Abstract:

BACKGROUND: Resin or post-core crown restoration is commonly utilized in repair defect of anterior teeth or dentition. To meet the need of cosmetology, the post-core crown is inevitably tilted to the roots; however, this tilt angle should be controlled in certain ranges to guarantee the articulation. Most studies with regard to the tilt angles are concentrated on load test based on real simulation or finite element-simulated models.    
OBJECTIVE: To seek angle ranges for different materials auterior tooth.
METHODS: Three-dimensional spiral CT scan technology, based on the 0.5 mm layer thick 82 partially human maxillary cross-sectional images, read dicom format directly mimics the original image. After obtaining the nasorbital image fitting data as the reference to the simulation and mesiodistal to different angles of the post-core angle.
RESULTS AND CONCLUSION: A relatively accurate maxillary model, as well as a different angle procelain post-core procelain model, was established, which demonstrated that the ranges of tilt angles were changeable for different repair materials. ① The tilt angles were obvious different for anterior teeth restoration. For the Ni-Cr group, the roots were ≤ 25° tilted to the palatal, ≤ 20° to the labial, and ≤ 20° to the mesial-distal. For the titanium group, the roots were ≤ 35° tilted to the palatal, ≤ 30° to the labial, and ≤ 25° to the mesial-distal. ② By contrast, the Au-Pd showed superior entire system mechanical properties post at 30°. ③ Under load, the stress mainly concentrated on neck of the incisor.