W1 - Cr-Co Dentures - Abbott

Question 1

Overview of RPD components

Answer 1

Question 2

Requirements of major connectors

Answer 2

1. Rigidity
2. Provide cross-arch stability and force-distribution
3. No interference with tongue or disruption of anatomy (md or palate)
4. No food trapping
5. Cover no more tissue than absolutely necessary

Question 3

Design guidelines of Major connectors

Answer 3

1. Free from movable tissue
2. Avoids impingement of gingival tissue
3. Bony and soft tissue prominences to be avoided (if impossible, provide relief)
4. Borders should run parallel to the gingival margins of remaining teeth
5. If gingival margins of teeth must be crossed, should be crossed at right angles

Question 4

How far should the border of a maxillary major connector be from the free gingival margin

Answer 4

Question 5

How far should the border of a mandibular major connector be from the free gingival margin

Answer 5

Question 6

2 most commonly used mandibular major connectors

Answer 6

Lingual bar

Lingual plate

Question 7

When to use lingual bar vs lingual plate

Answer 7

Lingual bar - ideal, more comfortable, hygienic, go-to option

Lingual plate - if incisors are perio involved, if space btw gingival tissue and lingual sulcus is less than 8mm, frenum or tori

Question 8

What can be done to lingual plate if pt has diastemas

Answer 8

Use interrupted lingual plate

Question 9

6 Types of maxillary major connectors

Answer 9

1. Palatal strap
2. Anterior-posterior palatal strap
3. Palatal plate
4. U-shaped / horse-shoe
5. Palatal bar
6. Anterior-posterior bar

Question 10

2 Types of Saddles / retentive framework

Answer 10

Question 11

2 Functions of rests

Answer 11

1. Provide a vertical stop
2. Transfer force onto teeth and tissue

Question 12

Primary rest vs secondary / auxillary rest

Answer 12

Primary - rest that is part of retentive clasp assembly

Secondary - responsible for additional support or indirect retention

Question 13

3 types of rest design

Answer 13

Occlusal

Lingual/cingulum

Incisal

Question 14

Supra-bulge vs Infra-bulge clasps

Answer 14

Supra- occlusal approach (circumferential clasps)

Infra- gingival approach (bar types)

Question 15

List some examples of suprabulge clasps

Answer 15

Question 16

How do the reciprocal and retentive arms differ in suprabulge clasps?

Answer 16

⅓ of retentive arm engages undercut

Reciprocal arm never goes below surveyed line

Question 17

Contraindications of infra-bulge clasps

Answer 17

Deep cervical tooth undercut

Severe tissue undercut

Shallow vestibule (4mm)

When survey line is close to the occlusal surface

Question 18

What is the Height of Countour?

Answer 18

Surveyed line on abutment teeth

Question 19

Where should indirect retainers be placed?

Answer 19

Perpendicularly from the fulcrum line as far forward as practical

Question 20

What are the sequences of the design system of RPD

Answer 20

Support → Retention → Stability

Question 21

What RPD components make up the support system

Answer 21

Saddles

Rests

Question 22

What RPD components make up the retention system

Answer 22

Direct retainers (clasps or attachments)

Question 23

What RPD components make up the stability system

Answer 23

Reciprocation arms

Minor connectors

Major connector

Question 24

Alternatives to clasp-retained RPD

Answer 24

Rotational Path RPD

Twin Flex clasps

Tooth-color clasps

Attachments

Locator attachment Implants

Question 25

Answer 25

kennedy class 3

Question 26

Answer 26

kennedy class 4

Question 27

Undercuts greater than ______ cannot be used for Co-Cr

Answer 27

0.25 suggest acrylic denture

Question 28

Clinical steps of making RPD

Answer 28

1. Take alginate imps for study models 2. Survey study model 3. Design RPD - pencil sketch 4. Give pt estimate $$$ 5. Make special tray 6. Prepare dentition (ex- occlusal rests) 7. Take secondary impression (PVS or polyether) 8. Send imp to lab and ask for framework to be returned with wax rim attached 9. Check framework is seating properly (now is the time to reject) 10. Jaw relation and shade selection 11. Try in wax up, send for processing if happy 12. Insertion of RPD 13. Recall in 7 days

Question 29

What should be checked at trial insertion of RPD (3)

Answer 29

Clasp engagment Occlusal rest seating Articulation

Question 30

Answer 30

Question 31

How long should a retentive clasp be?

Answer 31

15 mm

Question 32

Where should the tip end in an I-bar clasp?

Answer 32

Tip should end at the most prominent part of the bucccal surface of the abutment tooth

Question 33

Where should the clasps be placed in a kennedy class 2 pt?

Answer 33

One clasp as close to saddle as possible Other clasp as far posteriorly as possible on opposite arch

Question 34

How should be the bur be held when preparing cingulum rest sites?

Answer 34

parallel to long axis of tooth

Question 35

Why can't composite be used to build up a rest site instead of drilling into tooth structure?

Answer 35

Question 36

What are the 5 basic parts of a clasp assembly?

Answer 36

1. Rest 2. Body of the clasp 3. Minor Connector 4. Retentive arm 5. Reciprocal arm

Question 37

Dimensions of occlusal rest seat preparation

Answer 37

1.5mm deep 2mm wide Spoon-shaped