17944451
Description
Mind Map by Alice Dolman, updated more than 1 year ago
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Created by Alice Dolman
over 5 years ago
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*Why are temporary crowns usedin restorative dentistry? Give twoexamples of different types oftemporary crowns manufacturedwithin the laboratory.
- Like other interim restorations, it serves until a final restoration can be inserted.
- Where medium- to longer-term temporization is envisaged (some months or more), consideration should be
given to an indirect temporary restoration, which is constructed in the dental laboratory.
- Functions:
- Protect the remaining tooth structure and prevent sensitivity
- Some 30 000 to 70 000 dentinal tubules are opened per square millimetre during
tooth preparation. The passage of oral bacteria into the freshly cut dentine must be
minimized as this will cause pulpal inflammation, which manifests as sensitivity if the
dentine is exposed to stimuli from the oral environment such as hot, cold and sweet.
- Some 30 000 to 70 000 dentinal tubules are opened per square millimetre during
tooth preparation. The passage of oral bacteria into the freshly cut dentine must be
minimized as this will cause pulpal inflammation, which manifests as sensitivity if the
dentine is exposed to stimuli from the oral environment such as hot, cold and sweet.
- Shape the gum tissue properly
- Provisional restorations offer dental aesthetics purposes especially
for anterior teeth.
- Patient can evaluate the aesthetic of the temporary crown so that
it can be changed in the definitive restoration.
- Maintain the tooth’s function, masticatory function for posterior
teeth can be restored as well.
- Prevent teeth shifting, Overeruption of opposing teeth and drifting of
adjacent teeth can be prevented by providing provisional restoration.
- It also allows the area to be cleaned more effectively and thus maintains a state of
gingival health. This decreases the incidence of gingival inflammation and bleeding at
the time of fitting the definitive restoration, which is particularly important when the
restoration is being bonded using a hydrophobic resin-based composite material.
- Protect the remaining tooth structure and prevent sensitivity
- Example 1-
- An acrylic, such as heat- or self-cured polymethylmethacrylate
- Advantages
- • Strong • High wear resistance • Good
aesthetics • Easy to modify
- • Strong • High wear resistance • Good
aesthetics • Easy to modify
- Disadvantages
- • Polymerisation shrinkage - can affect fit • Setting
reaction exothermic - can cause damage to dental pulp
• Unreacted monomer can damage gingivae and pulp
- • Polymerisation shrinkage - can affect fit • Setting
reaction exothermic - can cause damage to dental pulp
• Unreacted monomer can damage gingivae and pulp
- Advantages
- An acrylic, such as heat- or self-cured polymethylmethacrylate
- Example 2-
- ceramic bonded to metal – non-precious metal alloys are normally chosen on grounds
of lower cost.-
- Advantages
- • Very strong and durable • Highly resistant to wear • Porcelain
can mimic natural tooth appearance
- • Very strong and durable • Highly resistant to wear • Porcelain
can mimic natural tooth appearance
- Disadvantages
- • Aggressive tooth reduction required • Porcelain can rapidly
wear opposing teeth if its surface becomes rough • Porcelain
prone to impact fracture
- • Aggressive tooth reduction required • Porcelain can rapidly
wear opposing teeth if its surface becomes rough • Porcelain
prone to impact fracture
- Advantages
- ceramic bonded to metal – non-precious metal alloys are normally chosen on grounds
of lower cost.-
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