SURVEYING OSCE

Question 1

Why is a surveyor used?

Answer 1

to indicate the maximum convexity of the tooth/soft tissues in relation to planned path of insertion
- highlights undercuts

Question 2

what is the path of insertion?

Answer 2

the path followed by the denture from its first contact with the teeth until it is fully seated
(may or may not be the same as the path of displacement)

Question 3

what is the path of displacement?

Answer 3

the direction in which the prosthesis/denture tends to be displaced during function

Question 4

Where are the undercuts in a marked cast?

Answer 4

anything below the first survey line

Question 5

what is the purpose of tripodding?

Answer 5

allows for the cast to be reorientated to the desired path of insertion

Question 6

what material coincides with an undercut gauge of 0.25mm?

Answer 6

Cobalt Chromium

Question 7

what material coincides with an undercut gauge of 0.5mm?

Answer 7

Wrought Gold

Question 8

what material coincides with an undercut gauge of 0.75mm?

Answer 8

Stainless Steel

Question 9

How do you ensure that the casting table is level?

Answer 9

Lay a ruler on the cast so that is lies flat. (only on the anterior teeth)

Question 10

Where should the tripod lines be situated?

Answer 10

1 on back of cast

2 on rounded area/front of cast

Question 11

Outline the practical method you would take to survey a cast?

Answer 11

• place cast on top of table
• use ruler to ensure cast/table is sitting flat
• insert analysing rod into surveyor and tripod the cast
• use analysing rod to check for undercuts (start on abutment teeth then work to soft tissues)
• insert graphite and ensure the point of the graphite is facing towards cast
• mark upper and lower survey lines onto cast