Relining and Rebasing

Question 1

What is relining?

Answer 1

Resurfacing tissue side of removable denture with new base material, thus correcting the fit of denture by increasing the accuracy of adaptation with gingiva

Question 2

When is relining commonly used?

Answer 2

• Old dentures (in service for sometime, but underlying bone resorption change ridge shape)
• Immediate dentures (due to post extraction resorption)

Question 3

What is rebasing?

Answer 3

Replacement of the entire denture base on an existing prosthesis
(usually not done as teeth worn out by time denture is worn)

Question 4

T/F Both relining and rebasing require impression to be taken

Answer 4

T

Question 5

T/F Relining can improve occlusion, adjust OVD or make alterations in tooth position or aestehtics?

Answer 5

F

Question 6

What should you inform the patient re. relining?

Answer 6

They will be without their denture for some time as lab is doing the procedure

Question 7

What are the clinical steps to relining a denture?

Answer 7

• Consult (check bite, and whether reline beneficial, remove undercuts and overextensions)
• Book in with technician
• Take impression by:
  (1) applying impression material to old denture
  (2) place denture firmly into position
  (3) get patient to close into centric occlusion
  (4) Muscle moulding
• Make sure denture doesn’t move out of position
• Get patient to keep together while material sets

-Send to lab with following instructions:
“Please reline FU in pink acrylic resin”
*Can also ask to make palatal seal a little deeper and wider than normal for uppers
*Can also ask to reline with Molloplast soft base

Insertion:
-Same as for normal denture

Question 8

What are the item codes for relining?

Answer 8

771: Temporary lining/tissue conditioners
737: Permanent lining/resilient lining

Question 9

T/F soft temporary linings are a powder/liquid mix

Answer 9

T

Question 10

What are soft temporary linings made from? Do they stay soft or turn hard after setting?

Answer 10

• Modified acrylic resin

- Stay soft

Question 11

What two brands of material are available for soft temporary lining?

Answer 11

Coe Comfort: White, lasts 1-2 weeks

Coe Soft: Pink, lasts 1-3 months

Question 12

What happens if soft temporary linings are not regularly replaced?

Answer 12

• Fully set
• Become porous
• Attract bacteria

Question 13

What are the steps to temporarily relining a denture with soft lining?

Answer 13

• Remove any old denture liners
• Mix powder and liquid of new liner
• Apply liner to material to denture
• Insert denture into patient’s mouth
• Muscle mould the material and leave to set
• Fill a denture cup with warm water
• Remove denture and place it into warm water to remove stickiness
• Remove excess with scissors and warm scalpel blade

Question 14

What instructions should be provided to patients after completing a soft temporary lining?

Answer 14

• Continue wearing while it is soft
• Leave it in water or denture clenaing tablet at night
• Dont brush too vigorously

Question 15

What are the two main types of soft resilient lining? What are the advantages/disadvantages of each one? What is an example brand of each one?

Answer 15

• Acrylic based
• Bonds to denture base better
• Easier to adjust and polish
• But hardens and crazes (develops craze lines/cracking) over time
• Brand: vertex
• Silicone base
• Lasts longer than acrylic based
• Stays softer longer
• Does not bond to denture base as well
• Difficult to handle (work with in lab, adjust and polish)–>requires good technician
• Prone to candida
• Brand: Molloplast B

Question 16

When can and can’t a soft resilient lining be used? Why?

Answer 16

• Applied to fitting surface of FL dentures–>cushion impact from resorbed/irregular/frail supporting tissues
• Can’t be used on FL as either too thin to be soft or will make denture base too thick

Question 17

What should you consider if patient comes to you with denture that has already got soft resilient liner on it and has had it for a while?

Answer 17

• Pt probably only been comfortable since soft lining was placed
• Do not try to make new dentures or reline with hard lining

Question 18

What is the minimum thickness required of soft resilient liners?

Answer 18

2-3mm

Question 19

What should be used to adjust silicone based soft resilient liners?

Answer 19

-Dedeco wheels

Question 20

What is the method for relining using a resilient soft liner (lab steps)?

Answer 20

• Note this was deduced by logic rather than reading something on it
• You need to understand flasking (investing), boiling and packing, deflasking and trimming to understand this, refer to google docs BDS4 if you do not

1. Receive the impression from clinic (which should be inside the denture as it was used as a tray)
2. Pour up model using impression
3. Perform investing procedure, with the master cast attached to the flask plaster as usual and place the denture on top of the master cast
4. In the boiling and packing stage, remove the impression material from the denture (the flask has pretty much recorded its position relative to the master cast/arch)
5. Apply resilient soft lining to the fitting surface of the denture
6. Place the flask lid and body back together, and wait for lining material to set
7. Deflask and trim

(If confusing refer to google docs Relining Resilient Soft liner steps bds4)