1) Several techniques can be used to remove or bypass separated instruments from root canals, including forceps, broaches, hypodermic needles, Masserann instruments, ultrasonics, and lasers. Success rates vary depending on the technique and operator skill. 2) Factors that influence whether a separated instrument can be removed include tooth type, location and position of the fragment within the canal, curvature of the canal, type of instrument separated. 3) If an instrument cannot be removed, options include bypassing it, cleaning around it, or surgical removal. Leaving a fragment poses a risk of reduced treatment success.

1. Ahmad A. Madarati et al
JOE — Volume 39, Number 5, May 2013

2. INTRODUCTION
• Separation rates of stainless steel
(SS) - 0.25% and 6%
• Separation rate of NiTi rotary
instruments -1.3% and 10.0%

3. Management Options
• Management of separated instruments includes orthograde
or surgical approaches.
• Orthograde approaches are as follows:
• Remove the fragment
• Bypass the fragment
• Cleaning/shaping and filling of the root canal to the level of
the fragment.

4. Factors Influencing Removal
of Separated Instruments
• Tooth factors
• Largely include anatomic factors that are dictated by the type of
tooth
• Cross-sectional shape and diameter of the root canal
• Position of the fragment within the root canal
• Location of the fragment with regard to root canal curvature
• Radius and degree of root canal curvature.

5. • It is claimed that if one-third of the overall length of a
separated instrument can be exposed, then it is accessible for
removal
• In this context, 3 main factors are relevant:
• Tooth type
• Fragment’s position
• Separated instrument–canal wall interface.

7. Separated Instrument Factors (Type, Design,
and Length)
• It is generally believed that NiTi rotary instruments are more
difficult to remove compared with SS ones for the following
reasons:
• Tend to thread into root canal walls
• Greater tendencies to fracture
• Curved root canals tend to lie against the outer root canal wall
• Usually fracture in short lengths

8. Operator Factors
• Successful removal is a challenge that relies on
knowledge, training, familiarity with techniques and
instruments, perseverance, and creativity.

9. Patient Factors
• Extent of mouth opening, limitations in accessing the
tooth, time constraints, anxiety level, and motivation to
retain teeth

10. Techniques Used for Removing
the Separated Instrument
• Variations in success rates have been reported according to
devices, techniques, methods, and protocols used for removal of
separated instruments.

11. Chemical Solvents
• The use of EDTA has been suggested as a method
• Other chemicals such as iodine trichloride, nitric acid,
hydrochloric acid, sulfuric acid, crystals of iodine, iron
chloride solution, nitrohydrochloric acid, and potassium
iodide solutions have historically been used to achieve
intentional corrosion of metal objects.

12. Mini Forceps
• Steiglitz forceps
• Peet silver point forceps
• Endo Forceps

13. Broach and Cotton
Wire Loops

15. Hypodermic Surgical Needles

17. Braiding of Endodontic Files

18. Masserann Instruments
• The Masserann kit (Micro-Mega, Besancon, France) consists
of 14 hollow cutting-end trephine burs (sizes 11–24) ranging
in diameter from 1.1–2.4 mm and 2 extractors (tubes into
which a plunger can be advanced). The trephines (burs) are
used in a counterclockwise fashion to prepare a groove
(trough) around the coronal portion ofthe fragment.

20. Extractors
• Endo-Extractor system

21. The Cancellier Extractor Kit

22. Instrument Removal System

23. Endo Rescue

24. Meitrac Endo Safety System

25. Post Removal System

26. Canal Finder System
• The system produces a vertical
movement with maximum amplitude of
1–2 mm that decreases when the speed
increases.
• In a clinical study that used the Canal
Finder System as the primary retrieval
technique, a 68% overall success rate
was reported.

27. Endo Pulse system

28. Ultrasonics
• Staging platform
• Modified Gates Glidden burs (no. 2–4) or ultrasonic tips
• Success rates for fragment removal by using ultrasonics in
clinical trials have ranged from 67% by Nagai et al (34) to 88%
and 95% reported recently by Cuje et al (30) and Fu et al (60),
respectively.
• K-type or Hedstrom files, spreader can be alternatives.

30. File Removal System

31. File Removal System

32. Softened Gutta-percha Point
• Rahimi and parashos
• Loose fragments located in the apical third of the root canal
• SS Hedstrom files #8, #10, and #15 are initially used to partially
bypass the fragment and to check that it is loose.
• Then, the apical 2–3 mm of a size 40, 0.04 taper GP point, or
different size and taper according to the canal accommodating the
fragment, is dipped in chloroform for approximately 30 seconds.
• The softened GP is then inserted to the maximum extent into the
canal and isallowed to harden for approximately 3 minutes.

33. Future Techniques
• Laser Irradiation
• Nd:YAG laser
• Minimum amounts of dentin are removed, reducing the risk of
root fracture.
• Fragments can be removed in a relatively short time (less than 5
minutes) in 2 ways: (1) the laser melts the dentin around the
fragment and then H-files are used to bypass and then remove it,
and (2) the fragment is melted by the laser.
Laser Irradiation

34. Dissolution of the Fragment via an Electrochemical
Process.
• Ormiga et al
• The contact between the
separated file and the anode as
well as an adequate
electrochemical potential
difference between the anode
and cathode electrodes results
in the release of metallic ions
to the solution, consequently
causing progressive
dissolution of the fragment
inside the root canal.

35. • Masserann kit-48%–55%,
• Hulsmann and Schinkel reported an overall success rate of
68%, including instruments that had been bypassed, with the
Canal Finder System technique.
• Alomairy reported a 60% success rate by using the Instrument
Removal System in ex vivo study.
• Higher success rates have been achieved since the introduction
of ultrasonics: 79% by Nagai et al , 91% by Nehme , 88% by
Fu et al , and 95% by Cuje et al .

36. • The innovative combination of dental operating microscope with
ultrasonics (microsonics) has also contributed to higher success
rates.
• Cuje et al and Suter et al attributed the higher success rates in
their reports (95% and 87%), compared with 69% reported by
Hulsmann and Schinkel, to the use of the dental operating
microscope, which has been considered as a prerequisite for
successful removal of separated instruments

37. • A protocol combining different techniques and methods in
sequential steps also can increase the success rate . Nevertheless,
although sophisticated techniques can be highly successful,
simple techniques are more effective in specific cases.

38. Complications Associated with Removal
of Separated Instruments
• Ledge formation.
• Separation of braided H-files/K-files, ultrasonic tips.
• Thermal damage of periodontium – ultrasonics
• Root perforation
• Extrusion of the fragment apically/beyond the apex.

39. Bypassing the Separated Instrument
• Attempting to bypass the fragment, partially or completely,
minimizes the contact between the fragment and root canal walls
and may even dislodge it.
• However, it is possible that a false channel parallel to the original
root canal can be created when a clinician attempts to bypass the
fragment, which in turn can lead to a root perforation.

40. Surgical Management of Separated Instruments
• Surgical management includes apical surgery, intentional
replantation, root amputation, or hemisection.

42. • Conclusions: Guidelines for management of intracanal
separated instruments have not been formulated. Clinical
experience and understanding of these influencing factors as well
as the ability to make a balanced decision are essential.

44. References
• Management of Intracanal Separated Instruments - Ahmad A.
Madarati et al
JOE — Volume 39, Number 5, May 2013
• Impact of a Retained Instrument on Treatment Outcome: A
Systematic Review and Meta-analysis- Piyanee Panitvisai et al
JOE — Volume 36, Number 5, May 2010