Dental Ceramics Flashcards
what is a dental ceramic?
made from ceramics such as PORCELAIN
used in restorations where crowns, bridges inlays and onlays are needed
good aesthetic properties
what are the general properties required of conventional dental ceramics?
- aesthetics
- chemical stability
- biocompatibility
- thermal & mechanical properties
- dimensional stability
what is the chemical stability of a dental ceramic?
- theyre very stable
- unaffected by the wide pH range of mouth
- dont take stain from food/drink
- no adverse effects on biological tissues
what are the aesthetic properties of a dental ceramic?
- colour stable & very smooth finish
- optical properties (reflectance, opacity, translucency, transparency)
what are the thermal properties of dental ceramics?
- similar to tooth substance
- thermal expansion is similar to dentine
- LOW thermal diffusivity (protects tooth from heat)
what are the mechanical properties of a dental ceramic?
- high compressive strength and hardness
LOW:
- flexural strength
- tensile strength
- fracture toughness
[these can lead to failure during loading]
only used anterior teeth since they break elsewhere
what is strong coping in dental ceramics?
A coping is the substructure of a dental ceramic, usually metal which provides it with support from stresses.
Strong coping refers to the ability of the ceramic material to resist fracture and breakage under stress (essential for dental restorations)
What is zirconia?
A ceramic material that is used because of its EXCEPTIONAL STRENGTH, DURABILITY and BIOCOMPATIBILITY.
what are the problems with zirconia cored crowns?
- expensive equipment needed
- potential for veneering porcelain to DEBOND from zirconia core
- zirconia core is OPAQUE (cant be seen through)
