The document discusses repair, relining, and rebasing of complete dentures. It describes common causes of denture fractures such as poor fit or dropping. Methods of repair include reassembling broken pieces and strengthening with acrylic. Relining adds new resin to improve fit after ridge resorption. Indications include poor adaptation or as an interim measure. Impression techniques maintain the occlusal relationship. Rebasing replaces the entire denture base while keeping the same teeth arrangement.
4. Causes of denture fracture
Key of repair = accurate reassembling
& alignment of the broken parts in
their original position.
Inside
the mouth
Outside
the mouth
Construction
causes
5. a. Causes in the moutha. Causes in the mouth
--Single dentureSingle denture
--Open-face dentureOpen-face denture
--poor fitpoor fit
--Lack of adequate reliefLack of adequate relief
--Stress concentrator ( deep frenal notchStress concentrator ( deep frenal notch,,
median diastemamedian diastema((
6. b. Causes out of theb. Causes out of the
mouthmouth
--Excessive pressure exerted by theExcessive pressure exerted by the
patient during cleaningpatient during cleaning
--Accidental dropping of the dentureAccidental dropping of the denture
--Accidental fracture during deflaskingAccidental fracture during deflasking
7. c. Construction causesc. Construction causes
--maxillary posterior teeth are too buccal tomaxillary posterior teeth are too buccal to
the crest of the ridgethe crest of the ridge
--Unusually thin wax upUnusually thin wax up
--incomplete polymerization of acrylic resinincomplete polymerization of acrylic resin
--Porosity of denture basePorosity of denture base
---Presence of previous repairPresence of previous repair
9. II) According to extent of fracture
With broken or
missing part &/or
teeth
Without broken or
missing part &/or
teeth
10. IV) According to cause of fracture
Operator Patient
III) According to timing of fracture
Early fracture Delayed fracture
11. 1. Midline fracture
(more common in maxillary dentures)
Causes:
1) No or insufficient relief in the midline. (M.P.R.)
(Early fracture)
2) Ridge resorption with loss of relief effect.
(Delayed fracture)
12. Procedures for repair of midline
fracture:
• Broken parts are
assembled & fixed
together with sticky
wax on the polished
surface.
• Assembled parts may
be strengthened with
burs or plastic sticks.
13. • Any undercut on the
fitting surface is blocked
out with wax or clay.
• The fitting surface is
painted with separating
medium.
Procedures for repair of midline
fracture:
14. • Stone plaster is poured
into the fitting surface.
After stone setting, the
denture is removed from
the cast and cleaned
from any traces of sticky
wax.
• Fractured edges are
reduced, widened (8-10
mm) along the fracture
line and beveled towards
the polished surface to
increase bonding
surface area.
• Dove tail cuts may be
made to strengthen the
repair joint.
15. • The cast is painted with
separating medium and the
denture is secured to the
cast with rubber bands.
• Self cure A.R. is applied
to the modified fracture
area until the area is
overfilled.
16. N.B.An alternate method is
to wax and contour the fracture
line to the desired form using
base plate wax, followed by
flasking, wax elimination,
packing with heat cure A.R. and
placing in the flask under press
for 2 hrs. then deflasking,
finishing and polishing is then
done in the usual manner.
17. Main cause: is falling on the ground or the sink
during cleaning.
Types:
I- Fracture with no missing part
Repaired as mentioned.
2.Any part fracture
18. II- Fracture with missing or lost part
• An impression is made with the
denture placed in patient mouth.
• After pouring the cast, either
self cure A.R. is applied to
replace the missing part,
or wax is added and carved to
resemble the broken denture
part, followed by flasking,
packing, curing, finishing &
polishing.
19. • Fractured teeth are cut
away with burs.
• On the lingual side,
enough acrylic is removed
and dove tailed.
• Teeth of same size,
shape & shade are
positioned in proper
alignment and waxed with
base plate wax.
III- Fracture with broken or missing
teeth
20. • A plaster index (key) is
made to record & secure
the position of waxed
teeth.
• Teeth to be repaired
are removed together
with all wax around
them.
• Teeth are then put
back exactly in their
original position aided
by plaster key.
21. •Self cure acrylic resin is added
from the lingual side until repair
area is over built. It is then
covered with tin foil.
• After curing, the index is
removed and the denture is
finished and polished.
22.
23. Def: Resurfacing or correction of denture
adaptation to underlying tissues by the
addition of a new resin material to its fitting
surface without changing its occlusal relation.
Relining of Complete Dentures
OROR
AdditionAddition of Material to the tissue side of aof Material to the tissue side of a
denture to improve its adaptation to thedenture to improve its adaptation to the
supporting mucosasupporting mucosa..
24. Relining & Rebasing : Main Objectives
1-Re-establish the correct relation of the
denture to the basal tissues
2-Restore lost occlusal and maxillomandibular
relationship
3-Restore stability and retention
26. Relining IndicationsRelining Indications
When the denture loses adaptation to the
underlying tissues after ridge resorption,
while all other factors as occlusion, esthetics,
centric relation, V.D.O. and denture base
material are satisfactory.
27. Relining IndicationsRelining Indications
11--Poor adaptation of the denture base toPoor adaptation of the denture base to
underlying tissues due to ridge resorptionunderlying tissues due to ridge resorption
22--After placement of immediate denture (3-After placement of immediate denture (3-
6 months6 months((
33--Geriatric patients who can not come forGeriatric patients who can not come for
several visits for construction of newseveral visits for construction of new
denturedenture
44--Patient can not afford the cost of newPatient can not afford the cost of new
denturesdentures
28. ReliningRelining
contraindicationscontraindications
11--Poor esthetics or unsatisfactory jawPoor esthetics or unsatisfactory jaw
relationrelation
22--Major speech problemMajor speech problem
33--Excessive ridge resorptionExcessive ridge resorption
44--presence of abused soft tissuespresence of abused soft tissues
55--severe occlusal wearsevere occlusal wear
30. Tissue rest
Patient is instructed to leave his denture out of his
mouth at least 48 hrs to allow for recovery of tissue
and reduce irritation caused by ill-fitted denture.
Tissue conditioner
If the Patient cannot leave the denture out of his
mouth for tissue recovery
Surgical management
Excessive hypertrophic tissues should be
surgically removed
31.
32. Tissue RecoveryTissue Recovery
ProgramProgram
Intermittent hot and cold rinsesIntermittent hot and cold rinses
Massage tissuesMassage tissues
Relieve of pressure areasRelieve of pressure areas
Correct faulty occlusions and denture bordersCorrect faulty occlusions and denture borders
Minimize stress byMinimize stress by
– Soft dietSoft diet
– Removal of denture at nightRemoval of denture at night
Use tissue conditionersUse tissue conditioners
33. 2- Denture preparation
• all undercuts are removed from the fitting
surface.
• Borders are reduced 2mm and squared to
provide a definite edge for addition of new resin
material.
•3 tissue stops are outlined in the tissue surface
•Tissue surface is relieved 1.5mm in all areas
except post dam & tissue stops
35. • A hole is made in the
palatal surface to allow
escape of excess impression
material.
• Border tracing & new
impressions are made under
centric occlusion to maintain
occlusal relationship.
• The denture with
impression material is boxed
and poured into stone.
1-Static Impression technique
36. . The denture is flasked, and the old resin material
is thoroughly cleaned and roughened.
37. . New acrylic resin material is packed, and the
denture is cured in pressure curing unit containing
water at 45°c for 20 min. to prevent porosity of
new resin material and warpage of the old resin
material (release of internal stresses).
. Finishing and polishing is done in the usual
manner.
38. N.B.
When both upper and lower dentures need
relining, lower denture should be completed first.
The upper may be relined against a stable lower
denture.
The denture should be clinically remounted to
perfect the occlusion.
45. Delivery of RelineDelivery of Reline
Pressure IndicatorPressure Indicator
Paste (PIPPaste (PIP((
))Ask the patient toAsk the patient to
bite on cotton rollsbite on cotton rolls
for 5 minfor 5 min..
49. Chair-side reliningChair-side relining
--If the patient does not have spare dentureIf the patient does not have spare denture
--Direct reline material ( powder & liquid) mixedDirect reline material ( powder & liquid) mixed
& applied to the prepared denture& applied to the prepared denture
--guide the patient to close in CR till the materialguide the patient to close in CR till the material
setssets
--disadvantages: mucosal burn, porous surface,disadvantages: mucosal burn, porous surface,
color instability & difficult removal of relinecolor instability & difficult removal of reline
material if it was wrongmaterial if it was wrong
50. Def: It is a process of readaptation of a denture
to the underlying tissues by replacing the denture
base material with a new one without changing its
occlusal relation.
Rebasing of Complete Dentures
Indications:
When the existing denture base is unsatisfactory
e.g. stained, crazed or porous.
51. • An impression is made
with the denture and a cast
is obtained.
• An occlusal and incisal
index of the teeth is made
in plaster using Hooper
duplicator. The posts of the
lower part of the duplicator
are seated in the upper part
to maintain the relationship
of the casts to the plaster
index.
52. • The denture with the impression material are
removed from the cast.
• Artificial plastic teeth are sectioned from the
denture and all base material around the teeth is
removed. (porcelain teeth are removed by
flaming)
• Teeth are placed and held in position in the
index using sticky wax on the labial and buccal
surface.
• A layer of base plate wax is placed over the
ridge of the cast.
53. • The upper part of the duplicator is closed and
denture base is waxed to the proper thickness
and contour to the cast.
• The cast is removed, flasked and processed in
the usual manner.
• After deflasking, the cast is reattached to the
upper part of the duplicator to adjust any
occlusal errors.
• Occlusion of rebased denture is further
perfected by clinical remount.