denture lining material malabar dental college & research centre

1. REPAIR,
RELINING AND
REBASING
DR. ALIYA
LECTURER
MALABAR DENTAL COLLEGE

2. INTRODUCTION
• Both biological supporting tissues and materials
used in complete denture fabrication are
vulnerable to time-dependent changes.
• Meticulous attention and care in the construction
of complete dentures can minimize adverse
changes in the supporting tissues and in associated
facial structures as well, but it cannot preclude
them.

3. INTRODUCTION
• Maintenance of the adaptation of the
denture bases to the mucosa that covers the
residual ridges is a critical part of a
complete denture service.
• The residual ridges have been described as
plastic in nature, always changing in topog-
raphy and morphology from many causes,
some known and many unknown.

4. DEFINITIONS
• According to Heartwell to reline a
denture is a process of resurfacing the
tissue side of the denture to make it fit
more accurately.
• According to Heartwell to rebase a denture is
a process of making an impression in an
existing denture and replacing the denture
base material without changing the occlusal
relations of the teeth.

5. TREATMENT RATIONALE
• The foundation that supports a denture changes
adversely as a result of varying degrees and rates of
residual ridge resorption (RRR).
• The variable reduction in vertical dimension of
occlusion (VDO) and resultant spatial reorientation of
the dentures also lead to esthetic changes in
circumoral support and, consequently, in the patient's
appearance.
• The changes in occlusal relationships can also induce
more adverse stresses on the supporting tissues, which
increase the risk of further ridge resorption.

6. TREATMENT RATIONALE
• The relining procedure is the most frequently
prescribed intervention and involves adding a
new layer of processed denture material to the
denture base.
• A thin layer of impression material is added to
compensate for resorptive changes that have
occurred in the basal seat.

7. DIAGNOSIS
• Patients who have worn dentures successfully for
a long time often return for further service
because of looseness, soreness, chewing
inefficiency, or perceived esthetic changes. These
difficulties may have been caused by
1. an incorrect or unbalanced occlusion that existed
at the time the dentures were inserted or, more
likely,
2. changes in the structures supporting the dentures
that are now associated with a disharmonious
occlusion.

8. DIAGNOSIS
• The stability and retention of the bases are
examined for each of the prosthesis
independently.
• Then check for the occlusion.

9. INDICATIONS
1. Immediate dentures at three to six months after
their original construction.
2. When the residual alveolar ridges have resorbed
and the adaptation of the denture bases to the
ridges is poor.
3. When the patient cannot afford the cost of
having new dentures constructed.
4. When the construction of new dentures with the
accompanying series of appointments can cause
physical or mental stress, such as for geriatric or
chronically ill patients

10. CONTRAINDICATIONS
1. When an excessive amount of resorption has taken place.
2. When abused soft tissues are present. The relining is not
indicated until the tissues recover and return as closely
as possible to normal form.
3. When the patient complains of temporo-mandibular joint
problems.
4. If the dentures have poor esthetics or unsatisfactory jaw
relationships.
5. If the dentures create a major speech problem.
6. When severe osseous undercuts exist, until surgical
removal and healing occurs.

11. RELINING TECHNIQUES
• There are two major relining techniques:
1. Open-mouth
2. Closed-mouth.
• In an open-mouth technique major emphasis is
given to making separate impressions, with
independent attention given to recording jaw
relations.
• In a closed-mouth relining technique a habitual
centric occlusion is usually accepted. This centric
occlusion may or may not be the same as centric
relation.

12. TISSUE PREPARATION
• Excessive hypertrophic tissue should be surgically
removed. The dentures can be used as a surgical splint.
• The oral mucosa should be free of areas of irritation.
• Removal of the dentures from the mouth during sleep is a
must for several weeks before treatment commences,
should the patient wear his dentures during sleep.
• The dentures should be left out of the mouth at least two to
three days before making the final impression
• Daily massage of the soft tissues is helpful to stimulate
their blood supply.

13. PRINCIPAL PITFALLS
• Do not increase the occlusal vertical dimension.
• Multiple even contacts (maximum intercuspation)
should be present in centric relation.
• Do not permit the maxillary denture to move
forward during impression making.
• Ensure that centric relation and centric occlusion
are identical.
• Ensure that an accurate posterior palatal seal has
been established.
• An equal thickness of final impression material
should be used.

14. CLOSED-MOUTH RELINING
MAXILLARY DENTURE
TECHNIQUE A
Centric relation- Centric relation is recorded before
the impression is made, using the medium of choice
Denture preparation- the denture is prepared before
making the impression by relieving all large undercuts
and by relieving 1.5-2 mm from the tissue surface.
The borders are reduced 1-2 mm except the posterior
border of maxillary dentures. A large part of the
middle of the palatal portion of the maxillary denture
is removed for visibility in positioning the maxillary
denture during the impression making.

15. CLOSED-MOUTH RELINING
MAXILLARY DENTURE
TECHNIQUE A
• Border molding- The borders of the dentures are
reformed to their functional contours by using low-
fusing modeling compound.
• Impression- Zinc oxide-eugenol impression paste is
suggested as the impression material. During the
border molding and impression making, the patient
closes lightly into the premade interocclusal record.
The impression of the exposed part of the palatal
section is made with quick-setting plaster.

16. CLOSED-MOUTH RELINING
MAXILLARY DENTURE
TECHNIQUE A / Advantages
1. The opening of the palatal portion will allow
better seating of the maxillary denture and
alleviate the increase in vertical dimension pitfall.
2. The premade interocclusal record helps to
position the dentures during the impression
making and to orient the dentures on the
articulator.
3. The two-step impression technique will reduce
the possibility of moving the maxillary denture
forward during the final impression making.

17. CLOSED-MOUTH RELINING
MAXILLARY DENTURE
TECHNIQUE A / Disadvantages
1. The wax interocclusal record is not an
accurate and safe record that the patient
can close on several times without the
possibility of damaging the record.
2. This technique, does not suggest any
solution for difficulties of relining both
dentures at the same time.

18. CLOSED-MOUTH RELINING
MAXILLARY DENTURE
TECHNIQUE B
• Centric relation- Existing centric occlusion and
intercuspation are used as a means to seat the
dentures.
• Denture preparation-A large part of the palatal
section is prepared to be removed as follows:
first, the outline of the area should be indicated
and deepened on the polished surface up to half
the thickness of the base. Holes are drilled at 5-
to 6-mm intervals inside this groove.

19. CLOSED-MOUTH RELINING
MAXILLARY DENTURE
TECHNIQUE B
• Border molding: Low-fusing modeling compound
(green stick) is suggested for border molding.
• Impression- A wax that flows at mouth
temperature, such as (Iowa wax) is the material
of choice in this technique. The impression is
made in two steps. The impression of the labial
flange and the crest of the alveolar ridge between
the canines is made as a second step.

20. CLOSED-MOUTH RELINING
MAXILLARY DENTURE
TECHNIQUE B
Advantage
• The two-step impression technique will reduce
the possibility of extreme forward movement of
the maxillary denture.
Disadvantages
• Wax impression material is difficult to work with
and the possibility of distortion exists.
• Errors of existing centric occlusion can produce
an inaccurate impression.

21. CLOSED-MOUTH RELINING
MANDIBULAR DENTURE
TECHNIQUE C
Centric relation: The existing centric occlusion
(intercuspation) is used as a means to seat the
mandibular denture during the secondary
impression.
• The occlusion is corrected during the establishment
of a new occlusal vertical dimension.
• Then a lower work impression should be made.

22. CLOSED-MOUTH RELINING
MANDIBULAR DENTURE
TECHNIQUE C
• After pouring the impression and mounting the
lower denture on an articulator, the lower denture
should be removed and cleaned.
• The denture is luted to the maxillary denture in
maximum intercuspation. Softened modeling
compound is placed inside the mandibular denture
and the articulator closed against the lower cast to
contact the incisal guide pin.
• The mandibular denture at this stage is used as a
tray for making the final impression.

23. CLOSED-MOUTH RELINING
MANDIBULAR DENTURE
TECHNIQUE C
Advantages
1. The loss of vertical dimension can be compensated for
during the relining procedures.
2. The error in centric occlusion can be reduced during the
laboratory stages.
Disadvantages
1. This technique is very time consuming from the
standpoint of clinical and laboratory procedures,
2. The procedure for establishment of occlusal vertical
dimension is highly questionable.

24. OPEN-MOUTH IMPRESSION
TECHNIQUE
TECHNIQUE D
• Centric relation- Utilizing both dentures as recording
bases, the jaw relation is recorded after making the
secondary mandibular and maxillary impressions.
• Denture preparation- A posterior palatal seal is formed
in modeling compound on the maxillary denture before
any other changes are made on the tissue side of the
denture. One millimeter of space is provided inside the
denture for the new impression material. The borders
are shortened 1 mm to allow space for the impression
material to form a new border.

25. OPEN-MOUTH IMPRESSION
TECHNIQUE
TECHNIQUE D
• Border molding- If the flanges are inadequate the
borders should be corrected with modeling compound.
• Impression- Zinc oxide—eugenol impression material is
suggested with the following technique: ‘Exactly 15
seconds after the denture has been placed in the mouth,
the patient is asked to pull his upper lip down and to
open his mouth wide. These actions mold the
impression material over the border of the denture.
The upper denture is laid aside until the lower
impression has been made.

26. OPEN-MOUTH IMPRESSION
TECHNIQUE
TECHNIQUE D /Advantages
1. The special trimming of the denture and making
room for the impression material will facilitate the
making of a reasonable impression during the
selective pressure impression technique without any
occlusal interference.
2. A separate interocclusal record using already made
impressions as the recording bases will allow the
operator to concentrate on recording the jaw
relation. It is possible to verify the centric relation
record if necessary.
3. The interocclusal record, which is made with quick-
setting plaster, is a reliable one.

27. OPEN-MOUTH IMPRESSION
TECHNIQUE
TECHNIQUE D
Disadvantages
1. Although this technique seems simple,
the performance of the procedures is
not easy.
2. This technique requires more clinical
and laboratory time.

28. RELINING

29. RELINING

30. RELINING

31. RELINING

32. REBASING

33. REBASING

34. REPAIR
• Breakage of a denture in the mouth almost
invariably starts with a small crack spreading
across the denture rather as though it were being-
torn instead of broken.
• Often the first thing to be noticed by the patient is
the sensation of the feel of a hair on the denture - a
hair which cannot be moved – and a very close
inspection is often required to see the small crack
at this stage.

35. REPAIR
Breakages are of two main kinds:
1. Fracture of the denture base.
2. Fracture of a tooth or teeth on the denture.

36. REPAIR
FRACTURE OF THE DENTURE BASE
1. POOR FIT
(a) Alveolar Absorption
(b) Warpage
(c) Inadequate Relief
(d) Excessive Relief
(e) Inaccurate Impression
2. UPPER TEETH SET OUTSIDE THE RIDGE

37. REPAIR
BREAKAGE OF A TOOTH OR TEETH
1. Cuspal Interference
2. Faulty Tooth
3. Deterioration of Retention
4. Contraction of Acrylic Resin
5. Excessive Grinding of a Tooth

38. REPAIR

39. REPAIR

40. REFERNCES
• ZARB,PROSTHODONTIC TREATMENT
FOR EDENTULOUS PATIENTS 12TH
EDITION PAGES 389-410.
• WINKLER S.,ESSENTIALS OF COMPLETE
SENTURE PROSTHDONTICS,2ND EDITION
,Pg318-40.
• HEARTWELL C M, SYLLABUS OF
COMPLETE DENTURES.4TH ED,PG:391-
405.
• FENN HRB,CLINICAL DENTAL
PROSTHETICS,2ND ED,326-336.