Mechanical behavior of endocrowns fabricated with different CAD-CAM ceramic systems

Author(s)

Dartora, Nereu Roque ^[1] ; Moris, Izabela Cristina Mauricio ^[1] ; Poole, Stephanie Francoi ^[1] ; Bacchi, Atais ^[2] ; Sousa-Neto, Manoel Damiao ^[3] ; Silva-Sousa, Yara Terezinha ^[1] ; Gomes, Erica Alves ^[1]

Affiliation

^[1] Univ Ribeirao Preto UNAERP, Sch Dent, Ribeirao Preto - Brazil

^[2] Merid Fac IMED, Sch Dent, Passo Fundo, RS - Brazil

^[3] Univ Sao Paulo FORP USP, Dept Restorat Dent, Dent Sch Ribeirao Preto, Ribeirao Preto - Brazil

• Document type: Journal article
• Source: JOURNAL OF PROSTHETIC DENTISTRY; v. 125, n. 1, p. 117-125, JAN 2021.
• Web of Science Citations: 1

Abstract

Statement of problem. The mechanical behavior of ceramic endocrowns is unclear. Purpose. The purpose of this in vitro and 3-dimensional finite element analysis (3D-FEA) study was to evaluate the mechanical behavior of endodontically treated teeth restored with ceramic endocrowns made by using different computer-aided design and computer-aided manufacturing (CAD-CAM) systems. Material and methods. Sixty mandibular human molars were endodontically treated, prepared for endocrowns, and divided into 4 groups (n=15) according to the following various ceramic systems: leucite-based glass-ceramic (LC group), lithium disilicate-based glass-ceramic (LD group), glass ceramic based on zirconia-reinforced lithium silicate (LSZ group), and monolithic zirconia (ZR group). After adhesive bonding, the specimens were subjected to thermomechanical loading and then to fracture resistance testing in a universal testing machine. The failure mode of the specimens was qualitatively evaluated. Three-dimensional FEA was performed to evaluate the stress distribution in each group. Data were analyzed by using a 1-way ANOVA and the Tukey HSD test (a=.05). Results. Statistically significant differences among the groups were observed (P<.05). The outcomes of the LC, LD, and LSZ groups were similar (1178 N, 1935 N, and 1859 N) but different from those of the ZR group (6333 N). The LC and LD groups had a higher ratio of restorable failures, while LSZ and ZR had more nonrestorable failures. Fractographic analysis indicated a regular failure pattern in the ZR group and irregular failure patterns in the other groups. Three-dimensional FEA revealed similar values and stress pattern distributions among the groups. Conclusions. The mechanical performance of monolithic zirconia was better than that of the other ceramic endocrowns considered in this research; however, monolithic zirconia presented a higher rate of catastrophic tooth structure failure. (AU)

• FAPESP's process: 16/25311-7 - Effect of pulp chamber filling with glass ionomer cement in endodontically treated teeth rehabilitated with endocrowns: in vitro and MEF-3D analysis
• Grantee: Erica Alves Gomes
• Support Opportunities: Regular Research Grants