3D intraoral scanner as an auxiliary tool for the diagnosis of dental hard-tissue conditions

Abstract

Aim: This in vitro study aimed to compare the direct (visual exam) versus indirect (3D-colored digital images exam) assessments of ICDAS (dental caries), BEWE (erosive tooth wear), and TF (enamel fluorosis lesions) indices performed on the occlusal surfaces of extracted human teeth for the detection and severity differentiation of dental caries, erosive tooth wear, and enamel fluorosis lesions. Materials and methods: A total of 453 occlusal surfaces from extracted human teeth were mounted on 28 typodont models. Surfaces were examined directly (visual) and indirectly using 3D-coloured intraoral scans (TRIOS 4, 3Shape). Three indices were assessed: International Caries Detection and Assessment System (ICDAS; caries), Basic Erosive Wear Examination (BEWE; erosive tooth wear), and Thylstrup-Fejerskov (TF; fluorosis). Agreement between methods was analysed using weighted kappa statistics and percentage agreement. Results: Substantial agreement was observed between direct and indirect methods: ICDAS (κ = 0.72, 64%), BEWE (κ = 0.70, 73%), and TF (κ = 0.75, 86%). Early lesions (ICDAS 1-2, BEWE 1) were more frequently misclassified. Conclusions: 3D-coloured intraoral scanner imaging shows substantial agreement with visual examination for detecting and grading caries, erosive tooth wear, and fluorosis. Clinical significance: This study supports the use of intraoral scanners as a practical adjunct to visual examination for documentation, education, and potentially remote consultations. Further clinical validation is warranted.