9 - Dental Ceramics II Flashcards
This lecture covers the available materials for current use of dental ceramics.
Although starting with the, now redundant, porcelain jacket crown,
the lecture builds on techniques for manipulation, and clinical
application, of dental materials suitable for aesthetic veneers and
crowns.
These techniques include the use of refractory die materials, the use of the lost wax technique and the now widespread use of CAD CAM as a method of indirect restoration manufacture
porcelain jacket crown:
made out of?
how much tooth reduction required?
prone to?
- feldspathic porcelain with added alumina
- need at least 1-2mm reduction
- prone to fracture
anatomy of a porcelain jacket crown?
- feldspathic porcelain
- alumina porcelain
- platinum foil (stone die only)
- stone or refractory die
veneer: how is it made?
- pour up impression: refractory die or stone die
- foil over stone die
- build up veneer and fire
- try in
- etch fit surface
- bond
dentine bonded crown:
made out of?
process?
when does the strength come?
- feldspathic porcelain on refractory die
- trial for fit (not occlusion), etch fit surface, bond
- strength comes once crown is bonded in situ
hot-pressed/injection moulded ceramics:
- uses what technique?
- how is it done
- what types of ceramics are used?
- lost wax technique
- ceramic is pressed into space
- leucite reinforced glass ceramic (IPS Empress)
- lithium disilicate glass ceramic (IPS Empress 2/E-max)
hot-pressed/injection moulded ceramics:
describe anatomy x4
- cast, hot pressed or injection moulded ceramic
- shoulder or chamfer margins
- phosphate bonded investment material
- shading or surface characterization (added after divestment)
improved coping strength:
coping made of a slurry containing?
how is coping removal eased?
veneered with?
- alumina (in-ceram alumina)
- alumina with magnesium (in-ceram spinell)
- alumina and zirconia (in-ceram zirconia)
- covers a shrinking refractory die, therefore coping removal is easier
- feldspathic porcelain
in-ceram crown: made out of?
- feldspathic protein
- slurry coping
- rounded shoulder or chamfer margin
- shrinking refractory die
3 components of the general design of an all ceramic crown?
- all ceramic crown material
- rounded shoulder or chamfer margin
- stone or refractory die
what is used at Dundee - porcelain and poly-crystalline ceramics?
- high alumina porcelain (DBC)
- feldspathic porcelain (DBC and MCC)
- lithium di-silicate glass ceramic (e-max)
- zirconia (lava)
what is used at Dundee - composites?
- ceromer (shofu ceramage)
- milled composite (lava ultimate)
high alumina porcelain:
how does it advantageous for DBCs?
can be used for?
- supports and strengthens feldspathic porcelain for DBCs
- can be etched, can be used for opaque metal substructure of MCCs prior to placement of feldspathic porcelain
feldspathic porcelain:
used for?
- aesthetic and etchable porcelain, used for:
- covering high alumina porcelain (in DBCs/opaque layer of MCCs)
- veneers made on either foil or refractory dies
- covering zirconia frameworks
lithium di-silicate glass ceramic (e-max):
advantages?
made using?
made for?
- aesthetic, high-strength and etchable glass ceramic
- made using CAD-CAM technology
- veneers, inlays/onlays, crowns, bridges, covering zirconia frameworks
