this presentation aims towards clinical and practical approaches for mishaps and retreatment of rct in nonsurgical way.

1. Retreatment in
endodontics
Dr Khirabdhi tanaya Mishra

2. Definition
A procedure to remove root canal filling
material from the teeth followed by
cleaning, shaping and obturating the
canal.
-GET-AEE

3. Causes
1) Preoperative causes
• Incorrect oral examination & misinterpretation
• Sinus tract, pain, vitality test, periodontal problems
Misinterpretation of radiographs
• Odontogenic, developmental lesions, anatomic landmarks
• Physical injury
• Improper case selection
• Patient cooperation • Technical difficulties • Patient systemic condition • Grossly destructed teeth • Root
resorption
• Inadequate sterilization of instruments

4. 2) Operative causes
• Failure to obtain Biomechanical objectives
Access preparation
• Perforation • Underextended preparation • Overextended preparation
• Canal preparation
• Perforations • Ledge formation • Canal blockage • Instrument separation & foreign objects
Failure To Obtain Biological Objectives • Removal of Potential Irritants From
• Coronal Portion • Root Canal System • Periapical Tissues
• Defective Obturation
• Overextended Filling • Underextended Filling • Periodontal Involvement- Lateral And Accessory Canals

5. 3) Post-Operative causes
• Trauma & fracture
• Impaired periapical healing
• Superimposed Non-endodontic involvement
• Excessive orthodontic forces, periodontal disease
• Poor post-endodontic restoration

6. Evaluations
Clinical
Radiographic
Histological

7. Indications
•Periapical radiolucencies even after 4 years
• Tenderness to percussion
• Apical pain to pressure
• Fistula formation
• Swelling of soft tissue
• Incomplete root canal filling - for prosthetic restoration even being asymptomatic

8. Contraindications
• Vertical fracture
• Poor periodontal status
• Non restorable teeth
• Access is difficult
• Patients with TMJ dislocation problems
• Resorption
• Anatomical limitations
• Non strategic position

9. Treatment Plan
The patient harbouring true endodontic
posttreatment disease has four basic
options for treatment:
• Do nothing
• Extract the tooth
• Nonsurgical retreatment
• Surgical retreatment

10. Non surgical retreatment

11. ● removal of restorations
● Removal of crown or prosthesis
● Removal of post and core
A) Coronal disassembly or Gaining access to root
canals
Removal of crown

12. Techniques for post
removal
• Ultrasonic vibration
• Rotosonic vibration
• Mechanical devices Ultrasonic troghing Mechanically post removal

13. B) Removal of
cement or paste
i) soft setting paste- Can be removed with proper instrumentation &
copious irrigation .
ii) hard setting paste -
a) dispersion by ultrasonics vibration
b) Drilling with rotary instruments.

14. Initially removed from the canal in the coronal one third finally eliminated from apical one
third then the middle one third.
• Following methods or combination of methods are used.
1) K-files or H-files
2) Gutta-percha solvent
3) Combination of paper points and gutta-percha solvent
4) Rotary instrument
5) Specialized rotary instruments designed for retreatment
6) Heat transfer devices .
7) Soft tissue laser
C) Removal of Gutta percha

15. H_files
G-P solvents
Rotary instruments

16. GP Solvents
• Chloroform
• Methyl chloroform
• Eucalyptol oil
• Halothane
•Turpentine
• Xylene
•Orange wood oil
•Chloroform
Proven to be most successful Evaporates
rapidly Potential carcinogenicity
•Eucalyptol:
Less irritating than chloroform
Antibacterial
Least effective GP solvent
•Xylene:
Highly toxic
Evaporates too slowly Dissolving effect less
than chloroform
•Orange wood oil:
Contraindicated - over extended fillings
• Halothane:
Longer time for dissolving than chloroform
Gp solv is a very
commonly used
solvent which is
orange wood oil
based

17. Application of gp solvent
● Using an irrigating syringe, the selected solvent is introduced into the coronal portions of the canals, which will
then act as a reservoir for the solvent. Then, small hand files (sizes #15 and 20) are used to penetrate the
remaining root filling and increase the surface area of the gutta-percha to enhance its dissolution.
● Once the working length is reached, progressively larger diameter hand files are rotated in a passive, nonbinding,
clockwise reaming fashion to remove the bulk of the remaining gutta-percha until the files come out of the canal
clean (i.e., with no pink material on them). The solvent should be replenished frequently, and when the last loose
fitting instrument is removed clean, the canal is flooded with the solvent, which then acts as an irrigant. The
solvent is then removed with paper points.
● Overextended gutta-percha removal can be attempted by inserting a new Hedstrom file into the extruded apical
fragment of root filling using a gentle clockwise rotation to a depth of 0.5 to 1 mm beyond the apical constriction,
which may engage the overextended obturation. The file is then slowly and firmly withdrawn with no rotation,
removing the overextended material
● Using rotary systems to remove gutta-percha in the canals has been advocated due to enhanced efficiency and
effectiveness in removing gutta-percha from treated root canals.
● Engine-driven instruments can also help with the removal of residual root-filling materials after the bulk of the
guttapercha has been removed.

18. D) retraction of solid objects
0
1
Bypassing with hand files 0
2
Bypassing with ultrasonic
instruments
0
3
Use of special file removal
systems

19. • Locating the ledge
• Irrigate, smaller instruments are preferred.
• No. 10 or 15 with a distal curve at the tip can be used
• Pointed towards the wall opposite to the ledge • "Tear
shaped" silicone stops can be used.
• Watch-winding motion .
• If resistance is felt, retract slightly, rotate and advance
again, until it bypasses and reach apically.
• Confirmed with a radiograph
• If ledge cannot be bypassed, then clean, shape and
obturate till obstruction.

20. F) management of blocked canals
• Well-angulated radiographs
• Coronal portion of the canal should be enlarged To
enhance tactile sensation
• Remove cervical and middle third obstructions in the canal
space
• Canal should be flooded with irrigant, and instrumentation
to the level of the
impediment should be accomplished using non-end-cutting
instruments
• Precurved #8 or #10 file used in pecking motion
• Determine if there are any "sticky" spots that could be the
entrance to a blocked canal.

21. G) Perforations management
Difficulty of the repair : Level of
perforation
• Furcal floor of a multirooted tooth or in
the coronal one third of a straight canal
(access)
• Considered to be easily accessible
Middle one third (strip or post
perforations): Difficulty increases
Apical one third (instrumentation errors)
• Predictable repair • Frequently, apical
surgery will be needed..
CEO
Berry Books
CFO
For For taVinny Viewer
Sales Director
Wendy Writer
Materials of choice for perforation
● Absorbable- collagen materials
Calcium sulfate
● Non absorbable- MTA

22. Conclusion
• Post Treatment endodontic disease does not preclude saving the involved tooth.
• In fact, the majority of these teeth can be returned to health and long-term function by
current retreatment procedures.
• In most instances the retreatment option provides the greatest advantage to the patient
because there is no replacement that functions as well as a natural tooth.
• Armed with the information in the preceding section, appropriate armamentaria, and the
desire to do what is best for the patient, the clinician will provide the foundation for longterm
restorative success.

23. Thank you.