<![CDATA[Background: Oral health knowledge supports preventive oral health practices, and Instagram may provide an accessible channel for repeated health education. Purpose: This study aimed to describe changes in oral health knowledge before and after exposure to digital posters delivered through Instagram. Methods: A pre-experimental one-group pre-test and post-test study was conducted online through the Instagram account @nairansc in April–May 2026. The population comprised 1,422 followers; 323 eligible participants were included through simple random sampling. Knowledge was measured using a 15-item questionnaire. Four digital posters addressed toothbrushing, tongue cleaning, interdental cleaning, and factors associated with dental damage. Each poster was published three times in rotation during a 19-day intervention period, followed by one week of reposting. Pre-test and post-test scores were compared using a paired analysis. N-Gain was described by sex, education, and age. Results: The proportion of participants with good knowledge increased from 79.3% (256/323) to 97.2% (314/323). The mean score increased from 12.87 ± 1.71 to 14.56 ± 0.98, an absolute increase of 1.69 points (p < 0.001). N-Gain was high for both males (0.73) and females (0.76), and for junior high school (0.71), senior high school (0.72), and university education (0.79). By age, N-Gain was 0.75, 0.63, 0.70, and 0.86 for the 18–22, 23–27, 28–32, and ≥33-year groups, respectively.Conclusion: Oral health knowledge was higher after exposure to the Instagram-based digital posters in this study population. Because the design lacked a control group, the observed change cannot be attributed exclusively to the intervention.]]>
