Welcome back in the course on fundamentals. This particular area is going to focus on restorative
material options for indirect restorations. This will influence your decisions on the
tooth preparation design you're considering. So, our ultimate goal, of course, is to mimic
tooth structure. Then we're dependent on not only the restorative materials, but the hands
that are going to be using ... or, fabricating the restorations. So, either you're dependent on you,
your staff if you're doing it in your office, or a dental laboratory. So here I show you the
final outcome before I show you the actual tooth preparations, because our goal is to mimic tooth
structure. So whether it's a crown or a veneer, so partial coverage versus full coverage, the upper
teeth are restored, the lower teeth are natural, the goal is to mimic the natural tooth structure.
Once you see the tooth preparation, I think we all realize we have to vary our preparation based on
our discoloration. 'Cause now I need to change the restorative material to mask severe discoloration,
where on teeth that are veenered, I may be able to use more translucent materials. Considering
partial coverage first - veneers - and I'm looking at monolithic restoration, so stain and glaze,
I have an option of a feldspathic or glass ceramic material. A very weak veneer, 80 megapascals in
strength. But maybe, and arguably, the most esthetic. Because I'm calling this monolithic
even though the technician can layer different colors and translucencies to fabricate it. But
it's 100% the same material. Then we get into leucite reinforced glass ceramic
Empress-type materials, lithium disilicate e.max-type materials, and then translucent
zirconia materials, which have to be manufactured by CAD/CAM. Increasing esthetics as we go up the
list, increasing strength as I go down the list. Monolithic means applying surface stains, and over
the top of that a surface glaze. So over a period of time, that can wear off. Some of the research
is showing as early as 8 to 10 years those surface stains can begin to be diminished, and yet we're
discussing veneers at an 83% survival rate at 20 years. So if you're doing monolithic restorations,
maybe stain and glaze is less expensive today, but maybe not as long lasting from an esthetic
perspective. When you get into bi-layered veneers, the weak link is always the layering material
that goes over the top of the substrate. That layering material is 80 megapascals in strength,
feldspathic or glass ceramic materials. I'm now including, again, feldspathic and glass ceramic
as a layered material because, again, it can be layered, as I've already discussed.
But it is monolithic because it's 100% the same material. But now the leucite, lithium disilicate,
and some manufacturers allow translucent zirconia to be layered with this 80 megapascal
layering material. And again, specifically manufactured by individual manufacturers
for their own materials. Looking at the layering, you can have a microlayer of three-tenths, you
can have five-tenths of a millimeter of the veneer material facially only, half of the incisal edge,
or overlapping the incisal edge. The more layering materials you use, you increase esthetics,
but you decrease the strength because the 80 megapascal strong material on the functioning
edge. So next we will move into crowns, but that completes our discussion materials for veneers.