Figure 1 (A) Line diagram showing preparation features (occlusal thickness, margins, pulpal extension) for endocrown that formed the basis of their designs. (B) Finite element models of endodontically treated maxillary first molar restored with endocrown using various preparation features. Model A (flat butt margin, 2 mm pulpal extension, 3 mm occlusal thickness; Model B (flat butt margin, 4 mm pulpal extension, 3 mm occlusal thickness); Model C (20 degree bevel margin, 2 mm pulpal extension, 3 mm occlusal thickness); Model D (20 degree bevel margin, 4 mm pulpal extension, 3 mm occlusal thickness); Model E (shoulder margin, 2 mm pulpal extension, 3 mm occlusal thickness); Model F (shoulder margin, 4 mm pulpal extension, 3 mm occlusal thickness). M – margin; PCE – pulp chamber extension; OT – occlusal thickness; mm – millimeters, ° – degrees. Figure created using MS PowerPoint, version 20H2 (OS build 19042,1466), Windows 11 Pro, Microsoft Corporation).