Seminar 2: Paraphenalia

Question 1

According to Grossman what are the groups of instruments

Answer 1

Exploring instruments
Debriding instrument
Cleaning and shaping
Obturating

Question 2

Give an example of exploring instrument.

Answer 2

DG16

Question 3

What instruments do we have for exploring calcified canals ?

Answer 3

Ultrasonics

Question 4

What method exist for measuring canal length ?

Answer 4

Patient feedback
Paper point
Tactile sense
Radiograph
Electronic apex locator

Question 5

What is the working length ?

Answer 5

Length to which instruments are used to

Question 6

What does the EAL measure

Answer 6

Canal terminus

Question 7

What shape is the apical foramen?

Answer 7

Inverted cone

Narrowest coronal and widest apically

Question 8

What tissue is the major foramen located in

Answer 8

Cementum

Question 9

What is the problem with the CDJ in determining canal length ?

Answer 9

Histologogical site only and not always consistent

Question 10

Why do we prep to the apical construction

Answer 10

Creates smallest wound
Apical to this is PDL
CoronaL to this is pulp

Question 11

Name two organisations that aim to improve instrument quality

Answer 11

ISO

ANSI (AMERICAN NATIONAL STANDARDS INSTITUTE)

Question 12

What is the taper of ISO files?

Answer 12

0.02 / 2%

Question 13

What is the working length of K files?

Answer 13

16mm

Question 14

What type of tip do k flex files have ?

Answer 14

Cutting

Question 15

Which cases are better suited for k flex files ?

Answer 15

Calcified

Question 16

Using k flex in curved canals can lead to?

Answer 16

Ledging

Question 17

Flexofiles are made from what shape blank?

Answer 17

Size 6 8 10 square blank (this means they aren’t too flexible and retain strength )
Size 15+ triangular blank (this means they are still flexible )

Question 18

What is the tolerance allowed for k files?

Answer 18

0.03-0.04 for larger files

Question 19

How does canal transportation occur?

Answer 19

When the tip is loose and remainder of file is bound

Question 20

What are the components of stainless steel files ?

Answer 20

Iron
Chromium ( at least 10.5%)
Carbon (less than 1.2%)
Nickel 8-10%
Other metal

Question 21

How do NiTi fail?

Answer 21

Cyclic fatigue

Torsional fatigue

Question 22

Between rotational and reciprocal files which have better cyclic fatigue resistance

Answer 22

Reciprocal

Question 23

How do ultrasonic and sonics work ?

Answer 23

Method of activating files by using electromagnetic energy

Question 24

What are the risks of using ultrasonics and sonic instruments ?

Answer 24

Risk of fracture

Must remain passive in the canal