Time and cohort changes in preventive practice among Mongolian dental students.

To evaluate time and cohort changes in preventive practice of dental students in Mongolia, a questionnaire was distributed to all clinical-year students in 2000 (n = 79) and in 2002 (n = 73) of the Dental School of the Mongolian National Medical University (MNMU). The questionnaire eliciting information on students' preventive care-related practice and knowledge, oral self-care (OSC) behaviour, and self-perceived competency, was administered to the students. Further, cross-sectional (between cohorts) comparisons to study changes over time and longitudinal (within-cohort) comparisons to reveal changes resulting from professional dental education were carried out. Statistical evaluations included chi-square test and linear regression model. Preventive practice of the students in 2002 tended to be better than that of their counterparts in the same study-year in 2000. Preventive practice among the fifth-year students improved significantly compared to that in their third year, except for counselling on nutrition. Survey-year, study-year, and knowledge of and self-reported competency in preventive care explained 38% of the variation in reported preventive practice. Besides the positive changes revealed, preventive practice among the students could still be improved. Regarding these tasks, professional education should provide meaningful learning experience on modern caries-preventive methods and dental community should support practice of preventive dentistry. A special programme could help to motivate the students to improve their own OSC.