Complete dentures - function and stability

Question 1

Denture security

Answer 1

Pt’s main concern

A function of retention and stability

Question 2

Denture security - need to consider

Answer 2

3 surfaces:

• occlusal
• polished
• fitting

Question 3

Denture stability

Answer 3

Ability to resist those forces attempting to displace it in directions, other than at right angles to the supporting tissues

Question 4

Denture stability - criteria

Answer 4

Size and shape of the residual alveolar ridge
Need to optimise 
-periphery
-occlusal surface
-polished surface

Question 5

Denture stability - periphery

Answer 5

Avoid encroachment onto muscle insertions: mylohyoid, buccinator, genioglossus and mentalis
Undetake functional moulding with impressions

Question 6

Denture stability - occlusal surface must achieve

Answer 6

Balanced occlusion: even bilateral contact between opposing surfaces in RCP - a static position
Balanced articulation: even and mutual stability in all lateral and protrusive movements - a dynamic relationship

Question 7

Denture stability - polished surfaces

Answer 7

Concave polished surfaces will enable the musculature to stabilise the dentures
Removal of undercut on lingual surface to prevent lingual disaplacement

Question 8

Neutral zone

Answer 8

Site where opposing surfaces exerted by the lips and cheeks and tongue are in balance

Question 9

Neutral zone criteria

Answer 9

Mandibular anterior region - lower lip

Mandibular posterior sextants - tongue cramp (lack of space for tongue)

Question 10

Neutral zone - technique

Answer 10

1. Request a heat-cured based after definitive imps for registration
2. Set registration rims in even contact
3. Remove most of the wax from the anterior region
4. Apply adhesive to the cut surface and replace the missing wax with a small amount of
   stiff alginate
5. Place in the mouth
6. Patient to touch the palatal surface of the upper anterior rim with the tip of the tongue,
   occlude, smile and…relax.
7. A similar procedure can be carried out in the posterior region

Question 11

Pre-contact check-record

Answer 11

To ensure occlusal balance
To remove discrepancies that occur as a result of errors during the recording of the jaw
relations and the processing of the denture

Question 12

Pre-contact check-record: need to consider

Answer 12

Three surfaces:

• occlusal
• polished
• fitting

Question 13

Complete dentures opposed by natural teeth

Answer 13

Pt’s main concern

Function of retention and stability

Question 14

Complete dentures opposed by natural teeth: need to consider

Answer 14

Three surfaces

• occlusal
• polished
• fitting

Question 15

Complete dentures opposed by natural teeth - clinical technique

Answer 15

1. Impressions - as normal.
2. Registration - be aware
   -that the upper anterior teeth of completed denture will overlap the lower
   anterior natural teeth
   -support is often needed posteriorly
3. Wax try-in - as normal
4. Placement - ensure that check record is carried out and that balance is achieved between natural teeth and denture in occlusion and in lateral excursions