Removable partial dentures

Question 1

What are the 6 steps to designing partial dentures?

Answer 1

1. Identify teeth to be replaced
2. Support
3. Retention
4. Major connectors
5. Indirect retention
6. Reciprocation

Question 2

What are the 4 classes of the Kennedy classification?

Answer 2

Class 1 - bilateral free end saddle
Class 2 - unilateral free end saddle
Class 3 - bounded saddle
Class 4 - bounded saddle crossing midline

Question 3

What is the definition of support?

Answer 3

Resistance of a denture to occlusal directed forces

Question 4

What is the definition of rest seats For support?

Answer 4

Provide support for dentures from vertical opposing forces

Question 5

How should a rest seat be prepared?

Answer 5

Remain in enamel 1mm minimum 0.5mm thickness

Should not be placed in occlusal centric stop

Question 6

What are the primary support for maxilla and mandible?

Answer 6

Maxilla:
- palate and palatine raphe

Mandible:
- pear shaped pad, buccal shelf and sulcus

Question 7

What are the secondary support for maxilla and mandible?

Answer 7

Maxilla:
- maxillary tuberosity, residual ridge, rugae, incisive papilla and torus

Mandible:
- buccal shelf (alveolar ridge)

Question 8

What is the definition of retention?

Answer 8

Resistance of a denture to vertical dislodging forces

Direct retention - resistance to vertical displacement

Indirect retention - resistance to rotational displacement

Question 9

What materials and size is required for retention clasps?

Answer 9

CoCr 0.25mm
Gold 0.5mm
Stainless steel 0.75mm

Question 10

What are the components of RPI system?

Answer 10

Mesial occlusal rest
Proximal guide plate adjacent to saddle 2-3mm undercut to permit movement
I-bar gingival approaching clasp

Question 11

Using maxillary connector how far should they be from gingival margin?

Answer 11

5mm

Question 12

Using mandibular connectors how far should they be from gingival margin?

Answer 12

3mm

Question 13

Lingual bar how much space does it required?

Answer 13

8mm
3mm from gingival margin
4mm for bar
1mm from functional level of FOM

Question 14

What extra function does a lingual plate provide?

Answer 14

Used for stabilisation of anterior periodontal compromised teeth

Question 15

A denture patient has the following teeth 45, 44, 43, 33, 34, 35, 36 and 37. What is the Kennedy classification?

Answer 15

Class 2 modification 1

Question 16

Gypsum products are prohibited on landfills because they produce which gas?

Answer 16

Hydrogen sulphide

Question 17

What is the setting reaction of acrylic?

Answer 17

Activation
Initiation
Propagation
Termination

Question 18

What are the components of CoCr alloy and their properties?

Answer 18

Cobalt 35-65% - rigidity 
Chromium 20-35% - corrosion resistance 
Nickel 0-30% - ductility 
Mo 0-7% - hardens and strengthens 
Carbon - embrittles

Question 19

A patient with new F/F returns complaining of difficulty pronouncing F and V sounded. What is the issue?

Answer 19

Incorrect buccal lingual position of teeth especially anterior teeth

Question 20

What occurs when PMMA construction is incorrectly cured?

Answer 20

Base becomes porous
Increased residual monomer
Develops whitening of acrylic

Question 21

The reference plane indicator for denar articulator identifies position 43mm from the incisal edge of 12 or cusp tip of 13. What is the practical importance of this?

Answer 21

To ensure the mounted casts are equi distant between upper and lower arms of the articulator.

Question 22

What denture components function is to determine path of insertion?

Answer 22

Parallel guide planes

Question 23

What is the average mesio distal width of a maxillary lateral incisors?

Answer 23

6.5mm