Teaching Others, Reflecting Self: Does Educating Patients Impact Students' Own Plaque Control?

INTRODUCTION: This retrospective exploratory study investigated whether instructing patients in oral hygiene influences dental students' own hygiene effectiveness. METHODS: Intraoral scans from a full-semester cohort of first-year clinical dental students (n=30) were analysed. At baseline (T0), students performed mutual intraoral scans (CS 3600, Carestream) of disclosed plaque during scanner training. During the semester, they guided their own patients through an Oral Care Programme (OCP) including 3D plaque visualisation and hands-on oral hygiene training. At follow-up (T1), students repeated mutual disclosed-plaque scans. Plaque coverage (P%) was quantified planimetrically on oral (i.e. lingual and palatal) and vestibular (i.e. buccal and labial) surfaces from T0 and T1 of all teeth. Plaque distribution, areas of loss, gain, and stability were assessed. Unsupervised clustering was performed using P%, gain, loss, stable areas, tooth type, and surface as features. RESULTS: Mean P% decreased from 14.6±4.4 at T0 to 13.1±3.7 at T1 (p=0.025), but the magnitude of change was small; P% correlated strongly between time points (r=0.690, p<0.001), indicating largely stable individual plaque-control profiles. Cluster analysis identified three patterns: (1) overall intermediate P%, predominantly on oral surfaces, (2) high overall P%, especially on vestibular molars and premolars, and (3) consistently low P%. Overall, plaque distribution and the spatiotemporal behaviour of plaque areas remained largely persistent. CONCLUSION: Students showed only small reductions in plaque coverage over one semester, while inter-individual patterns remained stable. Cluster-specific trajectories highlight heterogeneity in plaque-control profiles and may help identify the tooth surfaces and regions where targeted feedback may be most effective. Future curricula should emphasise self-reflection, personalised feedback, and practical skills training.