Toothbrush

Abstract

A tooth brush which is excellent in durability and can give a high massaging effect to a person even with weak gum with a low stimulus and without damaging the gum in various tooth brushing methods, especially in a Bass method. The toothbrush comprises bristles (4) tufted on an toothbrush head (20), wherein thermoplastic elastomer bristles (41, - - - ) are tufted in the inner portion (R1) in a width direction of the toothbrush head (20) and synthetic resin bristles (42, - - - ) harder than the thermoplastic elastomer bristles are tufted in the both outer portion (R2, R3) in a width direction of the toothbrush head (20) respectively. Especially, each tuft (5) tufted on the toothbrush head (20) is so trimmed that bristles (4) are continuously or stepwise shorter from the inner portion to the outer portion in the width direction

Description

TECHNICAL FIELD[0001]The present invention relates to a toothbrush.BACKGROUND ART[0002]Conventionally, a toothbrush has been proposed in which soft bristles, such as polyester thermoplastic elastomer, are tufted in outer portion in the width direction of a toothbrush head of the toothbrush and hard bristles, such as nylon, are tufted in an inner portion in the width direction of a toothbrush head of the toothbrush and which provides a massaging effect to the gum by the outer soft bristles at the outer portion, while maintaining a cleaning effect by the hard bristles at the inner portion mainly in the case of horizontal brushing method (rolling-stroke method) (e.g., Patent Documents 1 and 2).[0003]There are various brushing methods, such as a scrubbing method and a Bass method, in addition to the rolling-stroke method. Thus, it is necessary to employ the various methods while combining the advantages of each method. In particular, the Bass method refers to a method of finely vibratin...

AI Technical Summary

Benefits of technology

[0018]According to the toothbrush structured as described above of the present invention in this application, the above-described thermoplastic elastomer bristles are tufted in the inner portion in the width direction of a toothbrush head which contacts sensitive portions of the gum or the interproximal portions in the Bass method, and thus the gum or the interproximal portions are hard to damage and massaging effect of the gum is provided. Moreover, since synthetic resin bristles harder than an elastomer are tufted in the outer portion which contacts the tooth surface in the Bass method, cleaning effect of the tooth surface, the interproximal portions, and the gum can be improved; and the elastomer bristles at the inner portion are supported by the synthetic resin bristles at the outer portion to thereby prevent the elastomer bristles from spreading out, accordingly resulting in increased durability and the improvement in the cleaning effect by the elastomer bristles.

[0019]Moreover, since the diameter of the thermoplastic elastomer bristle is set to 0.1 mm to 0.4 mm, narrow part cleaning effect with the elastomer bristles for boundaries between the teeth and the gum and interproximal gaps can be improved.

[0020]Moreover, since synthetic resin bristles harder than the thermoplastic elastomer bristles are tufted in the tip hole and the hole nearest to the neck of handle in the central row and the outer rows, the soft elastomer bristles can be supported by the hard synthetic resin bristles from the longitudinal direction and the width direction, i.e., all directions, to thereby prevent the soft elastomer bristles from spreading out, resulting in that the cleaning effect by the elastomer bristles and the durability can be further improved.

[0021]Moreover, since the bristle length of each bristle tufted in a toothbrush head becomes successively or stepwise shorter from the inner portion to the outer portion in the width direction, the synthetic resin bristles at the outer row opposite to the side contacting the tooth surface can be avoided from contacting the gum at the time of cleaning by the Bass method; a sufficient massaging effect and narrow part cleaning effect can be obtained by the long elastomer bristles; and sufficient cleaning effect can be maintained by the synthetic resin bristles at the side contacting the tooth surface. Moreover, since the synthetic resin bristles at the outer rows are short as described above, the contact between the synthetic resin bristles and the gum is reduced at the time when horizontally brushed to thereby prevent damaging the gum.

[0022]Since the thermoplastic elastomer bristles are made of a thermoplastic elastomer having a hardness of 30 D to 100 D, outstanding cleaning effect can also be obtained simultaneously with that the stimulus to the gum is suppressed to thereby achieve a favorable massaging effect.

Problems solved by technology

However, when the above-described toothbrush is applied, the hard bristles at the inner portion damage the gum.

Thus, the above-described toothbrush cannot be used for persons with weak gum.

Moreover, although the above-described toothbrush can massage the gum by the soft bristles at the outer portions when horizontally brushed, such soft bristles are spread out in a short period of time in the course of using, giving a problem with durability.

Images