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GOOD
MORNING
DR ZARIR
CONTENTS
1. Introduction
2. Failures in diagnosis and treatment planning
3. Failures in mouth preparation
4. Failures in framework design
5. Failures in laboratory procedures
6. Failure in support for denture bases
7. Failures in occlusion
8. Failure in patient-dentist relationship
9. Conclusion
10. Bibliography
Failure of removable partial dentures is due to
inadequate
1. Diagnosis and treatment planning
2. Mouth preparation procedures
3. Design of framework
4. Laboratory procedures
5. Support for denture bases
6. Occlusion
7. Patient-dentist relationship
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I.
J Prosthet dent; 2001;86(3); 251-261
Making RPD’s using a 2 appointment system: one for diagnosis
definitive impressions, mouth preparation procedures and
second for insertion of partial denture.
FAILURE IN DIAGNOSIS AND TREATMENT
PLANNING
A.ERROR:-
1. IMPROPER DIAGNOSIS
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I.
J Prosthet dent; 2001;86(3); 251-261
SOLUTION:-
1ST appointment:- make an assessment of the patient,
diagnosis, take radiographs and make primary impression
2nd appointment:- make mouth preparations and impressions
for definitive casts and jaw relation can also re carried out.
3rd appointment:- try in of the metal framework
prosthesis.
4th appointment to deliver the denture and adjust the occlusion.
Give the patient instructions essential to successful function and
maintenance of the denture
5th mandatory follow up
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I.
J Prosthet dent; 2001;86(3); 251-261
Failure to a the analyze set of
diagnostic casts for each patient.
B.ERROR:-
SOLUTION:-
1.After only an intraoral examination, a patient
may appear to have a simple problem when, in
fact, the situation is very complicated.
2. Always make diagnostic casts and evaluate them
thoroughly before committing to treatment
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I.
J Prosthet dent; 2001;86(3); 251-261
C. ERROR:-
Failing to remove debris and plaque from the teeth before
impression is made
Routinely clean the teeth
with a lubricating
prophylactic paste before
making an impression,
In cases of extensive calculus
deposition oral prophylaxis
has to be carried out
SOLUTION:-
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I.
J Prosthet dent; 2001;86(3); 251-261
2) Surveying
Failure to use a surveyor during
treatment planning
SOLUTION
It is the responsibility of the
dentist to survey and draw the
design on the diagnostic cast
before sending it to the lab
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I.
J Prosthet dent; 2001;86(3); 251-261
FAILURES IN MOUTH PREPARATION PROCEDURES
1) Improper guide plane preparations:
Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
2) Improper height of contour:
 Improper positioning of the
retentive clasp arm and
reciprocal clasp arm
 Retention and Stability of
the prosthesis affected.
3) Rest and Rest Seat
Preparation:
Movement of the
abutment tooth or sliding
of the prosthesis
The forces transmitted
from the prosthesis to
abutment teeth would
occur against the inclined
plane.
Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
 Occlusal rest Preparation in a multi-
surface Amalgam Restoration.
-Amalgam tends to flow when placed
under constant pressure or even excess
preparation.
ERROR:-
SOLUTION:-
Dentist failing to tripod the
designed diagnostic cast
When the dentist designs the cast
it has to be tripoded so that the lab
technician can easily duplicate the
design.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I.
J Prosthet dent; 2001;86(3); 251-261
FAILURES IN DESIGN OF FRAMEWORK
1.Tripoding
2. Design transfer to master cast:
1. The design has to be outlined on the
refractory cast with minimum pressure.
2. The cast must not be abraded
during the transfer of the design
3. The position of individual clasp
tips is most important in the
design transfer
Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
3) Incorrectly located
RPD components:
 Incorrectly located
major connector
Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
1. Flexible major connector
2. Impinging on the
gingival margins
3. Failure to provide relief where
is crosses the gingival margins
 Incorrect use of clasp
designs
Use of clasps that are too
broad in tooth coverage and
have too little consideration
for esthetics
4) Beading of the cast:
 Tissue blanching and
inflammation or
ulceration seen when the
beading on the cast done
too deep
Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
5) Block out:
 Improper seating
of the framework:-
-Block out if not done
properly permitting
rigid part of the
framework to be
placed in undercuts.
Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
 Framework that does
not contact the
tooth:-
Block out wax added
above the height of
contour line or on the
guiding planes and not
removed during shaping
of wax.
Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
6) Contouring of the block out wax:
1. Done with blockout instrument properly positioned,
excess wax is carefully removed.
2. The blockout instruments can be electrically heated
or warmed over a flame
Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
7) Relief:
.
Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
ERROR:- Metal framework impinges on
the soft tissue
SOLUTION:-
1. The thickness of the relief wax has to be
adequate
2. The wax must not be separated and
lifted up from the cast during duplication.
1) Poor cast-forming
procedures:
Cast is inaccurate: not a true
reproduction of the anatomy of the
mouth.
2) Duplication:
1. Block out and relief wax
melted by reversible
hydrocolloid.
2. Mold damaged during
removal of the master
cast.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I.
J Prosthet dent; 2001;86(3); 251-261
3) Refractory cast:
ERROR: Abraded refractory
cast
SOLUTION:-
1.Surface treatment
of the cast has to be carried out.
2. The cast must not be retrieved
until it is completely set.
3. The refractory cast is then
trimmed on a dry cast trimmer.
Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
4) Waxing:
ERRORS:- patterns separate from
the refractory cast.
SOLUTION:-
1. The plastic patterns have to be
glued properly to the design
outline on the refractory cast
2. Mixture of acetone and plastic
pattern scraps mixed to watery
consistency ( TACKY LIQUID)
3. The liquid has to be applied in a
very thin layer
Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
5) Failure of technician to
follow the design and
written instructions:
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I.
J Prosthet dent; 2001;86(3); 251-261
6) Spruing
ERROR:-
1. Attaching the sprue lead to a
thin section of waxed framework
SOLUTION:- Always
sprue to the bulkiest portion
of the pattern
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II.
J Prosthet dent; 2001;86(3); 251-261
Small particles of investment in the casting:-
-Sprue leads joined to main sprue on wax
pattern improperly.
-Sprue hole was enlarged by cutting with
knife, leaving roughened surface for metal
to flow over.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II.
J Prosthet dent; 2001;86(3); 251-261
 Metal spilled when casting:-
-Sprue hole is too small for Bulk of metal.
-Sprue leads broken during investing
procedure
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II
J Prosthet dent; 2001;86(3); 251-261
 Internal mold deformations:-
-Constriction in the sprue lead
 Porosity in casting:-
-Improper spruing procedure
 Pattern failed to casting:-
-Pattern separated from crucible former during
investment
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II.
J Prosthet dent; 2001;86(3); 251-261
7) Investing:
If the cast is dried with teeth up,
white materials would be
deposited around the teeth. This is
due to deposition of salts which
form a positive layer that cannot
be removed without scraping and
damaging the cast.
 Cracks in the cast
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III.
J Prosthet dent; 2001;86(3); 251-261
8) CASTING defects:-
 Pitted casting
If the design is placed on the refractory cast with a
graphite pencil….
Contaminates…..
Burn out temperature…..
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II.
J Prosthet dent; 2001;86(3); 251-261
 Metal nodules and rough area on cast
framework
-Failing to use surface tension reducer correctly
on the waxed patterns would cause air trap, when
paint on investment flows
-If the surface tension, reducer is not allowed to dry
before applying the paint on investment
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II.
J Prosthet dent; 2001;86(3); 251-261
 Incomplete casting and rough areas or fins
in casting
-W: P ratio.
-If paint on investment layer is too thin.
-If the paint on layer is too thick.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II.
J Prosthet dent; 2001;86(3); 251-261
 Porous cast frame
work
If the mold moves in the
casting machine as the
casting arm starts to spin,
molten metal sometimes
may miss the sprue hole
and spill outside the mold.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II.
J Prosthet dent; 2001;86(3); 251-261
 Incomplete casting
1. If the sprue hole faces
upward during burn out.
2. Casting temperature
of metal….
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II.
J Prosthet dent; 2001;86(3); 251-261
 Warpage of the
Frame work
1.The air pressure of the
nozzle of air abrasion
machine is about 100 psi…..
2.If sufficient time is not
allowed for the metal to cool
to room temperature in the
investment (quenching the
mold)…..
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
 Nicks on the metal
casting
1. Carelessly cutting off the
sprue leads
2. Using the wrong mandrel
in high spread lathe
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
 Framework is too loose
Carelessly grinding the
inside of clasps
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
 Fracture of the clasps
Removing too much metal
from retentive clasps.
An improperly tapered
clasp or one that is thin
or having nicks encourages
breakage by concentrating
the strain….
Electro polishing for a
longer time.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
 Warpage of the
framework
Abrasive rubber wheels and
points can build up heat in the
framework very quickly
 Loose frame work
Polishing removes a definitive
layer of metal.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
 Distorted frame
work
1.Clasps and other parts of
the frame work can easily
catch in the polishing
wheel.
2.The force
usually distorts the
framework and injures the
operator.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
 Incomplete Casting of
the Metal frame work
1. Metal too cold when cast.
2. Improper spruing.
3. Gas trapped in mold.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
9) Mixing and packing
acrylic resin:
1. Packing the acrylic material
into the flask before allowing
them to cool down at room
temperature
2. Packing the resin into the
flask before it is ready to
pack.
3. Underfiling the mould.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
10) Deflasking and polishing the removable
partial denture:
1. Distorted framework
2. Increase in the vertical dimension
3. Warpage of framework
4. Scratches on the final metal framework
5. Damaged denture teeth
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
 Distorted clasps
-Using a cloth wheel that was not broken
properly would result in damaged removable partial
denture or injure the operator.
-A new cloth wheel has strings of material
protruding from it.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
-The strings could
tangle in the clasp or other
parts of removable partial
denture and snaps the
removable partial denture
from the operator’s hands
throwing it out with great
force.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
 Scratches on the denture
-Course pumice leaves scratches.
-It would be difficult to adequately polish around
the necks of denture teeth with a cloth wheel or a lathe
mounted bristle brush without damaging the contours
of the teeth.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
 Dull appearance of the denture
Detergent alone would not adequately remove
polishing compound from the removable partial
denture.
The remaining residue would prevent the
removable partial denture from achieving the luster.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
11) Fitting the
framework to the cast
and mouth:
1. Framework too retentive on
the definitive cast.
2. Frame Work not fitting
exactly in the mouth.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
12) Finishing and polishing of framework:
 Polished surface is dull with fine scratches
-Sequence of finishing steps not followed
 Major and minor connector over thinned and
flexible.
-Framework over thinned with abrasive stones
during finishing
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
 Clasps is nicked or
notched
 Framework
distorted
-Frame work caught
in lathe during finishing.
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
13) Fitting and adjusting the removable partial
denture to mouth :
 Failing to evaluate the denture borders when
placed intra-orally.
 Loss of retention and support.
 Soreness or Ulceration of soft tissue in the
patient’s mouth
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
 Increase in the vertical dimension of
occlusion
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
Warpage of the RPD
-If the patient does not seat the
removable partial denture correctly, they
may warp the removable partial denture or
be injured by it
 Inadequate ridge quality and
contour
 Complete extent of the
residual ridge not covered by
the denture
 Inadequate coverage of
basal seat tissues
 Failure to record basal seat
tissues in supporting form
FAILURE IN SUPPORT OF DENTURE BASE
1) Articulation:
Error in articulation of the cast
FAILURES IN OCCLUSION
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
2) Face bow transfer:
 Alteration in the jaw
relation
1. Positioning the face bow on
patient’s face.
2. Placement of the fork
Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III
J Prosthet dent; 2001;86(3); 251-261
3. Rocking of the
record
4. Trimming of the
record or metal
showing through the
record.
5. Face bow transfer
not done.
3) Correction of occlusal plane:
 Sensitivity of teeth or incipient caries-
after enameloplasty
4) Selecting and arranging teeth:
 Unable to interdigitate artificial teeth with
opposing natural dentition
 Insufficient space to set posterior tooth
replacement
 Anterior replacement teeth too short for
satisfactory esthetics
 Dentists failing to select type, shade and
mold of the denture teeth to be used
resulting in unaesthetic prosthesis not
accepted by patient
FAILURE IN PATIENT-DENTIST RELATIONSHIP
 Failing to make a follow up appointment for
the patient
 Failure of dentist to provide adequate
dental health care information, including care
and use of prosthesis
1. Rudd & Rudd, A review of 243 errors possible during
the fabrication of a removable partial denture: Part I
& . J Prosthet dent; 2001;86(3); 251-261
2. Rudd & Rudd, A review of 243 errors possible
during the fabrication of a removable partial denture:
Part II & . J Prosthet dent; 2001;86(3); 262-276
3. Rudd & Rudd, A review of 243 errors possible
during the fabrication of a removable partial denture:
Part III & . J Prosthet dent; 2001;86(3); 277-286
4. McCracken’s: Removable partial Prosthodontics. Eleventh
edition 2005
5. Stewart’s Clinical Removable Partial Prosthodontics.
fourth edition
6. A clinical overview of removable prostheses:3. principles
of design for removable partial denture .Dent update
2002;29.
7. A clinical overview of removable prostheses:4
technological consideration when designing removable
partial denture. Dent update 2003;30:7-9
THANK
YOU

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Failure in removable part denture my ppt

  • 3. CONTENTS 1. Introduction 2. Failures in diagnosis and treatment planning 3. Failures in mouth preparation 4. Failures in framework design 5. Failures in laboratory procedures 6. Failure in support for denture bases 7. Failures in occlusion 8. Failure in patient-dentist relationship 9. Conclusion 10. Bibliography
  • 4.
  • 5. Failure of removable partial dentures is due to inadequate 1. Diagnosis and treatment planning 2. Mouth preparation procedures 3. Design of framework 4. Laboratory procedures 5. Support for denture bases 6. Occlusion 7. Patient-dentist relationship Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I. J Prosthet dent; 2001;86(3); 251-261
  • 6. Making RPD’s using a 2 appointment system: one for diagnosis definitive impressions, mouth preparation procedures and second for insertion of partial denture. FAILURE IN DIAGNOSIS AND TREATMENT PLANNING A.ERROR:- 1. IMPROPER DIAGNOSIS Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I. J Prosthet dent; 2001;86(3); 251-261
  • 7. SOLUTION:- 1ST appointment:- make an assessment of the patient, diagnosis, take radiographs and make primary impression 2nd appointment:- make mouth preparations and impressions for definitive casts and jaw relation can also re carried out. 3rd appointment:- try in of the metal framework prosthesis. 4th appointment to deliver the denture and adjust the occlusion. Give the patient instructions essential to successful function and maintenance of the denture 5th mandatory follow up Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I. J Prosthet dent; 2001;86(3); 251-261
  • 8. Failure to a the analyze set of diagnostic casts for each patient. B.ERROR:- SOLUTION:- 1.After only an intraoral examination, a patient may appear to have a simple problem when, in fact, the situation is very complicated. 2. Always make diagnostic casts and evaluate them thoroughly before committing to treatment Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I. J Prosthet dent; 2001;86(3); 251-261
  • 9. C. ERROR:- Failing to remove debris and plaque from the teeth before impression is made Routinely clean the teeth with a lubricating prophylactic paste before making an impression, In cases of extensive calculus deposition oral prophylaxis has to be carried out SOLUTION:- Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I. J Prosthet dent; 2001;86(3); 251-261
  • 10. 2) Surveying Failure to use a surveyor during treatment planning SOLUTION It is the responsibility of the dentist to survey and draw the design on the diagnostic cast before sending it to the lab Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I. J Prosthet dent; 2001;86(3); 251-261
  • 11. FAILURES IN MOUTH PREPARATION PROCEDURES 1) Improper guide plane preparations: Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
  • 12. 2) Improper height of contour:  Improper positioning of the retentive clasp arm and reciprocal clasp arm  Retention and Stability of the prosthesis affected.
  • 13. 3) Rest and Rest Seat Preparation: Movement of the abutment tooth or sliding of the prosthesis The forces transmitted from the prosthesis to abutment teeth would occur against the inclined plane. Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
  • 14.  Occlusal rest Preparation in a multi- surface Amalgam Restoration. -Amalgam tends to flow when placed under constant pressure or even excess preparation.
  • 15. ERROR:- SOLUTION:- Dentist failing to tripod the designed diagnostic cast When the dentist designs the cast it has to be tripoded so that the lab technician can easily duplicate the design. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I. J Prosthet dent; 2001;86(3); 251-261 FAILURES IN DESIGN OF FRAMEWORK 1.Tripoding
  • 16. 2. Design transfer to master cast: 1. The design has to be outlined on the refractory cast with minimum pressure. 2. The cast must not be abraded during the transfer of the design 3. The position of individual clasp tips is most important in the design transfer Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
  • 17. 3) Incorrectly located RPD components:  Incorrectly located major connector Stewart’s Clinical Removable Partial Prosthodontics. 4th edition 1. Flexible major connector 2. Impinging on the gingival margins 3. Failure to provide relief where is crosses the gingival margins
  • 18.  Incorrect use of clasp designs Use of clasps that are too broad in tooth coverage and have too little consideration for esthetics
  • 19. 4) Beading of the cast:  Tissue blanching and inflammation or ulceration seen when the beading on the cast done too deep Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
  • 20. 5) Block out:  Improper seating of the framework:- -Block out if not done properly permitting rigid part of the framework to be placed in undercuts. Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
  • 21.  Framework that does not contact the tooth:- Block out wax added above the height of contour line or on the guiding planes and not removed during shaping of wax. Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
  • 22. 6) Contouring of the block out wax: 1. Done with blockout instrument properly positioned, excess wax is carefully removed. 2. The blockout instruments can be electrically heated or warmed over a flame Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
  • 23. 7) Relief: . Stewart’s Clinical Removable Partial Prosthodontics. 4th edition ERROR:- Metal framework impinges on the soft tissue SOLUTION:- 1. The thickness of the relief wax has to be adequate 2. The wax must not be separated and lifted up from the cast during duplication.
  • 24. 1) Poor cast-forming procedures: Cast is inaccurate: not a true reproduction of the anatomy of the mouth.
  • 25. 2) Duplication: 1. Block out and relief wax melted by reversible hydrocolloid. 2. Mold damaged during removal of the master cast. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I. J Prosthet dent; 2001;86(3); 251-261
  • 26. 3) Refractory cast: ERROR: Abraded refractory cast SOLUTION:- 1.Surface treatment of the cast has to be carried out. 2. The cast must not be retrieved until it is completely set. 3. The refractory cast is then trimmed on a dry cast trimmer. Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
  • 27. 4) Waxing: ERRORS:- patterns separate from the refractory cast. SOLUTION:- 1. The plastic patterns have to be glued properly to the design outline on the refractory cast 2. Mixture of acetone and plastic pattern scraps mixed to watery consistency ( TACKY LIQUID) 3. The liquid has to be applied in a very thin layer Stewart’s Clinical Removable Partial Prosthodontics. 4th edition
  • 28. 5) Failure of technician to follow the design and written instructions: Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I. J Prosthet dent; 2001;86(3); 251-261
  • 29. 6) Spruing ERROR:- 1. Attaching the sprue lead to a thin section of waxed framework SOLUTION:- Always sprue to the bulkiest portion of the pattern Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II. J Prosthet dent; 2001;86(3); 251-261
  • 30. Small particles of investment in the casting:- -Sprue leads joined to main sprue on wax pattern improperly. -Sprue hole was enlarged by cutting with knife, leaving roughened surface for metal to flow over. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II. J Prosthet dent; 2001;86(3); 251-261
  • 31.  Metal spilled when casting:- -Sprue hole is too small for Bulk of metal. -Sprue leads broken during investing procedure Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II J Prosthet dent; 2001;86(3); 251-261
  • 32.  Internal mold deformations:- -Constriction in the sprue lead  Porosity in casting:- -Improper spruing procedure  Pattern failed to casting:- -Pattern separated from crucible former during investment Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II. J Prosthet dent; 2001;86(3); 251-261
  • 33. 7) Investing: If the cast is dried with teeth up, white materials would be deposited around the teeth. This is due to deposition of salts which form a positive layer that cannot be removed without scraping and damaging the cast.  Cracks in the cast Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III. J Prosthet dent; 2001;86(3); 251-261
  • 34. 8) CASTING defects:-  Pitted casting If the design is placed on the refractory cast with a graphite pencil…. Contaminates….. Burn out temperature….. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II. J Prosthet dent; 2001;86(3); 251-261
  • 35.  Metal nodules and rough area on cast framework -Failing to use surface tension reducer correctly on the waxed patterns would cause air trap, when paint on investment flows -If the surface tension, reducer is not allowed to dry before applying the paint on investment Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II. J Prosthet dent; 2001;86(3); 251-261
  • 36.  Incomplete casting and rough areas or fins in casting -W: P ratio. -If paint on investment layer is too thin. -If the paint on layer is too thick. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II. J Prosthet dent; 2001;86(3); 251-261
  • 37.  Porous cast frame work If the mold moves in the casting machine as the casting arm starts to spin, molten metal sometimes may miss the sprue hole and spill outside the mold. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II. J Prosthet dent; 2001;86(3); 251-261
  • 38.  Incomplete casting 1. If the sprue hole faces upward during burn out. 2. Casting temperature of metal…. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II. J Prosthet dent; 2001;86(3); 251-261
  • 39.  Warpage of the Frame work 1.The air pressure of the nozzle of air abrasion machine is about 100 psi….. 2.If sufficient time is not allowed for the metal to cool to room temperature in the investment (quenching the mold)….. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 40.  Nicks on the metal casting 1. Carelessly cutting off the sprue leads 2. Using the wrong mandrel in high spread lathe Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 41.  Framework is too loose Carelessly grinding the inside of clasps Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 42.  Fracture of the clasps Removing too much metal from retentive clasps. An improperly tapered clasp or one that is thin or having nicks encourages breakage by concentrating the strain…. Electro polishing for a longer time. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 43.  Warpage of the framework Abrasive rubber wheels and points can build up heat in the framework very quickly  Loose frame work Polishing removes a definitive layer of metal. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 44.  Distorted frame work 1.Clasps and other parts of the frame work can easily catch in the polishing wheel. 2.The force usually distorts the framework and injures the operator. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 45.  Incomplete Casting of the Metal frame work 1. Metal too cold when cast. 2. Improper spruing. 3. Gas trapped in mold. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 46. 9) Mixing and packing acrylic resin: 1. Packing the acrylic material into the flask before allowing them to cool down at room temperature 2. Packing the resin into the flask before it is ready to pack. 3. Underfiling the mould. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 47. 10) Deflasking and polishing the removable partial denture: 1. Distorted framework 2. Increase in the vertical dimension 3. Warpage of framework 4. Scratches on the final metal framework 5. Damaged denture teeth Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 48.  Distorted clasps -Using a cloth wheel that was not broken properly would result in damaged removable partial denture or injure the operator. -A new cloth wheel has strings of material protruding from it. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 49. -The strings could tangle in the clasp or other parts of removable partial denture and snaps the removable partial denture from the operator’s hands throwing it out with great force. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 50.  Scratches on the denture -Course pumice leaves scratches. -It would be difficult to adequately polish around the necks of denture teeth with a cloth wheel or a lathe mounted bristle brush without damaging the contours of the teeth. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 51.  Dull appearance of the denture Detergent alone would not adequately remove polishing compound from the removable partial denture. The remaining residue would prevent the removable partial denture from achieving the luster. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 52. 11) Fitting the framework to the cast and mouth: 1. Framework too retentive on the definitive cast. 2. Frame Work not fitting exactly in the mouth. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 53. 12) Finishing and polishing of framework:  Polished surface is dull with fine scratches -Sequence of finishing steps not followed  Major and minor connector over thinned and flexible. -Framework over thinned with abrasive stones during finishing Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 54.  Clasps is nicked or notched  Framework distorted -Frame work caught in lathe during finishing. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 55. 13) Fitting and adjusting the removable partial denture to mouth :  Failing to evaluate the denture borders when placed intra-orally.  Loss of retention and support.  Soreness or Ulceration of soft tissue in the patient’s mouth Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 56.  Increase in the vertical dimension of occlusion Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 57. Warpage of the RPD -If the patient does not seat the removable partial denture correctly, they may warp the removable partial denture or be injured by it
  • 58.  Inadequate ridge quality and contour  Complete extent of the residual ridge not covered by the denture  Inadequate coverage of basal seat tissues  Failure to record basal seat tissues in supporting form FAILURE IN SUPPORT OF DENTURE BASE
  • 59. 1) Articulation: Error in articulation of the cast FAILURES IN OCCLUSION Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 60. 2) Face bow transfer:  Alteration in the jaw relation 1. Positioning the face bow on patient’s face. 2. Placement of the fork Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III J Prosthet dent; 2001;86(3); 251-261
  • 61. 3. Rocking of the record 4. Trimming of the record or metal showing through the record. 5. Face bow transfer not done.
  • 62. 3) Correction of occlusal plane:  Sensitivity of teeth or incipient caries- after enameloplasty
  • 63. 4) Selecting and arranging teeth:  Unable to interdigitate artificial teeth with opposing natural dentition  Insufficient space to set posterior tooth replacement  Anterior replacement teeth too short for satisfactory esthetics
  • 64.  Dentists failing to select type, shade and mold of the denture teeth to be used resulting in unaesthetic prosthesis not accepted by patient
  • 65. FAILURE IN PATIENT-DENTIST RELATIONSHIP  Failing to make a follow up appointment for the patient  Failure of dentist to provide adequate dental health care information, including care and use of prosthesis
  • 66.
  • 67. 1. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part I & . J Prosthet dent; 2001;86(3); 251-261 2. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part II & . J Prosthet dent; 2001;86(3); 262-276 3. Rudd & Rudd, A review of 243 errors possible during the fabrication of a removable partial denture: Part III & . J Prosthet dent; 2001;86(3); 277-286
  • 68. 4. McCracken’s: Removable partial Prosthodontics. Eleventh edition 2005 5. Stewart’s Clinical Removable Partial Prosthodontics. fourth edition 6. A clinical overview of removable prostheses:3. principles of design for removable partial denture .Dent update 2002;29. 7. A clinical overview of removable prostheses:4 technological consideration when designing removable partial denture. Dent update 2003;30:7-9

Notes de l'éditeur

  1. Good technique pays of. It is a saying tht has not only to be hanged on the wall but also praticed in day yo day life. The failures in removale partial denture can occur at anytime during the course of the fabrication.hence both the dentist as well as the technician have to be carefull in planning and executing a successful partial denture
  2. The guiding planes are formed so as to faciliate the easy removal and insertion of the prosthesis The guiding planes has to be maxium 2-4mm in hegth If the guiding planes are not fabricated properly then the path of inserton and removal will be hampered The guiding planes also help in stablizing the abutments against lateral destructive forces
  3. A flexibile major connector will cause damage to both the hard and soft tissue. It will also cause force concentration on a indivuila tooth Lead to ridge resoprtion The major connector has to be kept free from the gingival margins 6mm in the maxilliary 3mm in the mandibular