4. A- basic enlarging instruments :
K – reamer
k – file
Triangular
Square
Cross section
Loose
Tight
Twisting
0.5 – 1 f / mm
1.5 – 2.s f / mm
Flutes
Reaming only
Rotation & push / pull
Motion
60
90
Cutting angle
5. H – file
Comma shape cross section
Manufactured by machine grinding
Used in push / pull motion only
Helical angle approaches 90
Used in flaring of coronal & middle two
thirds
6. * Standardization of basic instruments
1- size :
Based on the diameter of the instruments in
hundredth of mm at the tip of the
instrument D0
Number : diameter at D0 X 100
- 0.02 mm # 6 , 8 , 10
- - 0.05 mm from # 10 – 60
- - 0.1 mm size 60 – 150
7.
8. 2 – length :
- overall length : 21 – 25 – 31 mm
- length of working part : 16 mm
3- taper :
Diameter increase at astandard rate
of 0.02 mm / mm length
9. 4 – tip angle
angle between the
instrument tip 75 +
or - 15
11. B – hybrid enlarging instruments
1- modification in instrument design
2- modification in method of manufacturing
3- modification in instrument material
12. A- modification in instrument design :
1- MODIFICATION IN CROSS SECTION
* Flex – R file
with triangular cross section
That allowing increasing of :
- Cutting ability
- - carrier effect
- - flexibility
13.
14. K – flex file :
square cross section of k – file modified
to rhomboid cross section
advantages :
1. - increasing cutting ability
2. - - increasing space for debris removal
3. - - increasing flexibility
15. S – file / uni-file
The single blade of H- file was
modified by adding a second blade
So , increasing cutting ability
18. 2- modification in cutting blades :
( a ) modification of depth and angle of
blades :
Decreasing depth of blades leading to
decreasing tendency of breakage
( b ) non cutting side of blade
( c ) flatting the edge ( radial land )
19. 3 – modification of taper :
0.02 mm to 0.04 ,
0.06 , 0.08 – 0.12 mm
20. 4 – modification in tip
design :
-Non cutting
pilot tip
-- partial
cutting tip
21. 5 – modification in numbering system :
- golden mediums
- profile series 29 : that provide constant
increase in diameter & provide fewer number
of instruments ( 13 )
22. B- modification in method of
manufacturing :
Twisting to grinding and milling
That decrease surface irregularities and
increase resistace to cyclic fatigue
23. C – modification in instrument material :
Carbon steel
Stainless steel
Nickel titanium
M - wire
R-phase
CM – wire Strength
increases
Flexibilty
increases
24.
25. Basic features of rotary instruments
1. Taper
2. Tip DesignS
3. Flute
4. Core
5. Pitch
6. Rake Angle
7. Helical Angle
8. Radial Land
26. 1. Taper
Def : increase in diameter per mm along file
working surface(from tip to shank)
Types:
1- fixed taper (standardized)
2- variable taper e.g GT
3- progressive taper e.g ProTaper
27.
28. 2. Tip Design
Types :
1. Cutting (Light speed)
2. Non cutting (K3,profile>)
3. Partially cutting (ProTaper)
29.
30. 3. Flute
Flutes , the grooves in working surface used to
collect soft tissue and dentin chips removed from
the wall of the canal.
Effectiveness of flutes depend on :
1)depth
2)width
3)configuration
4)surface finish
31. 4. Core
Is the central cylindrical part of the instrument having
its borders limited by flutes depth.
Types:
1. Large core diameter e.g Profile.
That increase strength and resistance to fracture
but at the same time decreases flexibilty
32. 4. Core cont.
2. small core diameter e.g RaCe.
Leading to decrease in strength but increase
in flexibilty
33.
34. 5. Helical Angle
Def. Angle between the cutting edge and the
long axis of the instrument.
Adv.
It determines which file technique to use.
Types,
1) Constant H.A
2) Variable H.A e.g GT system&K3
3) Allternating H.A e.g RaCe.
4) Non-helical angle e.g liberator.
35.
36.
37. 6. Rake Angle
Def. : angle formed between the leading edge and radius
of the file.
Types,
1)positive..resulting in cutting action (obtuse )e.g K3 file
2)negative….resulting in scraping action(acute)e.g
profile
3) neutral rake angle…..e.g light speed
N.B,
when flutes of the file are symmetrical
rake angle and cutting angle are the same.
38.
39. 7. PITCH
Def.: Distance between a point on cutting
edge and corresponding point on following
leading edge
N.B
The smaller the pitch the more the helical
angles increase cutting efficiency.
41. 8. Radial Land
Radial land is the flat surface extending
between two following cutting edge
42. Landed versus non landed instruments
Landed instruments Non landed instruments
Advantages:
1) Decreases screwing - in
tendency (decreases ledge
formation)
2) Decreases canal
transportation
Advantages:
Cut tooth more efficiently
43. Landed versus non landed instruments cont.
Landed instruments Non landed instruments
3)Decrease crack propagation
at file itself.
4) Limits cutting depth (no
aggressive cutting )
Disadvatages:
Slow cutting.
Examples:
(Profile ,GT,K3……)
Disadvantages:
Make distortion of the canal.
Examples:
(Hero 642 file ,ProTaper)
44. 1.Adequate access preparation.
2.Don't force files.
3.Difficult canal anatomy.
4.Don't over use files.
5.Avoid breakage takes practice.
6.Don't try to Bypass ledges.
7.Avoid cutting with the entire length of File.
45. 8.Don't start and stop.
9.Length control is critical.
10. Proper rotational speed and torque as recommended by
the manufacture.
11.It's important to use copious irrigation.
12.It's recommended to use gel based lubricant to reduce
Friction.
48. IN FACT,,,,,
The creation of a glide path allows the apical end of
the instrument to act as a passive pilot and thus
protects the instrument from breakage even with
high torque.
Clifford Ruddle 2009
52. GT ”Greater Taper” File:
Are made of nickel titanium alloy which provides both strength
and flexibility in curved canals.
Cross-sectional design:
Triple U shape.
-Cutting part: short.
-Taper: constant along the
length of the file and variable
in one kit provides flexibilty fo
most of root canals with
different anatomy
-Tip design: non-cutting.
Engagement to minimal amount
of dentine.
. Pushing the debris in a coronal
direction.
Decreasing the shaping errors.
53. GTX File:
- Are made with M-wire is a new type of NiTi
wire, has been developed by a series of thermo-
cyclic processing procedures.
This increases resistance to cyclic fatigue.
flexibility
cutting efficiency
-other advantages: 1-wider flutes
2-deeper chip
54. peripheral strength behind the cutting
blade
friction
Screwing by centering and
stabilizing the instrument
K3 file
Asymmetrical three edges
55. resistance to cyclic fatigue and better cutting effeciency
fracture resistance and flexibility
Intermediate phase between austenite and martensite
56. TF cutting flutes are created by twisting the file, not grinding, eliminating
micro fractures for greater strength. The advanced surface conditioning and
electropolishing treatment removes the surface defects and irregularities.
Twisted file
Ground file
Twisted file
57. Advantages:
1. Exhibits virtually no memory while traditional NiTi files are
flexible, they will always try to straighten when flexed within
a canal. This causes unbalanced lateral forces along the
canal wall and often results in ledging as well as excess
tooth structure being removed unnecessarily
2 . The vast majority of CM instruments showed multiple crack
origins, whereas most instruments made from conventional
NiTi wire had one crack origin.
Fabricated by special thermomechanical process
58. 3. Effortless, regardless of the curvature of the canal,
because adapt perfectly to the canal path for precise
and conservative removal of tooth structure
4. Aggressive and safe
5. During autoclaving, the instruments can regain their
shape
6. A hybrid formed of a mixture of austenite and
martensite structures.
60. 2.Hyflex:
Cross section square
3.Neyy:
Cross section square
N.B An advantage of HyFlex® CM files is that they can be used with
multiple techniques (crown-down, step-back) or with the single-length
technique proposed by the manufacturer.
61.
62. Protaper system
Made from Ni/Ti
alloy
Characterize by variable
taper along the entire length
of the instrument.
Comes in a set
of 6 files:
-3 shaping files ,
S1,s2,sx
-3finishing files,
F1,f2,f3
63. Made from M-wire
Comes in aset of 5 files:
Shaping files,
X1,x2
Optional files,
X3,X4,X5
Second
generation
Of ProTaper
system.
64. Wave one single files
Made from M-wire
Single use ,single file system.
Used in receprocating manner.
Receprocating angles are:30 counter clockwise
150 clockwise.
Available in length of:21,25,31.
65. Profile file system Have a non-cutting tip so has maximal
security and minimizing preparation
errors.
tapers from 2 to 8%, enables you to treat
successfully the three canal thirds using
the crown-down technique
Has U-shape cross section with 3
radial lands that centralize the
instrument inside the canal
Has high flexibility.
66. PROFILE VORTEX
THE NEXT GENERATION IN THE
PROFILE® INSTRUMENT SERIES
Made from M-wire so
there is increasing in
flexibility.
Available in ISO tip sizes from 15 to 50 and
in .04 and .06 taper.
67. Light speed system
Has non cutting tip.
This instrument similar in design with gates
glidden,only the tip is the working part of
instrument .
Can be used in hand piece of higher rpm
speeds.
68. Revo-S files
NICKEL-TITANIUM instruments
Has asymmetrical cross section so,
1. Enter the canal in snake like
movement.
2. Less stress applied on
instrument.
3 file system sc1, sc2 & su
69.
70. Mtwo system
Made from super elastic Ni/Ti
Its cross section is s-shaped with
two cutting edges which improves
its cutting efficiency “aggressive
files
cuts automatically while advancing
apically and also laterally when
using brushing file movement
71. Reciproc system
made from M-Wire nickel-titanium
designed for use in reciprocation
Receprocating angles:
50 clockwise
170counterclockwise.
73. 73
Straight
« Twisted »
It does NOT thread !
+
FKG exclusive feature no.1
RaCe
Reamer with Alternating Cutting Edges
74.
75. 75
features:
NiTi
Triangular X-section : better penetration
Sharp edges & round tip
Excellent removal of debris
Electro-polishing surface treatment
SMD to control fatigue and uses per instrument.
78. New shank for Easy identification of instruments
Depth marks to allow easy determination of the position of the instrument on
Silicone Endo stop to mark working length, radio opaque
Optimal cutting efficiency
Triangular cross-section with sharp edges so Cuts better and faster, without any pressure
The smaller core grants a higher flexibility (2) and allows a better progression in curved canals
Thin core for increased flexibility
More space for debris removal
79.
80. Ultrasonic concept
ultrasound is sound energy with a frequency above
the range of human hearing, which is 20 kHz.
In dentistry the range of frequencies employed in
the first ultrasonic units was between 25 and 40 kHz
.Later 1 to 8 kHz ultrasonic handpieces were
developed
81. Methods of producing ultrasound
:- 2 basic methods :-
The first is magnetostriction,.
The second method is based on the
piezoelectric principle
82. When used as enlarging instrument it has many
disadvantages
within a tightly fitting canal , the oscillatory pattern will be reduced or
even eliminated
uncontrolled filing in the apical third of the root canal .
difficulty of controlling the exact position of the tip
Improper use of Ultrasonics may cause straightening or excessive
removal of the canal wall, ledging or perforation In curved canals
Ultrasonics may cause strip perforations
84. 1) Access Enhancement
Finding and Breaking Into Hidden Canals and Access
Enhancement
the ultrasonic is a valuable tool to treat calcified and difficult to
find canals
finding MB2 canals in more than 40% of their maxillary molar
cases."
Uncovering a calcified canal in a
maxillary molar. (Courtesy of Dr.
Helmut Walsch, Germany)
85. Two main types :
BL Tips
Start-X
A newer entry to the marketplace is the BL series of tips
from BL1 to BL 6
And The Start –X : From X1 to X5
BL-1 and -2 in the pulp chamber.
87. Streaming improve debridement and disruption of the smear layer and
biofilm.
88. Passive Ultrasonic Irrigation
Ultrasonic activation of irrigants produces at least 2 helpful
effects:
(1) cavitation
and (2) acoustic streaming
89. Example of Irrigation : Irrisafe
Irrisafe (Clinical Research Dental) tips for irrigation
(ACETON North America/Clinical Research Dental).
The Irrisafe tip is activated in the canal at low-to-
medium power at least one mm short of working length
for one minute in each canal.
90. 3) Retreatment :
removal of a metal post, a silver
point, gutta-percha, obturation
carriers, etc.
91. 1) Central upper incisor, where the
fractured post can be clearly seen
within the root canal after removal of
debris and cement using the ultrasonic
chisel.
2) Radiographic aspect of the same
tooth
3) Ultrasonically powered chisel being
used to fragment and wash away
cement.
92. 4) The Masseran trepan is advanced
along the cement interface.
5) Ultrasonic vibration being applied to
the post via the Masseran trepan and
ultrasonic chisel.
6) Radiograph of the tooth after post
removal.
7) The removed fragment.
93. 4)Root canal obturation :
Ultrasonic condensation of gutta percha
That can use in softening the gutta percha
Plastisizing gutta percha
96. Advantages of ultrasonics :-
the cutting of dentin is facilitated and transfer of
vibrational energy along the shaft.
filing action to take place along the total length of the
root canal
High efficiency of Ultrasonics in dentin removal with
reduced operator fatigue in shaping of root canals
97. Conclusion
Due to these disadvantages , ultrasonics is no
longer used in root canal enlargement but limited
only to access cavity refinement , root canal
irrigation & obturation ,endodonic retreament
and endodontic surgery
98. Conclusions
the development of new files is a fast and the
clinician may find it difficult to pick the file and
technique most suitable for an individual case
99. Conclusions
Clinicians must always keep in mind that all file systems have benefits and
weaknesses.
Ultimately, clinical experience, handling
properties, safety, and case outcomes, rather than
marketing or the inventor’s name, should decide the
fate of a particular design.
100. At the end we wish you many “endodontic”
success and satisfactions!