Interdental cleaning tool
Provided is an interdental cleaning tool that can be smoothly inserted between back teeth. An interdental cleaning tool according to the present invention includes: a cleaning tool body that is made of a synthetic resin, and includes a grip portion that is capable of being gripped with fingers of a user and a shaft portion that extends in one direction from the grip portion; and a cleaning portion configured to clean between teeth, covering a leading end of the shaft portion, and made of an elastomer, wherein (angle b)/(angle a) is 0.82 or more, where the angle a is a rotational angle (degrees) when a torque value A is measured, the torque value A being a maximum torque value (N·cm) when the grip portion is rotated at a rotational speed of 10 rpm about a position located 6 mm away from a leading end of the cleaning portion, and the angle b is a rotational angle (degrees) when a torque value B is measured, the torque value B being a maximum torque value (N·cm) when the grip portion is rotated at a rotational speed of 10 rpm about a position located 10 mm away from the leading end of the cleaning portion.
1 . An interdental cleaning tool comprising:
a cleaning tool body that is made of a synthetic resin, and includes a grip portion that is capable of being gripped with fingers of a user and a shaft portion that extends in one direction from the grip portion; and
a cleaning portion configured to clean between teeth, having bristles, covering a leading end of the shaft portion, and made of an elastomer,
wherein
the shaft portion includes a first region that extends from a leading end of the grip portion and a second region that extends from a leading end of the first region to an upper end of the cleaning portion,
the cleaning portion is adjacent to the second region of shaft portion,
the first region is formed in a substantially triangular shape in a plan view in a thickness direction of the grip portion so that a width of the first region decreases along a longitudinal direction extending from the grip to the second region in the plain view, and in the substantially triangular shape, a length of the first region in the longitudinal direction, as a height, is longer than the width, as a base, in a direction perpendicular to the longitudinal direction,
the second region is formed in a shape of a rod in cross-section,
a length in the second region from the leading end of the first region to the second end of the bristles of the cleaning portion is shorter than the height of the substantially triangular shape of the first region,
(rotational angle b)/(rotational angle a) is 0.82 or more, and
each of the rotational angles a and b is 28 degrees or more,
where the rotational angle a is a rotational angle (degrees) when a torque value A is measured, the torque value A being a maximum torque value (N·cm) when the grip portion is rotated at a rotational speed of 10 rpm about a position located 6 mm away from a leading end of the cleaning portion, and
the rotational angle b is a rotational angle (degrees) when a torque value B is measured, the torque value B being a maximum torque value (N·cm) when the grip portion is rotated at a rotational speed of 10 rpm about a position located 10 mm away from the leading end of the cleaning portion.
2 . The interdental cleaning tool according to claim 1 ,
wherein (torque value C)−(torque value A)≥0.8 is satisfied,
where the torque value C is a maximum torque value (N·cm) when the grip portion is rotated at a rotational speed of 10 rpm about a position located 15 mm away from the leading end of the cleaning portion.
3 . The interdental cleaning tool according to claim 2 ,
wherein an outer diameter of the cleaning portion located 6 mm away from the leading end thereof is 0.4 to 1.5 mm, and
an outer diameter of the cleaning portion located 15 mm away from the leading end thereof is 0.5 to 2.0 mm.
4 . The interdental cleaning tool according to claim 2 , wherein the cleaning tool body contains a glass fiber.
5 . The interdental cleaning tool according to claim 1 ,
wherein an outer diameter of the cleaning portion located 6 mm away from the leading end thereof is 0.4 to 1.5 mm, and
an outer diameter of the cleaning portion located 15 mm away from the leading end thereof is 0.5 to 2.0 mm.
6 . The interdental cleaning tool according to claim 1 , wherein the cleaning tool body contains a glass fiber.