Journal of Dental & Oro-facial Research Vol 10 Issue 2 Jul-Dec 2014 JDOR

REVIEW ARTICLE
Rotary Systems: An Insight
1
Manmohan R Soni, 2Swaroop Hegde, 3Sylvia Mathew, 4K S Madhu
1
Post-graduate Student, Department of
Conservative Dentistry and Endodontics, ABSTRACT
Faculty of Dental Sciences, MS Ramaiah
University of Applied Sciences, Bengaluru,
Karnataka, India. In modern day practice, with time being the essence, it has become a necessity to strive
2
Professor, Department of Conservative for newer advances in technology. Keeping this in mind utmost patient benefit is the
Dentistry and Endodontics, Faculty of Dental prime goal for an endodontist. Successful endodontic treatment relies upon endodontic
Sciences, MS Ramaiah University of Applied
Sciences, Bengaluru, Karnataka, India.
instruments used for cleaning and shaping of the root canal system, which ultimately
3
Professor & Head, Department of Conservative determines the clinical outcome. Rotary systems have proved to be safer, quicker and
Dentistry and Endodontics, Faculty of Dental more efficient over the conventional instruments. The modern day dental surgeon is
Sciences, MS Ramaiah University of Applied
Sciences, Bengaluru, Karnataka, India.
faced with the challenge of using the best rotary system among the plethora of systems
4
Assistant Professor, Department of available. This review gives a brief insight into the design and features of different rotary
Conservative Dentistry and Endodontics, instrument systems.
Faculty of Dental Sciences, MS Ramaiah
University of Applied Sciences, Bengaluru,
Karnataka, India.
Correspondence: Dr. Manmohan R Soni.
Department of Conservative Dentistry and
Endodontics, Faculty of Dental Sciences,
MS Ramaiah University of Applied
Sciences, M.S.R.I.T. Post, M.S.R. Nagar,
Bengaluru - 560 054, Karnataka, India. Mobile:
+91-9164731189. Email: mansoni06@gmail.com
How to Cite:
Soni MR, Hegde S, Mathew S, Madhu KS. Key Words: Nickel titanium, root canal preparation, rotary instruments.
Rotary systems: An insight. J Dent Orofac Res
2014;10(2):16-21.

Introduction flexibility, shape and memory, potentially allows shaping of

narrow-curved canals without causing aberrations.6 These files
Success in modern day endodontics is based on various principles also show superior resistance to torsional fracture due to higher
comprising of diagnosis and treatment planning, knowledge ductility.
of anatomy and morphology, thorough debridement of the The variety of rotary instruments for endodontic treatment is
root canal system, mechanical preparation of root canal along staggering. There has been a constant quest for quicker, safer and
with chemical disinfection and three-dimensional obturation, effective instruments for the treatment protocol. Each system
followed by the coronal restoration.1 In order to facilitate the has been introduced with benefits, which are apparent in their
obturation of root canal system, adequate shaping of root canal near perfection in root canal preparation. In order to improve
is necessary. the efficiency and reduce the limitations of these existing
Endodontic instruments play a significant role in the success systems, manufacturers keep bringing up new instruments
of endodontic treatment starting from the preparation of the or modifications from time to time. Hence, there is a need for
access cavity to the final obturation of the root canal space.2 standardization of rotary NiTi instrument systems.7,8
A continuously tapering funnel shape with the smallest diameter In addition, the increasing NiTi file fracture rate has also posed
at the end point and the largest at the orifice has been deemed to a challenge for the clinicians.9 Nonetheless, understanding the
be the most appropriate canal shape for filling with gutta-percha basic features of these various systems will help the practitioners
and sealer.3,4 to use these instruments effectively and significantly reduce the
Since the introduction of the first rotating nickel-titanium (NiTi) errors.
files for the preparation of the root canal systems in endodontics, Thus, this article tries to throw some light on the various rotary
the domain of endodontics has changed.5 Their increased systems commonly used in the present day scenario. We have

Received: 15 May ‘14  Accepted: 20 August ‘14  Conflict of Interest: None

Rotary systems … Soni MR et al 16

 Table 1: The design features of the commonly used rotary files.
Instrument Manufacturer/ Introduced Cross‑section/ Rake angle Helical angle Cutting surface Tip design Sizes Taper Speed
system year by transverse (%) (rpm)
section
LightSpeed LightSpeed Wildey & Triple U shape Neutral N/A 3 radial lands Non‑active 20‑140 N/A 700‑2000
(LSX) Endodontics, San Senia
Antonio TX/1992

Profile Dentsply Tulsa Ben Johnson Triple U shapeNegative Open (20°) 3 radial lands Non‑active 15‑90 2, 4, 5, 6, 150‑350
Dental/1993 (20°) 7, 8

Rotary systems … Soni MR et al

Quantec SC, Sybron McSpadden S‑shaped design Positive Close 2 radial lands Active (SC) 15‑45 2, 3, 4, 5, 6, 300‑350
LX Endo/1996 non‑active (LX) 8, 10, 12
GT files Dentsply Tulsa Buchanan Triple U‑shape Neutral Variable 3 radial lands Non‑active 20‑70 6, 8, 10, 12 300‑500
Dental/1998 (grows from
tip to shaft)
HERO 642 MicroMega/ Daryl Green Triangular Positive Open 3 cutting blades Non‑active 20‑45 2, 4, 6 300‑600
1999
RaCe FKG, ‑ Triangular or Negative Variable and 3 or 4 cutting Non‑active 15‑40 2, 4, 6, 8, 10 300‑600
Switzerland/1999 square alternated blades
Flexmaster VDW Munich ‑ Triangular Positive ‑ 3 cutting blades Non‑active 15‑70 2, 4, 6, 11 300
Germany/2000
ProTaper Dentsply Tulsa P Machtou, Convex Negative Variable 3 cutting blades Non‑active 17‑30 Variable: 250‑350

17
Dental/2001 C Ruddle, J triangular (grows from Sx ‑ 3.5‑19,
West tip to shaft) S1‑2‑11,
S2‑4‑11.5,
Journal of Dental & Oro-facial Research Vol 10 Issue 2 Jul-Dec 2014

F1‑7‑5.5,
F2‑8‑5.5,
F3‑9‑5.5
K3 Sybron McSpadden 3 asymmetric Positive Variable 2 radial lands, 1 Non‑active 15‑60 4, 6 300
Endo/2001 surfaces (grows from cutting blade
tip to shaft)
M two VDW, Munich, ‑ Italic S Negative Variable 2 cutting blades Non‑active 10‑40 4, 5, 6, 7 300‑350
Germany/2003 (grows from
tip to shaft)
Twisted file Sybron Endo, ‑ Triangular ‑ Variable 2 cutting blades Non‑active 25‑40 4, 6, 8, 10, 500
Orange, CA, 12
USA/2008
Self‑ ReDent, Raanana, Zvi Metzger NiTi lattice N/A N/A Hollow thin Non‑active 1.5 and 3000‑5000
adjusting file Israel/2010 walled cylinder (Asymmetrical) 2 mm
(diameter)
Hyflex Coltene‑ Riacrdo Double fluted Positive Variable, 2 cutting blades, Non‑active 15‑40 4, 6, 8 500
JDOR

Endo/2011 Caiecedo, Hedstroem accelerated no radial lands

Stephen design flute design
Clark
(Contd..)
 Journal of Dental & Oro-facial Research Vol 10 Issue 2 Jul-Dec 2014 JDOR

Table 2: Cross‑sectional design of various rotary systems.

Instrument system Cross‑sectional design
(rpm)
Speed

300

300

300

300
ProFile
GT
LightSpeed

X1‑4, X2‑6,
X3‑7, X4‑6,
Variable
Taper

5, 6, 8

X5‑6
(%)

6, 8

4, 6
Triple U‑shaped with radial lands
Protaper
WaveOne
21‑40

25‑50

17‑50

17‑40
Sizes

Convex triangular, no radial lands

Hero 642
Flex Master
Introduced Cross‑section/ Rake angle Helical angle Cutting surface Tip design

3 cutting blades Non‑active

2 cutting blades Non‑active

Non‑active
4 cutting blades Active

Triangular shape, positive rake angle,

no radial lands
K3
time) with radial
(2 active at a

lands

Positive rake angle, three radial lands

with peripheral blade relief
Table 1: (Continued...)

RaCe
(grows from

(grows from
tip to shaft)

tip to shaft)

Twisted file
Variable

Variable

Variable

Triangular shape, no radial lands

‑

Hyflex CM
Modified convex Negative

Double S‑shaped Negative

Double fluted hedstroem design

‑

M two
(annealed heat
(offset design)

Reciproc
cross‑section

cross‑section
Rectangular

Quantec
transverse

triangular

Parabolic

treated)
section

S‑shaped design, no radial lands

GT: Greater taper
Machado

tried to compare the various systems based upon their design

Ricardo

features (Tables 1 and 2).10-30

by

NiTi: Nickel‑titanium, GT: Greater taper

‑

Common Design Features of a Rotary File

Edge Endo/2013
Manufacturer/

Germany/2011
Dentsply Tulsa

Dentsply Tulsa
VDW GmbH,
Dental/2011

Dental/2013

Tip design
Munich,

A rotary cutting instrument may have an active or a non-active

year

tip (Figure  1). Cutting tips on the rotary files make them too
aggressive.31
Instrument

Active tips: It has cutting edges on its surface and can help to
Wave‑one

ProTaper

Edge File
Reciproc

shape the narrow, calcified canals. However, it has a disadvantage

system

of accidental apical perforation or transportation. E.g. Quantec

Next

file.

Rotary systems … Soni MR et al 18

 Journal of Dental & Oro-facial Research Vol 10 Issue 2 Jul-Dec 2014 JDOR

Non-active tip: No cutting edges present and create a concentric

circle at the end of the root.
Eg. Profile, ProTaper, M two file, etc.

Taper
It is the amount of increase in the file diameter with each
millimeter along its working surface from the tip toward the file
handle. It is a very important feature of the rotary file systems
and varies from 2% to 12%.10,32
Constant taper: Instrument with the same taper but varying
apical tip diameters. E.g. Profile system
Varying or graduating taper: Instrument with same apical
diameter but varying taper (4-12%). E.g. Quantec system
Progressive taper: Instrument with progressive taper along the
shank. E.g. ProTaper system Figure 1: Tip design (active vs. non-active).

Rake angle31
• The rake angle is the angle formed by the cutting edge and a
cross-section taken perpendicular to the cutting edge
• The cutting angle is the angle formed by the cutting edge
and the radius when the file is sectioned perpendicular to the
cutting edge
• It can either be positive, negative or neutral (Figure 2).

Positive rake angle: If the angle formed by the leading edge and
the surface to be cut is obtuse, the rake angle is said to be “positive
or cutting.” E.g. K3, Quantec systems.
Negative rake angle: If the angle formed by the leading edge and
the surface to be cut is acute, the rake angle is said to be “negative
or scraping.” E.g. Profile, ProTaper, M two, etc.
Neutral or zero rake angle: When the face of the blade coincides with Figure 2: Rake angle.
the radial line it is said to be neutral or zero rake angle (planing).
E.g. LightSpeed, Greater taper (GT) file systems.

Radial land33
It is defined as the surface projecting axially from the central axis
as far as the cutting edge between flutes (Figure 3).

Functions
• Reduces the tendency of the file to screw into the canal
• Reduces transportation of the canal a b
• Supports the cutting-edge
• Limits the depth of cut.
Full radial land – ProFile, GT.
Recessed land – Quantec.
Modified radial land – K3.
No radial land – ProTaper, Race, Endowave, Hero 642.

Helical angle34 c d
It is the angle formed by the cutting edge with the long axis of the Figure 3: Radial land (RL), (a) full RL, (b) recessed RL, (c) no RL,
file. It can be of two types (Figure 4). (d) modified RL.

Rotary systems … Soni MR et al 19

 Journal of Dental & Oro-facial Research Vol 10 Issue 2 Jul-Dec 2014 JDOR

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