Flashcards in week 4- temporary crowns Deck (7)
what are the types of temporary crowns we can use
posterior stainless steel crowns
directa anterior crowns
integrity crowns with a model
advantages of a temporary crown
Promote pt comfort by sealing exposed dentine
Protecting tooth vitality
Gingival health and contour maintained- a poor fitting crown can lead to gingival overgrowth, food packing or difficult for the patient to clean this area
Occlusal stability- reduces the likelihood of overeruption or drifting
A temporary crown also allows clinicians to see whether enough reduction has been done
how do we take a custom made temporary crown
1. A mould is taken before any preperation is done to the tooth
2. We can use three types of material
◊ Alginate impression/silicone impression
◊ The alginate has the advantages of absorbing the resin exotherm where the silicone putty is more durable and can be used again
PVC vaccuum formed splint is constructed by a technician prior to the appt
how do we make a custom temp crown
1. Place Vaseline on the prepared tooth and the adjacent teeth-
2. Syringe In the chosen material- today we use integrity into the deepest area of the tooth
Be careful of air bubbles- this can be prevented by self mixing tip in the material
3. Support the index and wait until the material hardens to the gel stage before carefully removing it. You can place a small amount of the integrity on the back of your hand so you can monitor when this gel stage has been reached.
4. Carefully remove the set temporary crown from the index. Sometimes, the temporary crown can remain on the prepared tooth. If this occurs carefully try to remove the temporary crown from the preparation without damaging it.
5. If the index was fully seated then minimal adjustments would be required, except for the excess flash material at the crown margins.
6. Using a slow-speed hand piece, mandrel and a series of soflex discs the excess flash material can be removed extra-orally from the side of the crown to ensure the margins are well adapted and contoured. Following this the occlusion can be checked and adjusted if required.
7. Once the temporary crown meets the aesthetic and functional criteria with good margin adaption, can it then be cemented in position with a temporary cement, such as Tempbond or Tempbond NE. Remember not to over fill the crown with the temporary cement, otherwise it can be hard to fully seat the crown due to the hydrostatic pressure.
why do we place Vaseline on the neighbouring teeth
will encourage the temp crown to be removed more easily
how do we carry out remargination
a. Removing some material at the crown margins with a bur or a soflex disc- it is useful to flare out the inside of the crown margin with a bur which will increase the SA
b. Apply a thin layer of scotbond universal, evaporate the solvent and light cure for 30 seconds- following this add a small amount of composite onto the outer aspect where the deficiency is
c. Reset the crown adjust the composite if necessary
d. Once the composite is cured, the temporary crown can be adjusted to remove flash material to ensure well fitting materials
The final temporary crown can then go through the final stages of checking the occlusion, finishing and polishing