Abstract
<title>Abstract</title> <p> Background Individuals from unselected population samples have limited capacity to remove dental plaque. Dental professionals perform better. This study aimed to understand the impact of the dental curriculum on oral hygiene effectiveness and how self-perception of oral hygiene skills relates to it. Methods This cross-sectional study assessed self-perceived curricular influences on personal oral hygiene in N = 255 dental students from all semesters at the Justus Liebig University Giessen. Of these, N = 82 were available for assessment of gingival inflammation (Papillary Bleeding Index, PBI) and remaining plaque deposits (Marginal Plaque Index, MPI) after best possible toothbrushing. Self-perceived oral cleanliness (SPOC) after brushing was also assessed. Results Final-year students showed lower inflammation ( <italic>p</italic> = .031, <italic>d</italic> = 0.74) and plaque after best possible brushing ( <italic>p</italic> = .037, <italic>d</italic> = 0.71) than first-year students. Students’ overestimation of their oral cleanliness after brushing did not differ between first- and final-year students ( <italic>p</italic> = .217, <italic>d</italic> = 0.31). N = 160 students reported curricular influences on their oral hygiene with 102 clearly assignable to a specific semester, the majority (n = 50) referencing the third semester. Plaque levels differed most between the 3rd and the 4th semester. Students most often named periodontology and conservative dentistry courses and content as being important for their changes in oral hygiene. Conclusion Periodontology and conservative dentistry content appears to prompt the greatest improvement in oral hygiene among dental students. Persistent deficits in oral hygiene may be explained by students overestimating their own effectiveness, resulting in a lack of motivation to improve their skills. Trial registration: https://drks.de/search/en/trial/DRKS00031601/details ; #DRKS00031601; submission date: March 31, 2023; registration date April 17, 2023 </p>