IADR Abstract Archives
Load to Failure of 1 mm Multi-Layered Zirconia Restorations
Objectives: To examine the load bearing capability of four dental multi-layered zirconias in 1 mm uniform thickness restorations.
Methods: Four groups of zirconia materials were tested: Group 1: KatanaTM UTML (5Y-TZP high translucency chroma-gradiated zirconia) Group 2: KatanaTM STML (4Y-TZP high translucency chroma-gradiated zirconia), Group 3: IPS e.max®ZirCAD MT Multi (4Y to 5Y-TZP high esthetic powder-gradiated zirconia), Group 4: IPS e.max®ZirCAD Prime (3Y to 5Y-TZP high esthetic powder-gradiated zirconia). A 1 mm uniform thickness molar crown and was designed using the 3Shape Dental manager software. Crowns (10/group) were milled in each material using Wieland Zenotec Select Hybrid milling unit from the middle of the zirconia puck. All Groups were fired according to the manufacturer’s instructions in a Programat S1 zirconia sintering oven (Ivoclar Vivadent). The crowns were bonded to composite preparations using an adhesive cement (Variolink® Esthetic DC, Ivoclar Vivadent, Inc.) and stored in an incubator for 24 hrs (37degC/100% humidity). The specimens were loaded to failure using a 15-mm diameter steel ball at a crosshead speed of 1.0 mm/min with an Instron Universal Testing machine.
Results: The mean failure loads (N) were as follows: Group 1: 3307±1023; Group 2: 4008±840; Group 3: 4802±876; and Group 4: 6611±1226.
Using ANOVA (p≤0.05), a statistical difference was found between Group 4 and the other 3 groups. Group 2 was not statistically different than Groups 1 or 3 though Group 3 is statistically greater than Group 1.
Conclusions: Within the bounds of this study, the multilayered zirconia containing a 3Y core (IPS e.max®ZirCAD Prime) had a statistically significant higher load to failure value than zirconia groups with the core of 4Y or 5Y zirconia materials (Groups 1-3).
Methods: Four groups of zirconia materials were tested: Group 1: KatanaTM UTML (5Y-TZP high translucency chroma-gradiated zirconia) Group 2: KatanaTM STML (4Y-TZP high translucency chroma-gradiated zirconia), Group 3: IPS e.max®ZirCAD MT Multi (4Y to 5Y-TZP high esthetic powder-gradiated zirconia), Group 4: IPS e.max®ZirCAD Prime (3Y to 5Y-TZP high esthetic powder-gradiated zirconia). A 1 mm uniform thickness molar crown and was designed using the 3Shape Dental manager software. Crowns (10/group) were milled in each material using Wieland Zenotec Select Hybrid milling unit from the middle of the zirconia puck. All Groups were fired according to the manufacturer’s instructions in a Programat S1 zirconia sintering oven (Ivoclar Vivadent). The crowns were bonded to composite preparations using an adhesive cement (Variolink® Esthetic DC, Ivoclar Vivadent, Inc.) and stored in an incubator for 24 hrs (37degC/100% humidity). The specimens were loaded to failure using a 15-mm diameter steel ball at a crosshead speed of 1.0 mm/min with an Instron Universal Testing machine.
Results: The mean failure loads (N) were as follows: Group 1: 3307±1023; Group 2: 4008±840; Group 3: 4802±876; and Group 4: 6611±1226.
Using ANOVA (p≤0.05), a statistical difference was found between Group 4 and the other 3 groups. Group 2 was not statistically different than Groups 1 or 3 though Group 3 is statistically greater than Group 1.
Conclusions: Within the bounds of this study, the multilayered zirconia containing a 3Y core (IPS e.max®ZirCAD Prime) had a statistically significant higher load to failure value than zirconia groups with the core of 4Y or 5Y zirconia materials (Groups 1-3).