The whole process of filling tooth decay in children includes cleaning the decay, cavity preparation, filling the tooth, and root canal treatment if there is damage to the tooth nerve. 1. Clean up the decay: remove the decay on the surface of the decayed tooth, the decay is caused by the usual food residues, which are not cleaned up, and cleaned up with a special dental handpiece. 2.Preparation of cavity: It is necessary to prepare a good fixation shape and resistance shape to prevent other dental tissues and fillings from falling out and not fitting together; 3. Filling: children are younger, the cavity is small, generally choose the filling material to use a shorter period of time, easier to fix; if the dental cavity is larger, you can choose the crown to do the shape of the restoration. If there is damage to the nerve, it is recommended to do root canal treatment. Be sure to go to a regular dental hospital for treatment.