Interdental cleaning instrument

An interdental cleaning instrument comprising:

• a base part having a shape extending from a base end to an insertion end section in an axial direction of the interdental cleaning instrument, and having a first hardness;
• and
• a cleaning part that is composed of an elastomer having a second hardness lower than the first hardness of the base part, covers at least a portion of the base part from the insertion end section, and is capable of cleaning an interdental space, wherein
• the base part has:
• a grip part that extends from the base end along the axial direction and has a shape to receive a grasp of fingers;
• and
• a shaft part which has a shape that is insertable to an interdental space between neighboring teeth, and has the insertion end section and a base end section at which the grip part is connected to the shaft part;
• the shaft part has a shape that can be flexurally deformed to displace the insertion end section in a direction which is perpendicular to the axial direction of the shaft part with respect to the base end section;
• the cleaning part has a shape that covers the insertion end section to form a tip end of the cleaning part and a portion of the shaft part extending from the insertion end section by a length equal to or less than the entire axial dimension of the shaft part;
• the base part has an in the axial dimension of 35 mm or more;
• and
• the shape of the base part is set to obtain a first pressing force ranged from 0.3 N to 1.4 N to cause 10 mm of displacement at a first portion distant by 2.5 mm from the tip end of the cleaning part when the first pressing force is applied to the first portion in a state in which the interdental cleaning instrument is fixedly held at a portion 10 mm apart from the tip end of the cleaning part to the grip part side;
• and
• a second pressing force ranged from 0.5 N to 2.5 N to cause 10 mm of displacement at a second portion distant by 8.0 mm from the tip end of the cleaning part when the second pressing force is applied to the second portion in a state in which the interdental cleaning instrument is fixedly held at a portion 35 mm apart from the tip end of the cleaning part to the grip part side.