Special techniques with complete dentures Flashcards
Denture security is (3)
Pt's main concern Function of retention and stability Need to consider three surfaces -occlusal -polished -fitting
Denture retention (1) with CD (2) and RPD (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
Retention with a CD is compromised by (3)
Poor denture adaptation - old or badly made
Unfavourable supporting anatomy - fibrous ridges, atrophic alveolus, post-surgery
Dry mouth - lack of cohesive seal
Denture stability definition (2)
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
Denture stability - need to optimise (3)
Periphery
Occlusal surface
Polished surface
Denture stability: optimising periphery (2)
Avoid encroachment onto muscle insertions - mylohyoid, buccinator, genioglossus and mentalis
Undertake functional moulding with impressions
Denture stability: optimising occlusal surface (2)
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
Denture stability: optimising polished surfaces (2)
Concave polished surfaces will enable the musculature to stabilise the dentures
Removal of undercut on lingual surface to prevent lingual displacement
Denture stability resists diaplcement in what direction? (2)
Non-axial direction
Encountered during mastication
Denture stability is compromised by (2)
Uneven or unfavourable occlusal contacts
Lever arm forces that cause a tipping effect
Lack of stability is caused by (2)
Poorly designed occlusal patterns (CDs) Retained teeth (RPDs)
Aim of denture adhesives (4)
Help with denture retention To enable effective function Avoid social embarrassment Achieved with minimal inconvenience -alteration of taste -difficulty of application and removal
Evidence for denture adhesives (2)
Can enhance retention, stability, bite force and overall patient well-being
Can improve retention of well-fitting dentures
Denture adhesives effectiveness will be compromised when? (2)
With poorly adapted dentures
Grossly unstable dentures
Do denture adhesives work? Compare when two types would be used (6)
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
What is the neutral zone? (3)
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)
Neutral zone technique (7)
- Request heat-cured base after definitive imps for registration
- Set reg rims in even contact
- Remove most of the wax from the anterior region
- Apply adhesive to cut surface and replace the missing wax with small amount of stiff alginate
- Place in mouth
- Pt to touch palatal surface of upper anterior rim with tip of tongue, occlude, smile and relax
- Similar procedure can e carried out in posterior region
Pre-contact check record (3)
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
Single arch denture over natural teeth
- Imps as normal
- Registration - be aware that the upper anterior teeth of the completed denture will overlap the lower anterior natural teeth
- support often needed posteriorly - Wax try-in as normal
- Placement - ensure that check record is carried out and that balance is achieved between natural teeth and denture in occlusion and in lateral excursions
