denture design

Question 1

In Kennedy Classifications, which saddle determines the classification?

Answer 1

the most posterior saddle

Question 2

Kennedy Class I

Answer 2

bilateral free end saddle

Question 3

Kennedy Class II

Answer 3

unilateral free end saddle

Question 4

Kennedy Class III

Answer 4

bounded saddle

Question 5

Class IV

Answer 5

anterior bounded saddle
(crosses midline, no modifications)

Question 6

When surveying, what does the black line represent?

Answer 6

the path of displacement

Question 7

When surveying, what does the red line represent?

Answer 7

path of insertion

Question 8

When planning to use clasps, where should they engage and where would this be represented on a surveyed model?

Answer 8

Engage the areas of undercut, this is below the survey line.

Question 9

When an anterior saddle is present, what would the path of insertion be?

Answer 9

anterior to posterior
(posterior tilt - heels down)

Question 10

When a posterior saddle is present, what is the path of insertion?

Answer 10

posterior to anterior
(anterior tilt - heels up)

Question 11

Support

Answer 11

Resistance to forces towards the mucosa -
provided by saddles, rests, collets, connector.

Question 12

Retention

Answer 12

resistance to forces away from the mucosa -
guide surfaces, clasps, ridge undercut.

Question 13

Stability

Answer 13

resistance to horizontal forces / rotational movement away from the mucosa

Question 14

Reciprocation

Answer 14

compensating element provided to counteract the horizontal forces from the active clasp -
collets, passive arms opposing clasps, rests.

Question 15

Bracing

Answer 15

resistance to horizontal forces when the denture is seated -
collets, passive arms, rests, clasps, flange extension, connector on vertical surfaces, guide planes.

Question 16

Connector

Answer 16

links components of the denture, located in a position so as not to damage tissues -
plate / horseshoe / gingival free plate / lingual plate / ring /lingual bar / sublingual bar.

Question 17

Indirect Retention

Answer 17

resistance to displacive forces along the retentive axis

Question 18

What is the rule for placing rests in a Co-Cr denture?
(preston’s golden nugget)

Answer 18

You can have a rest without a clasp but you CAN’T have a clasp without a rest.

Question 19

Minimum depth of a rest -

Answer 19

0.5mm

Question 20

For a free end saddle, where would you place the rest?

Answer 20

mesially

Question 21

For a bounded saddle, where would you place rests?

Answer 21

on either side of the saddle

Question 22

3 examples of gingivally approaching clasps

Answer 22

• i bar
• t roach
• j roach

(ones that are gingival on design)

Question 23

How many mm should there be between a gingivally approaching clasps and the gingiva?

Answer 23

1mm (and 4mm from the buccal sulcus)

Question 24

What is meant by the term gingivally approaching?

Answer 24

approaching the undercut from a gingival direction.

Question 25

What is meant by the term occlusally approaching?

Answer 25

approaching the undercut from an occlusal direction.

Question 26

4 types of occlusally approaching clasp

Answer 26

- C-clasp (any direction) - 3 arm clasp (upper molars - distally pointed) - ring clasp (lower molars - begins mesially) - reverse clasp

Question 27

Amount of undercut required for **gold clasp**:

Answer 27

0.75mm

Question 28

What is the minimum clasp length for a gold clasp?

Answer 28

5mm

Question 29

Amount of undercut for **stainless steel clasp** -

Answer 29

0.5mm

Question 30

Minimum clasp length for stainless steel -

Answer 30

7mm

Question 31

Amount of undercut needed for **Co-Cr** clasp -

Answer 31

0.25mm

Question 32

Minimum clasp length for CoCr -

Answer 32

14mm

Question 33

What are the rules for providing **gingival clearance**?

Answer 33

1. must **start and end on HALF COLLET** 2. **2** interstitial spaces.

Question 34

How much clearance is required for a lingual bar?

Answer 34

3mm, minimum of 7mm required.

Question 35

What does an alma gauge measure?

Answer 35

naso-labial angle for lip support

Question 36

Explain to a pt what an alma gauge is -

Answer 36

helps to see whether the denture supports the lip in the correct way or gauge the appearance of lips and incisor position on an existing denture.

Question 37

What does Fox’s Occlusal Plane Guide measure?

Answer 37

interpupillary line relative to ala-tragal line

Question 38

Explain to the pt what a Fox’s Occlusal Plane Guide is used for -

Answer 38

allows us to see whether the alignment of the jaw and teeth are correct to allow for comfortable chewing and eating processes.

Question 39

What does the Willis Buite Gauge measure?

Answer 39

OVD and RFH - allows correct freeway space.

Question 40

Describe what a Willis Bite Gauge does to a pt -

Answer 40

allows us to see whether there is enough space between dentures to bite and chew comfortably whilst maintaining correct height of the face.

Question 41

Explain denture care to a pt -

Answer 41

- take dentures out at night and store in water - can soak acrylic dentures in cleaning solution but **not overnight** - clean daily with toothbrush and soapy water over a sink of water to prevent dropping and breaking. - rinse with water after meals

Question 42

Additional advice given to edentulous pts who wear dentures -

Answer 42

brush gums, tongue and palate.

Question 43

5 things determined by surveying:

Answer 43

1. determine path of displacement 2. path of insertion 3. guide surfaces 4. undercuts 5. denture design

Question 44

Design Sequence:

Answer 44

1. draw on saddles 2. support - rests, collets. 3. retention - guide surfaces, path of insertion, clasps. 4. bracing & reciprocation 5. indirect retention 6. connect

Question 45

Where must collets sit on the survey line and if not, what occurs?

Answer 45

should sit ON the survey line and if not will cause **gum stripping**.