en <div style=text-align: justify;><span style=font-size:14px;><strong>Aims: </strong>Social media has increasingly been used as a tool to deliver health education. This study examined the effect of a Telegram delivered oral health education program on self-efficacy, perceived benefits and barriers, gingival index, motivational beliefs, and dental cleaning behavior among students with gingivitis.<br> <strong>Materials & Methods:</strong> This randomized controlled trial was conducted in Sanandaj city, Iran, from January to December 2019. A total of 160 students were recruited from 8 schools and randomized into intervention and control groups. An oral health education program aimed at increasing dental cleaning behavior was developed based on the trans-theoretical model. The program consisted of 9 sessions delivered via a social media app called Telegram for 24 weeks. Outcomes included dental cleaning behavior, perceived self-efficacy, benefits, barriers, motivational beliefs, and gingival index, measured at baseline and 24 weeks after the intervention.<br> <strong>Findings:</strong> There were significant differences between the intervention and the control groups in the mean scores of perceived self-efficacy (p=0.01), perceived benefits (p=0.01), motivational beliefs (p=0.01), and gingival index (p=0.01) after the intervention. Further, 71.3% (n=57) of students in the intervention group (versus 10.1% (n=10) in the control group) performed the dental cleaning behavior after intervention (p<0.01).<br> <strong>Conclusion:</strong> The findings showed that an oral health education program delivered via social media apps could improve students' oral health. Social media apps could reach a broad range of users, thus could improve access to oral health education programs.</span></div> Oral Health,Education,Social Media,Students,Gingivitis,Behavior, 1 7 http://hehp.modares.ac.ir/browse.php?a_code=A-10-10928-8&slc_lang=en&sid=4