Transcript relining & rebasing

By
Dr. Aamir Mehmood Butt,
Assistant Professor
Deptt: Of Prosthodontics
LUMHS, Jamshoro
Denture Relining
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Definition:
“ procedure
used to resurface the
tissue side of a
denture with new
base material,
producing an accurate
adaptation to the
denture foundation
area”
( GPT 2005)
Indications
1. Resorption of the bone could leads to:
 Loss of retention & stability
 Loss of VD
 Loss of support of facial tissues
 Incorrect occlusal relationship
2. Immediate denture after 3 -to - 6 months of
construction.
3. Economics
4. Geriatric or chronically ill pt:
5. Time problem
6. Loose denture at the time of delivery
Contra- Indications
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Poor quality of denture base
Exaggerated bone resorption
Abused or traumatic oral tissues
Poor teeth arrangement
Unsatisfactory jaw relationship
Speech problem
Undercuts
TMJ problems.
Relining Materials
1.
According to time:
a.
Short–term liners
example: tissue conditioners, preformed sheets of acrylic gel.
b
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long-term liners
plasticized acrylic( heat & chemical activated forms are available)
Heat activated silicones
RTV ( room temperature vulcanization ) silicones
Plasticized vinyl polymers & copolymers
Hydrophilic polymers
Polyphosphazine fluoropolymers
Fluoroethylene
PVS
Relining Materials

According to type of Activation
1.
Heat activation
Chemical activation
2.
Uses of short-term liners
1.
2.
3.
4.
5.
Treatment &
conditioning of abused
oral & supporting
tissues.
Diagnostic purposes
such as recovery of
VD.
Temporary relining of
immediate denture/
surgical splints/ cleft
palate speech aids etc.
Tissue conditioning
during implant
healing.
Functional impression
material.
Qualities of an ideal long-term
reliner
Biocompatibility
2. Dimensional stability
3. Low water sorption & solubility
4. Low surface tension
5. Permanent softness
6. Abrasion resistance
7. Good bond to denture base material
8. Simple to manipulate
9. Color stability
10. Resist microorganisms growth
1.
Comparison of plasticized
acrylic versus silicon rubber

PLASTICIZED ACRYLIC:
1.
Less resilient
Hardens by time
Good bonding with base material
Acceptable tear resistance
Better abrasion resistance
Resistance to damage by denture cleansers
2.
3.
4.
5.
6.
Comparison of plasticized
acrylic versus silicon rubber

SILICONE
RUBBER:
1.
Highly resilient
Poor bonding to acrylic
denture base
More water sorption
More susceptibility to
microorganism growth
Low tear & abrasive
resistance
Less resistance to
damage by denture
cleansers
2.
3.
4.
5.
6.
REBASING

DEFINITION:
“ The laboratory procedure of
replacing the entire denture base material
on an existing prosthesis”
(GPT 2005)
Indications
1.
2.
3.
4.
Where the observed clinical changes are
moderate to sever.
Some processing fault in denture base e.g:
porosity
Discoloration of base material.
Where porcelain teeth have been used.