Purpose: To analyse the effect of information technologies on improving the frequency of the use of dental floss among adolescents. Materials and Methods: A randomised, controlled clinical trial was conducted with 291 adolescents (mean age: 16.1 years) in three phases. Phase I involved the application of a questionnaire and clinical examinations using the simplified Oral Hygiene Index and gingival bleeding index. In phase II, the adolescents were randomly allocated to four groups: oral counseling (OR) and the use of an application (App) for smartphones; OR without the app; video (VD) and app; and VD without app. Messages were set through the app for 30 days. Phase III involved the second administration of the questionnaire and clinical examination. The frequency of dental floss use was evaluated in phases I and III. The groups were categorised into the use of technology (VD and/or App) and non-use of technology (OR alone). Results: Statistically significant reductions in the clinical indices were found with all educational methods (p 0.005) and improvements were found in the use of dental floss (p 0.001). Moreover, information technologies were associated with an improvement in the frequency of dental floss use (p 0.033). Conclusion: All methods were effective at improving clinical indicators. The use of information technologies can be considered an effective tool for improving dental floss use among adolescents. Keywords: adolescent, Information technology, oral health