All-Ceramic restorations

Question 1

……… is the process of firing thecompacted ceramic powder at high temperature to ensure optimal densification

Answer 1

Sintering

Question 2

Zirconia forms are

Answer 2

1- monoclinic at room temperature. 2- Tetragonal zirconia (1187c-1206 –c) 3- cubic zirconia ( 1167 °C- 2367 °C)

Question 3

The more restrictive term porcelain refers to a specific compositional range of ceramic materials originally made by …………., ………..and …………and…………and……..

Answer 3

• mixing kaolin (hydrated aluminosilicate),
• quartz (silica)
• feldspars (potassium
• sodium aluminosilicates),
• firing at high temperature.

Question 4

zirconia-based ceramic for soft machining is consists of tetragonal zirconia polycrystals partially stabilized by….

Answer 4

addition of 3 mole percent yttrium (3Y-TZP)

Question 5

Zirconia forms are:

Answer 5

1- monoclinic at room temperature.
2- Tetragonal zirconia (1187c-1206 –c)
3- cubic zirconia ( 1167 °C- 2367 °C)

Question 6

Characteristics of zirconia:

Answer 6

1- superior toughness, strength, and fatigue resistance.
2- in addition to excellent wear properties and
3- Zirconium (Zr) is similar chemical and physical properties to titanium (Ti).
4- is a white crystalline oxide of zirconium.