One of the most dreaded nightmares of any clinician is broken instruments in the midst of an endodontic treatment. NiTi rotary instruments show a high incidence of instrument fracture despite their favourable qualities.

1.  Dr. K. PALANI SELVI MDS
 Conservative Dentist & Endodontist

2.  Separation of endodontic instruments is a
PROCEDURAL MISHAP during endodontic
treatment
 It is mainly attributed to two parameters:-
1. CYCLIC FATIGUE
2. TORSIONAL FATIGUE
 According to studies instrument seperation in
SS files (0.25 – 6%)
NiTi files (1.3 – 10%)
 Though there is great advent in the NiTi
metallurgy, Instrument fracture is influenced by
several contributing factors

4.  Allowing the separated instrument to be RETAINED in the canal and
treating the remaining portion of canal
 BYPASSING the separated fragment and treating the canal
 RETRIEVING the separated fragment and treating the canal
 SURGICAL APPROACH for retrieval of separated fragment followed by
treatment accordingly

5. Decision making

6.  Diameter, length & position of obstruction
 Canal anatomy – Diameter, length & curvature of canal
 Thickness of dentin
 One third of obstruction is exposed
 Straight line position of instrument
 Positioning of fragment in canal
 Ss easier to remove
 NiTi can be fractured or pushed apically
 Cutting direction of fracture file

7.  Chemical solvent
 Mini Forceps
 Broach
 Wire loops
 Hypodermic surgical needles
 Braiding of endodontic instruments
 Masserann kit
 Endo – Extractor system
 Cancellier extractor kit
 Instrument removal system
Endo Rescue
Canal finder system
Endo pulse system
Ultrasonics
File removal system
Softned gutta percha
Laser irradiation
Electrochemical process

8.  EDTA
 Softening root canal wall dentin
around separated instruments
 Facilitating the placement of files for
the removal of the fragment
 Irritating the periapical tissue, they
are no longer in use.

9.  Steiglitz forceps
 Peet silver point forceps
 Endo Forceps
 Presence of sufficient space within
the root canal system
 An instrument separated in a more
coronal portion of the root canal
can be grasped and removed by
using forceps
STEIGLITZ FORCEPS
PEET’S FORCEPS
ENDO FORCEPS

10.  Separated fragment is a barbed broach
and not tightly wedged in the root
canal
 Another small barbed broach with a
small piece of cotton roll twisted
around it can be inserted inside the
root canal to engage the fragment
 Then the whole assembly is withdrawn

11. This technique can be used to retrieve
objects that are not tightly bound in
the root canal
By using a small mosquito hemostat
The wire loop can be tightened around
the upper free part of the fragment
Then the whole assembly can be
withdrawn from the
root canal.

12. • Counterclockwise rotation may enhance removal of instruments with
right-hand threads and vice versa
• The groove (trough) around the fragment can also be prepared by
using thin ultrasonic tips or trephine burs
To remove the fragment, a
cyanoacrylate glue or strong dental
cement (eg, polycarboxylate) can be
inserted into the hypodermic needle,
and then (when set) the complex
(needle-adhesive-fragment) can be
pulled out delicately in a clockwise or
counterclockwise rotational movement

13.  Firstly, a #15 size H or K file can be
inserted into the root canal to engage
with the fragment
 Then insert 2 new H-files 25, and 30
 Braiding of these files and a short
outward pull resulted in the
instrument being removed from the
canal
 This method can be effective when
the fragment is positioned deeply in
the canal and not visible and the
clinician is relying on tactile sense
Natanasabapathy V, Sundar S, Koteeswaran V. Retrieval of
fractured Ni-Ti rotary instrument using ultrasonics and file
braiding technique under surgical operating microscope.
Endodontology 2017;29:65-8

14. The Masserann kit consists of 14 hollow cutting-end trephine burs
(sizes 11–24) ranging in diameter from 1.1–2.4 mm
The trephines (burs) are used in a counterclockwise fashion to prepare
a groove (trough) around the coronal portion of the fragment
When inserted into the groove and tightening the screw, the free part
of the fragment is locked between the plunger and the internal
embossment

15.  2 extractors (tubes into which a plunger can be advanced)
 The relatively large diameters of extractors (1.2 and 1.5 mm) require
removal of a considerable amount of dentin, which may weaken the root
and lead to perforation or postoperative root fracture
 This largely restricts the use of Masserann instruments to anterior teeth
 However, by creating a wider space between the tube and plunger inside
the tubular extractor, it can be used in the straight portion of canals of
posterior teeth
 This also increases retention while gripping the firmly wedged separated
instrument

16. (1) Modification of the
extractor to ensure
gripping by creating a
wider space inside the
tube
(2) Combined use of the
modified extractor with
an ultrasonic device
and a surgical
operating microscope

17. It has 3 extractors of different sizes and colors (red 80, yellow 50, and
white 30)
Each extractor has its corresponding trephine bur that prepares a groove
around the separated instrument

18. It contains 4 extractors with outside diameters of 0.50, 0.60, 0.70, and
0.80 mm

19. It contains 3 extractors
The black extractor has an outside diameter of 1 mm and is used in
the coronal one third of larger root canals
The red and yellow extractors (0.80 and 0.60 mm respectively) are
used in narrower canals

20. It consists mainly of a center drill called Pointier
that excavates dentin coronal to the fragment and
trephine burs that rotate in a counterclockwise
direction to remove the fragment
These instruments are available in 2 sizes, 090
(red) and 070 (yellow)

21. 1. Fractured instrument
2. Reshaping of access cavity
3. Create access to fragment
4. Down to fragment
5. Exposure of fragment surface by drilling
around fragment
6. Fragment is surrounded and seized.
Anticlockwise rotation. Removal of fragment
which is firmly held in trepan bur by residues
of dentin

22. It consist of a handpiece and specially designed files
The system produces a vertical movement with maximum
amplitude of 1–2 mm that decreases when the speed increases
Bypassing a fragment
Not to perforate the root or apically extrude the fragment,
especially in curved root canals
flutes of the file can mechanically engage with the separated
fragment
vertical vibration, the fragment can be loosened or even
retrieved

23. In a clinical study that used the Canal Finder System as the primary
retrieval technique, a 68% overall success rate was reported
This system has been recently replaced by the EndoPuls system in which
SS files are used in vertical reciprocation and a passive ¼ turn motion

24. Ultrasonic instruments have a contra-angled design with alloy tips of different
lengths and sizes to enable use in different parts of the root canal
Most ultrasonic instruments have an SS core coated entirely with diamond or
zirconium nitride; therefore, the instrument abrades along its sides in addition to
its tip
Titanium-based tips have a smooth surface
(uncoated) and can cut only at their tip
Tips are flexible and can penetrate into
curved root canals
Blind trephining of dentin

25. A staging platform is prepared around the most coronal aspect of the fragment by
using modified Gates Glidden burs (no. 2–4) or ultrasonic tips
The Gates Glidden bur is modified by grinding the bur perpendicular to its long axis at
its maximum cross sectional diameter
The platform is kept centered to allow better visualization of the fragment and the
surrounding dentin root-canal walls; therefore, equal amounts of dentin around the
fragment are preserved, minimizing the risk of root perforation
The ultrasonic tip is activated at lower
power settings, so it trephines dentin in a
counterclockwise motion around a fragment
with right-hand threads and vice versa

26.  With this trephining action and the vibration being transmitted to
the fragment, the latter often begins to loosen and then ‘‘jumps’’
out of the root canal. Other root canal orifices in the tooth, when
present, should be blocked with cotton pellets to prevent the entry
of the loose fragment.
 If excessive pressure on the ultrasonic tip is applied, the vibration
may push the fragment apically or the ultrasonic tip may fracture,
leading to a more complicated scenario
 Also, to prevent separation of the ultrasonic tip, it is important to
avoid unnecessary stress by only activating it when in contact with
root tissue

27.  K-type or Hedstrom files can be alternatives to ultrasonic tips
 The activated file should be of a tip size that enables trephination of
dentin around the fragment
 However, files that are too small should not be used because they
are themselves prone to separation
 Also, a spreader can be modified to a less tapered and smaller tip-
sized instrument that can be activated to trephine deeply around a
fragment

28. This system has been developed by Terauchi et al
The amount of dentin removed is minimal
It involves 3 sequential steps that use specially designed instruments
In step 1 - two low-speed burs (28 mm long) are used
The Cutting Bur A, with a diameter of 0.5 mm and a pilot tip, is used to enlarge the root
canal
The Cutting Bur B has a cylinder-shaped tip and a 0.45-mm diameter, so it removes dentin
around the coronal part of the fragment
Both burs are flexible, so they can be used in curved canals
They can loosen or even remove the fragment because they are used in a counterclockwise
motion
If this fails; step 2 is attempted
In step 2, an ultrasonic tip (30 0.2 mm) is used
to prepare a groove around the separated
fragment (at least 0.7 mm deep)
This usually loosens the fragment or even
removes it

29. • One part consists of a head connected
to a disposable tube (0.45 mm in
diameter), with a loop made of NiTi
wire (0.08 mm) projecting from it. The
second part is a brass body equipped
with a sliding handle on the side that
holds the wire of the head attachment.
• When the handle is moved downward, it
fastens the loop and vice versa . This
system has been effective in laboratory
studies and in some clinical cases of
instruments separated in the apical part
of the root canal when a relatively short
retrieval time was reported . However,
this system has not been introduced
into the market yet
In step 2 usually loosens the fragment or
even removes it. Otherwise, step 3 is carried
out
In step 3, to mechanically engage the
fragment and pull it out of the root canal, a
file removal device of 2 sections is used

30.  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
is allowed to harden for approximately 3 minutes
 The GP point and the H fragment can be then removed by using a delicate
clockwise and counterclockwise pulling Action
 This conservative technique may assist in removal of loose fragments that
are not easily accessible while using other removal techniques

31. Nd:YAG laser
Minimum amounts of dentin are removed
Reducing the risk of root fracture

32.  Fragments can be removed in a relatively short time (less than 5
minutes) in 2 ways:
 The laser melts the dentin around the fragment and then H-files are
used to bypass and then remove it, and
 The fragment is melted by the laser
 Heat generated within the root canal can carbonize or even burn
dentin, which in turn may disturb the close contact or bond between
the filling materials and root canal walls
 The probability of root perforation in curved root canals or thin
roots

33. Ormiga et al
Two electrodes are immersed in electrolyte; one acts as
a cathode and the other as an anode
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

34.  The tips of #20 K3 rotary files were exposed to sodium floride and
sodium chloride solution for 8, 17, and 25 minutes and until the
total consumption of the immersed portion (6 mm)
 Optical microscopy analysis revealed a progressive consumption of
the immersed portion of the files with increasing polarization time
 Despite its limitations (long time required for complete fragment
dissolution and the limited root canal space to accommodate the
electrodes), results are promising and suggest the need for further
studies to develop the technique before it is adopted clinically

35.  Evidence of adverse impact of periapical lesions on root canal treatment
outcome, a surgical approach can be considered as the optimum
management choice
 Surgical management includes apical surgery, intentional replantation, root
amputation, or hemisection
 When root-end resection is performed, a separated fragment located in the
apical root section is removed as a part of the procedure
 Otherwise, if the fragment is located in the middle or coronal part of the root
canal, the root-end cavity can be prepared and sealed with a root-end filling
without fragment removal
 In both instances, elimination of bacteria and infected tissue as well as
providing an excellent coronal and apical seal of the root canal system are
essential

37.  Each method vary in their effectiveness,
cost and mechanism of action
 Heulsmann & schinkel 2015 stated that
success rate of
Masserann kit (48-55%)
Canal finder system (68%)
 Alomairy in 2017 reported 60% success with
Instrument Removal System
 Ultrasonics showed higher success
rates
79% Nagai et al
91% Nehme et al
88% Fu et al
95% Cuje et al
• MICROSONICS
- innovative combination of
DENTAL OPERATING MICROSCOPE with
ULTRASONICS – improved success rates.
(95% Cuje et al, 87% Suter et al)
• Heulsmann and Schinkel advocated
the use of MICROSCOPE as a
prerequisite for instrument removal

38.  Ledge
 Perforation
 Stripping
 Heat generation – PDL damage
 Breakage of the removal instruments
 Excessive loss of root dentin
 Apical extrusion of fragment

39.  Avoid subjecting NiTi rotary instruments to excessive stress
 Use instruments that are less prone to fracture
 Follow an instrument use protocol
 Assess root canal curvatures radiographically and instrument them carefully
 Ensure that the endodontic access preparation is adequate
 Open orifices before negotiating canals
 Enlarge root canals with fine hand instruments
 Set rotational speed and torque at low levels
 Use the crown-down technique
 Irrigate and lubricate root canals during preparation
 Manipulate rotary instruments with a pecking or pumping motion
 If inexperienced, engage in preclinical training in the use of rotary
instruments

40.  Guidelines for management of intracanal separated instruments should be
based on the highest level of clinical evidence; however, this has yet to be
formulated.
 The decision on management should consider the following: constraints of
the root canal accommodating the fragment, the stage of root canal
instrumentation at which the instrument separated, the expertise of the
clinician, armamentaria available, possible associated complications, the
strategic importance of the tooth involved, and the presence/or absence of
periapical pathosis.
 Clinical experience and understanding of these influencing factors as well as
the ability to make a balanced decision are essential.