Inlay Onlay

Question 1

For an inlay Internal line angles should be

Answer 1

Round

Question 2

What is the minimum size of cavity for an inlay

Answer 2

2mm

Question 3

Requirements for an inlay

Answer 3

Divergent axial walls (10-15 degrees)
Minimum 2mm depth
Indented cavity-to ensure even material thickness

Question 4

How deep is a hollow ground chamfer

Answer 4

0.5mm created using a round bur

Question 5

What direction should the enamel rods be to the margin in an inlay

Answer 5

Paralllel to increase bond strength

Question 6

What is the minimal thickness of the cusp required for an inlay

Answer 6

1.5mm

Question 7

What are the retention and resistance form properties for an inlay

Answer 7

Lock
Hollow ground chamfer

Question 8

When prepping gold do the line angles need to be
A. Round
B. Sharp

Answer 8

B sharp

Question 9

When prepping for porcelain do the line angles need to be and why
A. Round
B. Sharp

Answer 9

A. Round to reduce risk of internal fracture

Question 10

Why does an inlay prep need divergent walls

Answer 10

The inlay is unable to flex and engage any undercuts

Question 11

What is the point of a hollow ground chamfer

Answer 11

To creat an effective seal and improve aesthetics

Question 12

When is an onlay indicated (2)

Answer 12

If there is less than 1.5mm from the outside of the cavity (undermined cusps)
If the cavity reaches the cusp tip

Question 13

What is the divergent angle of an inlay

Answer 13

20-30

Question 14

What are the different types of porcelain that can be used in an inlay

Answer 14

Stacked - placed in layers better aesthetics but not as strong and cracks can propagate through the layers

Conventional empress - pressed ceramic but monochromatic.

Milled porcelain emax- good strength

Question 15

What occlusal cusp reduction would be required for an onlay

Answer 15

1.5-2mm

Question 16

What labial reduction is required for an onlay

Answer 16

1.5mm