Relining & Rebasing in CD.pptx

19 April 2023 Relining & Rebasing in CD 1

Relining & Rebasing
in
Complete Dentures
Dr. Ch.Praveena
1st year Graduate
Student
Dept of Prosthodontics
SIBAR Institute of
Dental Sciences,
Guntur-09

• Introduction
• Definitions
• Review of Literature
• Difference between
relining & rebasing
• Indications
• Contraindications
Contents

• Relining Techniques
• Relining & Rebasing
Materials
• Conclusion
• References
Contents

Introduction

Definitions
. GPT 8,2005:
RELINING : The procedures used to resurface the
tissue side of a removable dental prosthesis with
new base material, thus producing an accurate
adaptation to the denture foundation area.
REBASING:The laboratory process of replacing the
entire denture base material on an existing
prosthesis.

Definitions
Winkler, 2nd Edition:
RELINING:The process of adding some material to
the tissue side of a denture to fill the space
between the tissue and the denture base.
REBASING: The process of replacing all the base
material of a denture. The purpose of such a
process is to fill the space between the tissue and
the denture base without changing the position of
the teeth and relation of the dentures

Definitions
Sharry:
RELINING: “The process of adding base material
to the tissue surface of a denture in a quantity
sufficient to fill the space which exists between the
original denture contour and the altered tissue
contour”.
REBASING: “Replacing all the denture base with
new material. Only the original teeth and their
arrangement remain”.

Relining Rebasing
vs
The only difference is that only
a layer of acrylic is removed
before wax up in relining but in
rebasing the entire denture base
is removed prior to wax up.

Relining Rebasing
vs
Rebase
Reline
Moderate to
maximal changes
Minimal to
Moderate changes

• In 1952 Buchman recommended using a central
bearing point and a needle point tracing in
connection with the relining procedure.
• In 1953 Swenson described a rebasing method
when only jaw has resorbed extensively , if the
occlusion is acceptable.
• Chase in 1960 used a thin layer of rubber base
impression material with a closed mouth
technique, making the impression with little
pressure.

• Nagle and Sears in the year 1962
recommended boiling the dentures for 5
minutes before relining them to minimize the
internal strains in the base material.
• In the year 1966 Sauer , described that the
dentures lined with a soft material may be
especially desirable when mechanical shock to
the supporting areas should be reduced

• The wing relining technique was described in the
year 1969 by Christensen FT; the method
incorporates a simple but effective control for
alterations in the vertical dimension of occlusion
during laboratory procedures by the use of resin
wings which are added to the denture.
• Feldmann EE et al in the year 1970 advocated a
relining method – relining a complete denture
with an oral cure silicone elastomer and also
fabricating a duplicate denture.

• Francis WS, William HF , in the year 1971
described a method of relining with closed mouth
technique .
• Jordan LG in the year 1972 again described a
newer closed mouth relining technique.
• In the year 1973 Boucher described a open
mouth technique for relining/rebasing which till
date is the only technique in literature explaining
relining upper and lower dentures same time.

• Occlusal vertical dimension
• Centric occlusion coincide with centric relation
• Esthetic
• Posterior limit of maxillary denture
• Denture base extensions
• Denture base extensions and force distribution
• Interocclusal distance
• Phonetics
• No existing hard or soft tissue condition
General Considerations

• Looseness & instability of
dentures.
• Immediate dentures.
• Cost Affordability
• Denture construction
causing physical & mental
stress.
• Presence of abused tissues.
Indications
for Relining &
Rebasing

• Discrepancies between the
tissue surface of the
dentures & supporting
structures.
• Patients presenting a
history of repeated
adjustments.
Indications
for Relining &
Rebasing

Cases of excessive amount of
resorption & excessive loss of
VD.
Poor esthetics /
unsatisfactory jaw relations.
TMJ problems.
Speech difficulties.
Severe osseous undercuts &
presence of abused soft
tissue.
Contra-
indications

Patient And Denture Pre-requisites For Relining
1. Tissues must be in a normal healthy state
2. The denture must be able to be stabilized by
border refining
3. The denture(s) must present reasonable
centric occlusion in harmony with centric
relation.
4. There must be reasonable (at least
correctable) vertical dimension rest and
occluding vertical dimension.
5. Absence of speech defects.

Clinical Procedures
Laboratory Procedures
Processed/Chairside
Impression/Controlled pressure or
functional technique
Hard acrylic/ Resilient
Complete/ Partial Dentures
a) Articulator method
b) Jig Method
c) Flask Method
a) Static
Open mouthed
Closed mouthed
b)Functional methods
c)Chairside
Techniques
Permanent/ Temporary
Relining
Techniques

Tissue Preparation

Denture Preparation

Principal pitfalls…
• Do not increase the occlusal vertical dimension.
• Maximum intercuspation in centric relation.
• Maxillary denture movement in forward
direction during impression making avoided.
• CR and CO are identical.
• Accurate posterior palatal seal.
• Equal thickness of final impression material.

a) Open mouthtechnique
Carl O.Boucher(1973)
b)Closed mouth impression
Technique A – Shaffer (1971)
Technique B – Hansen (1964)
Technique C – Christensen (1971)
Technique D – Jordan (1972)
Technique E – Gillis (1960)

Open mouth technique (Technique F)
 Proposed by Carl O. Boucher.
 Only method of relining both maxillary &
mandibular dentures at the same time.
 Impressions are made without existing CO.
 PPS is formed in modelling compound before
any other changes are made on the tissue
surface. Borders shortened by 1mm.
 Dentures are used are used as special trays for
final impression. ZOE is material of choice.

 After maxillary & mandibular impressions, a
new CR record is accomplished.
 All procedures are done in one appointment.
 Exactly 15 seconds after the denture has been
placed in the mouth, the patient is asked to
pull the upper lip down and to open his
mouth wide these actions mould the
impression material over the border of the
denture.
 The lower impression is made after making
the upper impression.

Advantages:
• Selective pressure impression can be made.
• Making a separate inter-occlusal record will
allow the operator to concentrate on
recording the jaw relation.
• Centric relation record can be verified.
• The inter-occlusal record is reliable.
Disadvantages:
• Difficult procedure.
• It requires more clinical and laboratory time.

Closed mouth techniques
 Maxillary and mandibular relining /rebasing
should be done separately.
• Technique A
• Technique B
• Technique C
• Technique D
 Technique A requires recording a new centric
relation record using modeling wax or
compound. Techniques B, C and D, use the
existing centric relation record in the existing
denture.

Technique A -Shaffer F.W & Filler (1971)

Advantages
• Palatal opening will allow better seating of the
denture and alleviate the increase in vertical
dimension.
• Pre-made inter-occlusal record helps to
position the denture during impression
making.
• It also helps in orienting dentures in an
articulator.
• Reduces the possibility of moving the
maxillary denture forward during final
impression making. It’s more reliable.

Disadvantages
• This procedure cannot be used to reline or
rebase the dentures simultaneously.
• Wax inter-occlusal record is not very
accurate.

Technique B –Hansen (1964)
Centric relation
Denture preparation
Special suggestion
Border Molding
Impression – Kerr’s
impression wax (Iowa wax)
Existing CR &
Intercuspation are used
Impression is made
in 2 steps

Advantages
• It will reduce the possibility of extreme
forward movement of the maxillary denture.
Disadvantages
• Wax impression materials are difficult to work
with and can distort easily. If the existing
centric relation record is wrong then the
impression becomes inaccurate.

Technique C– Christensen (1971)
Centric relation
Denture preparation
Special suggestion
Border Molding
Impression – No specific
impression material
Existing CR &
Labial & palatal
flanges are
perforated

Technique D– Jorden (1972)
Centric relation
Denture preparation
Special suggestion
Border Molding –not
suggested
Impression – Plaster of Paris
or ZOE
Existing CR &

Advantages
• Palatal opening will allow better seating of the
denture and alleviate the increase in vertical
dimension.
Disadvantages
• Existing centric occlusion may cause some
pressure points and faulty impressions.

Technique E -Gillis (1960)
• Hazards in relining a maxillary CD are greater
than relining a mandibular CD.
• Factors to be considered for relining
mandibular denture
a) Ridge form
b) Ridge relations
c) Characteristics of mucosa covering the ridges

Technique D– Jorden (1972)
Centric relation
Denture preparation
Special suggestion
Border Molding –not
suggested
Impression – modelling
compound & ZOE
Existing CR &
Not specified
• Loss of vertical dimension
is corrected by luting
softened modeling
compound to the occlusal
surfaces of the posterior
teeth.
• The patient is directed to
repeatedly pronounce the
letter ‘m’.

Advantages
• Loss of VD can be compensated.
• Error in CO can be reduced during laboratory
stages.
Disadvantages
• Time consuming.
• Procedure of establishment VDO is highly
questionable.

Functional Method
• It was suggested by Winkler.
• Here, the patient need not be without
dentures unlike previous techniques.
• Fluid resins (tissue conditioners) are used as
impression material. It is a simple and
practical procedure and is more popular.

Tissue conditioners are temporary soft liners
with the following characteristics:
• Easy to use.
• Excellent for refitting complete dentures.
• Capable of retaining for many weeks.
• Good in dimensional stability.
• Good in bonding to resin denture bases.

Chairside Relining Technique
This method makes use of acrylic that could
be added to the denture & allowed to set in the
mouth to provide instant relining & rebasing.
Indications
1. Where longer than six weeks service is
required
2. Around overdenture abutments
3. Border additions
4. RPD base areas

Contraindications:
1.Direct relines are not indicated for long term
service.
2. They are not good impression materials.
3. Some materials present problems of adhering to
denture base.
4. In many situations the resulting tissue surface is
rough and presents porosity.
5. Color stability is of short duration.
6. If the dentine is not properly positioned in
relining, correction is very difficult.
7. Tissue irritation.

Laboratory procedure
Articulator method
Jig method
Flask method
It is common for both relining & rebasing except
for a few differences.

Mandibular denture with porosities

Border trimmed-2mm Border molding with
green stick compound

Final impression with
Zinc-oxide Eugenol
Master cast fabricated

Indentations of the teeth
made
Cast mounted on upper
member

Wax build-up done
Denture trimmed Wax build-up done

Invested waxed denture

Hooper duplicator Jectron jig

Denture half - flasked Painting silicone mold
material

• These materials can
either be applied by the
dentist at the chair side
or by the technician in
the laboratory.

• “The polymeric material used to replace the
tissue contacting surface of an existing
denture” –Phillips,11th edition.
Liner
• “Polymeric material placed on the tissue-
contacting surface of a denture base to absorb
some of the energy produced by masticatory
impact and to act as a type of shock absorber
between the occlusal surfaces of a denture and
the underlying oral tissues” –Phillips.
Soft
denture
liner
Key Terms

• “Heat activated polymeric material
that is more durable than chemically
activated liners”. -Phillips,11th edition.
Longterm
liner
• “Chemically activated polymeric
material that tends to degrade more
rapidly than heat activated resins”.
- Phillips,11thedition.
Short-
term
liner
Key Terms

• “A soft material which is
applied temporarily to the
fitting surface of a denture for
the purpose of allowing a more
equal distribution of load, thus
permitting the mucosal tissues
to return to their normal
position”. -Wilson et al. (1966)
Tissue
Conditioning
Material
Key Terms

These materials can be classified as:
1) Rigid materials
2) Short-term soft lining material
3) Long-term soft lining material

Rigid Materials
• Frequently described as chair side reline materials.
• Composition:
Powder Liquid
Polymethylmethacrylate Butyl methacrylate
Clinical performance: best materials working life of
1 year.

Short term soft lining Materials
• Available in P/L form or ready-to-use sheet.
• Composition:
Powder Liquid
Polymethylmethacrylate Butyl methacrylate
Clinical applications: Tissue conditioning, temporary
Soft reline, diagnostic aid & functional impression.

Long-term soft lining materials :
• Long-term soft lining materials distribute stress
more evenly under dentures than do the hard
denture base materials.
• They also absorb impacts that can arise from
masticatory function. They can therefore be said to
have a shock-absorbing or cushioning effect.

Indications

Types of long-term soft lining :
• Silicone rubber -Cold curing
Heat curing
• Soft acrylic - Cold curing
Heat curing

Silicone Liners Acrylic Liners
1. Elasticity: Heat curing
silicone is elastic immediate to
application & removal of load.
1. Shows gradual response.
2.More shock absorbing. 2.Less shock absorbing.
3.Remain stable with time. 3.Becomes harder with time
& with immersion in water.
4.Heat cure bond strength
equal to denture bases.
Cold cure: poor bond strength.
4. Good bond strength.

Problems associated with relined/ rebased
dentures
1. Problems due to improper fit.
2. Improper preparation of soft tissue.
3. Loss of orientation.
4. Occlusal discrepancies.
5. Inadequate/ loss of PPS.

“While relining procedure is
none too satisfactory from
any stand point, it must be
done in certain
circumstances”.
-Chase.
Conclusion
“Relining complete denture is an
obligation of dentists and a real
service to denture patients”.
-Ostern.

References
• Winkler S. Relining & Rebasing Techniques In Essentials
of Complete Denture Prosthodontics.2nd edition:341-
351.
• Morrow RM. Rudd KD, Rhoads JE. Dental laboratory
Procedures Complete Denture Volume one.Mosby 2nd
edition.364-382.
• Bolender CL, Zarb GA.Relining & Rebasing In.
Prosthodontic Treatment for Edentulous Patients.10th
edition:577-586.
• Craig RG, Powers JM. Prosthetic Application of
Polymers In.Restorative Dental Materials Mosby 11th
edition 2002, 635-681.

• Anusavice KJ.Denture base Resins In. Phillips
Science of Dental Materials. Elesevier 11th edition
2003,721-736.
• Boucher CO. The relining of Complete Dentures.J
of Prosthet Dent;1973:30:521-526.
• Jordan LG. Relining the complete maxillary
denture.J of Prosthet Dent;1972:28:637-641.
• Christensen FT. Relining Techniques for Complete
Dentures. J of Prosthet Dent;1971:26:373-381.

• Shaffer FW. Filler WH. Relining Complete Dentures
with minimum occlusal error. J of Prosthet
Dent;1971:25:366-370.

Relining & Rebasing in CD.pptx

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