Lab Prescription Card

Question 1

What are the clinical stages of RPD design?

Answer 1

Primary impressions (with jaw registration?)
Master impressions with jaw registration
Tooth trial
Metal substructure trial - not in PMMA
Tooth & alloy base trial - not in PMMA
Finished dentures - delivery
Review

Question 2

What material should primary impressions be poured in?

Answer 2

100% dental stone

Question 3

How are wax spacers made?

Answer 3

2 thicknesses of modelling wax (3mm)

Question 4

What are special trays made of?

Answer 4

Light cured PMMA
Intra/extra oral handles
Perforated

Question 5

What is involved in the second clinical stage of RPD design?

Answer 5

Tooth prep if required
Master impressions
Jaw registration
Tooth shade & mould

Question 6

What material are master impressions poured in?

Answer 6

PMMA - 100% dental stone

Alloy base - Improved stone

Question 7

What is involved in the third clinical stage? (tooth trial)

Answer 7

Assessing tooth trial for fit, occlusion, aesthetics, saddle flanges
Make any necessary chairside adjustments

Question 8

What are the two extra clinical stages required for alloy base dentures?

Answer 8

Tooth trial takes place as normal, then extra 4th and 5th clinical stages required:
Metal substructure trial
Tooth and alloy base trial

Question 9

What occurs in the 4th(PMMA)/6th(alloy) clinical stage?

Answer 9

Finished denture delivery
Ensure it fits and is stable
Occlusion with no premature contact
Denture teeth and natural teeth in harmony
Clasps are functioning
Good aesthetics
Patient is happy

Question 10

What occurs in the last clinical stage?

Answer 10

Review of RPD with patient
Fits well and remains stable
No mucosal discomfort or ulceration areas
Good ICP relationship (occlusion)
Clasps are retentive in tooth undercuts
Provide denture cleaning instructions

Question 11

What is involved in the first lab stage?

Answer 11

Pour casts, make wax spacers & special trays

Mount casts, survey, potential design

Question 12

What is involved in the second lab stage?

Answer 12

Pour master casts
Mount casts with jaw registration
Survey & block out in relation to design
Duplicate casts and mount
Set teeth for tooth trial on duplicates using light cure bases & wax

Question 13

What is involved in the third lab stage?

Answer 13

Insert clasps as per design
Refine wax work
If PMMA denture then denture is processed in heat-cure PMMA, refined & polished.
Alloy base dentures still require two more lab stages.

Question 14

How many clinical stages are there in RPD design?

Answer 14

5-7 depending on if occlusion is stable or unstable (occlusal rims)