Special techniques with complete dentures

Question 1

Denture security is (3)

Answer 1

Pt's main concern
Function of retention and stability
Need to consider three surfaces
-occlusal
-polished
-fitting

Question 2

Denture retention (1) with CD (2) and RPD (2)

Answer 2

Resists displacement in an axial direction
Retention with a CD
-cohesion between denture - oral mucosa
-peripheral seal
Retention with an RPD
-cohesion between denture - oral mucosa
-tooth undercut

Question 3

Retention with a CD is compromised by (3)

Answer 3

Poor denture adaptation - old or badly made
Unfavourable supporting anatomy - fibrous ridges, atrophic alveolus, post-surgery
Dry mouth - lack of cohesive seal

Question 4

Denture stability definition (2)

Answer 4

Ability to resist those forces attempting to displace it in directions other than at right angles to the supporting tissues
Size and shape of the residual alveolar ridge
-atrophic fibrous ridge
-torus palatinus
-bulbous ridge

Question 5

Denture stability - need to optimise (3)

Answer 5

Periphery
Occlusal surface
Polished surface

Question 6

Denture stability: optimising periphery (2)

Answer 6

Avoid encroachment onto muscle insertions - mylohyoid, buccinator, genioglossus and mentalis
Undertake functional moulding with impressions

Question 7

Denture stability: optimising occlusal surface (2)

Answer 7

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 8

Denture stability: optimising polished surfaces (2)

Answer 8

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

Question 9

Denture stability resists diaplcement in what direction? (2)

Answer 9

Non-axial direction

Encountered during mastication

Question 10

Denture stability is compromised by (2)

Answer 10

Uneven or unfavourable occlusal contacts

Lever arm forces that cause a tipping effect

Question 11

Lack of stability is caused by (2)

Answer 11

Poorly designed occlusal patterns (CDs)
Retained teeth (RPDs)

Question 12

Aim of denture adhesives (4)

Answer 12

Help with denture retention
To enable effective function
Avoid social embarrassment
Achieved with minimal inconvenience
-alteration of taste
-difficulty of application and removal

Question 13

Evidence for denture adhesives (2)

Answer 13

Can enhance retention, stability, bite force and overall patient well-being
Can improve retention of well-fitting dentures

Question 14

Denture adhesives effectiveness will be compromised when? (2)

Answer 14

With poorly adapted dentures

Grossly unstable dentures

Question 15

Do denture adhesives work? Compare when two types would be used (6)

Answer 15

Thin film e.g. Super Wernets
-dentures are well adapted
-denture-bearing anatomy is unfavourable for effective retention
-there is need to enhance salivary cohesion
Volume fillers e.g. Polygrip Range
-dentures are ill-fitting
-poor adaptation between denture and mucosa
-there is a need to fill the gap

Question 16

What is the neutral zone? (3)

Answer 16

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

• mandibular anterior region: lower lip
• mandibular posterior sextants: tongue cramp (lack of space for tongue)

Question 17

Neutral zone technique (7)

Answer 17

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

Question 18

Pre-contact check record (3)

Answer 18

Method for registering coincidence of retruded and intercuspal positions
To ensure occlusal balance
To remove discrepancies that occur as result of errors during recording of jaw relations and processing of denture

Question 19

Single arch denture over natural teeth

Answer 19

1. Imps as normal
2. Registration - be aware that the upper anterior teeth of the completed denture will overlap the lower anterior natural teeth
   - support 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