Comparative Evaluation of Tooth Type and Pulp Chamber Depth on the Accuracy of Endocrown Scans Acquired Using Various Intraoral Scanners

OBJECTIVE: To evaluate the effects of pulp chamber depth, tooth type, and intraoral scanner (IOS) on the accuracy of endocrown digital impressions. MATERIALS AND METHODS: Standardized endocrown preparations with 2 and 5 mm pulp chamber depths were performed on molar and premolar typodonts. Digital impressions were obtained using three IOSs (Dexis, iTero, and 3Shape). Reference scans were acquired using a laboratory scanner. Accuracy was assessed following best-fit alignment. Cavity base and axial regions were separately evaluated. Data were analyzed using Kruskal-Wallis and Dunn post hoc tests (α = 0.05). RESULTS: Pulp chamber depth, tooth type, and IOS significantly affected scanning accuracy (p < 0.05). Increasing cavity depth increased deviations at cavity base while reducing deviations at axial region. Premolar preparations with 5 mm depth exhibited the highest cavity base deviations (99.5-107.2 μm). At axial region, iTero demonstrated the lowest deviations (28.2 μm) in 5 mm depth molar preparations. Dexis and iTero showed comparable performance at cavity base. CONCLUSIONS: Effect of cavity depth was region-dependent, negatively affecting cavity base while improving accuracy at axial region. Molar preparations demonstrated superior cavity base trueness, whereas premolar preparations exhibited better axial region trueness. Deep premolar preparations represented the most challenging condition for accurate digital acquisition.