Level of Agreement Between Plaque Detection with Clinical Assessment and Assessment on Intraoral Scanner

Background/Objectives: The aim was to evaluate the agreement between plaque detection with an intraoral scanner system (IOS) and a conventional clinical method and to evaluate the inter-rater reliability for scoring 3D models with and without a disclosing agent. Methods: A total of 14 participants were recruited from the Department of Operative Dentistry, School of Dentistry, National and Kapodistrian University of Athens. Participants eligible for inclusion were adults with good general health and a minimum of 20 teeth. Participants were clinically examined with plaque assessment according to the modified Quigley-Hein plaque index before and after using a disclosing agent (GC-Tri Plaque ID-Gel, GC, Europe N.V). Before and after the application of the disclosing agent, all study participants were scanned using the IOS (TRIOS5, 3Shape TRIOS A/S). The clinical examiner and three additional examiners blinded to the clinical examination assessed plaque status on the acquired 3D models with and without disclosing agent using the same index to evaluate the inter-rater agreement. Intraclass coefficient correlation, one sample t-test, and Cronbach's α for inter-rater reliability were calculated. Results: All methods showed moderate to strong correlations (Spearman's rho ranging from 0.527 to 0.618), and Cronbach's α ranged from 0.551 to 0.766. Conclusions: The level of agreement between conventional clinical registration and registration from 3D models was acceptable overall.