| 摘要 |
In the case of conventional toothbrushes whose bristles have all needlelike tapering tips, the bristles near tips becomes too flexible because they are too thin. On the other hand, in the case of toothbrushes whose bristle ends being rounded or hemispherical, it is difficult to go into the spaces between teeth or boundary spaces between teeth and gums. Thus, it is difficult for conventional toothbrushes to clean up in every nook and corner in the mouth. A toothbrush comprising a block head having brush portion, a handle and a neck portion connecting said block head with the handle, wherein a part of said tufts of the brush portion are made up of filament with polygonal cross section, and the rest of the tufts are made up of sheath-core structural filament whose core material is covered with sheath material so that the cross section thereof is concentric circles.
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