Biomedical Engineering Reference
In-Depth Information
Figure 9.5.
Ceramic onlay on a molar: a) tooth preparation; b) partial restoration in
lithium disilicate reinforced glass ceramic; c) bonded restoration (2-year follow-up)
9.3. Glass ceramics
Glass ceramics constitute a large family of “bondable ceramics”,
which can be divided into two subclasses: classical and reinforced
glass ceramics.
9.3.1.
Classical glass ceramics
Classical glass ceramics contain a variety of feldspar crystals and a
number of coloring agents. Indeed, these feldspathic ceramics are
designed to veneer all kinds of frameworks, metallic or ceramic, using
a hand-crafted process consisting of the application of a mix of
ceramic powder and modeling liquid on the framework with a brush
and the sintering in a liquid phase, layer-by-layer. They can also be
used in a monolithic way to produce veneers and onlays, which are
directly sintered on a replica of the restoration (Figure 9.6), or which
are milled out of an industrially sintered block with a CAD-CAM
system (Figure 9.7), and therefore are much more resistant. These
types of restorations can be manufactured easily with a CAD-CAM
system in the dental office: their long-term survival rate has been
shown to be very high
[OTT
08]. However, they are often
monochromatic and need to be tinted on the surface to improve the
esthetic result.
