A built-in interdental brush of the present application uses a structure in which an interdental brush is built in a bended tube of a guide head of a delivery component, after a working part of the interdental brush made of elastic material is aligned to a tooth clearance, a sliding mechanism on the delivery component is pushed to drive the working part of the interdental brush automatically bend along curvature of the bended tube, the working part of the interdental brush is aligned to the tooth clearance and pushed into the tooth clearance, and by pushing and pulling a sliding block on the sliding mechanism of the delivery component, the working part of the interdental brush moves back and forth in the tooth clearance to clean the tooth clearance. Because the delivery component has good stiffness, after an outlet of the bended tube of the guide head of the delivery component is aligned to the tooth clearance, the pushed out interdental brush directly enters the tooth clearance, and because the outlet of the bended tube of the guide head of the delivery component is almost close to the tooth clearance； therefore, the interdental brush is hard to be bended and controllability of the interdental brush is significantly improved, avoiding that when the interdental brush of the prior art is used to clean a clearance between molars, the interdental brush easily bends and hurts the gum. A lighting-enabled interdental brush of the present application includes an interdental brush and a delivery component, where a guide head, a housing, and a lighting system are disposed on the delivery component, the interdental brush is installed on the guide head, and the lighting system can provide lighting for the interdental brush； therefore, a lighting condition in an oral cavity is significantly improved, the clearance between molars may be clearly observed, and a process that the interdental brush enters the tooth clearance is directly observed, which is convenient for cleaning and
