| General
Description
|
Porcelain,
ceramic or glass-like fillings and crowns.
|
Porcelain
is fused to an underlying metal structure to provide strength
to a filling, crown or bridge.
|
Alloy
of gold, copper and other metals resulting in a strong,
effective filling, crown or bridge.
|
Alloys
of non-noble metals with silver appearance resulting in high
strength crowns and bridges.
|
| Principal
Uses
|
Inlays,
onlays, crowns and aesthetic veneers.
|
Crowns
and fixed bridges.
|
Inlays,
onlays, crowns and fixed bridges.
|
Crowns,
fixed bridges and partial dentures.
|
| Leakage
and Recurrent Decay
|
Sealing
ability depends on materials, underlying tooth structure and
procedure used for placement.
|
The
commonly used methods used for placement provide a good seal
against leakage. The
incidence of recurrent decay is similar to other restorative
procedures.
|
| Durability
|
Brittle
material, may fracture under heavy biting loads. Strength
depends greatly on quality of bond to underlying tooth
structure.
|
Very
strong and durable.
|
High
corrosion resistance prevents tarnishing; high strength and
toughness resist fracture and wear.
|
| Cavity
Preparation Considerations
|
Because
strength depends on adequate porcelain thickness, it requires
more aggressive tooth reduction during preparation.
|
Including
both porcelain and metal creates a stronger restoration than
porcelain alone; moderately aggressive tooth reduction is
required.
|
The
relative high strength of metals in thin sections requires the
least amount of healthy tooth structure removal.
|
| Clinical
Considerations
|
These
are multiple step procedures requiring highly accurate
clinical and laboratory processing. Most restorations require
multiple appointments and laboratory fabrication.
|
| Resistance
to Wear
|
Highly
resistant to wear, but porcelain can rapidly wear opposing
teeth if its surface becomes rough.
|
Highly
resistant to wear, but porcelain can rapidly wear opposing
teeth if its surface becomes rough.
|
Resistant
to wear and gentle to opposing teeth.
|
Resistant
to wear and gentle to opposing teeth.
|
| Resistance
to Fracture
|
Prone
to fracture when placed under tension or on impact.
|
Porcelain
is prone to impact fracture; the metal has high strength.
|
Highly
resistant to fracture.
|
| Biocompatibility
|
Well
tolerated.
|
Well
tolerated, but some patients may show allergenic sensitivity
to base metals.
|
Well
tolerated.
|
Well
tolerated, but some patients may show allergenic sensitivity
to base metals.
|
| Post-Placement
Sensitivity
|
Sensitivity,
if present, is usually not material specific.
|
| Low
thermal conductivity reduces the likelihood of discomfort from
hot and cold.
|
High
thermal conductivity may result in early post-placement
discomfort from hot and cold.
|
| Esthetics
|
Color
and translucency mimic natural tooth appearance.
|
Porcelain
can mimic natural tooth appearance, but metal limits
translucency.
|
Metal
colors do not mimic natural teeth.
|
| Relative
Cost to Patient
|
Higher;
requires at least two office visits and laboratory services.
|
Higher;
requires at least two office visits and laboratory services.
|
Higher;
requires at least two office visits and laboratory services.
|
| Average
Number of Visits To Complete
|
Minimum
of two; matching esthetics of teeth may require more visits.
|
Minimum
of two; matching esthetics of teeth
may require more visits.
|
Minimum
of two |