lec 1

Question 1

what is an RPD

Answer 1

A biomechanical prothesis that replaces teeth or tooth in a partially dentate arch. Removable from the mouth and replaced at patient’s will.

biomechanical - incorportates clinical and xray findings into the design

Question 2

4 treatment options for replacing teeth

Answer 2

1. No treatment
2. implant supported restoration
3. fixed partial denture = BRIDGE
4. removable partial denture

Question 3

Why is a fixed option usually the treatment of choice?

Answer 3

fixed:

1. implant supported restoration
2. fixed partial denture = bridge

b/c it feels more like their own teeth and functions better

Question 4

waht are the 10 indications for RPD?

Answer 4

1. long edentulous span
2. abscence or inadequate periodotnal support
3. cross arch stabilization
4. distal extension
5. structually and anatomically comprised abuntment
6. need to restore hard and soft tissue contours
7. age and health
8. anterior esthetics
9. attitude and desire of pt
10. ease of plaque removal

Question 5

waht is the #1 indication of RPD?

Answer 5

distal extension

Question 6

if a pt has HIGH caries risk, why is RPD a good option?

Answer 6

ease of plaque removal

Question 7

future of RPD is good bc?

Answer 7

1. aging population 65+ yo
   - now: 13%
   - future: double to 26%

[however edentulous pt are LOWERING]

2. osteointegrated implants
3. inexperienced dentists

Question 8

Ossteointegrated implants

Answer 8

1. implant supported restoratios - need for interim removable prothesis
2. implant removable prothesis [same biomechanics principles but improved RPD versions using implants

Question 9

why are implants not likely to replace implants?

Answer 9

• high cost
• other factors

Question 10

For edentulous pts –> complete dentures

waht is the ONE source taht completely supports the teeth?

Answer 10

oral mucosa

Question 11

for edentulous pts –> complete dentures

we have TOTAL CONTROL over the setup of their teeth bc we are _________ them

Answer 11

rehabilitating them

Question 12

why are RPD pt more difficult to treat than complete edentulous pts?

Answer 12

presence of remaining teeth:

• caries
• severe occlusal wear
• malpositioned teeth

Question 13

2 sources of support for RPD

Answer 13

1. oral mucosa
2. abuntment teeth

Question 14

Remaining teeth pose a problem for RPD pts bc:

Answer 14

1. reduced VDO
2. occlusal plane discrepancy
3. unstable centric occlusal contacts –> loss of posterior support
4. compromised esthetics

Question 15

treatment goals or objectives with RPD

Answer 15

1. stablize individual arch and protect remaining structure
2. organize interach function:
   - VDO
   - occlusal plane
   - centric
   - esthetics

Question 16

3 things for well designed RPD

Answer 16

1. cross arch stabilization, crossing the midline
2. unite remaining teeth
3. restores function and controls the direction of the force over the remaining teeth and tissue

Question 17

Controlling the direction of the forces over the remaining teeth and tissue for:

Answer 17

VDO

occlusal plane

centric

Question 18

5 parts to a well designed RPD

Answer 18

1. Rests - main support for vertical forces
2. major connectors - has to be very rigid and stiff to provide cross arch stabilization and connect all arches into one
3. minor connectors/ proximal plates - anything that connects the rests to the major connectors
4. denture base connectors - provides mechanical retention
5. retainers - aka clasp or ibar

Question 19

3 requirements to successful RPD r

Answer 19

1. retention - resistance vertical dislodging forces
2. stability - resistance to horizontal or torsional forces

3 . support - resistance to occlusal or vertical seating forces

Question 20

which of the 5 design parts of an RPD is most important

Answer 20

rest

why?

supports the vertical forces

Question 21

why is support the most important

Answer 21

bc support protects the remaining structrures:

• overlying bone
• teeth
• mucosa

Question 22

what are the main/primary support of RPD

what are 2ndary suport

Answer 22

-primary is RESTS - controls the direction of the force over the vertical axis of the teeth

[when rest are placed on the tooth = primary support]

-secondary support: major connectors and denture base connectors

Question 23

stability is?

Answer 23

resistance to horizontal and torsional forces

comes from:

1. proximal plates <<< Main
2. lingual plates
3. rests
4. denture base connectors
5. bracing clasp arms

Question 24

retention?

Answer 24

resistance to vertical dislodgment forces

from:

1. retainers <<< mostly
2. parallel guiding planes
3. indirect retainers [for extension base RPDs only]

Question 25

Diagnosis includes

Answer 25

1. patient evaluation - CC, expectation, attitude 2. History - dental [had they have RPD b4] and medical [any systemic diseases taht will affect our prognosis and tx plan 3. oral exam - hard tissue [lingual and palatal tori, teeth [malpositioned, caries, periodotnal status], maxillo-mandibular relationship - class III is the most difficult to treat] soft tissue - frenum location, denture bearing surfaces, attached gingiva, ht of soft tissue contour 4. habits - like tongue thrust 5. radiographs - pathology and abuntments 6. mounted diagnostic casts - with CR in proper VDO

Question 26

When making the mounted casts what are the steps?

Answer 26

1. prelimanary impressions 2. study casts 3. RPD design on paper and on study casts - survey - MAP [most advantageous position] - path of insertion and withdrawl for RPD - prep study casts 4. prep typodont [pt] 5. final impression 6. master casts

Question 27

goals of alginate impression for study casts

Answer 27

1. capture all remaining teeth and soft tissue surfaces 2. surfaces taht will be in contact with the future RPD 3. occluding tooth surfaces 4. critical landmarks: - retromolar pad - hamular notch - vestibular debths and edentulous regions - lingual frenum attachment

Question 28

waht are the criterias for stock tray selection for alginate impression

Answer 28

1. have even thickness of 3 -4 mm of alginate 2. test the stock tray in the mouth - should not be impinging anywhere and captures all the structures 3. check the length of the tray using a mouth mirror 4. tray alternations: - high palatal vault : rope wax or compound to have 3 -4 even thickeness - periphery wax for tray extension

Question 29

Alginante impression directions

Answer 29

1. dispense entire pouch content into mixing bowl 2. add 1 full water (3 parts) with 73 degrees into mixing bowl 3. mix 1 min for creamy consistency 4. have the pt rinse with warm water 5. fill tray, insert into the mouth using a mouth mirror, hold for 1 min till the stickiness is gone 6. break seal with one snap motion 7. rinse debris and blood from impression 8. pour up cast immediately past 10 min is no longer accurate

Question 30

mixing time \_\_\_\_ total working time \_\_\_\_\_ initial setting time \_\_\_\_

Answer 30

mixing time 1 min total working time 2 min and 15 sec intial setting time 2 min and 30 sec

Question 31

setting time is waht?

Answer 31

time you beginning mixing to the time the impression hardens 3 min and 30 sec

Question 32

pour up the impression

Answer 32

1. measure the proper water to power ratio 2. mix into vaccum power mix for even thickness 3. gentle vibration, flow the stone into indentations of impression 4. avoid air bubbles 5. bottom surface of the base should be rough to facilitate adding of base 6. suspend poured impression by tray holder 7. once stone fully set invert the cast and add base base 10 -15 mm thickness 8. afte 1 hour separate the cast from the impression

Question 33

trimming directions

Answer 33

1. begin trim only AFTER 24 HOURS 2. soak cast in slurry water for 5 min

Question 34

why should you soak the stone in slurry water for 5 min before trimming?

Answer 34

1. prevent damage to the cast 2. prevent sludge from adhereing

Question 35

why should the cast NEVER be soaked in water or rinsed?

Answer 35

dental stone is water solubel

Question 36

trim base to be ____ mm land should be ___ mm

Answer 36

10 - 15 mm base 4 mm land

Question 37

why do we ask the patient to stick their tongue out and stay on top of the tray when pouring impressions for MAN?

Answer 37

1. to capture the lingual frenum at its full extension 2. related to the choice of major connector