Lec 2/9 Retainers for RPD

Question 1

Need for retainers or partial RDP?

Answer 1

to modify dentition by enameloplasty and/or addition of composite resin for min prep, cast restos w GPs, rest seats, retentive UC’s or precision attachments

Question 2

Factors when considering to crown:

Answer 2

caries, existing restos, vitality , shape/ long axis of tooth, OH of pt, pdd, cost, experience of dentist

Question 3

TF? Must do full coverage restorations for abutment if endo needed

Answer 3

T

Question 4

Cheapest option for rest seats:

Answer 4

amalgam

Question 5

Purpose of surveying casts:

Answer 5

alignment of LA of teeth that support partial, POI, eval tissue UCs and their influence on design

Question 6

Seq of surveying:

Answer 6

occ table parallel to platform, GPs - AP, retentive areas - laterally, check for bony UC’s

Question 7

Seq of making retainers for RDP:

Answer 7

survey study cast, dx, tx plan, design retainers (clasps, rest seats, etc? check) and RPD, mouth prep, snapstone cast to verify, survey crown prep and impression of cast restoration, interocclusal record, definitive cast and die, wax up, lab order (tripod marks, specs, design w both sigs), casting, resurvey retainers, cement, RPD impression

Question 8

How many times should a survey crown be surveyed?

Answer 8

at least 4

Question 9

Which is done first, preparation of the rest of the mouth or preparation of the survey crown tooth when making retainers fro RPD?

Answer 9

preparation of the rest of the mouth: tooth mods, GPs, HOC, rest

Question 10

Why are you surveying the 2nd time?

Answer 10

to verify tooth mods

Question 11

Order of tooth mods:

Answer 11

GPs, axial contours, occlusal rests

Question 12

Order of wax mods for survey crown:

Answer 12

Gps, retention/reciprocation, rests

Question 13

Which arm of clasp should engage toth first?

Answer 13

reciprocal before retentive

Question 14

BL width of rest seat:

Answer 14

1/2X

Question 15

4 times to survey w survey crown fabrication:

Answer 15

study cast, survey to verify tooth mods, survey after final tooth prep, survey after crown returns from lab and before delivery in cast mods need to be made

Question 16

What to do if CCC survey crown needs adjustments after being surveyed and before delivery:

Answer 16

mill

Question 17

How to make a crown under an existing RPD:

Answer 17

tooth prep, impression, seat existing RPD, filled tray “picks up” partial in final impression

Question 18

Can a crown be made under an existing RPD digitally?

Answer 18

yes

Question 19

TF? RPD attachments are the same for existing tooth, crown and implants.

Answer 19

F, diff for implant

Question 20

Adv of implant supported partial:

Answer 20

esthetic, no clasps in anterior portion, retentive part in PRD

Question 21

Advantage of intracoronal attachment for RPD vs occlusal rest:

Answer 21

forces applied along LA of tooth, closer to fulcrum, more apically, and dissipated

Question 22

Benefits of force application closer to the fulcrum of tooth in intracoronal attachments:

Answer 22

red non axial loading, dec torquing forces, rotational movement of the abutments

Question 23

“Philosophy” for attachments for RPD in distal extension base cases:

Answer 23

“Broken Stress Philosophy”

Question 24

“Broken Stress Philosophy”:

Answer 24

Red stress to abutments bc it has stress free rotational/ vertical movements, applies different types of forces on the last retainer

Question 25

Part of distal extension for RPD:

Answer 25

external part that comes out and a partial denture that snaps on top

Question 26

Fulcrum between last natural tooth and the partial, direction of force:

Answer 26

Force directed gingivally in the posterior region

Question 27

Fulcrum between 1st and 2nd natural tooth from removable, direction of forces:

Answer 27

red on abutment, more rotation (check)

Question 28

Adv of intracoronal attachment for RPD compared to conventional clasp retainer:

Answer 28

Less fracture, less bulky, more esthetic, better retention and stability, less food trapping

Question 29

Type of intracoronal clasp to use for ACC:

Answer 29

none

Question 30

radicular attachments:

Answer 30

endo treated tooth, flattened out, attachment on post extending into abutment crrown, design snapped on post

Question 31

What type of attachment is the intracoronal retainer usually regarded as?

Answer 31

internal or precision attachment

Question 32

Intracoronal Attachment:

Answer 32

retainer is either cast or attached totally w/in restored abutment, typically prefab machined key/keyway w opposing vertical parallel walls that limit movement and resist removal of RPD through frictional resistance

Question 33

Female part, key or keyway?

Answer 33

key, keyways is fabricated inside the crown (sounds backwards)

Question 34

Examples of extracoronal attachments:

Answer 34

RPD clasp, micro ERA, Dala Bona (Dalbo)

Question 35

What type of resistance to displacement do Dala Bona and Micro Era use?

Answer 35

mechanical resistance

Question 36

Placement of extracoronal attachments:

Answer 36

on or attached to the external surface of abutment, inv manufactured attachments, interlocking components

Question 37

Which is used more freq today and why, Dala Bona or MicroERA?

Answer 37

MicroERA, doesn’t consume lots of vertical (forces?) check Slide 32

Question 38

What should be done when making an extracoronal attachment for an RPD using multiple teeth?

Answer 38

should be splinted before ERA has been attached (ERA? Extracoronal Retainer attachment?)

Question 39

When is the RPD made?

Answer 39

after cementing retainer