endo 4th year Flashcards

1
Q

what is failure?

A

presence of clinical S/S
enlargement of existing PR lesion
development of a new PR lesion
persistence of a PR radiolucent lesion associated with a tooth that had RCT at least 4 years prev

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

tx options for failure

A

monitor if asymptomatic
orthograde retx
PRS
extract +/- prosthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what must be mentioned if it is decided to monitor failure?

A

inform pt of possibility of a flare up

not ideal to monitor if tooth is a critical abutment in a definitive complex Rx

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

indications for non-surgical retx

A

intra-radicular infection
new complex restoration with technically poor RCT
loss of coronal seal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

principles of retx

A
remove restorative
assess restorability - check no fracture
remove all root filling
assess anatomy
refine/modify prep
complete tx as de novo case
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

removing insoluble resins

A

US

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

removing GP

A

handfiles
solvent (eucalyptus oil)
reciproc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

removing soluble pastes

A

handfiles
solvent (eucalyptus oil)
reciproc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

reciproc retx removing GP

A

remove GP from coronal 1/3 - US, GG, heat carrier

remove GP from mid 1/3 - R25 with stopper set at 2/3 of EWL - slow pecking motion

continue until GP removed from middle 1/3 of canal - use eucalyptus oil/chloroform if necessary

determine WL with small hand file

complete apical prep to CWL with R25. if necessary enlarge apical prep with R40/50 or K files

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how do you use a solvent?

A

fill orifice and pulp chamber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

why should you try to avoid solvents?

A

they lead to more GP and sealer remnants on RC walls, chamber and inside dentinal tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

when is WW good?

A

with K files

passing small files through canals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

balanced force technique

A

insert file and engage into dentine clockwise 1/4 turn
with continued pressure, 1/2 turn anticlockwise to strip dentine away
do 1-3 times before removing file
clean, check file, reintroduce, working your way to WL
safer for canal and file

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

reciproc file features

A

non-cutting tip
S shaped cross section
NiTi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

reciproc R25

A

red
narrow canals
ISO25

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

reciproc R40

A

black

medium canals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

reciproc R50

A

yellow
large canals
R50

18
Q

reciproc working length

A

16mm

19
Q

reciproc inverse/regressive taper

A

larger taper apically

allows for coronal shaping without unnecessary loss of tooth substance, compared to instruments with constant taper

20
Q

M wire technology (NiTi)

A

proprietary thermal tx process
increased flexibility
increased resistance to cyclic fatigue

21
Q

reciproc angles of reciprocation

A

150 degrees anticlockwise cutting the clockwise 30 degrees
- unequal rotation hence modified reciprocation
breaks in torque to protect instrument

22
Q

what do you use to select the correct reciproc instrument?

A

pre op radiograph

23
Q

reciproc - what do you use if the canal is partially/completely invisible and why?

A

R25

narrow canal

24
Q

reciproc - what do you use if the canal is completely visible and why?

A

wide or medium canal

if hand ISO30 goes passively to WL use R50

if hand ISO20 goes passively to WL use R40

if no - use R25

25
Q

what does passively to WL mean?

A

that the instrument goes directly to WL with a gentle WW movement (small right left rotations) but without filing action

26
Q

slow pecking motion

A
in and out
amplitude shouldn't exceed 3mm
v light pressure
the instrument will advance easily in the canal
one in and out movement = 1 peck
remove after 3 pecks and clean
27
Q

clinical reciproc procedure - coronal

A
estimate WL from pre-op radiograph
set stopper at 2/3 EWL
ensure SL access
irrigate and recapitulate
pecking motion
until 2/3 WL reached
no additional coronal enlargement necessary e.g. GG
28
Q

reasons for 3 peck movement

A

instrument does job of 4-5 rotary instruments and works from crown towards apex without instrument change
if instrument not cleaned - flutes will become blocked due to high cutting efficiency
- friction - instrument won’t work within canal

29
Q

reciproc in multirooted teeth

A

brush away from friction to reduce the risk of strip perforation

30
Q

rotary vs reciproc

A

rotary - “drill” continuous clockwise direction

reciproc - back and forwards, advances automatically

31
Q

reciproc - check if canal is free with hand instrument

A

insert to max 3mm past prepared length of canal
esp at start of RC prep, length has not yet been determined so dont bring instrument to WL
usually hand instrument only inserted to full/WL determination after prep of 2/3 of EWL

32
Q

reciproc - when is CWL determined ?

A

after 2/3 canal prep

electronic length - 0.5-1mm from reading

33
Q

reciproc- if ISO10 used for WL determination goes to WL without being pre-curved, what can the prep be finished with?

A

R25

34
Q

reciproc = why is creation of a glide path not necessary?

A

instruments centring ability based on reciprocation
instrument design (tip)
reciprocs cutting efficiency

35
Q

what is gradual curvature defined as?

A

if a hand ISO10 goes to WL even in a radiographically strong curved canal without being pre-curved, the curvature is described as gradual
the radius of curvature can easily be managed with a hand instrument even in case of a strong angle of curvature

36
Q

what is abrupt curvature defined as?

A

if hand instrument needs to be pre-curved

the radius of curvature is so small that the hand instrument can only pass if pre-curved

37
Q

reciproc blue

A

heat treatment on traditional NiTi alloy

higher flexibility, more fatigue resistance

38
Q

obturation with reciproc blue

A

guttafusion

variable tapered

39
Q

reciproc glide path management

A

if ISO 15 goes to WL without pre-curved, prep can be finished with R25
if not complete with hand files

40
Q

reciproc creating a glide path

A

ISO10 and 15 full WL
once done check K25 fits and have apical control - doesn’t advance with LAP past 0
if not go up to R40/50 or go up with hand files

41
Q

reciproc vs wave 1

A

reciproc - higher cyclic fatigue resistance - may be best suited in curved canals
WaveOne - higher torsional resistance - may be suited for use in constricted canals due to its ability to better resist torsional loads