The document discusses an altered cast technique for removable partial dentures. The technique involves making an impression of the edentulous ridge after the metal framework is cast. This refined impression is used to alter the edentulous areas of the master cast, accurately reproducing the supporting tissues. This provides correct denture base extension and favorable physiologic support when seated. The technique offers benefits like reducing adjustments and preserving residual ridges by improving stress distribution. Two case examples demonstrate using the altered cast technique for mandibular and maxillary removable partial dentures.

1. An altered cast procedure
to improve tissue support
for removable partial
denture
Journal of Contemporary Clinical Dentistry
Chandrashekar Sajjan
Department of Prosthodontics, AME's Dental College,
Hospital & Research Center, Raichur, India
Presented by :
Dr. Bhupendra Rizal
MDS 2nd year

2. CONTENTS
• Introduction
• Case report
• Discussion
• Conclusion

3. INTRODUCTION
• The most important consideration in designing a free-end saddles/distal
extension removable partial denture, or CPD, for optimum function is as DeVan
stated “the perpetual preservation of that which remains, and not the meticulous
replacement of that which has been lost.”
• Cast partial denture made using the altered cast impression technique helps
create an environment in which the teeth and the edentulous tissues support the
base as compatibly as possible.
• The result is a potentially more stable RPD that improves the support for the
occlusal relationship of the opposing dentition and the RPD restoration.

4. What is
altered cast
technique?
• Also known as corrected cast or slip cast technique.
• It is mainly a modification of functional impression through
laboratory procedure.
• Basically, the altered-cast procedure applies some of the principles
of impressions for complete dentures to the fabrication of the tissue
surfaces of extension removable partial dentures.
AN ALTERED-CAST PROCEDURE TO IMPROVE TISSUE SUPPORT FOR REMOVABLE
PARTIAL DENTURES
ROBERT J. LEUPOLD, AND FRANK J. KRATOCHVIL
U. S. Naval Dental School, National Naval Medical Center, Bethesda, Md.

5. • The refined impression of the edentulous tissue surfaces is made after
the metal casting has been completed and is used to alter the
edentulous areas of the master cast.
• The resultant cast accurately reproduces the supporting tissues in a
form that provides the correct denture base extension and favorable
physiologic support when the denture is in its fully seated position.
AN ALTERED-CAST PROCEDURE TO IMPROVE TISSUE SUPPORT
FOR REMOVABLE PARTIAL DENTURES
ROBERT J. LEUPOLD, AND FRANK J. KRATOCHVIL
U. S. Naval Dental School, National Naval Medical Center, Bethesda, Md.

6. • This technique has the potential benefits of reducing the number
of postoperative visits,
• Preserving the residual ridges,
• Improving stress distribution,
• Decreasing food impaction, and
• Decreasing the torquing of abutment teeth.
All of which lead to increased patient satisfaction.

7. Becker and colleagues critically reviewed the evolution of RPD and
outlined six principles of RPD design. These principles include :
• a rigid major connector,
• multiple positive rest seats,
• mesial rests,
• parallel guide planes,
• the I-bar clasp design and
• the altered cast technique.

8. CASE REPORT
1

9. Mandibular edentulous arch with distal extension
Maxillary edentulous arch with partial missing
teeth

10. • Preliminary impressions were made with irreversible hydrocolloid
and study casts were obtained.
• The study casts were placed on a surveyor for examination and
design of the cast framework.
• Mouth preparation was done and final impression of maxillary and
mandibular arch were made with medium bodied elastomeric
impression material.

11. • Secondary casts obtained were placed on a surveyor for
examination and design of the cast framework
• Master casts were duplicated, refractory cast were obtained, and the
design was transferred from the master cast to the refractory cast.
• Investing and casting was completed.

12. Mandibular metal framework
Maxillary metal framework

13. Mandibular metal try in
Maxillary metal try in

14. An acrylic resin custom tray attached to the mandibular metal
framework

15. Border molded tray for the desired extension
Final impression made using zinc oxide eugenol.
impression paste

16. Cast with two saw cuts perpendicular to each
other on either side of saddle
The cut surface of the cast with grooves

17. Seating of the framework on the cast with
sticky wax
Final impression with beading and boxing

18. An altered cast

19. Occlusal view of mandibular cast
partial denture
Anterior view of cast partial denture

20. CONCLUSION
A favorably extended base will provide stimulation to the underlying
bone and distribute forces uniformly. The altered cast technique allows
the ridge, recorded in functional form, to be related to the teeth so that
when the prosthesis is seated, it derives support simultaneously from
the teeth and the denture base. This technique produces the following
results :
• Remarkable stability in the denture base region of distal extension
removable partial dentures.
• A positive occlusion which will be maintained for long periods of
time.
• Reduced stress on abutment teeth from unfavorable forces.
• Reduced numbers of postinsertion adjustments.

21. CASE REPORT
2
Altered cast technique for management of large maxillary defects
The Journal of Indian Prosthodontic Society / July 2009 / Vol 9 /
Issue 3
G. N. Anandakrishna
Department of Prosthodontics, MS Ramaiah Dental College and
Hospital, MSR Nagar, MSRIT Post, Bangalore-560 054, India.

22. • A 58-year-old male patient reported to the department of
prosthodontics with a history of carcinoma of the maxillary sinus
five years ago.
• Unilateral maxillectomy defect on the left side extending from the
central incisor to the soft palate

23. Ill fitting interim acrylic obturator

24. A preliminary impression was made with
irreversible hydrocolloid
Reline impression is made with light viscosity addition
silicone material to make an accurate impression of the
defect

25. the altered cast
a denture base is fabricated, Jaw relation
is done for CR and tooth setup

26. The acrylized denture comprising of the
intaglio surface of the defect side and teeth

28. The final obturator is evaluated for the adequacy of fit, esthetics and
function

29. DISCUSSION
• Obturators and facial prostheses are important not only in rehabilitation and
esthetics, but also in patient re-socialization. The level of reintegration is directly
related to the degree of satisfaction with rehabilitation.
• In literature very little is written about usage of the altered cast technique for
fabrication of maxillary obturator using a two stage impression technique.
• Altered cast technique is typically used as a special procedure for removable of
partial denture in distal extension situations to equate the pressure between the
teeth and the edentulous space.

30. • When adapted to make impressions for large maxillary defects, it
provides distinct advantage since the framework seating makes
verification of jaw relation and the trial procedure more accurate.
• The recording of the defect is relatively easy as the tray size is greatly
reduced by using the framework to carry the impression material. Path
of insertion and removal can also be determined.
• The altered cast technique as an alternative to conventional impression
making in maxillofacial defects has not been discussed in literature.
Hence description of this technique may be quite useful in restoration
of large maxillary defects.

31. CONCLUSION
• Altered cast technique is one of the improvisations that can be
made while making an obturator for large maxillary defects. It not
only improves the impression making and fabrication easier but
also provides comfort to the patient by not trying to stretch open
the mouth during impression procedure.

32. THANK
YOU