Jaiane Bandoli Monteiro1, Hilton Riquieri2, Catina Prochnow3, Luís Felipe Guilardi4, Gabriel Kalil Rocha Pereira5, Alexandre Luiz Souto Borges6, Renata Marques de Melo7, Luiz Felipe Valandro8. 1. São Paulo State University (UNESP), Science and Technology Institute, São José dos Campos, São Paulo, Brazil. Electronic address: jaiane.monteiro@ict.unesp.br. 2. São Paulo State University (UNESP), Science and Technology Institute, São José dos Campos, São Paulo, Brazil. Electronic address: hilton.riquieri@terra.com.br. 3. Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil. Electronic address: catinaprochnow@hotmail.com. 4. Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil. Electronic address: luisfguilardi@hotmail.com. 5. Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil; School of Dentistry, Meridional Faculty - IMED, Passo Fundo, Rio Grande do Sul, Brazil. Electronic address: gabrielkrpereira@hotmail.com. 6. Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Institute of Science and Technology, São José dos Campos, São Paulo, Brazil. Electronic address: aleborges@ict.unesp.br. 7. Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), Institute of Science and Technology, São José dos Campos, São Paulo, Brazil. Electronic address: marquesdemelo@gmail.com. 8. Faculty of Odontology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil. Electronic address: lfvalandro@hotmail.com.
Abstract
OBJECTIVES: To evaluate the effect of ceramic thickness on the fatigue failure load of two zirconia-reinforced lithium silicate (ZLS) glass-ceramics, adhesively cemented to a dentin analogue material. METHODS: Disc-shaped specimens were allocated into 8 groups (n=25) considering two study factors: ZLS ceramic type (Vita Suprinity - VS; and Celtra Duo - CD), and ceramic thickness (1.0; 1.5; 2.0; and 2.5mm). A trilayer assembly (ϕ=10mm; thickness=3.5mm) was designed to mimic a bonded monolithic restoration. The ceramic discs were etched, silanized and luted (Variolink N) into a dentin analogue material. Fatigue failure load was determined using the Staircase method (100,000 cycles at 20Hz; initial fatigue load ∼60% of the mean monotonic load-to-failure; step size ∼5% of the initial fatigue load). A stainless-steel piston (ϕ=40mm) applied the load into the center of the specimens submerged in water. Fractographic analysis and Finite Element Analysis (FEA) were also performed. RESULTS: The ceramic thickness influenced the fatigue failure load for both ZLS materials: Suprinity (716N up to 1119N); Celtra (404N up to 1126N). FEA showed that decreasing ceramic thickness led to higher stress concentration on the cementing interface. SIGNIFICANCE: Different ZLS glass-ceramic thicknesses influenced the fatigue failure load of the bonded system (i.e. the thicker the glass ceramic is, the higher the fatigue failure load will be). Different microstructures of the ZLS glass-ceramics might affect the fatigue behavior. FEA showed that the thicker the glass ceramic is, the lower the stress concentration at the tensile surface will be.
OBJECTIVES: To evaluate the effect of ceramic thickness on the fatigue failure load of two zirconia-reinforced lithium silicate (ZLS) glass-ceramics, adhesively cemented to a dentin analogue material. METHODS: Disc-shaped specimens were allocated into 8 groups (n=25) considering two study factors: ZLS ceramic type (Vita Suprinity - VS; and Celtra Duo - CD), and ceramic thickness (1.0; 1.5; 2.0; and 2.5mm). A trilayer assembly (ϕ=10mm; thickness=3.5mm) was designed to mimic a bonded monolithic restoration. The ceramic discs were etched, silanized and luted (Variolink N) into a dentin analogue material. Fatigue failure load was determined using the Staircase method (100,000 cycles at 20Hz; initial fatigue load ∼60% of the mean monotonic load-to-failure; step size ∼5% of the initial fatigue load). A stainless-steel piston (ϕ=40mm) applied the load into the center of the specimens submerged in water. Fractographic analysis and Finite Element Analysis (FEA) were also performed. RESULTS: The ceramic thickness influenced the fatigue failure load for both ZLS materials: Suprinity (716N up to 1119N); Celtra (404N up to 1126N). FEA showed that decreasing ceramic thickness led to higher stress concentration on the cementing interface. SIGNIFICANCE: Different ZLS glass-ceramic thicknesses influenced the fatigue failure load of the bonded system (i.e. the thicker the glass ceramic is, the higher the fatigue failure load will be). Different microstructures of the ZLS glass-ceramics might affect the fatigue behavior. FEA showed that the thicker the glass ceramic is, the lower the stress concentration at the tensile surface will be.
Authors: Georgina García-Engra; Lucia Fernandez-Estevan; Javier Casas-Terrón; Antonio Fons-Font; Pablo Castelo-Baz; Rubén Agustín-Panadero; Juan Luis Román-Rodriguez Journal: Medicina (Kaunas) Date: 2020-03-18 Impact factor: 2.430