Principles of partial denture design

Question 1

What are 5 things to think about with RPD?

Answer 1

indications
complexity
design
preparations
maintenance

Question 2

List indications for RDP?

Answer 2

Patient preference

Need for flange

Limited dentition and limited bone

Need for future additions/modifications

2 or more edentulpus saddles

Use of teeth as over denture abutments

Interim solution

Question 3

What guide should you refer to for assessment of complexity of RDP?

Answer 3

Charlotte Stilwell et al

Question 4

What are the principles of design for o-Cr dentures?

Answer 4

Must be hygienic

Provide good support

Make sure the connector is rigid

Keep it simple

Question 5

How do you ensure the co-cr is hygienic?

Answer 5

Avoid gingival coverage - otherwise can be plaque retentive

Easy for patient to clean and maintain

Question 6

What gap should be between the gingival margin and the denture?

Answer 6

3 mm

Question 7

Why does the denture need to be rigid?

Answer 7

Distribute evenly the load of the denture

Question 8

What are the 8 steps to design co-cr dentures?

Answer 8

1. Saddles
2. Support
3. Retention
4. Bracing/reciprocation
5. Indirect retention
6. Guide planes
7. Connectors
8. Review principles of design

Question 9

What colour do you draw saddles in co-cr denture design?

Answer 9

Yellow

Question 10

What colour are do you draw the support in co-cr design?

Answer 10

Red

Question 11

What colour are do you draw the Retention in co-cr design?

Answer 11

Green

Question 12

What colour are do you draw the Bracing/reciprocation in co-cr design?

Answer 12

Blue

Question 13

What colour are do you draw the Components apart from saddles, support, retention and bracing/reciprocation?

Answer 13

Black

Question 14

What is the flange?

Answer 14

Question 15

When designing the saddle in a free-end-saddle denture, what needs to be decided?

Answer 15

Flange design to utilise undercuts? - retention

Avoid under cuts, if too deep or in wrong place

Saddle design must be hygienic - avoid creating stagnant areas around abundant teeth

Extension of denture base in saddle area

Usually required to cover maximum possible area to spread occlusal load as wide as possible

Minimum load/unit area - enhance possibility of patient comfort during use

Decide on shape of polished surface

Placement of teeth in the correct neutral space

Appropriate shape and design can assist stability and resist displacement

Question 16

Why do you sometimes avoid undercuts when it comes to saddle design?

Answer 16

Can resist insertion of appliance or cause trauma to underlying tissues

Question 17

What can be incorporated into saddle areas?

Answer 17

Appropriate support and retentive devices (clasps, rests)

Question 17

What question do you alway ask when it come to saddles?

Answer 17

Do we need to fill this edentulous space

Question 18

What areas supply support to denture - bounded saddles?

Answer 18

Nearest surface of each abutment tooth

Question 19

What areas supply support for free-end saddles?

Answer 19

Mesial side of the abutment tooth

Question 20

For a bounded saddle, what allows retention of the denture?

Answer 20

Retention on both abutment teeth

Question 21

When can a saddle not have a slap on at least one abutment tooth?

Answer 21

Aesthetics in the way

Question 22

For a free-end saddle, what allows retention?

Answer 22

On the abundant tooth on the saddle

Question 23

Why do you not add clasps anteriorly?

Answer 23

Because of the rotation about the clasp axis, there is no point in adding further clasps more anteriorly to this.

They will rotate down and not engage when pilling (sticky food)

Question 24

What happens if you have too much much or undercut in the wrong place?

Answer 24

We can re-shape the tooth by cutting a guide plane or adding composite

Question 25

How do you add a bubosity in the lab?

Answer 25

Add wax to area

In clinic, etch and bond tooth for composite

Question 26

What do you check for bracing/reciprocation?

Answer 26

Check resistance to lateral and anterior/posterior movement

Flanges extended properly to aid with bracing

Question 27

What do you check reciprocation?

Answer 27

Check reciprocation of each retentive clasp arm

Consider using guide places for reciprocation in vulnerable teeth

Question 28

What is indirect retention?

Answer 28

Resistantce to the rotational displacement in a tooth that supports denture

Question 29

How can you combat rotation of denture?

Answer 29

Adding rest seats

Aka indirect retention

Question 30

What are guide planes?

Answer 30

two or more vertically parallel surfaces on abutment teeth and/or fixed dental prostheses oriented to contribute to the direction of the path of placement of RPDs.

Question 31

List the purposes of guide planes?

Answer 31

For single path of insertion

For reciprocation (on vulnerable teeth)

For indirect retention

To create a path of insertion radically different from path of displacement

To prevent distortion of co-cr clasp arms

Question 32

List the 6 maxillary connectors?

Answer 32

Anterior palatal bar

Mid palatal bar

Posterior palatal bar

Horse shoe

Palatal plate

Ring

Question 33

List the 5 mandibular connectors?

Answer 33

Lingual bar

Sublingual bar

Lingual plate

Dental bar

Buccal bar