Temp and Provisional Crowns (weird af, watch lecture)

Question 1

What are temporary crowns usually made of

Answer 1

Acrylic resins e.g. MMA/PMMA
OR
Chemical/light cured composite e.g. DMA

Question 2

What is the function of the temporary crown

Answer 2

• Protects open dentine tubules from micro-leakage avoiding hypersensitivity and protecting root canal treated teeth from bacterial invasion
• Maintain occlusal relationship to prevent over eruption
• Maintain interdental space and contacts to prevent teeth shifting
• Prevent gingival hyperplasia at margins
• Maintain appearance

Question 3

What is the use of a provisional crown

Answer 3

This is a temp crown but is used to test change in the crown shape, colour and occlusion during function and is expected to last longer than a few weeks

Question 4

What is an iwanson gauge used for

Answer 4

To measure thickness, in this case it would be to confirm there is enough occlusal reduction

Question 5

What is the procedure needed for lab made provisionals

Answer 5

• Completion of preparations
• Chairside temporaries as interim crowns
• Impression of preparations using silicone
• Facebow and jaw registration
• Cementation of temp crowns
• Impressions and jaw records sent to lab with instructions and shade
• Lab provisionals returned for fit

Question 6

What are some of the materials that are used to make chair side provisionals

Answer 6

• Poly vinyl ethyl methacrylate (Trim)
• Poly ethyl methacrylate (Snap)
• Bis acryl composite (protemp II, quicktemp)
• Poly methyl methacrylate (duralay)

Question 7

What is the most common technique to make temps and provisionals

Answer 7

• Overimpressions using alginate or putty

Question 8

AY BAWS CAN I HABE DE NOTE PLZ

Answer 8

Apparently using a half tray or an appropriate sized lower tray for an upper tooth is useful when making an over impression

Question 9

If the core of the tooth is broken how can you fix it to take the over impression for temp crowns

Answer 9

Fill the space temporarily with red carding wax

Question 10

Describe the steps of taking an over impression to make a temp crown

Answer 10

• After the prep and before the impression, the putty/alginate index is filled with Trim, Snap or Protemp/Quicktemp and refitted over the preparation in the mouth
• Material is allowed to set to the rubbery stage and then removed, before setting hard into the undercuts
• Preparation margin is trimmed back using an acrylic bur followed by so flex discs
• ## Maintain occlusal anatomy and contact points

Question 11

Describe the steps of the vacuum formed matrix method of making temp/provisional crowns

Answer 11

• ## Made from a stone cast of the teeth to be prepared and a couple of teeth either side