles had a diameter of 8/1000 inch.
Toothbrush C: Spherical portions were formed at the free ends of the bristles. The length of the bristle was equal.
The portion of each bristle other than the spherical portion thereof had a diameter of 8/1000 inch.

~;~7;~

Toothbrush D: Toothbrush according to the present invention having the previously-mentioned distribution of bristles.
Table 1 Average Value of( Pressure due( ) Type of load on measured to 1 kg load toothbrush toothbrush pressure on toothbrush A 1.13 kg 0.064 kg/cm2 0.057 kg/cm2 - B 1.17 0.083 0.071 C 1.18 0.109 0.092 D 1.20 0.135 0.113 Testing method:
A load (average load on toothbrush _ on Table 1) of about 1 kg is applied to a toothbrush as a whole to read the value (value of measured pressure b on Table 1) appearing on the pres-sure-sensitive paper. This value represents the pressure applied to the teeth and gums via the bristles. The pressure c due to the 1 kg load on the toothbrush is determined by dividing _ by _.
When the value c is large, it means that a high pressure is applied to the teeth and gums with a smaller tooth-cleaning force, and that a toothbrush having such a large value c has excellent plaque removing and gum massaging effects. It is under-stood from Table 1 that the toothbrush according to the present invention is superior to the other toothbrushes.

Claims (5)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A toothbrush comprising a handle, bores and bristles implanted into said bores, said bristles having a diameter of from 6/1000 to 15/1000 of an inch and having a free spherical end portion with a diameter of from 1.1 to 2.5 times the bristle diameter, said bristles being a mixture of longer and shorter bristles wherein the length difference between said longer and shorter bristles is within the range of from 1 to 4 mm, and wherein the lengths of 50% or greater of said bristles which are adjacent to any one arbitrary bristle are of a different length to said arbitrary bristle.
2. A toothbrush according to claim 1 having 20 to 30 bores.
3. A toothbrush according to claim 1 having 30 to 50 bristles implanted into each of said bores.
4. A toothbrush according to claim 1 wherein said bristles have a bristle density range of from 417 to 833 bristles/cm2.
5. A toothbrush according to claim 1 wherein said bristles have lengths of from 9.1 to 12.0 mm.
CA000510433A 1986-05-30 1986-05-30 Toothbrush Expired - Lifetime CA1273171A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA000510433A CA1273171A (en) 1986-05-30 1986-05-30 Toothbrush

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA000510433A CA1273171A (en) 1986-05-30 1986-05-30 Toothbrush

Publications (1)

Publication Number Publication Date
CA1273171A true CA1273171A (en) 1990-08-28

Family

ID=4133250

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000510433A Expired - Lifetime CA1273171A (en) 1986-05-30 1986-05-30 Toothbrush

Country Status (1)

Country Link
CA (1) CA1273171A (en)

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