Accuracy of a Digital Intraoral Scanner in Recording Occlusal Contact Points in Patients with Natural Dentition Compared to 8-µm Articulating Paper: A Cross-Sectional In-Vivo Study

Background Recent developments in digital dentistry have introduced intraoral scanners (IOSs) as potential alternatives to conventional methods for recording occlusal contact. However, clinical evidence comparing their diagnostic accuracy against the gold standard (8-μm articulating paper) remains limited, particularly regarding tooth-type-specific performance. Objective This cross-sectional comparative study evaluated the accuracy of the Cameo Elegant 3 intraoral scanner (IOS) for static occlusion contact detection compared to 8-μm articulating paper and determined whether tooth type (premolars vs. molars) influences contact point accuracy. Materials and methods Thirty-five patients (11 men, 24 women; aged 21-29 years) underwent occlusal assessment during a single visit. Occlusal contacts were marked with 8-μm Bausch articulating paper. The marked contact points were then immediately scanned using the Cameo Elegant 3 IOS. Digital scans of mandibular/maxillary arches and bite registration were obtained. Digital models were superimposed in Exocad software to identify matching and non-matching contact points (n=412 contacts across 140 posterior teeth). Point-level analysis was performed using confusion matrices and Cohen's kappa, while tooth-level data were analyzed using the Wilcoxon signed-rank test. Premolar-molar differences were assessed via chi-square/Fisher's exact tests, Mann-Whitney U, Spearman's correlation, and ROC curves using SPSS v27 (α=0.05). Results The scanner showed high sensitivity (90.4%, 95% CI: 87.4-93.0) but poor specificity (14.3%), with significant under-recording vs. articulating paper (p<0.001). Premolars outperformed molars (κ=0.115, p=0.002 vs. κ=-0.040, p=0.411), though overall agreement was negligible (κ=0.014). Conclusion The Cameo Elegant 3 intraoral scanner demonstrated high sensitivity but poor specificity for detecting static occlusal contact points compared with 8-μm articulating paper, with significant under-recording, particularly in the molar regions. While the scanner showed acceptable performance in premolars, the overall agreement was negligible. These findings indicate that IOSs should be used as adjunctive tools rather than being used as a standalone method for occlusal assessment. Combining digital scanning with conventional thin articulating paper remains essential for reliable clinical evaluation.