Temporary Crowns Flashcards
(43 cards)
Why do we need temporary crowns?
- To protect the tooth before permanent crown is made
- Temporarily bring it back to function between appointments
To restore aesthetics between appointments - To prevent dentinal sensitivity
- Protection from reinfection between appointments
- To prevent unwanted tooth movement
- To test any changes we are making to aesthetics or occlusion
How long does it take for a permanent crown to be made in the LDI?
3 weeks
What causes dentinal sensitivity
Exposure of dentinal tubules due to the removal of enamel
Name the mechanism that describes how dentinal tubules lead to sensitivity
Hydrodynamic flow theory
What is try consequence of teeth over erupted after preparation?
When you place you permanent crown it may not sit right (may sit too high) due to over eruption of the prepared tooth
Temporary crowns used to check aesthetics are termed as?
Provisional crowns
What are the benefits of using provision crowns?
If you are modifying the aesthetics of the tooth the patient get an almost taster session of how they will look once the permanent crown has been placed
This gives the patient enough time to decide if they like the restoration or not
What are temporary crowns used to prevent?
- Sensitivity of dentine
- Bacterial invasion of denial tubules
- Over eruption and drifting of teeth
- Overgrowth of gingiva
What are temporary crowns used to restore
- Aesthetics
- Occlusion
- Contact points
List some ideal properties of a temporary crown
- Aesthetic
- Sufficient strength to be functional
- Restore contact points
- Accurate margins to prevent plaque accumulation
- Retentive BUT easily removed when needed
- Biocompatible
Name the 3 main methods of manufacturing a temporary crown
1, Direct custom made
- Prefabricated
- Indirect lab made
Name the most common method we use to manufacture temporary crowns
Direct chair side custom made technique
Talk through the direct chair side custom made technique of temporary crown making
- Make a mould of the tooth
- Crown prep
- Use the mould to make the temporary crown: place bis acryl composite into the mould
- Let the composite set then you can remove it from the putty mould
- Remove any excess (flash) of the temporary crown
- Cement the temporary crown with temporary cement
What is the trade name for bis acryl composite?
Integrity
What are the benefits of using bis acryl composite for making a temporary crown
- Adequate strength
- Accurate fit
- No mixing required
- Acceptable aesthetics
- Choice of 2 shades
- Can repair with composite
What are the disadvantages of bis acryl composite for making a temporary crown
- May have a granular finish (can be resolved by polishing)
- Only 2 shade choices so won’t be a perfect match
- Poor stain resistance
What is the disadvantage of the the chair side direct custom made technique?
- What is the tooth that needs the crown is in poor shape to start with
- What if if want to change the shape of the teeth
We cannot use a mould in these scenarios as we want a different finishing
Talk through the stages of the direct lab made technique for making temporary crowns
- Take a mould of the teeth and send this mould to the lab
- The lab can then produce an ideal tooth shape which can now be used as the template
- Crown prep
- Lab can make an index for the whole arch using PVC material
- Use the mould to make the temporary crown: place bis acryl composite into the mould and Let the composite set then you can remove it from the putty mould
- Remove any excess (flash) of the temporary crown
- Cement the temporary crown with temporary cement
Asking the lab to produce an ideal tooth shape from a mould is called what?
Creating a diagnostic wax up
What are trey benefits of the lab making a vinyl PVC mould of the entire arch?
It is easy to use and is permanent so if patient comes again and needs another tooth crowned we already have the perfect model ready to make the temporary crown
What is the disadvantage of the direct lab made technique for making temporary crowns
When removing the excess flash of the temporary crown you need to do it in the mouth and the excess can get trapped in the undercuts of the mouth and can be difficult to remove once the composite has gotten hard
Talk through the stages of using prefabricated temporary crowns
- Crown preparation
- Select crown from range of sizes
- Customise the prefabricated temp crown to fit the tooth accurately by using the integrity
What are the benefits of using prefabricated temporary crowns
- Come ready made
- usually made of a hard wearing material
- Durable
What are the disadvantages of using prefabricated temporary crowns
Need to be adjusted to fit each individual tooth
