Flexural Strength and Morphological Study of Different Multilayer Zirconia Dental Materials

• Published in: Materials Vol. 17; no. 5; p. 1143
• Main Authors: Labetić, Andrea, Klaser, Teodoro, Skoko, Željko, Jakovac, Marko, Žic, Mark
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01-03-2024; MDPI
• Subjects: CAD/CAM; Ceramic materials; Ceramics; Cercon ht ML; Composition; Cooling; Crack propagation; Dental equipment and supplies industry; Dental materials; Dentistry; Flexural strength; Fracture toughness; Investigations; Katana ZIRCONIA YML; Manufacturers; Mechanical properties; Microstructural analysis; Microstructure; Milling machines; Modulus of elasticity; Modulus of rupture in bending; Morphology; multilayer zirconia; Multilayers; Prostheses; Qualitative analysis; Sintering; Statistical power; Testing equipment; Tetragonal zirconia polycrystals; Yttria-stabilized zirconia; Yttrium oxide; ZirCad Prime; Zirconium dioxide; Zirconium oxide; Liechtenstein; Cercon ht ML; Katana ZIRCONIA YML; flexural strength; ZirCad Prime; multilayer zirconia
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma17051143

Nowadays, yttria (Y
)-stabilized ZrO
(Y-TZP) is the most commonly used material in dental prosthetics. Y-TZP dental ceramics are mainly stabilized via the addition of 3 mol% yttrium oxide (Y
O
). These ceramics exhibit excellent mechanical properties, including high flexural strength, fracture toughness, elastic modulus, etc. Some manufacturers have recently introduced a new class of dental materials with multilayer composition with the aim of combining the advantages of adding more or less Y
O
to the ceramic composition in one Y-TZP material. The flexural strength values of multilayer Y-TZP may vary depending on the dimensions of the specimen, layer distributions, and especially the layer exposed on the maximum tension side, i.e., loading configuration. Although previous studies have examined the flexural strength of separate Y-TZP layers, capturing the flexural strength of multilayer Y-TZP is still challenging. However, one should keep in mind that multilayer flexural strength is important for clinical indications. The objective of this study is to compare the flexural strength of three distinct multilayer translucent Y-TZP materials made up of layers with different Y
contents. Rectangular samples (2 mm × 2 mm × 16 mm) were prepared from CAD/CAM discs using the milling machine Programill PM7 (Ivoclar Vivadent AG). Milled bars were tested for flexural strength in a three-point bending test (ISO 6872:2015) using a universal testing machine (Inspekt Duo 5kN; Hegewald & Peschke, Nossen, Germany) at a crosshead speed of 0.5 mm/min. Representative samples of each type of material were selected for quantitative and qualitative analysis of the microstructure. Representative samples of each type of material were selected for structural, mechanical, and microstructural analyses.