Study aim: To determine and compare the effectiveness of digital flashcard teaching method versus lecture-based method on initial learning and one-month long-term retention among dental students in periodontitis diagnosis Design: A randomized controlled clinical trial with a parallel design (two groups, random allocation), unblinded, conducted as a comparative study, with a sample size of 50 (25 per group) Settings and conduct: This study is a parallel randomized controlled clinical trial (with two parallel groups: the digital flashcard intervention group and the traditional lecture control group) conducted to compare the effectiveness of two educational methods in the Department of Periodontics, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, on 50 dental students (25 per group). The educational intervention is carried out over 3 days, and learning is evaluated immediately and one month after the intervention. This study is conducted as an unblinded trial. Participants/Inclusion and exclusion criteria: The study is conducted on 50 dental students passing the Periodontics (1) course; Inclusion criteria include informed readiness, willingness, and sufficient motivation; Exclusion criteria comprise prior experience with digital flashcards to prevent prior exposure bias and using auxiliary study methods other than routine handouts and PowerPoint slides Intervention groups: The intervention consists of two groups: the digital flashcard group receiving 20 interactive flashcards over 3 days (15 minutes daily), and the control group (traditional lecture) receiving a 45-minute lecture with PowerPoint Main outcome variables: Learning score immediately after education; Retention score one month after education; Students' satisfaction level with the educational method