Effect of different CAD-CAM post and core materials in endodontically treated teeth without ferrule and with non-circular root canals: 3D finite element analysis.

Purpose: Restoring ferrule-lacking, noncircular canal endodontically treated teeth (ETT) poses challenges owing to the increased susceptibility to root fracture and post dislodgement. We aimed to evaluate the influence of different post and core materials on the stress distribution and maximum Von Mises stress in ETT.

Methods: Four three-dimensional models were generated using different customized post and core materials: gold alloy, resin nanoceramic, polyetheretherketone (PEEK), and polyetherketoneketone (PEKK). A static load of 200 N was applied at an angle of 45 ° to the occlusal surface. The stress distribution and maximum Von Mises stress were analyzed using finite element analysis.

Results: The stress distribution patterns in all the models were concentrated in the tooth structure, post and core, and cortical bone. The gold model exhibited stress accumulation predominantly on the buccal side along the post length, with the highest maximum Von Mises stress value (330.69 MPa). The resin nanoceramic model exhibited an even stress distribution. The PEEK and PEKK models showed stress transfer to adjacent structures with the lowest maximum Von Mises stress values in the post and core sections (21.50 MPa and 29.46 MPa, respectively).

Conclusions: Different post and core materials influenced the stress distribution and maximum Von Mises stress values in ferrule-lacking, noncircular canal ETT. Resin nanoceramics have emerged as promising alternative materials, exhibiting an even stress distribution owing to their similar elasticity to dentin, thus potentially mitigating the risk of root fracture and post debonding.