Effect of thickness and CAD-CAM material on fatigue resistance of endodontically treated molars restored with occlusal veneers

Author(s)

Noronha, Mayara dos Santos ; de Carvalho, Marco Aurelio ; Anh Quynh Do ; de Araujo Neto, Vitaliano Gomes ; Campos, Camila Heitor ; Giannini, Marcelo ; Magne, Pascal

• Document type: Journal article
• Source: JOURNAL OF PROSTHODONTICS-IMPLANT ESTHETIC AND RECONSTRUCTIVE DENTISTRY; v. 32, n. 2, p. 11-pg., 2022-10-02.

Abstract

Purpose To evaluate the influence of the thickness and type of computer-aided design and computer-aided manufacturing (CAD-CAM) material on the fatigue resistance and failure mode of endodontically treated teeth (ETT) restored with occlusal veneers (OV). Materials and methods Seventy-five (N = 75) ETT were restored with Herculite XRV in the endodontic access. Five experimental groups (n = 15) were tested. Four groups had two different thicknesses (0.6-0.7 mm or 1.4-1.6 mm) and two different CAD-CAM materials: zirconia-reinforced lithium-silicate (LS/Celtra Duo) and composite resin (RC/Cerasmart). The fifth group (control) did not have occlusal veneers. All the specimens were subjected to accelerated fatigue (5 Hz frequency) with an occlusal load increasing up to 1800 N and 131,000 cycles. The number of cycles was recorded when the machine stopped or at the completion of the test. Fatigue resistance was analyzed using the Kaplan-Meier survival test (95% significance level, log-rank post hoc pairwise comparisons). The samples were categorized according to failure mode. The CAD-CAM materials were examined through scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Results No differences were found between the thicknesses, regardless of the type of the CAD-CAM material. The thick LS OV outperformed the RC and control groups. The thin RC OV and control groups showed a higher percentage of repairable and possibly repairable failures than the other groups. LS was more homogeneous under SEM, and the EDS analysis detected Si and Zr, but not Li. Conclusions A larger thickness did not improve the resistance of the CAD-CAM materials. Thick LS showed a higher cumulative survival rate to fatigue than the RC and control groups. The direct composite alone (control) survived similarly to the experimental groups, except for the thick LS. (AU)

• FAPESP's process: 17/04257-7 - Effect of thickness and type of prosthetic material on load to failure and fatigue resistance of full crowns and overlays made with CAD/CAM system
• Grantee: Mayara dos Santos Noronha
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 15/02461-0 - Load to failure and fatigue resistance of CAD/CAM crowns: evaluation of prosthetic materials and adhesive luting procedures
• Grantee: Marcelo Giannini
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/11658-3 - Effect of Thickness and Type of Prosthetic Material on Ultimate Fracture Load and Fatigue Resistance of Endodontically Treated Molars Restored with CAD/CAM Overlays
• Grantee: Mayara dos Santos Noronha
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate