Acrylic partial denture Copyright (c) Department of Prosthodontics University of Dental Medicine, Yangon

1. ACRYLIC PARTIAL DENTURE

2. INTRODUCTION
In General,
Permanent treatment options for replacing missing teeth
- Fixed prostheses
- Metallic removable partial dentures
- Implant supported prostheses

3. DENTURE BASE MATERIALS
 Metallic
 cobalt chromium alloy
 gold alloy
 stainless steel
 Non metallic
 Acrylic resin (Heat cured)
 Vinyl resin

4. ACRYLIC VS METAL
 cheaper alternative
 easy to construct in lab
 easy to repair and reline
 wrought wire component incorporate
 less accurate
 relatively bulky
 low impact strength (fracture)

5. Metal framework is more desirable
- strength
- permit more hygienic design
But Acrylic partial denture is one option for
replacing missing teeth

6. INDICATIONS
 To prevent drifting of teeth
 Rapid and temporary replacement of anterior tooth/teeth
 inadequate support potential from remaining natural teeth
for tooth-borne denture
 tooth of poor prognosis
 when patient is to receive complete immediate denture
without previous experience and training or treatment
denture
 patients with limited financial resources (cost effective
option)

7. COMPONENT OF ACRYLIC PARTIAL DENTURE
 Acrylic denture base
 Artificial teeth (Acrylic/porcelain)
 Direct retainer (clasps)

8. PRINCIPLE OF DESIGN
 factors to be considered when designing APD,
 no different from metal-based denture
 acrylic denture base
mucosa borne (common)
tooth borne (may be)
 direct retainer
 artificial teeth

9. PRINCIPLE OF DESIGN
 Acrylic denture base
a) unification of components
b) retentive factor (major & minor connector)
c) indirect retainer
d) load distribution
e) stabilization (resisting horizontal forces)

10. PRINCIPLE OF DESIGN
 Acrylic denture base
mucosa borne (common)
 base must be well clear of the gingival margin

11. EVERY DENTURE
 in 1949, Every suggested APD design for
replacement of anterior teeth (Kennedy IV)
 Gingival protection design

12. EVERY DENTURE
 another acceptable design of acrylic denture
 special design to minimize periodontal damage and
maximize retention
 can be used for restoring multiple bounded
edentulous areas in the maxilla

13. EVERY DENTURE
 can be used for restoring multiple bounded
edentulous areas in the maxilla
 need to plan the retention with the aid of surveyor
 unwanted undercuts may be block out with plaster on
processing cast
 base will retain using planned undercuts
 positioning of clasps ----- essential to retention
 occlusal area of artificial posterior teeth
 smaller occlusal tables (should be smaller than that of
the teeth they replace)
 reduced resistance to food penetration

14. EVERY DENTURE (CHARACTERISTICS)
 uncovered gingivae
 no contact with gingival t/s
 palatally, the acrylic should be 3mm away from gingival margin
 point contacts
 between artificial teeth and abutment teeth
 to reduce lateral stress to minimum
 for retention
 Wide embrasures

15. EVERY DENTURE (CHARACTERISTICS)
 Free occlusion
 no tendency to interlock between upper and lower cusps
 no hinder movement
 Distal stabilizer
 posterior wire stops
 to prevent distal drift of posterior teeth with consequences of
opening of contact points
 also contributes retention

16. EVERY DENTURE (CHARACTERISTICS)
 with flanges --- to assist the bracing of the denture
 maximum retention
 follow the principles of complete denture construction
 covers as large as possible
 accurate denture base fitting
 polished surfaces should be designed to assist muscular forces

17. EVERY DENTURE
 open design ---- hygienic denture
 retentive and stable with minimum damage to the
supporting t/s
 require bounded saddle --- point contact can be maintained
throughout the arch form

18. ACRYLIC LOWER PARTIAL DENTURE
 problems in achieving effective design
 Adequate Support
 load should be spread as wide as possible
(external oblique ridge, buccal shelves, 1/3 of
retromolar pad)
 fail ---- accelerated alveolar ridge resorption
 bilateral free end case ---- thick acrylic major
connector
 wrought lingual bar
 to reduce tissue morbidity
 space to inferior border of bar (not to press into floor of
the mouth)
 tooth support ((not to press into floor of the mouth)

19. ACRYLIC LOWER PARTIAL DENTURE
 indirect retention ---- difficult to achieve (bulky
acrylic)
 occlusal rest --- adequate thickness of acrylic
must be surround the connectors (bulky acrylic)
 bulk of prosthesis
 strength
 greater awareess

20. TO PROVIDE RPD IN ACRYLIC RESIN
Limitations of material should be borne in mind
 weak
 less rigid
 tendency to flex and fracture
To minimized these problems
 relatively bulky ---- less tolerance
Narrow scope for denture design

21. TO PROVIDE RPD IN ACRYLIC RESIN
Radiolucent --- major disadv:
 difficult to locate (if denture is swallowed or
inhaled)
Acrylic RPD in mandible
 highly tissue damage