Effectiveness of Individually Trained Oral Prophylaxis Education on Long-Term Oral Health in Medical and Dental Students: A Two-Year Prospective Cohort Study

This is a prospective, two-year cohort study conducted at the School of Medicine, University of Mostar (Bosnia and Herzegovina), during the 2021/2022 and 2023/2024 academic years. The study is designed to evaluate the long-term effectiveness of a single-session oral hygiene education program, known as Individually Trained Oral Prophylaxis (iTOP), on periodontal health in medical and dental students.

• Study Population and Setting: Participants include first- and fourth-year students of medicine and dental medicine at the University of Mostar during the 2021/2022 academic year. Eligibility criteria include active enrollment and provision of informed consent. Students with systemic diseases affecting periodontal health (e.g., uncontrolled diabetes) or those using medications known to cause gingival overgrowth will be excluded.

• Study Design: Participants will be randomly assigned using a computer-generated list to either the intervention group (iTOP) or the control group. Group allocation will be concealed from examiners to minimize assessment bias. Both groups will receive professional dental cleaning and standardized oral hygiene kits at each examination point. Clinical assessments will be performed by a board-certified periodontist and a calibrated teaching assistant.

• Intervention: The intervention group will receive individualized oral hygiene instruction based on the certified iTOP methodology. This includes hands-on training in toothbrushing, interdental brush use, and flossing. A follow-up motivational session will be scheduled at 3 months. The control group will receive no structured oral hygiene education beyond standard cleaning and kit distribution. Adherence to oral hygiene recommendations will not be systematically monitored.

• Outcomes and Assessments: The primary clinical outcomes include plaque index, bleeding on probing, probing depth, and clinical attachment level. These will be measured at six sites per tooth using a UNC-15 periodontal probe and recorded on the Bern Periodontal Chart. Assessments are scheduled at baseline (2021/2022), at 3 months, and at the 2-year follow-up (2023/2024). Standardized oral hygiene kits (Curaprox toothbrushes and interdental brushes) will be provided at each time point.