Relining and Rebasing Flashcards
What is relining?
Resurfacing tissue side of removable denture with new base material, thus correcting the fit of denture by increasing the accuracy of adaptation with gingiva
When is relining commonly used?
- Old dentures (in service for sometime, but underlying bone resorption change ridge shape)
- Immediate dentures (due to post extraction resorption)
What is rebasing?
Replacement of the entire denture base on an existing prosthesis
(usually not done as teeth worn out by time denture is worn)
T/F Both relining and rebasing require impression to be taken
T
T/F Relining can improve occlusion, adjust OVD or make alterations in tooth position or aestehtics?
F
What should you inform the patient re. relining?
They will be without their denture for some time as lab is doing the procedure
What are the clinical steps to relining a denture?
- 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
What are the item codes for relining?
771: Temporary lining/tissue conditioners
737: Permanent lining/resilient lining
T/F soft temporary linings are a powder/liquid mix
T
What are soft temporary linings made from? Do they stay soft or turn hard after setting?
- Modified acrylic resin
- Stay soft
What two brands of material are available for soft temporary lining?
Coe Comfort: White, lasts 1-2 weeks
Coe Soft: Pink, lasts 1-3 months
What happens if soft temporary linings are not regularly replaced?
- Fully set
- Become porous
- Attract bacteria
What are the steps to temporarily relining a denture with soft lining?
- 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
What instructions should be provided to patients after completing a soft temporary lining?
- Continue wearing while it is soft
- Leave it in water or denture clenaing tablet at night
- Dont brush too vigorously
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?
- 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
When can and can’t a soft resilient lining be used? Why?
- 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
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?
- Pt probably only been comfortable since soft lining was placed
- Do not try to make new dentures or reline with hard lining
What is the minimum thickness required of soft resilient liners?
2-3mm
What should be used to adjust silicone based soft resilient liners?
-Dedeco wheels
What is the method for relining using a resilient soft liner (lab steps)?
- 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
- Receive the impression from clinic (which should be inside the denture as it was used as a tray)
- Pour up model using impression
- Perform investing procedure, with the master cast attached to the flask plaster as usual and place the denture on top of the master cast
- 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)
- Apply resilient soft lining to the fitting surface of the denture
- Place the flask lid and body back together, and wait for lining material to set
- Deflask and trim
(If confusing refer to google docs Relining Resilient Soft liner steps bds4)
