Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
55 Cards in this Set
- Front
- Back
|
Vertical movement of RPD is affected by?
|
support and retentions
|
|
|
Horizontal movement of RPD is affected by?
|
stability
|
|
|
where is RPD support derived from?
|
tooth abutments via rest seats
residual ridge via denture base Hard palate and buccal shelves |
|
|
What provides RPD retention?
|
path of insertion
guide planes retentive clasp arms |
|
|
What affects the stability of the RPD?
|
number of teeth
Height of residual ridge amount of tooth coverage by RPD |
|
|
What would be more stable...a class II or a class III mod I?
|
class III bc you have more teeth that create a balance. Think of a table. You want symmetry
|
|
|
why do we use a dental surveyor?
|
To determine parallelism and undercuts of the tissues, relative to a particular path of insertion
|
|
|
What are some examples of soft tissue undercuts? Are they favorable?
|
canine eminences, tuberosities, lower incisors, recent extractions.
NO they are very unfavorable |
|
|
4 things that determine the tilt of the surveyor
|
1.guide planes
2. favorable undercuts 3.elimination of unfavorable undercuts 4.esthetics |
|
|
which teeth are not good candidates for cingulum rests?
|
Incisors and mand canines
|
|
|
What are the purpose of guide planes?
|
path of insertion (guide RPD insertion and removal)
stability (stabalize clasp assembly) retention |
|
|
What is the purpose of rests?
|
-PRDP support
-distribution of occlusal load |
|
|
Where is the ideal height of contour for Direct Retention?
|
in gingival 1/3rd
|
|
|
why use a custom tray?
|
-create uniform thickness of impression material for greatest accuracy
-optimize border extensions -minimize amount of impression material |
|
|
What is direct retention influenced by?
|
-type of clasp used
-amount of undercut engaged -flexibility of retentive arm |
|
|
what are the benefits of a cast clasp?
|
simpler to fabricate and less expensive
|
|
|
what are the benefits of a wrought wire clasp?
|
more flexible and easier to adjust and more durable
|
|
|
IS there more or less undercut for cast claso vs wrought wire?
|
there is less undercut for clasp bc of increased rigidity (.25)
-wrought is more flexible so more undercut required (.5) |
|
|
flexibility of clasp is influenced by what?
|
length, diameter and taper of clasp
round vs half round type of alloy used |
|
|
what is the difference between reciprocation and bracing?
|
reciprocation - resists displacement of toth DURING seating of prdp
bracing- provides resistance to displacement ONCE FULLY SEATED |
|
|
what are the 3 components of a suprabulge clasp?
|
shoulder
midsection terminus |
|
|
where is the primary fulcrum line?
|
the axis of rotation passing between the most posterior rests
|
|
|
where is the retentive fulcrum line?
|
the axis of rotation passing between the tips of the most posterior direct retentive arms tips
|
|
|
what is a primary fulcrum resisted by?
|
broad, well adapted denture base
|
|
|
what is a retentive fulcrum line resisted by?
|
an indirect retainer anterior to the fulcrum line
*includes rest under lingual plate |
|
|
do you have indirect retainers on class III RPDs?
|
no, only on class I and II
|
|
|
How are class I and II prdps different from other prdps?
|
-missing posterior abutment
-sore soft tissue support -more movement under function -indirect retention preferred -direct retainer clasp assembly (WW combination clasp asse,bly/RPI) |
|
|
class I and II Prdps use WW direct retainers. Where would these be located ?
|
on anterior abutments adjacent to distal extension base
-in class II there would also be an abutment anterior to loading and retentive fulcrum lines . |
|
|
what is the term for this part of a PRDP?
-connects all components (via minor connectors) -connects right and left sides (cross arch stabilization) -distributes forces: must be rigid -design incorporates comfort, esthetics, phonetics and hygiene. |
major connector
|
|
|
what is blockout?
|
fill in unfavorable undercutson cast ?
|
|
|
what is relief?
|
intentional space created on cast
|
|
|
max major connector must clear gingiva by at least ____ mm.
mand major connector must clear gingiva by at least ____ mm |
6mm
3mm |
|
|
space required for lingual bar?
|
5mm for height of bar and at least 3mm to gingiva
8mm total! |
|
|
what are tissue stops for distal extension bases?
|
-contact cast on ridge at end of framework well anterior to retromolar pad or hamular notch
-required to stabalize frameworks during processing of acrylic resin (class I and II) -no relief under tissue stop |
|
|
when would we sue braided post or nailhead retention?
|
-good for single teeth and anterior teeth
|
|
|
when would we use a reinforced acrylic pontic?
|
-anterior tooth replacement bc goos strength and esthetics
|
|
|
why do we minimize coverage of the anterior half of the palate where possible?
|
to reduce interference with speech and tongue function
|
|
|
the maxillary major connector has no relief of palate but what do we score?
|
we score the cast to create a beaded finish line (1.0 mm depth)
|
|
|
what type of maxillary major connector is preferred for most class I , II, III with no missing anterior teeth?
|
palatal strap
-at least 1-2mm thick -8mm wide |
|
|
what type of max major connector is preferred when anterior teeth are missing or at risk for loss?
|
anterior posterior palatal straps
|
|
|
what type of max major connector is preferred in maxillae with a minor torus?
|
anterior U-shaped connector "horseshoe"
|
|
|
what maxillary major connector is preferred if most teeth are at risk of loss?
|
palatal plate.
-consider replacing most of the metal with acrylic resin. We think of this as a transition to complete dentures.. |
|
|
what mandibular major connector is preferred in most class I II and III mandibles with no missing anterior teeth?
|
Lingual bar
-you must have ADEQUATE HEIGHT (8mm) |
|
|
what mandibular major connector is preferred for mandibles with anterior teeth missing or at risk for loss or when there is not adequate height? (<8mm or <5 mm attached gingiva)
|
lingual plate
-a rest is needed at each end of the plate for support (preferably the mesial |
|
|
what is an alternative for mandible with spaces between anterior teeth and no adequate height for a lingual bar in the lingual vestibule?
|
a sublingual bar
-challenging bc it sits in floor of mouth |
|
|
What are the choices for Denture Base retention?
|
-mesh or open web
-RAP -metal surface with retentive elements (bead, braided post, nailhead) |
|
|
Why would you choose mesh?
|
when ridge resorption is likely to occur
-excellent retention for large denture flange |
|
|
Why would u choose RAP?
|
-missing maxillary anteriors with well healed ridge
-not designed for large flange |
|
|
Why choose beading on metal surface?
|
-for areas requiring acrylic resin for appearance but with minimal interarch space (<5mm)
|
|
|
Why choose braided post or nailhead on metal surface?
|
For missing single teeth with a well healed ridge
|
|
|
Briefly, what are the 11 steps in a PRPD??
|
1. Determine Kennedy classification
2. Mark anatomical landmarks on cast 3. survey casts 4. rest seat locations and types 5. guide planes 6.Direct retention 7. reciprocation 8. Indirect retention if indicated 9.Major connector 10. denture base retention 11. written details and special considerations |
|
|
One of Applegates rules is that classification should follow extractions rather than precede them bc they might alter the original classification. What are the rest?
|
-missing 3rd molar and not replaced, do not consider it.
-3rd molar present and used as abutment, consider it. -2nd molar missing and not replaced, dont consider it. -most posterior edentulous space determines class -mod spaces -# of mods -no mods in a class IV |
|
|
What is the only part of the rpd framework that should be felxible?
|
the retentive arm tip
|
|
|
What sits above the height of contour?
|
the reciprocative arm clip or linguoplate
|
|
|
bracing arm
|
retentive clip touches before reciprocal on insertion of PRDP
|
