Relining and rebasing in cd

Guided ByDr. Sumathi
Zunzani

Submitted ByIrfan
BDS – Final

year

Table of Contents
 Introduction
 Treatment Rationale
 Definitions :- Relining & Rebasing
 Objectives
 Common Indications For Relining &











Rebasing
Contraindications
General Complaints
General Consideration Prior To
Reining Or Rebasing
Materials Used
Pretreatment Procedures :Tissue Preparation
Denture Preparation
Techniques :Clinical Procedures
Laboratory Procedures
Chair Side Technique
Conclusion

Introduction
 A number of changes can occur in

tissues that support complete
denture., these changes can entirely
be avoided, and the need to
“servicing” complete denture to keep
pace with the chanaging
foundations becomes mandatory.
The clinical efforts that aim at
prolonging the useful life of
complete dentures involve a Reline
or Rebase procedure.

Treatment Rationale
 As the denture foundations

change, the impression surfaces
of dentures cease to fit the tissue
properly . The procedure used is
a reining one, & the dentist
achieves this by adding new
denture base materials to the
existing denture base , thereby
refitting the denture.
Rebasing of dentures is
undertaken when the dentures
need to be refitted &
simultaneously reoriented as
well. This is done so as to
compensate for vertical &
horizontal changes in both

Relining
The procedure used to resurface the
tissue surface of a denture with new
base material to make the denture fit
more accurately. -- GPT
Or
The process of adding base material to
the tissue surface of the denture in a
quantity sufficient to fill the space,
which exist between the original
denture contour and the altered tissue
contour. – SHARRY

Rebasing
Rebasing is a process of replacing all
the base material of a denture. Only
the
original
teeth
and
their
arrangement remain.
Or
It consists of replacing all of the

Objectives
The main objectives of relining or
rebasing are to:
 Re-establish the correct relation of

the

denture to basal tissue.

 Restore stability and retention

 Restore lost occlusal and maxillo-

mandibular relationship.

Common Indications for
Relining and Rebasing
 Imperfection in the denture base

 Defects in the impression surface of the

denture due to
 Improper handling of the tissues during
impression making.
 Processing defects
 Porosities, shrinkage/contraction,
gaseous, granular.
 Crazing of the material
 Alveolar resorption
 Continued resorption of the residual alveolar

ridge under the complete denture.
 Decreased occlusal vertical dimension
 Due to faulty techniques
 Immediate dentures
 Regular periodic relines are required

Common Indications for
Relining and Rebasing
 Socioeconomic constraints
 New denture costs are unaffordable

 Physical/ mental state of the patient.
 Chronically ill patients
 Geriatrics
 Mentally compromised individuals

Contraindications
 Excessive resorption of the alveolar





ridge
Highly inflamed/ abused soft tissues
Poor, unacceptable esthetics
TMJ problems
Unsatisfactory jaw relation
 Horizontal, vertical and orientation relations

 Severe osseous undercuts which

require surgical correction
 Severe speech problems

General Complaints
After a period of successful denture wear
the patient complains of
 Looseness
 Ill-fitting dentures with loss of

stability and retention.
 General soreness and inflammation
 Chewing inefficiency over a period of

time
 Aesthetic problems.

General Consideration Prior
to Relining Or Rebasing
Satisfactory VDO
CO should coincide with CR.
Satisfactory esthetics
Healthy oral tissues
Adequate denture base extensions
Adequate load distribution on the basal
seat
 Satisfactory speech
 Suitable/healthy soft tissues with out







Materials
PMMA

1.
•
•

Heat cured acrylic resin
Cold cured acrylic resin

Modifications of PMMA

2.
•

Butyl meth acrylate

Soft liners/ tissue conditioners

3.
•

Plasticized acrylic resin
•
•

•
•

Chemically activated…. short term denture
liners
Heat activated…. long term denture liners

Vinyl resins
Silicone materials



Chemically activated
Heat activated

Pretreatment Procedures
The clinical procedures of relining and
rebasing includes both tissue and denture
preparations

1.Tissue Preparation:
A). Tissue Rest:
1. Instruct the patient to leave the old
dentures out of the mouth at least
8 hours preferably at night.
2. The dentures should be left out of
the mouth at least two to three
days before making the final
impression.
3. Massage of the soft tissues two or
three times a day to stimulate the
blood supply and aid recovery.
B) Use of Tissue Conditioner
1. Extensive tissue abuse
2. Pt. cannot leave the dentures out
for tissue recovery.
3. Transmission of masticatory forces
to the supporting mucosa are
equalized by eliminating isolated
pressure spots typical of a loose, ill
fitting denture.

The material is renewed periodically
every 3 to 7 days.
5. When the tissues had returned to a
clinically discernible healthy state, the
patient is scheduled for making the
impression.
C). Surgical management:
Excessive hypertrophic tissue should be
surgically removed. The denture can be
used as a surgical splint.
4.

Denture Preparation
1.

2.
3.
4.
5.

Balanced occlusion to ensure that
uneven contact does not bring about a
bodily shift or tilt of the denture when the
patient is asked to close together.
Reduction of sharp and overextended
borders.
Pressure areas in the tissue surface of
the dentures should be relieved.
Borders should be shortened to allow
space for new impression material.
All undercuts should be removed.

Techniques
 Clinical procedures
 Static Methods:
 Open Mouth Technique
 Closed Mouth Technique

 Functional Method

 Laboratory procedures
 Articulator Method
 Jig Method
 Flask Method

 Chair side technique

Clinical procedures
 Static Method Open Mouth Technique: Given by Carl O. Boucher.
 Reining & rebasing of both upper &

lower dentures at the same time.
 Dentures are used as special trays for
making secondary impression. ZnOE is
the material of choice , then the
impressions are made.
 After impression a new Centric
Relation is recorded.

Advantages:
 Selective Trimming helps to make

selective pressure impression.
 Interoccusal record is reliabe b/c jaw
relation is under consideration.

Disadvantages:
 Difficult procedure b/c more clinical

and lab work is involved.

 Closed Mouth Technique:-

Relining or rebasing
can not be done simultaneously for
maxillary & mandibular dentures.
There are 4 techniques:i. Technique A
ii. Technique B
iii. Technique C
iv. Technique D


Technique A:Centric relation (inter-occlusal record) is
recorded using wax or compound 1.5 to 2 mm relief
should be given to large undercuts. Borders are
reduced by 1 to 2 mm excepted the posterior region.

The centre portion of the palate in the
denture can be removed for visibility in positioning
the maxillary denture during impression making.

Border moulding is done & impression is
made from ZnOE impression material .
Patient is asked to close lightly to
interocclusal record & if the palatal
portion is cut, quick setting plaster
should be used to make impression.
Advantages Palatal opening will allow better seating of
denture & alleviate the increase in vertical
dimension.
 Pre-made interocclusal record helps to
position the denture during impression
making.
 It also helps in orienting dentures in an
articulator.
 2 step procedure – Reduces possibility of
moving the maxillary denture forward
during final impression.
Disadvantage Simultaneously maxillary & mandibular
dentures are not relined or rebased.

o
o
o

Technique B :Existing Centric relation is used.
Dentures are prepared as Technique A.
Border moulding is done using low fusing
Impression Compound.

Impression is made in 2 stepso Ist Step- Impression of all areas except

labial flange & alveolar crest in b/w
canines is recorded.
o IInd Step- Labial flange & alveolar crest in
b/w canines is recorded.

Advantage – It will reduce the extreme
forward movement of the denture.
Disadvantage - Wax distort easily.
 Technique C:o Existing centric relation is used.
o Denture prepared as in Technique A.
o Labial & palatal flanges are perforated to

decrease the pressure inside dentures
during the impression making.
o Border moulding & impression making is

 Technique D:-

o Existing centric relation is used.
o Denture prepared as in Technique A.
o
o

o
o
o

o

Borders & shortened & made flat.
Large opening is made at mid palatal
region.
Adhesive tapes are attached over the
buccal & labial surfaces of both
debtures 2 mm above the denture
borders.
Dental plaster & ZnOE is used for
impression.
Plaster of paris used for palatal
portion.
After impression making, a deep
groove is cut into labial & buccal
surfaces of the dentures at the junction
of impression material & adhesive
tape, & filled with molten wax.
Wax at the edge is used to record
sulcus.

Procedure of Technique
“D”

 Functional Method:-

Given by

Winkler.
 Dentures are not required for laboratory
procedures.
 Fluid Resin (tissue conditioners) are used as
impression material.
 Tissue conditioners are usually soft liners with
following characteristics :o Easy to use.
o Excellent for refitting C.D.
o Capable for retaining for man weeks.
o Good in dimensional stability.
o Good in bonding to resin denture base.
Procedure Avoid night wear of the denture.
 Occlusal errors should be corrected so Centric
Occlusion coincides with Centric Relation.
 Tissue surface is reduced to accommodate tissue
conditioning material.
 Tissue surface is dried & tissue conditioning
material is placed. It should flow evenly as a thin
layer to cover the entire impression surface of
denture & its borders.

.

 Now the denture is inserted & the

patient’s mandible is guided to Centric
Relation, in order to stabilize the
denture & the material is allowed to set
. Once the material is set impression is
removed & excess material is trimmed.

If poor recording of borders
has been done b/c of un-supported
area the border moulding is done with
green stick compound.
 After 3 to 5 days dentures are
examined for depressed areas which
should be relieved. The material
should be renewed periodically (once
in a week) till tissue healing is
complete.
 Then impression with ZnOE is taken
over the tissue conditioner material & a
cast is poured immediately. During the

Laboratory procedures
 Articulator method: Impression is obtained.
 Cast is poured.
 Maxillary cast is mounted on articulator

with face bow.
 Mandibular denture is mounted using
an inter-occlusal record, if occlusal
discrepancy is present.
 For relining the required amount of
tissue surface of the existing denture is
trimmed always using an acrylic bur. If
rebasing is to be done, the denture
base should be trimmed to just leave 2
mm of acrylic around the existing
teeth.

 After trimming the dentures are placed

in the articulator & waxed up without
altering the vertical height.

 Jig method:-

Two types of jigs are there1. Hooper’s Duplicator – Having 3
pillars.

2.

Jectron Jig – Having 2 pillars.

 Flask Method :-

Procedure-

Chair Side Procedure
The method makes use of acrylic that
could be added to the denture & allowed to
set in the mouth to produce instant
relining/rebasing.
 Disadvantages Material produces a chemical burn in oral

mucosa.
 Material is porous & develops a bad odour.
 Poor color stability.
 Material is not easy to remove if not placed
correctly.

Now-a-days Visible light cure resin is used.

 Conclusion :Each of the method can produce
satisfactorily result. Impression materials
include both auto polymerizing resin & tissue
conditioners. Success depends on both
clinical & laboratory skills of the operators.
Choice of treatment whether to perform
relining or rebasing depends on the condition

Reference
 Boucher's Prosthodontic Treatment

for Edentulous Patients.
 Essentials of Complete Denture
Prosthodontics by Sheldon Winkler.
 gr.dentistbd.com

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