08-11-2016, 10:17 AM
1466479533-RECENTADVANCESINDENTALCERAMICS.ppt (Size: 1.07 MB / Downloads: 59)
INTRODUCTION
Though conventional ceramics provide esthetically pleasing retorations they have many drawbacks which limit their use.With more and more studies coming in the field of ceramics and with the advent of digital technology newer and better products are flooding the market these days.The “chinese clay” of olden days have become the unavoidable product in esthetic dentistry...
HISTORY
Since the stone age ceramics have been important for humans.
1789-de_chemant & Duchateau.
1822-baking process.
1825-commercial production by Stockton.
1903-Dr.Charles Land-first ceramic crown
1962-Patents by weinstien and wenstein.
1965-Mclean & Hughes
One of the most serious drawbacks with the early dental porcelains were their lack of strength and toughness, which seriously limited their use. In order to overcome these problems, there are two possible solution.
One solution is to provide the dental porcelain with support from a stronger substructure.
The other option is to produce ceramics, which are stronger and tougher.
Metal free ceramic systems
All ceramic systems can provide better esthetics.
Wide range of tranlucency opacities are available
Soft tissue health
No over contouring
Glass infiltrated alumina
In-ceram alumina
Supplied as one of the three core ceramics.
1)in-ceram spinell
2)in-ceram alumina
3)in-ceram zirconia
In - ceram
A slurry of material is slip cast on porous refractory die and heated in a furnace to produce a partially sineterd coping.
This coping is infiltrated with glass at temp1100*c -4hrs
In-ceram alumina
Indication-anterior and posterior crowns and anterior 3-unit FPDs.
Flexuarl strength-500mPa
The final ICA core consists of 70wt% alumina and 30wt%sodiumlnathanum glass.