Retreatment

Question 1

What does retreatment depend on

Answer 1

• Strategy depends on material found in root canal

Question 2

What do we do if the filler is insoluble resin

Answer 2

○ Insoluble resin = ultrasonics

Question 3

What do we do if the filler is GP

Answer 3

○ Gutta percha = hand files +/- solvent and then protaper D/reciproc

Question 4

What do we do if the filler is GP

Answer 4

○ Soluble pastes = hand files +/- solvent and then protaper D/reciproc

Question 5

How do we remove poorly condensed gp

Answer 5

• Poorly condensed GP is easier to remove and can be done with hedstroem files

Question 6

How do we remove well condensed GP

Answer 6

• Well condensed GP is harder to remove and so we need to create a space within the GP mass to allow files to move and we may require solvent too
○ C plus files are rigid instruments which can allow us to penetrate into the GP mass
○ May use eucalyptus oil to dissolve the GP and let the file penetrate deeper

Question 7

What is pro taper D1

Answer 7

○ Has an active tip and allows better initial penetration into material
Must be careful with a curved canal as can lead to perforation

Question 8

What is the pretreatment sequence

Answer 8

• Protaper D1 for coronal filling removal
• Protaper D2 for middle filling removal
Protaper D3 for apical filling removal

Question 9

What is the procedure for pro taper resequenced

Answer 9

1. Select lowest speed that effectively engages obturation material (500-700rpm)
   
   2. Gently press D1 into GP and remove frequently to clean flutes
   3. Continue with D1 until obturation material removed from coronal one third of canal
   4. Auger obturation material from middle one third of canal with D2
   5. Remove material from apical third with D3 stopping 2-3mm short of apex

Question 10

How can ledges be bypassed

Answer 10

using precurved C+ files

Question 11

What are the 3 files from reciproc system

Answer 11

r25 (narrow canals)
r40 (medium canals)
r50 (large canals)

Question 12

Describe the reciproc system

Answer 12

• Very efficient
• Remove bulk of GP (US, heat carrier) and soften the rest
• Use solvent (chloroform, eucalyptus oil)
• Use R25 as described with a pecking motion
• Increased apical enlargement use R40 and R50
• Brushing with reciproc
Once preparation is complete and GP is removed, can finish with reciproc or reciproc blue

Question 13

Why is solvent sometimes needed even with reciproc

Answer 13

Solvent is sometimes necessary even with reciproc as we want to avoid leaving a smear layer of GP on the surface that can block the dentinal tubules