Endo techniques

Question 1

What probe do you use to identify canal orifice?

Answer 1

DG16 probe

Question 2

What is the purpose of putting 10K file to 2/3 ewl>

Answer 2

Checking freedom of movement into canal space

Question 3

Which premolar are more likely to have 2 canals?

Answer 3

the 4

Question 4

Explain how to coronal flare for modified flare technique

Answer 4

Coronal flare of root canal - GG 4 to 2/3 EWL - brush lightly against walls
10K recapitulate and irrigate
GG3 to 2/3 EWL drops coronal flare more apical
10k R + I
GG2 to 2/3 EWL
10K R + I

Question 5

What is the purpose of re-capitulation?

Answer 5

Lifts debris into solution to prevent blockages

Question 6

What does a zero/ red reading mean on apex locator?

Answer 6

The file has gone into the PDL
You want to step 0.5-1mm back from this to get CWL

Question 7

What is cyclic fatigue?

Answer 7

When repeated compression and tension cycles in instrument occur from rotation
Causes work hardening and eventual failure

Question 8

What is torsional fatigue

Answer 8

When instrument is inserted into the canal and it binds, but another part of it continues to rotate
When you rotate the instrument past its elastic phase and instrument FAILS.
Leads to torsion (twisting), deformation and FAILURE.

Question 9

How to you prevent torsional fatigue?

Answer 9

By ensuring glide-path

Question 10

How to you prevent hypochlorite accident?

Answer 10

Use your finger not thumb to irrigate
Do not inject at high pressure/ quickly
Do not inject too deep into canal
Do not lock syringe in canal

Question 11

Explain coronal prep with reciproc?

Assume LA, rubber dam and access already achieved

Answer 11

R25 to 2/3 EWL 3 pecks
Everytime you do 3 pecks, recapitulate and irrigate every time
Keep going with 3 pecks and R + I until 2/3 achieved with reciproc

Question 12

What is apical gauging?

Answer 12

When file of equal diameter to size that canal has been prepped to is inserted into the canal to test for resistance encountered - to ensure snug fit to reduce chance of extrustion in obturation

Question 13

Descibre apical prep of reciproc?

Answer 13

Achieve CWL with apex locator - step bakc 0.5-1mm back from zero reading
15K WW to CWL
R + I + patency filing
R25 to CWL 3 pecks each time with R + I + PF until CWL reached
Check rubber stop periodically throughout

Question 14

What is manual dynamic irrigation and when should you do this?

Answer 14

Moving a file in and out of canal with irrigant to lubricate, done at final EDTA 17% irrigation (1 minute)