| 摘要 |
A toothbrush in which the bristles are less likely to have mechanical damage such as cracks and bends and that clearly indicates the time of toothbrush replacement by the degree of spread of the bristles. The toothbrush (10) has tufts (15) inserted into a tuft insertion surface, and the tufts (15) are each formed by binding bristles (1) made of a polytrimethylene terephthalate resin. Recesses (2) are formed in the surface of a bristle (1). The minimum cross-sectional area (S1) of the bristle (1) at the position where a recess (2) is formed is 40 to 80% of the maximum cross-sectional area (S2) of the bristle (1). |
