Endo Tribune Asia Pacific No. 1, 2016

Twisted files and adaptive motion technology: A winning combination for safe and predictable root canal shaping / A commitment to German quality / Apical transportation

Open PDF View E-paper Edit Epaper Edit Epaper ads save

Table of contents

Open Link

Open Link

) ) [pdf_filetime] => 1729664213 [s3_key] => 70419-f5c5069d [pdf] => ETAP0116.pdf [pdf_location_url] => https://e.dental-tribune.com/tmp/dental-tribune-com/70419/ETAP0116.pdf [pdf_location_local] => /var/www/vhosts/e.dental-tribune.com/httpdocs/tmp/dental-tribune-com/70419/ETAP0116.pdf [should_regen_pages] => 1 [pdf_url] => https://epaper-dental-tribune.s3.eu-central-1.amazonaws.com/70419-f5c5069d/epaper.pdf [pages_text] => Array ( [1] =>

ENDOTRIBUNE
The World’s Endodontic Newspaper · Asia Pacific Edition
www.dental-tribune.asia

Published in Hong Kong

Vol. 14, No. 11

Twisted files and adaptive motion technology
A winning combination for safe and predictable root canal shaping
By Dr Gary Glassman, Canada; Prof. Gianluca Gambarini, Italy & Dr Sergio Rosler, Argentine
The ultimate goal of endodontic
treatment is the prevention and/or
treatment of apical periodontitis,
such that there is complete healing
and absence of infection1 while
the overall long-term goal is the
placement of a deﬁnitive, clinically
successful restoration and preservation of the tooth.2 Successful
endodontic treatment depends on
a number of factors, including
proper instrumentation, successful
irrigation and decontamination of
the root-canal system right to the
apical terminus in addition to hard
to reach areas such as isthmuses,
and lateral and accessory canals3, 4
(Fig. 1a & b).
The challenge for successful
endodontic treatment has always
been the removal of vital and
necrotic remnants of pulp tissue,
debris generated during instrumentation, the smear layer, microorganisms, and micro-toxins from
the root-canal system.5 It has been
accepted that even with the use of
rotary instrumentation, the nickel-titanium instruments currently
available only act on the central
body of the root canal, resulting
in a reliance on irrigation to clean
beyond what may be achieved
by these instruments.6 ‘Shaping
canals creates sufﬁcient space to
hold an effective reservoir of irrigant that, upon activation, can penetrate, circulate and digest tissue
from the uninstrumentable portions of the root canal system.’ 7, 8
Several challenges often arise
during root canal preparation.
Some of the most common ones
are anatomic factors that may prevent negotiation to the apical termini, as well as ledge formation,
perforation and ﬁle separation.The
introduction of Nickel-Titanium
(NiTi) alloy in endodontics presented a signiﬁcant improvement,
allowing good results in terms
of cleaning and shaping of root
canals, while reducing operative
time and minimising iatrogenic
errors.9, 10
Thanks to the superior mechanical properties of the NiTi
alloy, it was possible to use endodontic instruments of greater
tapers in continuous rotation, increasing the effectiveness and
rapidity of the cutting. However,
several studies reported a signiﬁcant risk of intracanal separation
of NiTi rotary instruments.11–14 In
fact, ﬁle separation via torsional
and cyclic fatigue has created the
biggest fear and risk for dentists
using rotary NiTi ﬁles for root
canal treatment.11, 12, 15

Because TF ﬁles are twisted and not
ground, no surface microfractures
occur on their surface and therefore do not need be polished away;
thereby not dulling the cutting
edges and retaining their efﬁcient
cutting ability.21–23

1a

1b

Figs. 1a & b: The complexity of root canal anatomy is demonstrated by these
cleared samples of maxillary molars.

Although multiple factors contribute to ﬁle separation, cyclic
fatigue has been shown as one of
the leading causes.16 Fatigue failure
usually occurs by the formation of
microcracks at the surface of the
ﬁle that starts from surface irregularities often caused by the grinding process during the manufac-

treatment technology that changes
the crystalline structure completely so the triangular cross section NiTi ﬁle blank can be twisted
while maintaining the natural
grain structure. More precisely, TF
instruments are created by taking
a raw NiTi wire in the austenite
crystalline structure phase and

Because of the increased ﬂexibility, the TFs maintains the original canal shape better, minimises
canal transportation and stays
centred even in severely curved
root canals.24, 25 In addition to the
development of heat treated TF
technology to improve the performance and safety of NiTi instruments, the ﬁle design has
also been changed with respect
ﬁle dimensions, tip conﬁguration,
cross-section and ﬂute design.
More recently, a third factor has
become important in this search
for stronger and better instruments: Movement Kinematics, the
branch of motion in which the
objects move.26

3

2

Fig. 2: Colour-Coded File Identiﬁcation. An intuitive, colour-coded system designed for efﬁciency and ease of use. Just like a
trafﬁc light – start with green and stop with red.—Fig. 3: ElementsTM Motor. Settings for TFTM Adaptive, TFTM, K3, Lightspeed,
M4 Safety Handpiece and custom settings for personal preference.

turing. During each loading cycle
microcracks develop, propagating
getting deeper in the material,
until complete separation of the
ﬁle occurs.17 All endodontic ﬁles
show some irregularities on the
surface, and inner defect, as a consequence of the manufacturing
process, and distribution of these
defects inﬂuence fracture strength
of the endodontic instruments.18, 19
Since the introduction of NiTi
in 198820, varied instrument designs with claims of superior cyclic
fatigue resistance have been propagated. However, there were no
major changes in the manufacturing process/raw materials until
the introduction of the second
generation of NiTi ﬁles, ie, M-Wire
(DENTSPLY Tulsa Dental Specialties) in 2007 and Twisted File (TF,
Kerr Endodontics Formerly Axis/
SybronEndo) in 2008.

transforming it into a different
phase of crystalline structure
(R-phase) by a process of heating
and cooling. In the R-phase, NiTi
cannot be ground but it can be
twisted. Once twisted, the ﬁle is
heated and cooled again to maintain its new shape and convert it
back into the austenite crystalline
structure, which is super elastic
once stressed. The manufacturing
process aims at respecting the
grain structure for maximum
strength as grinding creates microfracture points during the
manufacturing of the instruments.

Recent literature data shows
that a reciprocating motion can
extend cyclic fatigue resistance of
NiTi instruments when compared
to continuous rotation,27, 28 mainly
because it reduces instrument
stress. As the instrument rotates
in one direction (usually the larger
angle) it cuts and becomes engaged into the canal then it disengages in the opposite direction
(usually with the smaller angle)
and the stresses are therefore reduced. Following these concepts
new instruments have been recently commercialised; Reciproc
(VDW) and WaveOne (DENTSPLY
Maillefer), which uses speciﬁcally
developed motors that produce a
speciﬁc reciprocating movement
(using approximately 150 to 30°
angles).
This reduction of instrumentation stress (both torsional and
bending stress) is the main advantage of reciprocating movements.
It has been shown that a lot of different reciprocating movements
can be used, each one affecting the
performance and the safety of
the NiTi instruments. Therefore,
when discussing the advantages
and disadvantages of reciprocation,
the exact motion should also be
mentioned, since the actual angle
of reciprocation can have substantial inﬂuence on both the clinical
and experimental behaviour of
NiTi instruments.15
Another possible advantage
of reciprocation could be better
maintenance of original canal trajectory, mainly related to lower
instrumentation stress and consequently its elastic return. However, it must be underlined that
reciprocation does not affect the
inherent rigidity of the instruments. If a quite rigid NiTi instrument of greater taper is slightly
forced into a curved canal, it will
create more canal transportation
than a more ﬂexible one, due to its
inherent tendency to straighten.
Moreover, tip design could strongly inﬂuence canal transportation,

SM1: #20/ .04

SM2: #25/ .06

SM3: #35/ .04

ML1: #25/ .08

ML2: #35/ .06

ML3: #50/ .04

SMALL (SM)

MEDIUM/
LARGE (ML)
4

TF instruments are manufactured using a proprietary heat

For more than a decade, NiTi
instruments have been traditionally used with a continuous rotary
motion, but more recently a new
approach to the use of NiTi instruments in a reciprocating movement had been introduced by
Yared.11 The clockwise (CW) and the
counterclockwise (CCW) rotations
used by Yared were four-tenths
and two-tenths of a circle respectively and the rotational speed
utilised was 400 rpm. The concept
of using a single NiTi instrument to
prepare the entire root canal was
made possible due to the fact that

a reciprocating motion is thought
to reduce instrumentation stress.

5

Fig. 4: The motion of TFTM Adaptive instrument changes from rotary into reciprocation mode, with speciﬁcally designed CW
and CCW angles which may vary from 600–0° to 370–50°.—Fig. 5: File size reference chart.

[2] =>

ENDO NEWS

with a cutting tip being more
dangerous that a non-cutting pilot
tip.
While reciprocation with NiTi
instruments have become very
popular in recent years, with a signiﬁcant number of published articles, some of these studies have
shown that there is also inherent
disadvantages in the reciprocating

torque demand on the ﬁle, due to
entrapment of debris within the
ﬂutes. To reduce this tendency
some authors have advocated the
use of NiTi rotary glide path instruments, before using a WaveOne or Reciproc instruments, but
in this case the overall technique is
no longer a single ﬁle technique
but a more complex and more
costly technique which utilises

stant, but vary depending on the
anatomical complexities and the
intracanal stresses placed on the
instrument. This ‘adaptive’ motion
is therefore meant to reduce the
risk of intracanal failure, without
affecting performance, due to the
fact that the best movement for
each different clinical situation is
automatically selected by the
Adaptive motor. It is quite interest-

Fig. 6: Deep shaping. The clinical use of a second instrument (06/35) after the 08/25 signiﬁcantly increases the preparation
in the apical one third, improving the quality of canal shaping and allowing room for enhanced irrigation. This will also allow the use of the apical negative pressure devices such as the EndoVac to safely deliver abundant quantities of sodium hypochlorite to the apex without the risk of apical extrusion.—Fig. 7: M4 Safety Handpiece.

movements. It is well known that
a small inadvertent extrusion of
debris and irrigants into the periapical tissues is a frequent complication during the cleaning and
shaping procedures, both with
manual stainless steel and nickel-titanium rotary instrumentation techniques.29, 30 However, recent studies have shown that
commercially available reciprocating instrumentation techniques
seem to signiﬁcantly increase the
amount of debris extruded beyond
the apex31, 32 and, consequently, the
risk of postoperative pain. A clinical study comparing Reciproc and
NiTi rotary instruments has also
conﬁrmed these ﬁndings.33 Since
reciprocation movement is formed
by a wider cutting angle and a
smaller releasing angle, while rotating in the releasing angle, the
ﬂutes will not remove debris but
push them apically. Reciproc and
WaveOne motions are very similar
(even if not precisely disclosed by
manufacturers), and this fact could
also explain the higher incidence
and intensity of postoperative pain
that has been found in recent research studies.33, 34
Moreover, both WaveOne and
Reciproc techniques use a quite
rigid, large single-ﬁle of increased
taper (usually 08 taper, size 25),
which is directed to reach the apex.
In many cases, in order to reach the
apical working length, reciprocating instruments are used with apically directed pressure, which produces an effective piston to propel
debris through a patent apical foramen, and possibly directing debris
laterally, making canal debridement more difﬁcult. Since instruments are commonly used without ﬁrst performing preliminary
coronal enlargement, this may
result in a greater engagement of
the ﬁle ﬂutes and consequently
may produce more torque and/or
applied pressure on the ﬁle. Moreover, the cutting ability of a reciprocating ﬁle is decreased when
compared to continuous rotation.
Debris removal is also less, thus increasing the frictional stress and

TF Adaptive

ing that the clinician will hardly
perceive the differences in the
changing motion, due to a very sophisticated algorithm, which permits a smooth transition between
the changing angles.

The TF Adaptive technique
has been proposed in order to
maximise the advantages of reciprocation, while minimising its
disadvantages. By using a unique,
patented motion, the innovative
TF Adaptive Motion technology,
together with an original three-ﬁle
technique, most clinical cases can
be treated effectively and safely
(Fig. 2).

As far as disadvantages of
reciprocation are concerned, TF
Adaptive motion is a reciprocating
motion with cutting angles (CW
angles) much greater than WaveOne/Reciproc movements. This
results in the TF Adaptive instrument is working for a longer time
with a CW angle, which allows better cutting efﬁciency and removal

two different types of Niti instruments, glide path instruments and
then shapers.35, 15

TF Adaptive employs a patented unique motion technology,
which automatically adapts to instrumentation stress, when used
in the Elements Motor while in
TF Adaptive setting (Fig. 3). When
the TF Adaptive instrument is not
(or very lightly) stressed in the
canal, the movement can be described as a continuous rotation,
allowing better cutting efﬁciency
and removal of debris. The crosssectional and ﬂute design are
meant to perform at their best in
a clockwise motion.
More precisely, it is an interrupted motion with the following
CW-CCW angles: 600–0°. This interrupted motion is as effective as
continuous rotation in lateral cutting, allowing optimal brushing
or circumferential ﬁling for better
debris removal in oval canals.
This interrupted motion also minimises iatrogenic errors by reducing the tendency of ‘screwing in’
(aka pull down), that is commonly
seen with NiTi instruments of
great taper that are used in continuous rotation.
On the contrary, while negotiating the canal, due to increased
instrumentation stress and metal
fatigue, the motion of the TF Adaptive instrument changes into a reciprocation mode, with speciﬁcally
designed CW and CCW angles that
may vary from 600–0° to 370–50°
(Fig. 4). These angles are not con-

Endo Tribune Asia Pacific Edition | 11/2016

As mentioned before, ﬂexibility is a fundamental property to
minimise iatrogenic errors while
negotiating canals, both in reciprocation and in continuous rotation. The use of a reciprocating
movement, therefore, does not signiﬁcantly help a NiTi instrument
of greater taper to negotiate
curved canals with no iatrogenic
errors. It mainly helps to reduce
instrumentation stress and the
risk of intracanal failure. In addition, a study aimed to compare the
frequency of dentinal microcracks
after root canal shaping with two
reciprocating (Reciproc and WaveOne) and one combined continuous reciprocating motion Twisted
Files Adaptive (TFA) rotary system.
Ninety molars were chosen and
divided into three groups of 30
each. Root canal preparation was
achieved by using Reciproc R25,
Primary WaveOne and TFA systems. All the roots were horizontally sectioned at 15, 9 and 3 mm
from the apex. The slices were
then viewed each under a microscope at x 25 magniﬁcation to determine the presence of cracks.
The absence/presence of cracks
was recorded, and the data were
analysed with a Chi-square test.
The signiﬁcance level was set at
P < 0.05. The results found that
instrumentation with Reciproc
produced signiﬁcantly more complete cracks than WaveOne and
TFA (P = 0.032). The TFA system
produced signiﬁcantly less cracks
then the Reciproc and WaveOne
systems apically (P = 0.004). The
study concluded that within the
limits of this study, the TFA system
caused less cracks then the full

used only when a greater apical
enlargement is needed due to
larger original canal dimensions
and/or enhanced ﬁnal irrigation
techniques. The sequences are also
different in their shaping concepts. Each ﬁle of the sequence
being used is taken to full working
length in a ‘crown down’ manner
so that the root canal wall is internally sculpted incrementally,
allowing dentin debris and tissue
to be evacuated coronally rather
than to be pushed apically. This
may reduce the risk of canal blockage and the extrusion of debris
into the apical tissues. The SM 1 ﬁle
(single colour band green, 04 taper
20 tip size) is an excellent ﬂexible
Glide Path ﬁle which may be
used with either sequence to preenlarge the canal thereby decreasing instrument stress for the next
larger size ﬁle in sequence. This
also allows better maintenance
of the original canal trajectory
(Figs. 2 & 5).
The ﬁnal apical enlargement
with a size #35 ﬁle is not only
meant to allow the use of the
Endovac (EndoVac Kerr Endodontics,
Orange, CA) irrigation technique,
but to improve canal shaping by
touching more canal walls. Figure 6
clearly shows how improved and
deeper the apical one-third shape
is when a 06 taper 35 tip instrument follows a 08 taper 25 tip instrument. This is why in the majority of cases two instruments
are much better than a single ﬁle
technique, provided that the second instrument is a ﬂexible one.
The superior ﬂexibility allowed by
the use of TF technology permits

Fig. 8: TFTM Adaptive Technique Card. Size and Sequence Determination.—Fig. 9: EndoVac Apical Negative Pressure Irrigation
System. The Master Delivery Tip (MDT) accommodates different sizes of syringes ﬁlled with irrigant, the macro cannula is
attached to the autoclavable aluminum hand piece and the micro cannula is attached to an autoclavable aluminum ﬁnger
piece. The macro cannula, the micro cannula and the MDT are connected via clear plastic tubing. The tubes are connected to
the high volume suction of the dental chair via the Multi-Port Adaptor.

of debris (and less tendency to
push debris apically and laterally),
because the ﬂutes are designed to
remove debris in a CW rotation.
This results in TF Adaptive taking
advantage of the use of a motion
that is more similar to continuous
rotation for optimal debris removal. There are obviously some
changes in the angles depending
on canal anatomy (the more complex, the smaller the CW angle), but
they do not seem to signiﬁcantly
inﬂuence the overall result. On the
contrary, these changes inﬂuence
resistance to metal fatigue, since
TF instruments used with Adaptive motion were found to have
superior resistance to cyclic fatigue
when compared to the same TF
instruments used in continuous
rotation.36

reciprocating system (Reciproc
and WaveOne). Single-ﬁle reciprocating ﬁles produced signiﬁcantly
more incomplete dentinal cracks
than full-sequence adaptive rotary motion.39
The TF Adaptive technique is
basically a three ﬁle technique,
designed to treat the majority of
cases encountered in clinical practice. Available are two sets of three
ﬁle systems, one for small, calcifying and severely curved canals and
one system for more ‘standard’
and larger canals, allowing adequate taper and increased apical
preparation in both scenarios. The
number of instruments within
each sequence can also vary and
adapt to canal anatomy, with the
last instrument of the sequence

TF Adaptive to follow these criteria, and safely enlarge canals with
minimal risk of iatrogenic errors
like tooth weakening and canal/
apical transportation. The use of
a more rigid alloy would have not
made this possible, especially in
curved canals.”15

TF Adaptive technique
TF Adaptive is an intuitive,
color-coded system designed for
efﬁciency and ease of use. The
colour-coded system is based on
a trafﬁc light. The ﬁrst instrument
in sequence is green. The second
instrument in sequence is yellow
and the third instrument in sequence, if required, is red. Green
means go. Yellow means continue
or stop. Red means stop (Fig. 2).

[3] =>

Endo Tribune Asia Pacific Edition | 11/2016

ENDO NEWS

Coronal access
and glide path

Adaptive matching Paper Points
may be used to dry the canals.

1. Place rubber dam.
2. Obtain straight line coronal
access with slightly diverging
axial walls adhering to the concept of Minmimally Invasive
Endodontics.37
3. Achieve apical patency and establish an apical glide path using
#8 hand ﬁle, follow that with
a #10 hand ﬁle and continue at
least with a #15 hand ﬁle. Glide
path may be facilitated with
the M4 Safety Handpiece (Kerr
Endodontics, Orange, CA) (Fig. 7).
The pulp chamber should be
ﬁlled brimful with NaOCl (Sodium Hypochlorite).

Obturation

Canal size and
ﬁle sequence
determination (Figs. 5 & 8)
Small Canals (SM)
Using tactile feel, if you struggle to get a #15 K-File to working

Dr Gary Glassman is the author of
numerous publications. He lectures
globally on endodontics, is on staff at
the University of Toronto, Faculty of
Dentistry in the graduate department
of endodontics, and is Adjunct Professor of Dentistry and Director of Endodontic Programming for the University
of Technology, Kingston, Jamaica. Gary
is a fellow of the Royal College of Dentists of Canada, Fellow of the American
College of Dentists and the endodontic
editor for Oral Health dental journal.
He maintains a private practice, Endodontic Specialists in Toronto, Ontario,
Canada. His website is www.drgary
glassman.com and his ofﬁce website is
www.rootcanals.ca. He can be reached
at drg@drgaryglassman.com.

Gianluca Gambarini is a full-time
Professor of Endodontics, University of
Rome, La Sapienza, Dental School. He
is head of the Endodontic Department
International lecturer and researcher.
He is author of more than 450 scientiﬁc articles, three books and chapters
in other books. He has lectured all
over the world (more than 350 presentations) and has been invited as a
main speaker in the most important
international (AAE, IFEA, ESE) and
national endodontic congresses in
Europe, North and South America,
Asia, Middle East, Australia and South
Africa. Prof. Gianluca Gambarini still
maintains a private practice limited to
Endodontics in Rome, Italy.

Dr Sergio A. Rosler has been the Assistant Clinical Teacher in numerous
graduate and post-graduate Endodontic Programs and was Clinical
Fellow Teacher at Warwick Dentistry
University in the United Kingdom.
Dr Rosler has lectured at conferences
and several universities around the
world. He maintains a private practice limited to Endodontics in Buenos
Aires, Argentine and can be reached at
sergiorosler@gmail.com.

TF Adaptive matching Gutta
Percha in combination with the
Elements Free Cordless Obturation
system37 may be used to obturate
the root canal system. Alternatively,
TF Adaptive carriers may be used.

Conclusions
10

Fig. 10: CBCT (Cone Beam Computerised Tomography) three dimensional visualisation of TFA preparation (SM sequence) in a complex molar, showing proper
shape, tapered preparation and excellent maintenance of canal trajectories.
(Courtesy of Dr Lucila Piasecki, Brazil and Prof. Gianluca Gambarini, Italy)

length (WL) then the canal size
is deemed to be ‘small’. Use the
Small Pack (one colour band) and
its instrument sequence. The small
sequence may also be used in severely curved canals as well as
roots that may be very thin and
the risk of strip perforation is a
possibility.
Medium/
Large Canals (ML)
Using tactile feel, if a #15 K-File
feels loose at working length then
the canal size is deemed to be
‘medium/large’. Use the Medium/
Large Pack (two colour bands) and
its instrument sequence.
Establish working length
Working length should be established with a reliable apex
locator. A radiograph may help the
clinician as well.

TF Adaptive
canal shaping
technique
1. Use the ‘TF Adaptive’ setting on
your Elements Motor (Fig. 3).
2. Ensure the pulp chamber is
ﬂooded with NaOCl or EDTA and
make sure the ﬁle is rotating as
you enter the canal.
3. Slowly advance the green (SM1
or ML1) with a single controlled
motion until the ﬁle engages
dentin then completely withdraw the ﬁle from the canal.
Do not force apically. Do not
peck.
4. Wipe off the ﬂutes. Deliver irrigant to the pulp chamber and
conﬁrm canal patency with a
#15 handﬁle K-File.
5. Repeat steps 3 and 4 using the
ﬁle you started with until working length is achieved.
6. Repeat steps 3 and 4 with the
yellow SM2 or ML2 until the ﬁle
reaches working length. If the
desired apical size is achieved
the sequence is complete. For
larger apical sizes, repeat steps
3 and 4 with the red SM3 or ML3
until the ﬁle reaches working
length.
Note: All TFA ﬁles may be used
in a brushing manner directed
towards the external surface of
the root away from the canal
curvature when retrieving the ﬁle
from the canals.

Irrigate and dry
When irrigating with EndoVac
(apical negative pressure irrigation
system),2 in small canals, you must
take SM3 to working length. In medium/large canals, you must take
at least ML2 to working length.
Note that the Microcannula is
.32 mm in diameter (Fig. 9). TF

have also found that Adaptive
Motion Technology works well with
other ground ﬁle rotary systems
making their use safer especially
in smaller and curved canals. This
technology allows the TF Adaptive
ﬁle to adjust to intra-canal torsional forces depending on the
amount of pressure placed on the
ﬁle. This means the ﬁle is in either
a rotary or reciprocation motion
depending on the situation and
adjusts appropriately.
This winning combination results in exceptional debris removal
with the tried and trusted classic
rotary Twisted File design and less
chance of ﬁle pull down and debris
extrusion with Adaptive Motion
Technology.

TFA employs Twisted File
technology and Adaptive Motion
Technology. The TF Adaptive ﬁle
design is based on clinically proven
Twisted File technology, which
means the ﬁle is twisted to shape
for improved ﬁle durability, features R-Phase Technology to improve ﬁle ﬂexibility and strength
while maintaining the original
canal curvature minimizing canal
and apical transportation (Fig. 10).

Editorial Note: A complete list of references is available from the publisher.
This article originally appeared in
Oral Health dental journal MAY 2016.

Adaptive Motion Technology
is based on a patented, smart algorithm designed to work with the TF
Adaptive ﬁle system. The authors

Disclaimer: Drs. Gambarini and
Glassman are the inventors of Adaptive Motion and receive a nominal
royalty from Kerr.
AD

[4] =>

ENDO BUSINESS

Endo Tribune Asia Pacific Edition | 11/2016

A commitment to German quality
By Marc Chalupsky
In the ﬁeld of endodontics, instruments of different sizes and angles
and with various handles have been
developed for root canal therapy—
from simple stainless-steel ﬁles to
today’s high-tech instrumentation
systems. VDW is one of the most
well-known manufacturers of endodontic products in the world.
Most of the 52 million instruments
it produces annually are manufactured in Munich in Germany. For
more than 145 years, VDW has been
operating from its site in the heart
of Europe, where it manufactures
endodontic instruments in a shift
operation. The company granted
Dental Tribune an exclusive look
behind the scenes of its high-tech
facility, spanning 3,000 m2.
Every dentist knows that optimal root canal preparation requires a highly ﬂexible ﬁle system
with extremely good cutting performance and low material fatigue.
Furthermore, the ﬁle system must
be easy and quick to use and suitable for preparing even severely
curved root canals. Today, there
is a range of systems available
to dental specialists including
those based on reciprocating or
continuously rotating motion, as
well as hand instruments. With
its single-ﬁle reciprocating system
RECIPROC, for example, VDW offers a safe solution for optimal root
canal preparation.

Not all ﬁles are equal
Endodontic instruments are
essentially of three designs: K-typeﬁles, reamers and Hedstrom ﬁles.
Reamers and K-type-ﬁles have a
triangular or square cross-section
and a cutting edge angle that determines the cutting and debriding
performance and therefore the
effectiveness of the instrument.
The design of the instrument tip,
which cuts either actively or passively, is crucial. An inactive tip
advances the instrument safely
within the canal. The instruments
generally have a handle, a shaft and
a working part. While the length of
the working part always remains
the same at 16 mm, the length of
the shaft can measure between
5 mm and 15 mm.
A colour-coding system is used
for easy visual identiﬁcation of the
diameter. The ISO standard speciﬁes the lengths, dimensions, toler-

ances and minimum requirements
for mechanical resistance. Colour
coding of white, yellow, red, blue,
green and black, and various symbols indicate the individual types
and sizes of instruments. The
standard also precisely speciﬁes
the conicity, accurate to the millimetre. The tolerance range is less
than 0.02 mm, but the measurement of the tolerance may be signiﬁcantly over the limit, depending on the manufacturer. Additionally, silicone stoppers are used to
determine the length of the root
canals.
The manufacturing process for
Hedstrom ﬁles consists of eight
steps: straightening the wire,

The instrument’s cross-section and
the material used play an important part here, and this in turn has
an effect on the production. Finally,
the angle of twisting (deﬂection)
and the strength determine the
quality of the instrument, especially the cutting performance.
Sharpness decreases with repeated
use.

Visions of endodontic
heaven
Dental Tribune was granted direct access to operations at one of
the most innovative manufacturers in the ﬁeld of endodontics.
While the company has a 145-year

grinding, washing, ring marking,
injection moulding of the handle,
printing, attaching the stopper and
packaging. For barbed broaches,
the wire is also ﬁrst straightened,
then machined, washed and
straightened again, the handle injection moulded and the instrument ﬁnally packaged. Reamers
and ﬁles are generally machined
into a triangular or square form
and then twisted. In this way,
depending on the bending moment, torsion and deﬂection, instruments are formed that have
absolute ﬂexibility and the highest
possible fracture resistance. The
bending moment indicates that
moment of the bending of the instrument during production when
it no longer reverts to its original
form. An instrument once bent
cannot be bent again, otherwise
there is a risk of brittleness and
fracture. The torsion, that is the
twisting of the ﬁles, differs depending on the force effect and material.

divided into sterile and non-sterile
instruments. Using the Flexicut
and NiTi K-type-ﬁles, preparation
is problem-free even in the case of
severely curved and narrow root
canals. The company is particularly
proud of its RECIPROC system,
consisting of reciprocating instruments for mechanical preparation,
paper points and gutta-percha.
Apex locators, obturation systems
such as GUTTAFUSION, an ultrasonic device and materials for
ﬁlling root canals are displayed in
another glass case.
The tour began with the machines for cutting and straightening the wires (Fig. 1). Most ﬁle
systems use highly ﬂexible, frac-

ﬁnished instruments using a digital measuring system and visually
inspecting them under a microscope. This system, like the entire
production process, is fully automated (Fig. 2). The process is properly validated to ensure that VDW
can always provide the same quality and reliable monitoring. The
washing plant cleans the instruments and completely removes the
oil used in production, for example. A gripper then takes the deposited instruments and machines in
the ring marking. The colouring is
done within a few seconds. The ink
is then dried and the instrument is
inspected again by camera (Fig. 3).
The next procedure is attaching
the handle. The robot trims the
instrument at the top so that it is
wide enough to connect the wire
ﬁrmly to the handle. “This step is
often left out with fake copies so
that the handle slips off,” said
Picard, referring to the counterfeit
products on the market, which is
a global concern for both manufacturers and dentists. This is followed
by the injection process to form
handles around the wires, which
are ﬁrst placed into moulds, depending on the ISO diameter of
the instruments. The plastic used is
a high-performance polymer that
can be sterilised repeatedly and
can therefore be used in autoclaves.
The granules are recycled to a
certain extent. Injection moulding

history, the well-maintained business premises look very modern.
VDW was one of the ﬁrst European manufacturers of endodontic instruments, and today offers
products for the entire treatment
process—including preparation
and irrigation, root canal ﬁlling
and post-endodontic maintenance.
VDW emphasises simplicity and
efﬁciency in its systems, allowing
both general practitioners and specialists to provide optimal treatment in a few steps. At the facility
in Munich, Gregor Picard, Director
of Operations at VDW, took us
through the entire production
process for the company’s manual,
rotating and reciprocating instruments.
Just in front of the main entrance, visitors are given an overview of VDW’s products, such as
ﬁle and reamer sets for root canal
preparation with rotational cutting, debriding and ﬁling action,

ture-resistant stainless steel combined with a special alloy. For
almost 30 years, the industry has
relied not only on chromium–
nickel–stainless-steel alloys but
also on nickel–titanium alloy
(NiTi), known for its pseudo-elasticity. NiTi ﬁles are used particularly
in severely curved root canals.
Owing to other beneﬁcial properties, including shape memory (the
material returns to its original
form), super-elastic behaviour and
good biocompatibility, dentists are
increasingly opting for NiTi ﬁles,
but not dispensing with stainless-steel ﬁles. “We are constantly
working on new alloys, materials
and geometries. However, it is just a
question of reﬁnements these days;
the conical tapered form of the instruments and the NiTi alloy have
proven themselves,” said Picard.
The wires are subsequently
machined. Straight after this procedure, an employee checks the

is applied gently, but extremely
quickly. The precise injection
moulding machines are some of
the fastest in the industry. Injection moulding of the handles requires a great deal of expertise and
experience. The high-performance
robot produces 16 instruments in
14 seconds.
The instruments are printed on
using tampography (pad printing),
a special process used for printing
on the front and side of the instrument. The silicone stoppers are
then applied according to instrument length. The stopper is brought
from the hopper machine in an automated process and a collet chuck
holds it ﬁrmly while the instrument is pushed through the stopper. The instruments go into large
machines during the washing process, and here a technician must
constantly ensure a sterile environment. Therefore, a machine creates
a clean room environment in order

[5] =>

ENDO BUSINESS

Endo Tribune Asia Pacific Edition | 11/2016

cially as standards of living continue to improve,” said Di Hu, Export Manager for Asia at VDW.

to allow sterile packaging after the
washing procedure. An automated
packing facility sorts all of the instruments into boxes and blister
packs. The instruments are then
deposited into crates within the
clean room environment. Employees line these with sterile bags and
they are then sealed with lids in
the clean room area and sent for
ﬁnal packaging. They are marked to
indicate sterilisation status. VDW
sends the goods for sterilisation
again before shipping in order to
ensure that there are no bacteria
when they leave the warehouse.
If desired by a customer, a small
laser can be used to mark the blisters for individual needs.
6

The warehouse follows a chaotic storage process—in a positive
sense. With storage locations deﬁned according to aisles, the products are stored in available spaces
where they ﬁt best, rather than according to category. This allows for
the most efﬁcient use of space. The
system tracks the available spaces,
scans the goods and knows automatically when sufﬁcient goods
have been removed. Each order is
digitised and production begins
immediately after receipt. Because
the logistics and production are
precisely controlled according the
number of each product, there is no
over- or underproduction. At the
time of the visit, an employee was
preparing a few pallets for China
(Fig. 4).

Everything is monitored
Even more impressive than the
almost fully automated production is the monitoring technology.
The specially developed camera
system is probably one of the most
advanced in the dental industry.
One example is the ring marking.
Each ring is checked for diameter,
width and colour application. The
system will then indicate “green”,
signifying that all is OK, or “red” to
ﬂag a problem (Fig. 5). Instruments
with no ring colour are automatically removed. Another camera
checks the twisting of reamers and
ﬁles according to length and degree
of twisting, preventing any warped
instruments from going any further in the production process. Yet
another camera checks the barbs
on the broaches. A further camera
monitors the status of the boxes
and blisters and veriﬁes the geometries of the instruments and their
colours by means of images. The
camera detects the tiniest deviations in the instruments and packaging—even individual particles—
and these packs are separated automatically. Another camera checks
the labels. If there has been a printing error or an incorrect label has
been used, the affected item is
immediately separated by the machine.
Each process step undergoes
quality control by camera (Fig. 6).
This means that no rejects proceed
to the next stage. “The longer a defective item is in the production
process, the greater the associated
costs incurred. A single defective
ﬁle in a blister means that the en-

tire pack must be removed,” explained Picard. In this way, the
company guarantees the safety
and quality of its products and
fulﬁls the strict regulatory requirements.

machines rather than trying to get
the last out of the old machines.
As a result, a new technology centre
is created almost every two years.”
Achieving German quality requires
German thinking.

Tried and tested and
constant change

That nasty term
“ﬁle breakage”

Even after 145 years, manual
work still has its place in production. Each reamer and ﬁle are elaborately ﬁnished by hand (Fig. 7).
VDW initially wished to automate
this manual work too, but the employees are so good at their work
that they can produce the tip with
exactly the required cutting angle
very quickly. Thirty-ﬁve million instruments therefore include some
manual production and additional
inspections. In another respect too,
people remain central at VDW.
Throughout the building complex,
there are boxes and blackboards for
idea generation where employees
can give their suggestions. Particularly good ideas are rewarded. This
may be one of the reasons that
every employee appeared to be so
focused—but friendly and receptive too. Most of the employees
have been with the company for
many years, have detailed knowledge of the processes and participate actively, according to Picard.

During the tour, the term “ﬁle
breakage” came up often. All dentists are familiar with the nuisance
of an instrument breakage, for
both themselves and their patients.
There are many reasons for a breakage, ranging from a complicated
root canal anatomy to incorrect
preparation techniques or poor
processing of materials. In the case
of severely curved root canals especially, the ﬁle fragment can only
be removed with a great deal of patience. As recently as 30 years ago,
stainless-steel instruments with

ing the possibility of ﬁle breakage
even further. Owing to a new production process, the ﬁles are significantly more ﬂexible, and the dentist can prebend the instruments
in order to gain easier access to
severely curved canals. These new
properties are made possible by a
particular heating protocol. Once
the RECIPROC instruments have
been manufactured according to
the proven process followed, they
are subjected to a heating process
that is speciﬁed in detail. This
changes the molecular structure
of the NiTi in such a way that the
RECIPROC instrument acquires the
additional properties described.
The colour of the ﬁle changes to
blue owing to the heating process. Otherwise, the application of
RECIPROC blue is the same and it
can be used with the tried-andtrusted VDW endodontic motors.
RECIPROC blue will be available in
the coming months.

only a rotational cutting action led
to frequent ﬁle breakage. The cutting action of reciprocating instruments, however, virtually rules out
ﬁle breakage if these instruments
are used correctly. To further reduce the likelihood of breakage,
dentists should opt for torquecontrolled motors instead of hand
instruments. The motor detects when
the pressure on the instrument is
too high and prevents breakage
with a backward movement. Furthermore, material fatigue is reduced if ﬁles are used only once.

A speciﬁc focus on Asia

Production is being restructured currently with the individual injection moulding machines
being combined, creating dedicated areas within the manufacturing process. Monitoring by camera will ensure that no products are
mixed up or swapped. The restructuring process is to be completed
by the end of the year, but may
require additional changes once
VDW buys and installs more new
machines “It is extremely important to us to improve ourselves and
remain at the cutting edge. We have
to keep pace with the dynamics of
the market and steer them,” stated
Picard. Although many of the older,
mostly green-coloured, machines
are still running without problems
and an in-house workshop monitors and repairs the equipment,
replacement parts are often not
available. “Therefore, we feel new
acquisitions are a better investment. Provided there is proper justiﬁcation, the group opts for new
grinding and injection moulding

Just in August, VDW announced
the next generation of reciprocating root canal preparation instruments with RECIPROC blue, reduc-

VDW is focusing particularly
on this prospering region at the
moment. With an annual growth
rate of 5 per cent, China, India and
South Korea are currently among
the most important markets for
endodontic instruments. “We feel
that there is an increasing need for
safe, high-quality root canal therapy in these countries. Only several
years ago, hardly anyone was talking about reciprocating instruments, endodontic motors with integrated apex locators or root canal
irrigation systems like our EDDY.
Particularly in the last ﬁve years,
however, we have witnessed an
increasing demand for them, espe-

Indeed, the standard of living
of the population in the Asia-Paciﬁc
region has signiﬁcantly improved
in the last ten years. Rising salaries
and improvements in health care,
especially for older patients, have
led to greater demand for durable
endodontic instruments. Dentists
in India and China cannot afford to
have a ﬁle break in a root canal either. Finally, the level of information about endodontic treatment
has improved in these particular
countries. Dentists are progressively educating their patients and
showing them that root canal therapy with the right instruments is
no more unpleasant than a ﬁlling.
Owing to their quality, Germanmanufactured products are becoming ﬁrst choice for a growing
number of dentists.
VDW has been represented in
Japan for 60 years, and the other
Asia-Paciﬁc countries have been
directly served since 2007. “The
Asian market has great potential
for us. Since 2015, China has been
the number one market in Asia.
Of course, we are continually entering new markets for our products;
for example, VDW has been represented in Vietnam since the beginning of 2016,” Hu explained.
For some years, VDW has been
focusing more intensely on China
(Fig. 8). “In June, VDW had its own
stand at the Sino-Dental exhibition
in Beijing. Being the largest dental
trade fair in China, it attracted
about 60,000 visitors. Sino-Dental

went very well for VDW. We focused
on established products that are already successful, such as RAYPEX 6,
VDW.GOLD RECIPROC motors and
RECIPROC instruments. At the
stand, we offered various lectures
and hands-on activities, which
were very well received.”
There is a great need for information on and products for endodontic treatment in China and its
neighbouring countries. However,
Germany and Europe remain home
and the most important market
for VDW. Therefore, the company’s
production facilities in Munich
will remain and be steadily expanded, reﬂecting the company’s
commitment to German quality.

[6] =>

TRENDS & APPLICATIONS

Endo Tribune Asia Pacific Edition | 11/2016

cleaning, disinfection and proper
ﬁlling. Thus, these steps should be
performed as well as possible and
be followed by an apical microsurgery to remove the untreated apical
region.

Apical transportation
Microsurgical handling of a procedural error during apical mechanical preparation
Prof. Leandro A.P. Pereira, Brazil
Endodontics is the dental specialty
that is concerned with treating or
preventing pulpal pathologies and
apical periodontitis. The main objectives of endodontic treatment are to
clean and disinfect the entire length
of the root canal system up to a
healthy level.1 When, through meticulous treatment, such objectives are
achieved, success rates can exceed
94 per cent.2, 3 In pursuit of such
results, during endodontic therapy,
mechanical preparation is carried
out with endodontic instruments
and chemical preparation with irrigating solutions.

facilitating ﬂow of larger volumes
of irrigating solutions to the apical
third.6, 1 It also creates a favourable
conical shape for endodontic ﬁlling.
Therefore, it directly inﬂuences the
quality of the disinfection process
and, consequently, the prognosis of
the case.
Procedural errors during mechanical preparation may make
it impossible to achieve the required disinfection levels. Yousuf
et al. evaluated 1,748 endodontically
treated teeth using digital radiography and found procedural errors in

tion; may lead to ledge formation
and possible perforation.”
The inadvertent use of rigid
endodontic ﬁles, such as stainless
steel, especially of larger diameters,
without previous examination of
the internal dental anatomy as part
of the procedure, increases the risk
of transportation of the foramen.
Insufﬁcient cleaning of canals,
especially the apical third, predisposes treatment to endodontic
failure.10, 11 Transportation of the
foramen may not only impair dis-

Clinical case

• Type I represents a minor movement of the physiological position
of the foramen.
• Type II represents a moderate
movement of the physiological
position of the foramen, resulting
in a considerable iatrogenic relocation on the external root surface. In this type, a larger communication with the periapical space
exists.
• Type III represents a severe movement of the physiological position
of the foramen and the canal, resulting in a signiﬁcant iatrogenic
relocation.

A 55-year-old female patient
(American Society of Anesthesiologists Physical Status Class I) visited
the dental ofﬁce complaining about
spontaneous, constant pain, exacerbated during mastication and
apical palpation in the region of
teeth #13 and #11, which had been
treated endodontically over the
course of the last three months. The
patient reported that she did not
feel pain before the initial endodontic treatment began. After the
ﬁrst endodontic session, during
which teeth #13 and #11 were

Fig. 1: Initial clinical view of tooth #11.—Fig. 2: Initial clinical view of tooth #13.—Fig. 3: Initial radiograph.—Fig. 4: Tomographic image demonstrating the transportation of the foramen of tooth #11.—
Fig. 5: Tomographic image demonstrating the transportation of the foramen of tooth #13.—Fig. 6: Clinical image captured under the operating microscope showing the original canal trajectory and apical
deviation of tooth #11.—Fig. 7: Radiograph of an endodontic ﬁle positioned in the apical deviation of tooth #11.

After cleaning and shaping, endodontic ﬁlling must be performed
to ﬁll three-dimensionally and seal
the endodontic space in order to
prevent bacterial recontamination,
maintaining the sanitation conditions achieved through the previous steps. The mechanical preparation of the root canal system is of
utmost importance in the process
of establishing endodontic sanitisation. 4, 5 It is responsible for physically removing the infected dentine and, consequently, bacteria
located within the dentinal tubules.
In addition, it increases the diameter and shapes the main canals,

32.8 per cent (574 teeth) of them.
Transportation of the apical foramen, whether leading to root perforation or not, is among the most
common errors during endodontic
treatment, especially in curved canals.7–9
The Glossary of Endodontic
Terms by the American Association of Endodontists deﬁnes “canal
transportation” as “Removal of
canal wall structure on the outside
curve in the apical half of the canal
due to the tendency of ﬁles to restore themselves to their original
linear shape during canal prepara-

infection of the canal system by disabling access to its original trajectory, but also irritate the periapex
by extruding bacteria and their
by-products and derail the ideal
apical adjustment of a gutta-percha
cone. These technical hindrances
due to operational error in the
preparation phase can negatively
inﬂuence apical sealing and appropriate bacterial control.12 As a result,
they worsen the prognosis of the
clinical case involved.
According to Gluskin et al.,
transportation of the foramen can
be classiﬁed into three categories:

Treatment of apical transportation cases can be performed according to various clinical approaches.
Canals with Type I transportation
can usually be cleaned and ﬁlled.
Type II may be ﬁlled after the application of an apical barrier to control
bleeding and to serve as a physical
shield to prevent extrusion of
the endodontic ﬁlling material. In
these situations, placing an apical
cap with mineral trioxide aggregate
(MTA), followed by conventional endodontic ﬁlling, can be considered.
However, in clinical cases with apical transportation of Type III, it is
generally not possible to achieve

Fig. 8: Apical cap with MTA Repair HP.—Fig. 9: Canal drying of tooth #12 with SurgiTip (MANUFACTURER).—Fig. 10: Retroﬁlling of tooth #12 with MTA Repair HP.—
Fig. 11: Immediate postoperative radiograph.—Fig. 12: Control radiograph ﬁve months later of the periapical repair.

treated at the same time, the pain
began and had worsened after the
third day. On the fourth day, the
patient had to receive intravenous
dipyrone and ketoprofen to control
the pain. Concurrent with the systemic medication, an occlusal adjustment was performed. After
two days, the pain returned and
the patient went to another dentist,
who administered sodium dipyrone
500 mg/ml every four hours and
nimesulide 100 mg every 12 hours
orally for seven days. The pain decreased, but did not cease.
Two days after systemic medication ended, the patient again felt
pain. She went to a third dental professional, who initiated endodontic
retreatment of teeth #11 and #13.
However, the therapy performed
was not able to control the pain
effectively. After four days, the
patient also began showing febrile
conditions. It was reported that, in
none of the endodontic procedures
performed, was absolute sealing
achieved.
Clinical examination established endodontic access at teeth
#13 and #11. Inadequate geometric

[7] =>

Endo Tribune Asia Pacific Edition | 11/2016

configuration of endodontic access
already suggested problems in
chemical-mechanical preparation
of the root canal system (Figs. 1 & 2).
Endodontic therapy was begun in
teeth #13 and #11, and transportation of the foramen Type III was radiographically observed. On tooth
#12, there was a full crown, a metallic intra-radicular retainer and
signs of a poor endodontic treatment (Fig. 3). On the CT scan, it was
possible to visualise the transportation of the foramina of the two
teeth (Figs. 4 & 5).
Owing to the severe apical deviation of teeth #11 and #13, the
recommended treatment was endodontic retreatment, complemented
by an apical microsurgery. Treatment of tooth #12 was also needed
through cleaning, shaping and
disinfection of the canal system
with consequent endodontic filling.
However, as the prosthetic crown of
this tooth was adapted and microsurgery was already planned for the
neighbouring teeth, the decision
was to perform a retrograde endodontic treatment.
Treatment was initiated with
the endodontic retreatment of
tooth #11, followed by that of tooth
#13. The canals were irrigated with
2.5 % sodium hypochlorite, followed
by 17 % EDTA, both with passive
ultrasonic irrigation and prepared
with RECIPROC 50 (VDW). Using an
operating microscope and periapical radiographs, it was possible
to visualise the apical deviation of
tooth #11; however, it was not possible to follow the original trajectory
(Figs. 6 & 7). The same occurred with
tooth #13. Owing to the great irregularity of the walls of the canals
after transportation of the foramina, it was not possible to perform
the proper locking of a gutta-percha
cone. For this reason, the decision
was to perform an apical cap of
4 mm with MTA Repair HP cement
(Angelus; Fig. 8). The filling of the
rest of the canals was performed
using thermo-plasticised guttapercha with MTA-Fillapex cement
(Angelus). MTA-Fillapex contains
particles of MTA in its composition.
After the end of this stage, the
patient underwent apical microsurgery, during which the apical area
corresponding to the apical iatrogenic region was removed with a
piezoelectric instrument and a W1
tip (CVDentus). On tooth #12, a piezoelectric apicectomy using the same
instrumentation was performed,
and the canal was retro-prepared
to the depth corresponding to the
apex of the molten metal core
present. After drying the canal with
a surgical suction pump coupled to
a vacuum pump, the procedure
continued with retrofilling using
MTA Repair HP (Figs. 9–11).
MTA has been the material of
choice for sealing perforations,
retrograde preparations and apices
with irregular, not circular, morphology due to root resorption
or incorrect apical preparation. Its
superior features of marginal adaptation, biocompatibility, sealing
ability in wet environments, induc-

tion and conduction of hard-tissue
formation, and cementogenesis
with consequent formation of normal periodontal adhesion make it
the most suitable material for these
clinical situations. MTA Repair HP
is available in powder and liquid
form. It preserves all the features of
traditional MTA with the addition
of easier clinical handling. This last
property is due to a change in the
particle size of the MTA powder and
the addition of a plasticiser to the
liquid.

TRENDS & APPLICATIONS

Five months after microsurgery, the patient returned for
clinical and radiographic control.
Clinically, she did not complain
about pain or discomfort. Radiographically, a rapid repair of the
periapex of the three teeth involved
was observed (Fig. 12).

Conclusion
The chemical-mechanical preparation phase of the root canal
system is of utmost importance for

the success of endodontic therapy.
Operational errors at this stage, including transportation of the foramen, can dramatically compromise
the prognosis of a case.
Therefore, it is extremely important to prevent these. Depending on the severity of the error,
however, it can be repaired. Postoperative clinical and radiographic
control showed that microsurgical
complementation can be a safe and
predictable clinical option.

Editorial note: A list of references is
available from the publisher.

Leandro A.P.
Pereira is a professor at the
São Leopoldo
Mandic dental
school in Brazil. He can be
contacted at
leandroapp@gmail.com.
AD

[8] =>

Dental Tribune International

ESSENTIAL
DENTAL MEDIA
www.dental-tribune.com

) [page_count] => 8 [pdf_ping_data] => Array ( [page_count] => 8 [format] => PDF [width] => 846 [height] => 1187 [colorspace] => COLORSPACE_UNDEFINED ) [linked_companies] => Array ( [ids] => Array ( ) ) [cover_url] => [cover_three] =>

[cover] => Endo Tribune Asia Pacific No. 1, 2016

[toc] => Array ( [0] => Array ( [title] => Twisted files and adaptive motion technology: A winning combination for safe and predictable root canal shaping [page] => 01 ) [1] => Array ( [title] => A commitment to German quality [page] => 04 ) [2] => Array ( [title] => Apical transportation [page] => 06 ) ) [toc_html] =>

Table of contents

[toc_titles] =>

Twisted files and adaptive motion technology: A winning combination for safe and predictable root canal shaping / A commitment to German quality / Apical transportation

[cached] => true )