Background: Social media is an increasingly common source of dental information but may also disseminate misinformation about root canal treatment (RCT). This study evaluated the association between social media misinformation and patient perception of RCT and treatment-related decision-making.

Methods: An analytical cross-sectional study was conducted among 251 adults in Jammu, India. A validated 21-item questionnaire assessed RCT perception, misinformation exposure, previous RCT experience, and treatment-related decision-making. Associations were analysed using the Chi-square test, Cramer's V, and binary logistic regression.

Results: Positive perception of RCT was reported by 218 (86.9%) participants. Misinformation exposure was reported by 96 (38.2%), of whom 28 (11.2%) believed the information. Negative perception was significantly higher among participants exposed to misinformation than those not exposed (24.0% vs. 6.5%; χ² = 14.2, p = 0.001; Cramer's V = 0.32). Misinformation exposure was independently associated with negative perception (AOR = 3.8; 95% CI: 1.9–7.5; p < 0.001). Social media influence on treatment-related decision-making was also associated with negative perception (AOR = 2.1; 95% CI: 1.1–4.0; p = 0.020).