Endo

Question 1

Why are rotary files favourable?

Answer 1

NiTi maintain original curvature of RC
Superior flexibility + shape memory
Time efficient

Question 2

Benefits of ProTaper system

Answer 2

Cross section: convex triangle

Red. contact area b/w file + dentine

• enhanced cutting
• improved safety (red. torsional load)

Progressively tapered shaping file engage smaller load of dentine

• red. torsional load
• red. file fatigue
• red. risk breakage

Question 3

Importance of ProTaper files being non-cutting

Answer 3

Should only advance in canals which have been opened + explored
Use hand files (10-20) OR ProGlider to create glide path to EWL

Question 4

Difference b/w ProTaper shaping + finishing files

Answer 4

Shaping

• prep coronal 2/3
• inc. % taper over length of cutting blades

Finishing

• prep apical 1/3
• fixed taper in apical
• dec. % taper over coronal 2/3

Question 5

Procedural steps for rotary endo

Answer 5

Access: SLA
Explore coronal 1-2/3 w/ DG16 + F10
Prepare coronal 1/2/3 w/ SX
Explore apical 1/3 w/ F10 @ E.WL
Create glide path to E.WL
Establish patency
D.WL radiograph w/ F15
Prepare apical 1/3 w/ S1+2 @ D.WL
Finish apical 1/3 w/ F1+2 @ D.WL
Dry + obturate

Question 6

Golden rules of rotary endo

Answer 6

Assess difficulty pre-Tx; curved/sclerosed canals
Provide adequate access
Prepare w/ hand files pre-rotary
Light touch + low rpm

Question 7

Why are hand files still req. for rotary endo?

Answer 7

Determine SLA
Provide info re RC anatomy
Scout canal to create/confirm glide path

Question 8

How is success of RCT assessed?

Answer 8

ASA 2006

Monitoring of healing/development of pulpitis or apical periodontitis
Monitored for min. 1yr + subsequently as req.
Clinical + radiographic evidence

Question 9

Define favourable, uncertain + unfavourable outcome of RCT

Answer 9

Favourable

• absence of pain/swelling/other symptoms
• no sinus tract
• no loss of function
• X-ray: normal PDL space around root

Uncertain
- X-ray: lesion remained same/slightly diminished
— monitor until resolved OR at least 4yr
— persists = considered associated w/ post-Tx disease

Unfavourable
- signs + symptoms of infection 
- X-ray
— lesion appeared post-Tx
— pre-existing lesion inc.
— evidence continuing root resorption

Question 10

Scope of surgical endo

Answer 10

Root end/Apical resection 
Root end filling
Periapical curettage 
Root resection 
Hemisection
Surgical repair

Question 11

When is surgical endo indicated?

Answer 11

Re/RCT impractical
Re/RCT failure
Adjunct to non-surgical reTx
Ix: biopsy req.