Dental instruments

Question 1

Rotation speed of a high speed

Answer 1

greater than 200,000 rpm

Question 2

Rotation speed of a low speed

Answer 2

less than 12,000

Question 3

Connector line of a high speed, how many holes?

Answer 3

1. fiberoptic
2. drive air
3. exhaust
4. coolant

Question 4

Straight connector used for?

Answer 4

extraoral procedures

Question 5

2 types of friction grip bur heads (theres also a latch type head)

Answer 5

Push button, bur tool type

Question 6

3 parts of bur

Answer 6

shank, head, neck

Question 7

Head of bur is usually what type of material

Answer 7

tungsten carbide

Question 8

Neck and shank of bur are usually what type of material?

Answer 8

stainless steal

Question 9

what are bladed burs used for

Answer 9

excavating tooth or finishing

Question 10

The greater the number of blades of a bur the …. the finish

Answer 10

smoother

Question 11

Bladed instrument are used for what kind of drilling?

Answer 11

intracoronal

Question 12

Diamond burs are more abrasive so they’re used for… procedures

Answer 12

extracoronal (crown prep)

Question 13

…. restoration: Dental material placed in a soft state directly in cavity prep to restore contour before it sets hard

Answer 13

direct

Question 14

… restoration: fabricated outside the oral cavity and then cemented or bonded to tooth

Answer 14

indirect

Question 15

Two types of handpieces

Answer 15

1. air driven

2. electric- popular, quieter, cuts with high torque, less stalling, smoother cutting

Question 16

In regards to the coupler, what does the high speed have that the slow speed does not have?

Answer 16

fiberoptic

Question 17

Distal diameter of a 330 bur

Answer 17

0.8mm

Question 18

Length of 330 bur

Answer 18

1.5mm

Question 19

Taper of a 245 bur

Answer 19

4 degree

Question 20

Taper of a 330 bur

Answer 20

8 degree

Question 21

Length of a 245 bur

Answer 21

3mm

Question 22

Neck of a bur is thinner for

Answer 22

operators visibility

Question 23

2 mechanisms of cutting

Answer 23

1. brittle fracture

2. ductile fracture

Question 24

Abrasive cutting is MORE efficient with … materials

Answer 24

brittle (like enamel) (micro cracks)

Question 25

Abrasive cutting is NOT efficient with.... material

Answer 25

ductile (dentin)

Question 26

Ductile fracture mechanism of cutting is.... deformation of the material by shearing

Answer 26

plastic

Question 27

Bladed cutting more efficient is MORE efficient with ... material

Answer 27

ductile

Question 28

Blade design- The surface that forms the chip and the surface of the blade towards the direction of cutting

Answer 28

Rake face

Question 29

Blade design: The surface that clears the chip and that goes away from the direction of cutting

Answer 29

Clearance face

Question 30

The angle that provides clearance between the cutting edge and the tooth structure

Answer 30

clearance angle

Question 31

Angle between the radial line and the rake face

Answer 31

rake angle

Question 32

angle between the rake and clearance surfaces

Answer 32

edge angle

Question 33

... rake angle has a higher cutting efficiency and larger chips are produced. But there is a small chip space so its more likely to clog

Answer 33

Positive

Question 34

A rake angle is positive when the blade is... to the perpendicular

Answer 34

behind

Question 35

A rake angle is negative when the blade is ... of the perpendicular

Answer 35

in front

Question 36

....rake angle has a decreased cutting efficiency and smaller chips are produced so there is no clogging

Answer 36

negative

Question 37

Purpose of the clearance angle

Answer 37

prevents blade from rubbing on the tooth surface

Question 38

...clearance angle means less friction, dulling minimized and bur life lengthened

Answer 38

Bigger

Question 39

Vibration and heat generation may lead to ...

Answer 39

plural trauma and discomfort to the patient (water coolants used)

Question 40

1st number of the 3 unit instrument formula is the...

Answer 40

width of blade (10 = 1mm)

Question 41

2nd number of the 3 unit instrument formula is the

Answer 41

length of blade (7=7mm)

Question 42

3rd number of the 3 unit instrument formula is the

Answer 42

angulation of the blade to the long axis of the handle (14)

Question 43

Gingival margin trimmer does what kind of cutting?

Answer 43

lateral