Handpiece having root canal length measurement function

A handpiece with a root canal length measurement function, comprising:

• an angle having one side provided with a root canal treatment file for removing dental pulp inside a root canal and for expanding the root canal;
• a lip hook provided such that the lip hook can be cradled on subject's lips;
• an LED module provided with an LED light source;
• and
• a body portion electrically connected to the file through a first terminal connector, into which a first terminal provided on the other side of the angle is to be inserted, and electrically connected to the lip hook through a second terminal connector, into which a second terminal of the lip hook is to be inserted, and electrically connected to the LED module through a third terminal connector, into which a third terminal of the LED module is to be inserted,
• wherein the body portion includes:
• multiple connectors for electrically connecting a battery, and the LED light source, the file, and the lip hook;
• and
• a control module for controlling operations of the battery such that a color of LED light emitted by the LED light source changes according to position information and length information of a dental root end, which are acquired by measuring an impedance value that varies as the file approaches from a tooth surface to the dental root end, and
• the LED module includes,
• wherein the LED Light source is constituted by multiple LED light sources that irradiate LED light of different colors so that the color of the LED light is changed according to the position information and length information of the dental root end, and
• in the multiple LED light sources, only an LED light source irradiating the LED light of the color according to the position information and length information of the dental root end operates, and the LED light of the color according to the position information and length information of the dental root end is irradiated through a panel into which the multiple LED light sources are inserted,
• a main body including an operating switch which is to operate the LED light source;
• and
• a band portion for allowing the main body to surround an outer peripheral surface of the angle, which is in close contact with the outer peripheral surface of the angle based on a time when the third terminal is inserted into the third terminal connector.