Files And Papers

Question 1

When and why were NiTi files developed?
What paper

Answer 1

Zupanc et al 2018
1980’s
To have more centred preparations with less perforations

Question 2

What are the three key features of NiTi files?

Answer 2

Nickel : Ti : 55% vs 45%
5 x more more flexible than other alloys
Pseudoelasticity due to autenitic phase
Shape memory due to martensitic phase

Question 3

How are NiTi files manufactured?

Answer 3

They are milled not twisted otherwise surface irregularities would form

Question 4

What phase are most NiTi files finished in?

Answer 4

Aut with Mart embedded
Need martensitic to bypass ledges as can pre bend

Question 5

What were the first generation NiTi files ?

Answer 5

1992: Mcspadden 2% taper
1994 Profile 4% and 6% taper

Question 6

What was the second Gen NiTi file?

Answer 6

2001 Pro Taper Universal
Variable taper with cutting edge

Question 7

What was the third generation NiTi

Answer 7

M wire 2007
Heat treatment with greater flexibility
400% increased resistance to cyclic fatigue

Question 8

What is the fourth Gen NiTi files?

Answer 8

Wave one 2011
All fourth Gen are single file

Question 9

What design does the wave one have ?

Answer 9

Reverse helical

Question 10

What direction of movement does wave one move in?

Answer 10

Bi directional
Unequal reciprocation
150 CCW disengage then 30 CW

Question 11

What benefit do reciprocating files offer?

Answer 11

Increased cutting efficiency
Debris driven out of the Canal

Question 12

What are the tapers for wave one?

Answer 12

0-8mm 7% taper
8-12 6% taper
12-16 3% taper

Regressive taper reduces taper lock effect by minimising file contact with the walls

Question 13

What are the fifth Gen files?

Answer 13

Offset mass of rotation
PTN 2013
Swaggering effect reducing screwing in to walls

Question 14

What are the features of Pro Taper Gold?

Answer 14

Ruddle 2001
Triangle cross section
Variable taper - small parts of file in contact at one time
Changing helical angle: aids debris removal from canal

Question 15

What is special about SX file?

Answer 15

Faster rate of taper to efficient
Rounded non cutting tip so follows canal better

Question 16

For the S1 and S2 what part of the canal do these shape ?

Answer 16

Coronal
S1 coronal
S2 middle

Question 17

According to who what is the benefit of reciprocating file systems?

Answer 17

Pedule et al 2013
Increase resistance to cyclic fatigue

Question 18

What are the outcome measures ?

Answer 18

1) prom
2) periapical status
3)pain
4)function
5) survival

Question 19

What are the prognostic factors that cannot be controlled ?

Answer 19

Age
Sex
Tooth type
Lesion (this is the only one that had an impact on outcome)

Question 20

What paper suggests when re rct needed following exposure to saliva?

Answer 20

Stritharn et al 2001
@ 30 days risk of exposure

Question 21

Klevant and eggink 1983 showed what with regards to unfilled canals?

Answer 21

Teeth with large lesions decreased after 6 months

Question 22

What paper suggests that large PARL take longer to heal?

Answer 22

Klevant and Eggink 1983