rpd, shammasm, intro to dentures, removable prosthodontics

2. Denture base and teeth
for removable partial
dentures

3. Learning outcomes
1. Define a denture base.
2. Describe the types of denture
bases and their indications.
3. Compare the advantages and
disadvantages of denture bases.
4. Describe the methods of
attaching teeth to the denture
bases.

4. Components of a RPD
1. Major connectors
2. Minor connectors
3. Rests
4. Direct retainers
5. Indirect retainers
(CLASS I AND CLASS II ONLY)
6. Denture bases
7. Teeth

5.  Denture base: the part of a
denture that rests on the
foundation tissues and to which
teeth are attached.

6. Types of denture base
 1. Acrylic resin denture bases
(with metal mesh/lattice work)
 2. Metal denture bases

7. Acrylic resin denture bases –
indications
 1. Kennedys class I and II
 2. Long span Class III and IV
 3. Need to reline or adjust the base
 4. Need to restore anatomic
contour and esthetics.

9. Advantages
 Esthetically better than metal
bases
 Easy to repair

10. Disadvantages
 Dimensional stability- warpage
 Lower strength/wear resistance
than metal
 Porous – hygiene problems
 Low thermal conductivity

11. Metal denture bases –
indications
 1. Short span Kennedys class III
 2. Limited vertical height
with less space for resin
 3. Maximum strength
required.
 4. Relining not anticipated.
 5. Where esthetics is not of concern

12. Advantages
1. Accuracy and Permanence of
Form
Cast metal bases, whether of gold,
chrome, or titanium alloys, not only
may be cast more accurately than
denture resins but also can maintain
their accuracy of form without
changes in the mouth.

13. 2. Comparative Tissue
Response
The cleanliness of the cast metal
base contributes to the health of oral
tissues when compared with an
acrylic resin base.

14. 3. Thermal Conductivity
Freedom of interchange of
temperature between the tissues
covered and the surrounding tissues
contributes much to the patient’s
acceptance of a denture and may
help avoid the feeling of the presence
of a foreign body.

15. 4. Weight and Bulk
Metal alloy may be cast much
thinner than acrylic resin and still
have adequate strength and rigidity.

16. Disadvantages
 Its principal disadvantages are
that it is difficult to adjust and
reline.

17. Methods of Attaching Artificial
Teeth
 Artificial teeth may be attached to
denture bases:
- with acrylic resin,
- with cement,
- cast with the framework

18.  Use of acrylic-resin to attach
artificial teeth to a denture base is
the most common method.

19. Porcelain or Acrylic-Resin Artificial
Teeth Attached With Acrylic-Resin

20.  Artificial porcelain teeth are
mechanically retained. The posterior
teeth are retained by acrylic-resin in
their diatoric holes. The anterior
porcelain teeth are retained by acrylic
resin surrounding their lingually placed
retention pins.

21.  Artificial resin teeth are retained by a
chemical union with the acrylic-resin
of the denture base that occurs during
laboratory processing procedures.

22.  Attachment of acrylic-resin to the
metal base may be accomplished
by nailhead retention, retention
loops, or diagonal spurs placed at
random.

23. Porcelain or Resin Tube Teeth and
Facings Cemented Directly to Metal Bases
Tube Teeth

24. Metal Teeth- cast with the framework
 The use of cast metal teeth in RPD
applications is restricted to the
replacement of posterior teeth.
 Such pontics are used where interarch
space is extremely limited.

25. Metal teeth