The results of treatment and prevention in preschool children with inflammatory periodontal diseases. incorporating the lessons of oral hygiene, controlled cleaning of teeth and use of the device «Fotosan». After a preliminary analysis of the oral cavity (OHI-S, PMA), the children of the study were divided into two subgroups, one of which lasted for controlled cleaning of teeth, in the other - combined with the use of photoactivated disinfection. After application of photoactivated disinfection dynamics analysis allowed us to establish the PMA index decreased in preschool children by 92%.