Quiz 1: Rotary Cutting Instruments

Question 1

Shank:

• • Fits into what?
• • Connects what two things?….. To provide what?
• • Held in the handpiece by what type of mechanism (2)?

Answer 1

• Fits into the handpiece
• Connects the head of the bur to the instrument providing the rotary motion
• • Held in the handpiece by close fitting compression mechanism (friction) or mechanical latching.

Question 2

Neck:

Connects what two things?

Answer 2

• Connects the head to the shank

Question 3

What part of the handpiece is considered the working part of the instrument?
– What two things does it do to the tooth structure?

Answer 3

• • Head

- - Cutting edges or points shape the tooth structure

Question 4

What two characteristics of the head form the basis for classification:

Answer 4

• • Bladed or abrasive

- - Head size and shape

Question 5

What are the five types of rotary cutting instruments and make sure to note what numbers go with the shapes

Answer 5

• Round (1/4-8)
• Inverted cone (30series)
• Pear-shaped (329/330)
• Straight fissure
• Tapered fissue (169, 170,171)

Question 6

In a blur blade design, each blade has how many angles?

– What is a negative angle?

Answer 6

• Each blade has three angles

- - a negative angle: rake face ahead of the radius

Question 7

Define clearance angle on a blur blade design

Answer 7

• • Provides clearance space for the chips formed ahead of the following blade
• • Increasing the clearance angle will decrease the edge angle

Question 8

Carbide blurs generally have two angles at what angle (#)?

Answer 8

– Generally have negative rake angles and edge angles of about 90 degrees.

Question 9

What are Rank Angles normally used for?

– What does it help minimize?

Answer 9

– For cutting hard brittle materials – minimizes fracture

Question 10

Edge Angle help reinforce what?

Answer 10

– Reinforces the cutting edge