Ceramics Flashcards
What are hue, chroma and value
- Hue- Colour
- Chorma - saturation
- Value - brightness
What is sintering?
Densification of polycrystalline object closer to but below the melting point of the material
What are the four broad categories of ceramics
- Predominantly glass
- Particle filled glass
- Polycrystalline (no glass)
- Other
what is predominantly glass cermic?
Feldspathic porcelain
What are particle filled glass ceramics?
Ceramics with filler particles added to improve mechanical properties such as thermal expansion and strength
What is porcelain largely made of?
- Silica
- Alumina
What is the crystalline matrix of ceramic usually made from?
Usually alumina.
Glass infiltrated ceramics have varying amounts of silica.
Example of a high glass content ceramic:
- IPS Empress I
- Leucite-reinforcement
Example of a low glass content ceramic
- IPS Emax
- Lithium Discilicate crystal structure
Two examples of polycrystaline ceramics
- Procera Alumina
- Zircona
What are hybrid ceramics?
Ceramic particles held in a resin matrix.
Inorganic, non-metallic materials made by heating of raw minerals at hight temperatures:
Dental ceramics
What is the difference between ceramics and porcelain?
Ceramic is a compound of metallic elements such as aluminium and non-metallic elements such as oxygen. Porcelain is a ceramic consisting of a glass matrix phase and one or more crystalline phases.
4 disadvantages of resin cements
- Risk of polymerizatio shrinkage resulting in marginal leakage
- Require good isolation
- May change shade
- Will not compensate for poor fit
