CONTENTS INTRODUCTION

PROFILE SYSTEM

PROFILE GREATER TAPER ROTARY INSTRUMENT

PROTAPER ROTARY SYSTEM

LIGHT SPEED ROTARY SYSTEM

K3 ROTARY NICKEL TITANIUM

REAL WORLD ENDO-SEQUENCE FILE

RACE (REAMER WITH ALTERNATING CUTTING EDGES)

LIBERATOR

V-TAPER ROTARY SYTEM

HERO-642

QUANTEC ROTARY SYSTEM

MITY ROTO 360°

NAVI-FLEX ROTARY SYSTEM

CONCLUSION

REFERENCES

1

RECENT ADVANCES IN BIOMECHANICAL PREPARATION

INTRODUCTION:

The main objective of the biomechanical preparation is

removal of organic substrate and micro organisms from

root canal system.

1899 first endodontic hand piece introduced. The

problem associated with stainless steal hand instruments

are

Canal preparation is inconsistent making obturation

less predictable

Many instruments and steps are needed. Hence it is a

tome consuming.

Canal transportation occurs when larger stiffer

instruments are used.

Traditional coronal enlargement instruments remove

more dentin.

In order to overcome these problems the rotary

instruments are evolved. These instruments are made up

of

2

54% Nickel

44 % Titanium

2% Cobalt

Boran added to improve the surface hardness.

The first rotary system which developed is profile

system

THE PROFILE SYSTEM:

The Profile system was developed by Tulsa Dental In

1994. Their first product was Profile 29 Series. The 29

indicates that the rate of increase between file sizes in

this series is at a constant rate of 29%. In sometime,

some part of Nickel was substituted by 2% cobalt.

They are made up of Nickel-titanium i.e. 55% wt nickel

and 45wt% titanium. These NiTi files have unique

properties of super elasticity and shape memory. Due to

these properties, the instruments adapt well in curved

canals and maintain canal shape better than stainless

steel files.

3

Some unique features of these instruments

include:

- Strength and flexibility in curved canals.

- Radial landed U-shaped flutes and cutting edges with

20° negative rake angles which leave the debris

coronally and prevent the instruments from screwing

into dentin.(fig b)

- Bullet shaped nose with rounded transition angle. This

design helps the file remain self-centered in the canal

and also reduces the chances of canal transportation

and procedural errors.(fig c)

- Variable taper shafts that reduces the number of

instruments( fig a)

Fig a fig b fig

c

4

Range of instruments:

The Profile range comprises 3 instrument types with each

type having different length. They can easily identified by

the coloured rings on shanks.

Profile orifice shapers:

5 to 8% taper.

Available in no. 1-6 (20-80).

Length 19mm

Used to prepare coronary section of canal, removing

gutta-percha and sealer before inserting a root post.

The Profile 0.5 also can be used for the root canal

treatment of deciduous teeth. The handle has 3 rings.

5

0.06 profile taper:

Taper 6%

- Available in no. 15-40.

Length: 21mm-25mm.

These files used to prepare middle section of canal. The

handle has 2 coloured rings.

0.04 profile:

Taper 4%, No. 15-90.

It is available in length 25, 21 and 31mm.

The handle of 0.04 profile carries single coloured ring.

Motor and speeds:

6

For best performance and avoid any breakage the

instruments should used at constant speed between 150-

350rpm.

For this, independent electric motor can be used. This

motor will provide high torque and run quickly allowing

comfortable vibration free working.

These may also used directly on the dental chair unit with

a high gear reduction rate contra-angle hand piece.

E.g. electrically driven (40,000rpm) with a speed of

300rpm obtained with 120:1 contra angle.

Golden Keys:

1) Light pressure: Only light pressure is needed, no

heavier than when writing with pencil. Profile

instruments, particularly the smaller size should

never forced into canal otherwise wind up may

occur, possibly to the point of breakage.

2) In and out movement:

The high frequency bending caused by high-speed

rotation especially in curved canals, leads to stresses

in the Ni- Ti alloy used. It can be best avoided by a

slight in and out movement (2-3mm) while working. It

7

will help in distributing the fatigue uniformly along the

length of instrument. Each instrument is used in the

root canal for a period of only 5-10 seconds.

3) Irrigation:

Through out entire sequence irrigate as frequently

and abundantly with syringe using 2.5% sodium

hypochlorite. For apical preparation and final

preparation NaOCl and EDTA can be used

alternatively.

For very difficult canals, in an early preparatory

stage a lubricant like Glyde may be of advantage.

4) Before canal preparation started with Profile, it is

very important to insert stainless steel hand files to

the level 2mm deeper than the desired depth. The

advantage of these are two-fold:

1) It gives information regarding canal morphology

and curvature

2) Creates a patent pathway for rotary instruments.

Operational Sequence:

1) Crown-down:

8

Estimate the provisional working length using

diagnostic X-ray. The first objective is to pen the root

canal as far as minimum estimated working length i.e.

for e.g. if your estimated working length is 21mm,

21mm-3mm, 18mm. The stopper on the instrument is

adjusted to the 18mm. Then the instruments are used

in following sequence:

Profile 0.5 No. 3 (0.06/40:. It is 19mm relatively and

it is easily inserted into the canal. Without any

hindrance, from opposing teeth, with # 30.5 already

rotating in canal, insert without any excessive

pressure and apply simple in and out movement, for

about 5-10 seconds. When the progression become

difficult do not increase the pressure. 90 for next size

file.

Profile 0.5 No. 2 (0.06/30): It is smaller than No. 3

0.5 so it moves more apically compared to the

previous instrument. Use it in the same way as before;

withdraw as soon as progression is difficult.

Profile 0.06/25: This Profile has a smaller diameter

than the previously used instruments and is more

flexible due to greater length of its cutting section

used in this instrument same as previous one.

9

Profile 0.06/20: The instrument penetrates more

apically than the preceding one .Use in same way as

before.

Profile 0.04/25: Same as the previous one.

2)

Determination of working length: By using

conventional K-file (No.10, No. 15) with help of

radiograph.

If preferred, an apex locator is also used to complete

the crown-down procedure and determine working

length.

3) Apical preparation until the exact working length.

Profile 0.04/20: Use this instrument to exact working

length.

Profile 0.04/25: Use to exact working length.

10

If the canal anatomy is large No. 30, No. 35 can be

used each till exact working length.

4) Final flaring: It is by using 0.06 / 20 profile with the

profile 0.06/20 inserted into the canal while it is

rotating without an apical pressure and is applied in

an in and out movement.

For wide canals:

1. Crown down 0.5 # (.07/50)0.5 # 3 (.06/40)0.6/300.6/250.4/300.4/25

2. Determination of working length:

11

Apical preparation .04/25.04/30

Final flaring (.06/25) profile

Advantage of profile 29 series:

1. These files stay centered in canal and maintain

canal curvature.

2. The instrumentation time required for profile

system is less compared to stainless steel files. It

reduces the operator and patient fatigue.

3. The instrument is wider at DIG (end of cutting part).

Therefore gives necessary coronal flare to root

canal automatically.

4. The tip is bullet shaped so that there is less chance

of canal transportation and procedural errors.

5. Less debris extrusion compared to step back

technique (Hinrich et al).

6. Prepare the root canal with 3-D effect.

Disadvantage:

12

1. Loss of tactile sensation: There is less feed back

from rotary instruments regarding direction of

curvature and location of apical terminus.

2. Intracanal separation is most often problem while

using profile system. Breakage of NiTi instruments

can occur without any visible signs of permanent

deformation.

3. The Ni-Ti rotary profile system has low cutting

efficiency.

4. There is chance of corrosion of profile rotary

instruments when used along with sodium

hypochlorite. It leads to chloride corrosion which

leaves micropitting on instruments, surface leading

to crack formation and instrument failure.

13

PROFILE GREATER TAPER ROTARY INSTRUMENTS

(GT ROTARY)

Designed by Steve Buchanan. These instruments create

funnel shaped root canal more efficiently.

The instrument has variable pitched flutes that are closer

nearer the tip and further apart toward shank. It allows

the instrument to be stronger at tip where stress can be

more extensive. The larger spacing of the flutes at the

shank provides good flexibility and cutting efficiency.

14

Range of instruments:

1) GT rotary files: There are 4 files in this group

length 21mm, 25mm. These files have two

coloured rings. Each of the file has different taper

i.e. G.T. 12% (0.12)

GT 10% (0.10)

GT 8% (0.08)

GT 6% (0.06)

Ran

ge of instruments

- 4% taper.

- 20-35 no.

Available in 21, 25 and 31mm. They have only one

ring. They are mainly used to prepare the terminal

part of root canal.

15

G.T. Accessory files: These are 12 taper available in

35, 50, and 70 size length 21mm and 25mm.

Identified by the three grooves on handle.

Used to refining the final preparation.

Operations sequence:

1) Crown down: It can be done using G.T. rotary files.

a. Profile G.T. 0.012 taper with tip size 20 take to

resistance.

b. Profile G.T. 0.10 taper with tip size 20 taken to

resistance.

c. Profile G.T. 0.08 taper with tip size 20 taken to

resistance.

d. Profile G.T. 0.06 taper tip size 20 taken to

resistance.

Before this patency of is canal checked with No. 8

stainless steel file.

2) Determination of working length.

3) Apical preparation.

a. Profile 0.04 taper size 20.

16

b. Profile 0.04 taper size 25

c. Profile 0.04 taper size 30.

d. Profile 0.04 taper size 35

4) Final refining of root canal. This is by using G.T.

accessory files.

PROTAPER ROTARY SYSTEM:

These instruments have following design features:

1. Progressive taper: The protaper has varying tapers

within one file ranging from 3.5% to 19% this makes

it possible to shape the specific sections of root

canal with one file.

2. Modified guiding tip and varying tip diameter:

- The modified guiding tip allows one to follow the

canal better without any transporation and

procedural errors.

- The varying tip diameter helps in cutting the

specific areas of root canal without stressing the

instrument in other sections.

3. New cross-section of instrument:

17

- These instruments will have convex triangular

cross-section. This design results in a reduced

contact are between cutting blade and dentin. It

increases the cutting efficiency and decreases the

torsional strain of instrument.

4. Varying helicle angle and pitches:

5. New shorter handle: The length of the handle

reduced to 15mm to 12.54mm to allow for better

access.

18

Range of instruments:

Available in two sets:

- Shaping files (3 files) i.e. SX1, S1 & S2.

- Finishing files (3 files) F1, F2 & F3.

SX or auxiliary shaping file (SX):

Identification by lack of its ring on handle. This

instrument has highest increase in taper from D0 to D9

(3.5% to 19%). These files are mainly used for initial

preflaring and relocation of canal orifices.

S1 or shaping file 1: It has purple identification ring on its

handle.

19

S2 or shaping file 2: It has white identification ring on its

handle.

These instruments (S1 & S2) mainly useful in shaping of

coronal and middle third of canal.

Finishing file: 3 in number:

- Finishing file (F1): Tip diameter 0.20 yellow

identification ring.

- Finishing file 2 (F2): Tip diameter 0.25, red

identification ring.

- Finishing file 3 (F3): Tip diameter 0.30, blue ring.

These instruments has fixed taper from D1 and D3 i.e.

F1-7%, F2-8% and F3-9%.

These instruments mainly used in preparation of apical

third of canal at full working length.

20

Guidelines for use of pro-taper:

1. Establish straight line access.

2. Use instrument in well irrigated and lubricated canal

i.e. NaOCl 17% EDTA also can be used.

3. Establish a smooth glide path with No. 10, and no.

15 stainless steel file.

4. Clean the flutes of file frequently and inspect for

any signs of distortion.

5. Use torque controlled electric motor with handpiece

at 200-300rpm.

6. Force should never be applied to a file; only a light

brushing motion should be used.

7. Use the instruments in recommended sequence.

21

Operation sequence:

1. Establish straight line access and gliding path, using

no. 10 and no. 15 stainless steel file. Determine

estimated working length using diagnostic x-ray.

2. Flood the canal with NaOCl and begin shaping with

shaper S1 using light brushing motion .Go no.

deeper than 3-quarter of estimated length

recapitulate and irrigate.

3. Now use SX to improve straight line access and

relocate the canals, with same motion. Insert the

instrument while it is rotating. If a light resistance is

felt it is withdrawn in a brushing motion. Never

force instrument once you feel resistance. This

instrument will cut more coronal dentin create more

flare and thus allow better instrumentation in apical

region.

4. Now determine exact working length using stainless

steel file (No. 10 or no. 15) with help of well

angulated radiograph or electronic apex locator.

22

5. Now use S1 and S2 to full working length with

brushing motion.

6. Now with finishing file (F1) passively extend the

preparation 0.5mm short of working length

withdraw after 1 second.

The F1 has tip diameter 0.20mm. If no. 20 hand

instruments found to be snug at the apex, preparation

is finished.

If F1 and no. 20 hand instrument is loose continue

preparation with F2. It has tip diameter 0.25mm. Again

confirm with no. 25 hand instrument, if it is snug.

Irrigate and finish the preparation.

If F2 is loose continue preparation with F3 which

0.30mm tip diameter, followed by confirmation with

no. 30 hand instrument. If it is snugly fitting finish the

preparation.

Between each instrument it is very important to

irrigate copiously with NaOCl and recaputation with K-

file to maintain patency.

23

OPERATION SEQUENCE

Advantage:

- High cutting efficiency.

a. Triangular cross section.

b. Balancing pitch and helicle angle.

- Fewer instruments to complete the preparation.

Straight line axis & gliding path S1-file

(brushing motion)

SX-file Determination of W.L.And S1 to full W.L.

S2 file – full W.L. F1 file – full W.L. Gauging of apical Foramin (K-file #20)

F2 file – full W.L.

24

Straight line axis & gliding path

SX-file

S2 file – full W.L. F1 file – full W.L.Gauging of apical -file #20)

F2 file – full W.L.

- Less debris in apical region.

- File stress is minimized.

- Modified guiding tip enables file to easily follow a

prepared glide path without goughing side walls.

- Increased tactile sense due to triangular cross-

section.

Disadvantage:

- Cutting efficiency decrease with use.

- Possibility of canal transportation. Therefore

instrument is immediately removed once working

length has been reached.

- Severely curved canal difficult to use so hand

Protapers are better option.

-

25

LIGHT SPEED ROTARY SYSTEM:

It was so named because light touch is needed and as the

speed of instrumentation is increased.

This instrument is specially engineered nickel-titanium

Gates-Glidden-like reamers that allows enhanced tactile

controls and enhanced apical preparation larger than

those created with other rotary systems.

The instrument consists of set of ISO sized rotary files i.e.

from no. 20 to 140 in length 21, 25, 31mm. Light speed

instruments also have half sizes 22.5, 27.5, 32.5. These

half sizes are color coded exactly same to that of

previous size but also have white or black ring on handle

them easy in identification from full size.

Some unique design feature of light speed

instrument:

- Short cutting heads and long non-cutting taper less

shafts.

- They have radial lands and U-shaped spiral grooves

between radial lands.

26

- lightly longer non-cutting pilot tip.

Guidelines:

1. These instruments should rotate at constant speed

between 1500-2000. It should not exceed 2000.

This constant speed is very important because Ni-

Ti files will not sustain repeated change in torque.

2. Straight-line access to mid-root is very important

because they glide the rotating instrument in

curves of root canal.

3. Maintain patency of canal using hand-instruments

before starting the preparation with light speed

instruments.

4. Always use progressively larger instruments in

correct sequence from smaller to larger .Never skip

a size to gain time.

5. Irrigate copiously with sodium hypochlorite and

EDTA alternatively between each instrument.

27

6. Once the instrument reached to W.L. do not linger

at that point and immediately withdraw while

rotating.

Technique:

Zurich Light speed technique:

1. Initial apical rotary (IAR): First light speed

instrument which begins to cut canal wall at W.L.

2. Master apical rotary (MAR):

It is the last instrument to form the apical

preparation. This is G-12 light speed larger than

IAR.

3. Final rotary (FR):

The last step back instrument which completes the

preparation.

It has 4 steps:

Access and coronal pre-flaring:

Once the orifices are located they are enlarged using

Gates-Glidden drills (No. 12).

28

Determination of working length and IAR:

W.L. should determined using 15 No. stainless steel

file and verified radiographically or electronically.

Now start using light-speed instruments (No. 20) to

W.L. The first few instruments are may not ream the

canal wall because canals are too large these

instruments are called non-binding instruments. Always

begins with No. 20 never skip the size. Eventually one

instrument will begin to cut at W.L. It is called initial

apical rotary (IAR).

Determine MAR:

All light speed instruments used after IAR are called

binding instruments. These instruments are used in

controlled forward and backward movement (3-4mm) it is

called pecking movement. This forward movement

reams the canal and backward motion tends to clean the

head.

Now use the instrument sequentially with pecking

movement. The last instrument which used to prepare

the apical portion is depending on many factors like:

- Degree and angle of curvature.

29

- Presence of secondary or tertiary curves.

- Diameter of root apices.

Usually the size of MAR:

- For anterior 60-70 no.

- For posterior teeth 40-50.

Step back and recapitulation:

Light speed instruments are stepped back after selecting

the MAR. The step-back is 1mm from previous

instrument. Finally all canals are recapitulated with

respective to their MARS and irrigation should be done.

Manufacture recommended technique:

Here the initial apical rotary (IAR): file is identified by

gauging the apical canal diameter.

To gauge the light speed instruments must used by hand

advancing apically by advancing apically using moderate

pressure but never rotated. The initial smaller size

instrument easily goes to working length. One instrument

which is not going to full working length, it is called first

30

light speed size to bind (FLSB). From this instrument we

should begin rotary instrumentation.

Determining the apical preparation size: Start

instrumenting with FLSB with slow continuous movement

until it engages the canal wall. From this point give slowly

controlled forward and backward movements (pecking

movement). This pecking movement translates

downward cut of the dentin count the no. of pecks it

takes FLSB to reach the working length. Repeat the

counting of pecks for each sequentially larger

instruments.

The instrument which takes atleast 12 pecks to

reach working length is the MAR. This is called the “12

peck’s rule”.

Complete apical instrumentation:

After determining the MAR use next instrument

4mm shorter than the W.L. This enables the SimpliFill

G.P. Plug to closely match the size and shape of canal

preparation. If you are obturating with standardized GP

step back should start from 4mm so that each instrument

length is 1mm shorter than previous one.

Instrument middle root:

31

Instrument with sequentially larger size instrument

the 4-5mm of canal with only full size instruments (skip

half size instrument). These instruments should not enter

the apical 5mm of canal. Instrument with larger size

instrument until the size which will not pass easily the

apical extent of coronal third of canal.

Recapitulate: Recapitulate to working length with

MAR of each canal.

Light speed technique taper technique:

It is also called hybrid technique. In this technique

canals are cleaned and shaped in a crown-down fashion

by using tapered instruments. The apical portion of canal

cleaned by using light speed instruments. The master

apical rotary files are selected using 12 pecks rule.

Advantages:

1. The light speed instruments produce

larger apical preparation, because of their tip

design. Due to this there is better removal of

necrotic material and micro-organism in apical

area, with larger canal space more disinfecting

solutions reach apical area and ensure a better

disinfection.

32

2. There is no or little transportation when

canal prepared with light speed instruments.

(Glossen et al JOE 1995).

Disadvantage:

Time consuming because of too many

instruments used in the system.

33

K3 ROTARY NICKEL TITANIUM FILE SYSTEM

Designed by Dr. John McSpadden in 2002.

It has following design features:

1. Positive rake angle: The profile and most of

the other instruments has negative rake angle

which result in scraping rather than cutting

action. The slight positive rake angle as in the

case of K3 results in digging and plowing of

dentin. It will improve the cutting efficiency.

2. Variable flute angle: The flute angle is

variable i.e. taper increases from tip to

handle. So more debris removal from the

canal.

3. Wide radial land: In K3 has increased mass of

metal in peripheral area near the blade. It has

good mass of metal behind the cutting blade.

It makes the K3 resistant to torsional or rotary

stress.

34

Design of K3 Rotary system

35

4. Access handle: The K3 files has short handle so

that it can be used easily in posterior region of

the mouth.

5. Variable core diameter or flute depth: The flute

depth is less in the tip of the instrument where

the strength is more important. It gradually

increases as it moves up. It results in more

flexibility and increased debris removal.

6. Simplified color coding: The K3 system has

only two tapers 0.04 (green) and 0.06 (orange).

The instrument handle has two colour bands on

handle. The top band signifies taper and bottom

band conforms ISO sizing.

7. Safe ended tip: It avoids ledging, perforations

zipping and other nasty surprises.

36

Range of Instruments:

Body shapers: They have enhanced taper of 0.08, 0.10

and 0.12 with tip size no. 25 and in length 17, 21 and

25mm length. They are mainly used for coronal shaping.

Files are which are used for apical preparation 0.02 taper

files, tip size 15-40 in length 21mm, 25mm and 30mm.

0.04 taper files, 0.06 taper file} tip size 15-60, and in

length 21mm, 25mm, 30mm.

Guidelines:

1. Never force an instrument apically.

2. Frequent irrigation with sodium

hypochlorite with EDTA is desirable.

3. Patency should maintained during

preparation. Patency can be maintained

using small K-file (6-15) after every

rotary file.

4. Check the flutes of K3 files for bend, or

stretch, shiny spot, if found discard

immediately. In the case where root

canals are linked the files are discarded

after single use.

37

5. Use electric torque control motor with

auto reverse to rotate the files in

proper rpm (300-350rpm). The

instrument should not use more than 5-

7 seconds.

Technique:

- If the canals are severely curved,

scouting of middle third and coronal third with hand

files before advancing into rotary file is important.

- Crown down instrumentation is

desirable. It implies cleaning of coronal third is done

first then middle third and finally apical third.

- First obtain straight line access.

- Locate canal orifice and obtain

canal patency using hand files.

- Begin crown down by taking 0.12

taper K3 body shaper to resistance (3-4mm down

the canal). It should be done with EDTA gel followed

by flushing with NaOCl.

- Take next 0.10 taper K3 shaper to

resistance.

38

- Recapitulation and irrigation can be

done to clear the debris from coronal and middle

third of canal.

- Before rotary instrumentation in

apical area it is important to explore with hand

instruments (K-file 10-15). It helps to determine any

curvature calcification or patency. After achieving

this goal operator should passively introduce no. 10

or 15 K file to estimated working length.

- The working length is confirmed by

the use of a well angulated radiograph or electronic

apex locator.

- Once the true working length is

established the K3-rotary files are introduced in a

canal in a crown down fashion. It can be done by

two ways:

a. With sequence (from longer

tip size to smaller with fixed

taper).

b. With varying taper (mixing

the taper as tip size

diminishes).

39

- With sequence: Here

start instrumentation with tip size 35 (0.06 taper) or

large to tip size no. 20 or 15, until full working

length is achieved. In the case where canals are

narrow 0.04 taper series are also used in similar

fashion.

-

- Variable taper

sequence:

0.06 K3 + 40 to resistance.

0.04 K3 + 35 to resistance.

0.06 K3 + 30 to resistance.

0.04 K3 + 25 to resistance.

0.06 K3 + 20 to W.L.

0.04 K3 + 25 to W.L.

0.06 K3 + 25 to W.L.

Combination of K3 and light speed technique:

Hence shaping of coronal and middle third of canal done

by using K3 rotary system. The apical shaping can be

done using light speed instruments.40

Advantages:

1. Excellent cutting ability.

2. Moves smoothly in canal and give robust

sense of tactile control.

3. Excellent fracture resistance.

4. More flexible.

5. Due to their access handle they can be use

efficiently in posterior teeth or patient with

limited mouth opening (shortening of handle

by 5mm without affecting the working length

of file).

6. Less screwing in effect in K3 compared to

other brands of NiTi files (because of variable

flute pitch).

41

REAL WORLD ENDO-SEQUENCE FILE:

Developed by Brassler USA. It has following design

features.

1. It has alternate contact point design.

- Improves cutting efficiency.

- Prevents screwing into dentin.

- Enhances debris removal.

- Centres the file within the canal.

2. Electro-polished surface.

- Eliminates surface imperfections.

- Increases file sharpness.

3. Precision tip: It has a nonactive tip, fully active

precisely at 1mm (D1). The file has good self-

centring capacity in canal with less transportation.

4. No radial lands and with variable pitch and helicle

angle.

- Flexibility is maximized.

- Torque is minimized.

42

- Sharp cutting edge.

- Good controls over procedure.

DESIGN OF REAL WORLD ENDO-SEQUENCE FILE

Range of instruments:

43

The real word end sequence file available in both 0.04

and 0.06 tapers. The kit consists of following files.

Expeditor file: it is 0.04 taper, no. 27, 21mm used to

estimating the canal size.

0.06 taper file: with size extra small, small, medium, and

large.

0.04 taper file: with size extra small, small, medium, and

large.

i.e. small (no. 15-30).

Medium (25-40)

Large (35-50).

Speed: It run in portable hand piece with speed of 450-

600rpm. This portable handpiece has several

advantages.

- It is light in weight and good tactile

controls.

- It has torque controls and

autoreverse feature.

44

- Nine-speed options are available

(200-1000rpm) thus deliver a

outstanding power).

Technique:

1. After access opening confirm / establish patency by

moving a no. 10 or 15 stainless steel K-file with

help of no. 15 stainless K-file creating a glide path.

After obtaining the glide path working length

should determined with help of x-ray / Apex

locator.

2. Using an endo-sequence expeditor rotary file

penetrate the canal until significant resistance (i.e.

progress is no longer easy). Now remove expeditor

rotary file. Now we should choose the next size file

by information gained by.

- Preoperative radiograph.

- Resistance of # 10 hand file.

- Depth of penetration of expeditor.

If E-file is goes down half away it means canal is small.

If E-file goes more than half away it means canal is

medium.

45

If E-file is loose that means canal is large.

3. Now according to the size determined by expeditor

file choose appropriate size of file. Use these files

in a crown down fashion i.e. (30, 25, 20, 15 for

small canal). Use each file until resistance is

encountered .Usually no. 70 file with will go to full

working length with resistance.

46

RACE (REAMER WITH ALTERNATING CUTTING

EDGES)

Design feature:

1. Triangular cross section.

- Sharper cutting edges with good

cutting efficiency.

- Less torque required.

2. Electrochemical polishing:

- Removes microsurface

imperfections produced during

manufacture, it reduces the

fracture of instrument.

- Result in smooth cutting edge with

less stresses in the canal.

- Improved resistance to metal

fatigue.

3. Alternate helix angle of instrument . The cutting

edges of instrument has alternate helix angle as it

rotates in the canal.

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- Reduces the torque by 75% so

there is no screwing in effect.

- It reduces the cutting length of

instrument.

- Enhanced debris removal.

- Guard against binding, grabbing file

followup.

4. Softex tip:

- Ensure excellent centring in the

canal.

- Decreases risk of deviation.

48

DESIGN OF RACE (REAMER WITH ALTERNATING CUTTING

EDGES)

49

Range of instrument available:

These are available in different tapers:

0.2 taper (15-40 no.).

0.4 taper (25-35)

0.6 taper (25-40)

0.8 taper; 0.10 taper } (35-40).

These instruments have ISO sizing color coding .

Available in length 21, 25, 31 mms. These are available in

two kits i.e. 12mm handle and 15mm handle.

Speed: Cordless single micromotor can be used at a

speed (125-625rpm). These hand pieces:.

Are compact light weight, comfortable and have time

torque control with autoreverse feature.

Technique:

Five instrument technique:

Step 1: Establishing glide path using 10 no. hand K-file

(Schotlander and canal finder # 10 0.02 taper).

Step 2: Insert a 10, # 40 into canal in light in and out

painting motion, while moving circumferentially around

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the canal. Then use next 0.08 taper in a same manner.

These instruments are restricted to 4/3rd portion of canal

only.

Step 3: Measure working length.

Step 4: For preparation of apical portion of canal, start

with 0.02 taper no. 25 gradually inserted to working

length. If this file is not going to the working length,

instrument with hand file (k-file no. 15) .When working

length has reached, continue with 0.02 (no. 25), change

to 0.04 ± 25 and 0.06 ± 25 proceed to W.L.

Three instrument technique:

After some experience in wide canals we can use this

technique.

Here first 3 steps are same as above in step 4 go directly

to 0.06 taper ± 25 to full working length.

Advantages:

- Less work torque (75%).

- More debris removal.

- Optimum controls.

- Reduced risk of metal fatigue.

51

- Improved resistance to instrument

fracture.

52

TECHINQUE

Technique

53

LIBERATOR

Design:

1. Straight flute design: Most of the other rotary file

systems helically fluted like appearance. They act

like a wood screw, so natural tendency to self

thread. The liberator is a straight flute design so

there is 0% self threading.

2. Lack of radial lands so less friction. Liberator rotary

files have no land area so not friction.

3. Higher rpmm reduces torque. The liberator file

rotates at high rpm 1000 to 2000. So less torque

generated and less file separation.

4. Roane softex tip that keeps file centred and

minimizes ledging and file separation.

5. Efficient dentin removal – Liberator NiTi files quickly

and more efficiently removes dentin because of

their sharp cutting blades moving at high velocity.

So there is more kinetic energy generated.

(Liberator delivers 32 times more kinetic energy

than conventional file system).

54

6. Less transverse micro-cracks. The pattern of

grinding is parallel with axis of file. This compare to

conventional file where grinding pattern is

perpendicular to axis is resulting in transverse

micro-cracks in file.

Range of instruments:

The liberator files available in different tapers:

0.02, (25-70).

0.04 (30-70)

0.06 (35-80)

They available 21, 25, and 31 length.

Guidelines:

1. Complex canal systems may require.

- Reduced rotational speed.

- Use 0.2 taper files.

- Hand filing.

2. Be sure that straight line access is there for

canal orifices.

3. Operate liberator at 1000-2000 rpm.

55

4. Advance each liberator slowly (no-packing

movement).

5. Irrigate between each liberator file.

56

Straight flute design

Straight flute Helicle flute

57

Less transverse micro-cracks

Conventional file Liberator file

Technique:

For small root diameter:

Access opening and determine working length using

small flex file.

Establish gliding path using 10 no. file for select file tip

size according to root diameter. 70 no. liberator place

rotating file into the canal and apply sufficient pressure

to advance to depth 5mm short of working length.

60 no. liberator advance

4mm short of working

length.

58

55 no. liberator advance 3mm short of working length.

50 no. liberator advance 2mm short of working length.

45 no. liberator advance 1mm short of working length.

35 no. liberator advance 0.5mm short of working length.

25 no. liberator advance slightly beyond the foramen.

Shaping is completed irrigate dry and fill the canal.

For medium sized root diameter:

No. 70 liberator rotating file into the canal with slight

apical pressure advance to depth 2mm short of working

length.

No. 60 advance to depth 1mm short of working length.

No. 45 advance to depth 0.5mm short of working length.

59

No. 30 advance to depth slightly through apical foramen.

Shaping is completed.

File tip size for large root diameter:

80 no. liberator rotating file introduced into the canal and

55 liberator file is advanced to a depth 0.5mm short of

foramen.

35 no. Liberator file advanced to a depth slightly through

foramen. Shaping is completed.

60

V-TAPER ROTARY SYSTEM

Design feature:

1. Safe core, variable pitch and neutral rake angle.

Safe core – Reduces chances of instrument fracture,

variable pitch – Decrease screw in effect.

Neutral rake angle: eliminates gouging, and grabbing

of positive rake angle and inefficiency and heat build

of negative rake angle

2. No radial lands: Thus no dragging, friction heat build

and inefficiency which can cause fracture.

3. Non-cutting tip prevents ledging and transportation.

4. Variable taper: Natural root canal has variable

taper. So these variable taper files shape effectively

61

especially in apical third area. (Deep apical

preparation and eliminates taper lock), natural

shape of canal maintained.

5. Parabolic cross section: It is most efficient cross-

sectional design especially for deep hole reaming

action in root canal.

6. Endonol: It uses a specially formulated NiTi-alloy for

manufacturing of V-taper files. This metal has

superior mechanical features.

7. Easy color coding for identification.

8. Short handle.

Guidelines:

- Straight line access and establish

glide path (# 10 V hand file).

- Do not over prepare the working

length.

- Do not over heat NiTi files. Super

elastic and shape memory

properties may be lost.

- 1 second rule: Cut the dentin only

for 1 second.62

- Always use a lubricant.

- Set electric motor between 250-

400rpm.

- Use light apical pressure.

- Consider 21mm length whenever

possible for better access.

- Do not over use the file. The file

should be used for 3-4 individual

canals. If file damaged discard

immediately.

- When apical third of canal has

abrupt curvature use hand files for

preparation.

Range of instruments:

It is 3 file systems:

0.10 taper tip diameter 30

0.08 taper tip diameter 25

0.06 taper tip diameter 20

63

Technique:

1. Glide path: #10 V-hand files. 10 (VO2) - # 10 (VO4)

- # 10 (VO6). Determine working length.

2. Coronal shaping: 25(V08) – 30 (V09) to the point of

resistance.

3. Apical shaping: 30 (V10) – 25 (V08) – 20 (V06) to

the point of resistance.

4. Final shaping

30 (V10) to working length for large canal.

25 (V08) to working length for medium canal.

20 (V06) to working length for small canals.

64

HERO-642

Introduced by Daryl Green – manufactured by Micromega

instrument Co, from NiTi.

Features and benefits:

1. Three cutting edges for a positive cutting in curette

effect.

2. Bigger inner core provides better resistance to

fracture.

3. Progressive fluting present, so less screwing in

effect.

4. Three variable tapers which peel the canal wall on

small contact point.

5. Tip which stays centred in the canal.

6. Versatile it can be used along with sonics and hand

files.

65

7. Economical as it requires few instruments.

Speed: these files can be run in contraangle handpiece

at a speed of 300-600rpm.

Instruments: Available in 3 tapers.

2% taper # 20-45, in 21, 25, 29mm in length,

4% taper – 20-30 in 21, 25, 29mm

6% taper # 20-30 21mm, 25mm.

Technique:

For easy canals:

- Locate canal orifice and determine

working length.

66

- Use 0.06 taper # 30 to 2/3 of

working length by slow in and out

movement with circumferential

filling.

0.04 taper # 30 to 2mm short of working length.

- 0.02 # 30 taper to full working

length. Recapitulate with hand file

and irrigate.

For easy canals

Difficult canals

For canals with

67

Average difficulty

For canals with average difficulty

Same technique but the sequence begins with # 25

For difficult canals use the same procedure but sequence

begins with # 20.

68

QUANTEC ROTARY SYSTEM

Design: Features and benefits:

- Positive rake angle with active

cutting action.

- Wider radial lands which provides

blade support while providing peripheral strength

to resist torsional and rotary stress.

- The third radial land stabilizes and

keeps the instrument centered in canal and

minimizes over engagement.

- Radial land relief reduces the friction on the walls.

69

- Safe ended tip: Safe cutting; non

cutting.

- Short handle: So easy posterior

access.

Range of instrument: These instruments are available

in different taper.

It consists of range of instruments with identical tip size

# 25 17, 21, 25mm length.0.12 taper.0.10 taper0.08 taper0.06 taper0.05 taper0.04 taper0.03 taper0.02 taper } # 15-40, 17, 21, 25mm length.

70

This instrument run in high torque gear reduction slow

speed hand piece.

Technique: Crown down starting with larger taper file first

and progressing with file with lesser taper.

- Straight line access and check for

patency of canal.

- Determination of working length.

- Establishment of glide path.

- Use light pecking movement – now

start instrument with 0.12 taper instrument

advances till you meet resistance.

- Then follow the frequency

instrument till # 0.03 taper.

- Apical preparation with 0.02 taper

Quantec file from 15-40 to working length.

71

MITY ROTO 360°

Design:

- Unique 4-file design with flat edged

flutes prevents instrument from

getting caught on canal walls.

- It works in reaming motion provides

uniform canal preparation.

- Reduces preparation time.

Available in:

- 15-80 tip sizes in 21 and 25mm

length.

NAVI-FLEX ROTARY SYSTEM:

- Precision grounded flutes.

- Self-centering bullet tip.

- 18mm length for easy use in initial

flaring.

- ISO colour coded easy for

identification.

Range of instruments available in:

72

- 0.8 Taper (tip size 60, 45).

- 0.6 Taper (tip size 35, 25).

- 0.4 taper from no. 15-55.

73

Techniques:

Establishment of straight line access and patency.

Instrument in a crown down fashion.

- Navi-Flex 0.08/60 till significant

resistance.

- Naviflex 0.08/45 till significant

resistance.

- Naviflex 0.6/35

- Naviflex 0.6/25

Determine working length:

- NF 0.04 / 45 till resistance.

- 0.04 / 35 till resistance.

- 0.04/30 till resistance.

- 0.04 / 25 till resistance.

This sequence should repeated until the 0.04/25

taper reaches to full working length.

Irrigate and recapitulate.

74

CONCLUSION

Proper biomechanical cleaning and shaping of root canal system is

the basis of endodontic therapy. Since the introduction of first rotary

instrument, various new systems have been established in the market,

the benefits of which are apparent in their perfect preparation of the

root canal system. Their widespread use in regular practice is being

looked upon with skepticism because of overzealous tooth removal

and a highly mechanical approach.

Nevertheless, the combination of anatomic, biologic and

pathophysiologic knowledge of the tooth and skill of the operator

play a large role in optimizing the quality of root canal treatment.

75

REFERENCES:

GROSSMAN 11TH EDITION

COHEN 8TH AND 6TH EDITION

INGLE 5TH EDITION

STOCK 2ND EDITION

WALTON

WEINE 5TH EDITION

DCNA 2004

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