| 摘要 |
An object is to provide an electric toothbrush superior in plaque removal, producible at low costs, and utilized without damaging gum even by a patient with gingivitis. In the electric toothbrush (10) making brushing possible by linearly moving a tufted portion (31), the product of the distance (mm) of movement of the tufted portion (31) and the frequency (times) of back-and-forth motion per minute is set in the range of 3000-9000. Further, the distance ((x) mm) of movement of the tufted portion (32) and the frequency ((y) times) of back-and-forth motion per minute are set in a range which satisfies the following formula: y = ax + b, where a = - 3000, 10000 ‰¦ b ‰¦ 12500, x > 0. |
