Effect of occlusal anatomy of CAD/CAM feldspathic posterior crowns in the stress concentration and fracture load

Author(s)

Souto Borges, Alexandre Luiz ^[1] ; Mendes Tribst, Joao Paulo ^[1] ; de Lima, Aline Lins ^[1] ; de Oliveira Dal Piva, Amanda Maria ^[1] ; Ozcan, Mutlu ^[2]

Affiliation

^[1] Sao Paulo State Univ UNESP, Inst Sci & Technol, Dept Dent Mat & Prosthet, Sao Jose Dos Campos - Brazil

^[2] Univ Zurich, Ctr Dent & Oral Med, Div Dent Biomat, Clin Reconstruct Dent, Plattenstr 11, CH-8032 Zurich - Switzerland

• Document type: Journal article
• Source: CLINICAL AND EXPERIMENTAL DENTAL RESEARCH; JUL 2021.
• Web of Science Citations: 0

Abstract

Objectives: This study evaluated the effect of restoration occlusal design on the maximum fracture load and stress distribution of a feldspathic ceramic crown. Materials and Methods: Twenty dentin analogues were used to simulate a full-crown preparation. Next, 20 feldspathic crowns were milled according to the occlusal design parameter available in the CAD database (Young or Adult). The crowns were cemented with dual cure resin-cement and loaded until fracture at 1 mm/min cross-head speed. Data were analyzed by using one-way ANOVA and Tukey tests (p < 0.05). The same geometry and experimental setup was modeled and exported to the computer aided engineering software and tensile stress concentration was calculated using the finite element method with 300 N occlusal load simulation. Results: The occlusal anatomy significantly influenced the load-to-fracture (p < 0.05). Adult design showed higher mean values (1149 +/- 201 N) than Young design (454 +/- 77 N). The maximum principal stress criteria showed similar stress pattern for both designs, however, the highest stress concentration was calculated for Young design (91 MPa) in the occlusal surface. Conclusions: An anatomy design with reduced cusp angulation and less evident occlusal sulcus can reduce the stress concentration and increase the fracture load for feldspathic CAD/CAM posterior crowns. (AU)

• FAPESP's process: 13/14831-1 - The influence of cuspal angle and material toughness on stress distribution and fracture resistance of total crown
• Grantee: Aline Lins de Lima
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 14/00668-4 - Influence of occlusal anatomy, resin cements properties and connectors type on the strength and stress distribution in metal free prostheses
• Grantee: Alexandre Luiz Souto Borges
• Support Opportunities: Regular Research Grants