The device for the treatment of pulpits at the final stage of root canal disinfection after mechanical and medical treatment. The principle underlying the apparatus analogs safer , faster and cheaper. The treatment takes one step tooth of the patient, and the duration of the disinfection procedure is 40 seconds. Use sterile disposable optical fiber tip diameter of 0.2 mm allows for purity even in confined spaces of the channel. There is a prototype, is being prepared for clinical trials.