Files And Papers Flashcards
When and why were NiTi files developed?
What paper
Zupanc et al 2018
1980’s
To have more centred preparations with less perforations
What are the three key features of NiTi files?
Nickel : Ti : 55% vs 45%
5 x more more flexible than other alloys
Pseudoelasticity due to autenitic phase
Shape memory due to martensitic phase
How are NiTi files manufactured?
They are milled not twisted otherwise surface irregularities would form
What phase are most NiTi files finished in?
Aut with Mart embedded
Need martensitic to bypass ledges as can pre bend
What were the first generation NiTi files ?
1992: Mcspadden 2% taper
1994 Profile 4% and 6% taper
What was the second Gen NiTi file?
2001 Pro Taper Universal
Variable taper with cutting edge
What was the third generation NiTi
M wire 2007
Heat treatment with greater flexibility
400% increased resistance to cyclic fatigue
What is the fourth Gen NiTi files?
Wave one 2011
All fourth Gen are single file
What design does the wave one have ?
Reverse helical
What direction of movement does wave one move in?
Bi directional
Unequal reciprocation
150 CCW disengage then 30 CW
What benefit do reciprocating files offer?
Increased cutting efficiency
Debris driven out of the Canal
What are the tapers for wave one?
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
What are the fifth Gen files?
Offset mass of rotation
PTN 2013
Swaggering effect reducing screwing in to walls
What are the features of Pro Taper Gold?
Ruddle 2001
Triangle cross section
Variable taper - small parts of file in contact at one time
Changing helical angle: aids debris removal from canal
What is special about SX file?
Faster rate of taper to efficient
Rounded non cutting tip so follows canal better
For the S1 and S2 what part of the canal do these shape ?
Coronal
S1 coronal
S2 middle
According to who what is the benefit of reciprocating file systems?
Pedule et al 2013
Increase resistance to cyclic fatigue
What are the outcome measures ?
1) prom
2) periapical status
3)pain
4)function
5) survival
What are the prognostic factors that cannot be controlled ?
Age
Sex
Tooth type
Lesion (this is the only one that had an impact on outcome)
What paper suggests when re rct needed following exposure to saliva?
Stritharn et al 2001
@ 30 days risk of exposure
Klevant and eggink 1983 showed what with regards to unfilled canals?
Teeth with large lesions decreased after 6 months
What paper suggests that large PARL take longer to heal?
Klevant and Eggink 1983
