Navigating the Forgetting Curve: A Longitudinal Study of Knowledge Retention and Confidence Dynamics in Dental Education

Retention of foundational knowledge is critical in dental education, yet the implications of Ebbinghaus forgetting curve are often overlooked. This study examined how well dental students retained core periodontal concepts and how confident in their knowledge evolved over the dental school years. A standardized 20-question multiple-choice exam was administered to 120 students at six points: before and after each of three progressive periodontal courses. Students also rated their confidence for each answer. Data from 113 students were analyzed. During the first-year course, mean scores increased significantly from 42–46% to 76–81%. After a four-month gap, second-year pre-course scores dropped to 66–70% and then rebounded to 84–89% post-course. In the third year, despite a nine-month gap, pre-course scores remained relatively high (78–81%) and rose slightly to 80–83% post-instruction. Performance and confidence improved significantly over time (p < 0.001), and a strong positive correlation was observed between them (r = 0.87, p < 0.001). These findings support the value of repeated reinforcement in promoting long-term knowledge retention and increasing student confidence.