Saddles and Support Flashcards
What are saddles?
The part of the denture that covers the alveolar ridges and includes artificial teeth and gum work
Name 6 things to consider when designing a saddle
- Which spaces to fill
- Occlusal surface design
- Base extension
- Polished surface
- Fitting surface (acrylic / metal)
- Junction between saddle and tooth (open / closed)
Name 4 considerations when deciding which spaces to fill with an RPD
- Appearance
- Mastication
- Speech
- Maintaining oral health
Describe the occlusal surface design on RPDs
- As few teeth as required especially on lower DES (only 1 molar replaced)
- Narrower teeth
- Tapered towards occlusal surface
Describe the extension of lower DES
Cover at least 2/3 of the retromolar pad and to the full functional width and depth of the buccal and lingual sulci
Describe the extension of upper DES
Full extension to the hamular notch and full functional width and depth of the buccal sulcus
Describe polished surfaces when designing saddles
- Lingual polished surface concave
- Buccal polished surface convex
- Palatal contour follows underlying palate
Name 2 functions of polishing surfaces
- Aid muscular control
2. Improve stability
What is the most common fit surface used?
Acrylic embedded in spaced CoCr meshwork
When may metal fit surfaces be used?
When the space between opposing teeth and the alveolar ridge is minimal, usually due to over eruption
Describe closed and open saddle designs
- Combined design usually used
- Closed means close contact between saddle and teeth and usually used anteriorly as no spaces present
- Open means spaces present between saddle and teeth and used when possible as tends to be healthier
What is support?
Resistance to vertical load applied to prosthesis during function and ultimately borne by bone
Name 2 ways vertical load is ultimately borne by bone
Teeth - via PDL which is tensile force and perceived as healthy
Mucosa - directly to bone which is compressive and perceived as unhealthy
Why is mucosal support seen as more unhealthy than tooth support?
Bone can become resorbed if put under compressive forces
Name 5 denture components which can give support
- Occlusal rests
- Occlusal onlays
- Embrasure hooks
- Denture base
- Any components contacting above survey lines on teeth