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Endodontic instruments

Presented By -

payal singh

P.G. 1st YR

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CONTENTS• INTRODUCTION• ENDODONTIC INSTRUMENT STANDARDIZATION• CLASSIFICATION• PARTS OF A ROTARY FILES• HAND INSTRUMENTS• SLOW ROTARY INSTRUMENTS• CLASSIFICATION OF ROTARY HANDPIECES• ROTARY SYSTEMS• RECENT ADVANCES IN ENDODONTIC INSTRUMENTS• STERILIZATION OF INSTRUMENTS• STUDIES• CONCLUSION• REFERENCES

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INTRODUCTION• Instruments play a very important role in the success of a root

canal treatment therefore a basic knowledge of endodontic instruments is essential.

• Although general guidelines exist for root canal preparation, but due to the complex and varied canal anatomy each case presents unique characteristics requiring the clinician to vary the armamentarium and technique to adequately clean and shape the canals. A variety of instruments are thus available for this purpose.

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Endodontic Instrument Standardization• Before 1958, endodontic instruments were manufactured without

benefit of any established criteria.

• The numbering (1 to 6) was entirely arbitrary.

• An instrument of one company rarely coincided with a comparable instrument of another company.

• There was little uniformity in quality control

• No uniformity existed in progression from one instrument size to the next.

• There was no correlation of instruments and filling materials in terms of size and shape.

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Approximate correspondence betweenconventional and standardized instruments

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• In 1959, a new line of standardized instruments and filling material was introduced to the profession.

1. A formula for the diameter and taper in each size of instrument and filling material was developed.

2. A formula for a graduated increment in size from one instrument to the next was developed.

3. A new instrument numbering system based on instrument metric diameter was established.

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Original recommendation by Ingle for standardized instruments

INSTRUMENT DIAMETER AND TAPER

Cutting blades 16 mm in length

2 % Taper.

The diameter of the instrument at tip (D1) is determined by size in hundredths of millimeters.

Diameter 2 (D2) is uniformly 0.32 mm greater than D1.

Length- 21, 25, 31 mm.

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INCREMENTAL INCREASE IN SIZE AND COLOR CODING

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Two modifications were made in Ingle’s original proposed recommendation - additional measurement at D3, 3 mm from tip/ D1, and specification for shapes of the tip: 75 degrees, ± 15 degrees.

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• Earlier Two ISO standards pertained to endodontic instruments were -

• ISO no. 3630-1 deals with K-type files (ANSI no. 28)

Hedström files (ANSI no. 58)

Barbed broaches (ANSI no. 63)

and rasps

• ISO no. 3630-3 deals with condensers, pluggers, and spreaders (ANSI no. 71).

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• In 1989, the American National Standards Institute (ANSI) granted approval of “ADA Specification No. 28 for both endodontic files and reamers”

The ANSI/ADA standards have also been set for other instruments and filling materials: • No. 95, root canal enlargers• No. 57, filling materials• No. 73, absorbent points• No.78, obturating points.

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CLASSIFICATIONAccording to Grossman:

oExploring instruments: to locate the canal orifice and determine patency of the root canal. E.g. endodontic explorers, smooth broaches (pathfinders).

oDebriding instruments: to extirpate the pulp and remove any foreign debris. E.g. barbed broach.

oCleaning and Shaping instruments: to clean and shape the root canal laterally and apically e.g. reamers and files.

oObturating instruments: to cement and pack gutta-percha into the root. E.g. spreaders, pluggers and lentulospirals.

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Classification of cleaning and shaping instruments

Group I: Hand use only—Files, both K type (Kerr) and H type (Hedstroem); Reamers, K type and U type; and broaches, pluggers, and spreaders.

Group II: Engine-driven latch type— same design as Group I but made to be attached to a handpiece. Gates-glidden (GG) burs and Peeso reamers.

Group III: Engine-driven nickel-titanium rotary instruments — Profile And Profile GT , Protaper ,Lightspeed LSX , Quantec, Twisted File, Race ,Endosequence.

Group IV: Engine driven three dimensionally adjusting instruments — SAF

Group V: Engine driven reciprocating instruments —ENDO EZE

Group VI : Sonic and ultrasonic instruments

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• CLINICAL CLASSIFICATION• INSTRUMENTS USED FOR DIAGNOSIS• Endodontic explorer, smooth broach• Pulp tester• Tooth slooth

• Transilluminant

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• INSTRUMENTS USED FOR ACCESS OPENING

• Diamond rose head burs• Tapered fissure• Carbide burs• Safe end long bur• Tapered diamond Endo -Z bur

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• INTRA – CANAL PREPARATION INSTRUMENTS• A- Instruments used for pulp tissue removal:-

1- Broaches: Barbed broach.

2- Endodontic excavator.

• B- Instruments used for root canal preparation:-

1- Reamers

2- Files

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• Instruments used for root canal obturation• Lentulo spirals• Spreaders • Pluggers • Condensors • Heat carriers• Thermomechanical compactors

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Spreaders and Pluggers • Spreaders and pluggers are the significant instruments for

obturation.

• The spreader is a tapered, pointed instrument intended to displace gutta-percha laterally for insertion of additional accessory gutta-percha cones.

• The plugger is similar but has a blunt end.

• These instruments are available with handles or as finger-held instruments.

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• The instruments with handles are potentially dangerous, because the tips of the working ends are offset from the long axes of the handles.

• This results in strong lateral wedging forces on the working ends of the instrument if it is not operated carefully.

• The risk of vertical damage to the root is greatly reduced with finger spreaders and pluggers.

• Standardized instruments are available with the same taper as the files (eg, .02 taper).

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RCS30 RCS40 RCS50 RCS60 RCP50 RCP60

(hu-friedy spreader and pluggers)

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• In recent years spreaders and pluggers have become available in nickel-titanium.

• It has been found that Nickel-titanium spreaders reach deeper into canals than the stainless steel type when .02% tapered gutta-percha is used in canals with a curvature of more than 20 degrees.

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LENTULO SPIRALS • A lentulo spiral may be used for placement of the sealer,

cement, and calcium hydroxide dressings.

• It must be operated clockwise in the handpiece and started or stopped outside the root canal. If started in the canal, it may cut into the wall of the root canal and break.

• This instrument effectively drives the paste into the root canal. However, for optimal effect the spiral must be as large as possible so that the paste is forced forward.

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Hand Instruments• A typical set of endodontic instruments might include a

mouth mirror, a DG-16 endodontic explorer, cotton pliers, a spoon excavator, a series of pluggers, a plastic instrument, a hemostat, a periodontal probe, and a ruler.

• The DG-16 endodontic explorer is used to identify canal orifices and to determine canal angulation.

• The CK-17 endodontic explorer serves the same purpose, but its thinner, stiffer tip can be useful for identifying calcified canals.

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DG-16 endodontic explorer (top), CK-17 endodontic explorer (bottom).

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DG 16 Endodontic Explorer

DG 16/17 Endodontic Explorer

DG 16/23 Endodontic Explorer

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• The endodontic spoon can be used to remove coronal pulp and carious dentin easily because of longer shank.

• A #17 operative explorer is useful for detecting any remaining pulp chamber roof, particularly in the area of a pulp horn

Endodontic spoon (left)#17 operative explorer. (right)

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Micro-Opener & Micro-Debriders

• A new addition to finding and enlarging canal orifices is the Micro-Opener (Dentsply/Maillefer; Tulsa) with K-type flutes in 0.04 and 0.06 tapers, that can be used to uncover, enlarge, and flare orifices.

• This can be followed by the Micro-Debrider with ISO 0.02 taper and Hedstroem-type flutes to further flare down the canal.

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COMPONENTS OF A FILETaper It is expressed as the amount of file diameter increases each

millimeter along its working surface from the tip towards the file handle.

• SIGNIFICANCE: The ability to determine cross-sectional diameter at a given point on a file can help the clinician to determine the file size in the point of curvature and the relative stress being placed on the instrument.

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• Constant taper with variable tip size• Eg. Profile and K3• Common tip size with varying Taper• E.g Quantec, Race, System GT• No Taper• E.g Lightspeed • Multiple or Reverse Taper• E.g Protaper

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• INSTRUMENT TAPER• PROFILE FIXED 2%, 4%, 6%• HERO 642 FIXED 2%, 4%, 6%• K3 FIXED 2%, 4%, 6%• FLEXMASTER FIXED 2%, 4%, 6%, INTRO FILE-11%• RACE FIXED 2%, 4%, 6%, 8%,10%• QUANTEC SC FIXED 2%,3%, 4%, 5%,6%,

8%,10%,12%• M TWO FIXED 4%,5%,6%,7%• GT FILE FIXED 4%, 6%, 8%, 10%, 12%• LIGHTSPEED NO TAPER• PROTAPER VARIABLE TAPER

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b) Core • It is the cylindrical center part of the file having its

circumference outlined and bordered by the depth of the flutes.

• Significance :The flexibility and resistance to torsion is partially determined by the core diameter.

The depth of flute of the small instrument is approximately the same as for the larger instrument but it results in excess susceptibility to failure, whereas the larger instrument has adequate flexibility and adequate resistance to torsion failure.

25 k 15 k

Both files have flute with same depth

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c) Flute

It is the groove in the working surface used to collect soft tissue and dentin chips removed from the walls of the canal. The effectiveness of the flute depends on its depth, width, configuration, and surface finish.

• A progressively larger distance between flute space and blade is required so as to avoid any compaction of debris and also provides an effective channel for its removal.

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• D) Cutting edge: • The surface with the greatest diameter that follows the

groove (where the flute and land intersect) as it rotates, forms the leading (cutting) edge, or the blade of the file.

• Significance : The cutting edge forms and deflects chips from the wall of the canal and cut or snags soft tissue. Its effectiveness depends on its angle of incidence and sharpness.

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E) Land or Marginal width

The surface that projects axially from the central axis as far as the cutting edge between the flutes.

Functions :• Prevents ‘‘screwing in’’ of the file• Supports the cutting edge • Limits the depth of cut• Reduces the propagation of

microcracks on its circumference.• Maintains the file in the centre

of root canal.

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• To reduce frictional resistance, some of the surface area of the land that rotates against the canal wall may be reduced to form the relief.

• Wide lands can be very useful in small diameter files as it increases rigidity and enables the file to negotiate curvatures when canal enlargement is minimal.

• When lands present in the files are too wide for effective canal enlargement then the files can be used very effectively for removing gutta percha from the canal.

GPX Instrument

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F) Helix Angle• The angle formed by the cutting edge with the long axis of the

file.

• Helps in removing debris collected in the flute from the canal.

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• G) PITCH

The pitch of the file is the distance between a point on the leading edge and the corresponding point on the adjacent leading edge.

OR

It may be the distance between corresponding points within which the pattern is not repeated.

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• The smaller the pitch the shorter the distance between corresponding points more spirals the file will have greater the helix angle

• Most files have a variable pitch, that changes along the working surface.

• The result of a constant pitch

and constant helical angles is a

“thread-in” or “sucking down”

of file within the canal.

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• Profile has a constant pitch throughout its cutting shank. The GT has variable helical angles and a variable pitch. Their variable pitched flutes provide a reamer like efficiency at the shank and K-file strength at the tip

• K3 file has been designed with constant tapers, but with variable pitch and helical angles dramatic reduction in the “suck down” effect for file within the canal.

• • ProTaper has continuously changing pitch and helical angle

which reduces the screwing effect.

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Rake Angle : is the angle formed by the leading edge and the radius of the file when the file is sectioned perpendicular to its long axis.• 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

• Most conventional endodontic files utilize a negative or “substantially neutral” rake angle.

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If the angle formed by the leading edge and the surface to be cut (its tangent) is obtuse, the rake angle is said to be positive or cutting. Positive rake angles will cut more efficiently than neutral rake angles, which scrap the inside of the canal.

Examples of positive rake instruments are, hedstrom files, second generation rotary files and most dental burs. An overly positive rake angle will result in digging and gouging of the dentin. This can lead to separation of the instrument.

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However rake angle may not same as the cutting angle.

The cutting angle or effective rake angle is a better indication of the cutting ability of a file and is obtained by measuring the angle formed by the cutting (leading) edge and the radius when the file is sectioned perpendicular to its cutting edge.

.

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• If the flutes of the file are symmetrical the rake angle and cutting angle will be essentially the same. Only when the flutes are asymmetrical ,the rake angle and cutting angle will be different

• In some instances, as with some Quantec files, a file may have a blade with a negative rake angle and a positive cutting angle.

• Both angles may change as the file diameters change and may be different for file sizes.

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PROFILE

NEGATIVE CUTTING ANGLE

NEGATIVE RAKE ANGLE

NEGATIVE RAKE ANGLE

NEGATIVE CUTTING ANGLE

PROFILE GT

SYMMETRICAL FLUTE

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NEGATIVE RAKE ANGLE

NEGATIVE CUTTING ANGLE

NEGATIVE CUTTING ANGLE

NEGATIVE RAKE ANGLE

PROTAPER

RACE SYMMETRICAL FLUTE

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NEGATIVE RAKE ANGLE

LESS NEGATIVE CUTTING ANGLE

LESS NEGATIVE CUTTING ANGLE

NEGATIVE RAKE ANGLE

M TWO

HEROASYMMETRIC

AL FLUTE

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POSITIVE RAKE ANGLE

POSITIVE CUTTING ANGLE

NEGATIVE RAKE ANGLE

POSITIVE CUTTING ANGLE

QUANTEC

K 3

ASYMMETRICAL FLUTE

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Tip Design.• Tip design can affect file control, efficiency, and outcome in

the shaping of root canal systems.

• The tip of the original K-file resembled a pyramid.

• Instrument tips have been described as cutting, noncutting, and partially cutting, although no clear distinction exists among the three types.

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• The instrument tip has two functions: to enlarge the canal and to guide the file through the canal.

• If the canal is smaller than the file, a cutting tip would be more efficient.

• If the canal is larger than the tip, using a less effective cutting tip can help in preventing transportation.

• Powell et al pointed out that when this tip “angle” is reduced, the file stays centered within the original canal and cuts all sides (circumference) more evenly. This modified-tip file has been marketed as the Flex-R-file.

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Flex - R file with modified rounded tip

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• In a study done by Miserendino et al. it was found that although specific design features of the tip, such as tip angle, tip length, cross-section, and tip geometry, significantly effect the cutting efficiency of endodontic instruments, tip geometry plays the most important role.

Cutting Efficiency of Endodontic Instruments. Part I1:Analysis of Tip Design

JOE; VOL. 12, NO. 1, JANUARY 1986

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TORQUETorque is a measure of how much a force acting on an object causes that object to rotate.

• Torque is a twist and is applied to an object to make the object turn about its axis of rotation.

• When torque is applied it changes the object’s rate of rotational motion.

• Factors affecting the torque of a rotary file are the speed , axial pressure, contact area and presence of lubricants.

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• It includes files, reamer , barbed broaches and rasps .

• Firstly in 1904 Kerr Manufacturing Company designed the, K-style files and reamers. (ADA NO 28 / ISO standard no. 3630-1)

• Files are instruments that enlarge canals with reciprocal insertion and withdrawal motions. K Files blade angle makes them best suited for cutting dentin in the filing motion .

• Reamers cut and enlarge canals with rotational motions. K Reamers have a rake angle which makes them most efficient in rotary motion, hence reaming is prefered.

Group I – Manually Operated Instruments

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reamers K file

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Reamers Files

Working motion rotational motions reciprocal insertion and withdrawal motion

Cutting action retraction Primary during withdrawal, although it will cut in the push and pull motion as well.

Flexibility more Less

Cross section triangular square

Flutes Loose spiral, half of that of a same size file. (1/2- 1 per mm)

The tighter spiral (1 ½- 2/ mm)

Transport of debris Better because of space between flutes

because of closer flutes

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• K-type instruments are produced using one of two techniques.

1) It is the more traditional way of production . In which graduated sizes of round “piano”wire are ground into various shapes such as square, triangular, or rhomboid.

• A second grinding operation properly tapers these pieces.

• To give instruments the spirals that provide the cutting edges, the square or triangular stock is then grasped by a machine that twists it counterclockwise a programmed number of times—tight spirals for files, loose spirals for reamers.

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2 ) The second and newer manufacturing method is to grind the spirals into the tapered wire rather than twist the wire to produce the cutting blades.

Grinding is totally necessary for nickel-titanium instruments. Because of their superelasticity, they cannot be twisted.

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K-Style Modification• The Kerr Manufacturing Company in 1982 introduced a new

instrument design that they termed the K-Flex File.

• The cross-section of the K-Flex is rhombus or diamond shaped. This new cross-section presents significant changes in instrument flexibility and cutting characteristics.

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• The two acute angles of the rhombus increased sharpness and cutting efficiency.

• The two obtuse angles of the rhombus decreased contact of the instrument with the canal walls and provides a space reservoir that with proper irrigation enhance debris removal.

• Kerr has introduced a hybrid instrument the Triple-Flex File. It has more spiral flutes than a K reamer but fewer than a K file. It is made from triangular stainless steel and twisted, not ground.

• This instrument is more aggressive and flexible than the regular K-style instruments.

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• While testing five brands of K-type files for stiffness, it was found that K-Flex files were the most flexible. Moreover, not a single K-Flex file was fractured in torque testing, even when twisted twice the recommended level given by ADA.

Roth WC, et al. A study of the strength of endodontic files. JOE 1983;9:228.

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ISO Group I, K-style endodontic instruments. A. K-style file. B. K-style reamer. C. k- flex file.

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Flexo filesThey have a non-cutting tip which enables the instrument to traverse along the canal rather than gouging into it.

They are made from NiTi wire.

Flexofiles are also available in intermediate sizes. (Golden medium)

They are similar to k-flex file except that they have triangular cross section .This feature provide them greater flexibility and thus ability to resist fracture. but they have less cutting efficiency.

• .

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Flex-R file (a milled K-type file)

• They are made by removing the sharp cutting edges from the tip of the instrument .and the tip is rounded.

• The flutes are sharper and has less negative rake angle than a traditional twisted K-file.

• The manufacturing method allows greater control of strength and flexibility by controlling the angle of cutting edge and cross sectional area of metal bulk.

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Ultra flex files a milled K-type NiTi file.

The flutes are less sharp than in a steel counterpart

Sure flexa milled, K-type NiTi file has a greater helix angle than the Ultra Flex

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H-Type Instruments• Specification : ADA 58. ISO no. 3630-1.

• H-type files are made by cutting/grinding the spiraling flutes into the shaft of a piece of round, tapered, stainless steel wire.

• H-files cuts in only one direction—retraction/ pull motion.

• It is impossible to ream or drill with this instrument.

• Because of the very positive rake angle

of the flute design, they are also

as efficient as files.

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• Single helix, tear drop shaped cross-section.

• Deep grinding of the surface of H-file reduces central mass of metal and thereby weakned the structure. hence it should not to be used in a rotational manner.

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H-Style File Modification.• McSpadden was the first to modify the traditional Hedstroem

file.

• Marketed as the Unifile and Dynatrak, these files were designed with two spirals for cutting blades, a double-helix design.

• In cross-section, the blades presented

an “S” shape rather than the single-helix

teardrop cross-sectional shape of the

true Hedstroem file.

• The Hyflex file (Coltene/Whaledent) appears to have the same cross-sectional configuration.

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S- FILE • The “S” File (J-S Dental) also appears to be a variant of the

Unifile in its double-helix configuration.

• It is a perfect blend of flexibility, durability and cutting ability.

• The S-FILE is produced by grinding which makes it stiffer than H-file.

• This unique instrument can be used with any hand motion (filing or reaming) thus this file can also be classified as hybrid design.

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• Buchanan has further modified the Hedstroem file, the Safety Hedstrom file (Sybron Endo/Kerr), which has a noncutting side to prevent ledging in curved canals.

A. H-style instruments resembling a wood screw.

B. Modified Hedstroem file (left) with non-cutting tip

C.“Safety”Hedstroem (right) with flattened non-cutting side to prevent “stripping”.

C

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Barbed Broaches and Rasps• Specification : (ADA no. 63, ISO no. 3630/1).

• Barbed broaches are short-handled instruments used primarily for vital pulp extirpation.

• They are also used to loosen debris in necrotic canals or to remove paper points or cotton pellets.

• These instruments are manufactured by notching a round, tapered wire with a blade to form sharp, projecting barbs that cut or snag tissue.

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• These barbs are used to engage the pulp as the broach is carefully rotated within the canal until it begins to meet resistance against the walls of the canal.

• The broach should never be forced into a canal as its barb get compressed by the canal wall. And while removing it may break on applying pressure as these barbs gets embedded in to dentin.

• A “jammed broach” should be removed vertically without twisting.

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• Although similar in design, broaches and rasps show some significant differences in taper and barb size. The broach has lesser taper of .007 to .010/mm and the rasp has more taper of .015 to .020/mm .

• Barb height is much greater in the broach than in the rasp.

• In broach, barb extends up to half of its diameter and in rasp barb extend to one third of core diameter . therefore broach is a much weaker instrument than the rasp.

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• There is also smooth broach, sometimes used as a pathfinder.

• The newly released Pathfinder CS (Sybron- Endo/Kerr; Orange, Calif.), made of carbon steel, is less likely to collapse when forced down in a fine canal.

• But carbon steel will rust and cannot be left in sodium hypochlorite.

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Hand piecesCLASSIFICATION OF HANDPIECES:

ACCORDING TO INGLE: Engine driven instruments can be used in three types of contra-angle handpieces.

oFully rotary (latch / friction grip).

oReciprocating /quarter turn hand piece

oSpecial handpiece that imparts a vertical stroke but with an added reciprocating quarter turn that "cuts-in" when the instrument is stressed.

oUltrasonic and Sonic

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ACCORDING TO STOCK:They can be classified according to the type of movement

they impart to the cutting instrument.

I. Rotary

II. Reciprocal

III. Vertical

IV. Random

V. Sonic

VI. Ultrasonic

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ROTARY Work on the principle of continuous rotation within the

root canal at a fixed slow speed.

A, First-generation motor without torque control. B, Second-generation motor with sensitive torque limiter.

C, Frequently used simple torque controlled motor.

D, Newest-generation with built-in apex locator and torque control.

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Electric motors with gear reduction are more suitable for rotary NiTI systems because they ensure a constant rpm level ; however they also deliver torques much higher than required to break tips.

Examples -Micro Mega MM 324 reduction gear Handpieces, the Sprint EDM (Electronic Digital Motor handpiece).

Now a days newer electric hand pieces are available wherein not only the speed can be controlled but the torque as well, that is, the speed and torque can be set for a certain size instrument and the hand piece will “stall” and reverse if the torque limit is exceeded.

Examples- Aseptico ITR Motor handpiece, the Nouvag TCM ENDO motor, the new Endo-Pro Electric, and the new ProTorq motor handpiece.

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ATR Tecnika Vision

Nouvag TCM Endo Motor

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TRI AUTO ZX

 Combination of Apex locator and hand piece

It has four modes-• Electronic measurement of root

(EMR) mode• Low mode• High mode• Manual mode

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• The Tri Auto-ZX has three automatic functions:

1)The hand piece automatically starts when the file enters the canal and stops when the file is removed.

2) If too much pressure is applied, the hand piece automatically stops and reverses rotation.

3) It also automatically stops and reverses rotation when the file tip reaches the apical stop, as determined by the built-in apex locator.

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Reciprocating Handpiece. • 1-Giromatic

• 2-Endocursor• 3-M4 safety handpiece• 4-Endogripper

M4 Safety Hand piece which has a 30-degree reciprocating motion and a unique chuck that locks regular hand files in place by their handles.

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ENDOCURSOR

The root canal is prepared by means of a reciprocating movement of the instrument (approx 60º) using the“ balanced-force" technique.

The Endo-Gripper is a similar

hand piece, with a 10:1 gear ratio

and a 45-degree turning motion.

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VERTICAL STROKE HANDPIECE

CANAL FINDER SYSTEM • It is a specialized handpiece with a

vertical movement of 0.3-1.0 mm and a free rotational movement.

• The free rotational movement allows the tip to move away from an obstruction in the root canal.

• Increasing vertical pressure will stop the movement.

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CANAL LEADER:• Is a modified speed reducing handpiece.

• It has a vertical movement of 0.4-0.8 mm and a contra-rotational movement, which is restricted to 30°.

Three cutting instruments can be use with it :

• K-file with a safe-ended tip for narrow canals.• A more aggressive H-file.• A flexible H-file with a safe-ended tip.

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Group II: low speed rotary instruments

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• BursIn addition to conventional burs, burs with extended shanks for low-speed contraangle handpieces are useful for providing good visibility during deep preparation of the pulp chamber.

Various surgical length burs. The longer length of these burs

allows a direct view

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Gates Glidden Drill: This has a long, thin shaft ending in a

flame-shaped head with a non-cutting safe tip to guard against perforation. It is ade of hardened carbon steel.

Uses:• For initial opening of the canal-

orifices.• To remove the lingual shoulder in

anterior teeth.• Coronal flaring in coronal-apical BMP

technique.

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• This instrument was designed to have a weak spot in the part of the shaft closest to the handpiece, so that, if the instrument separates, the separated part can be easily removed from the canal.

• The flame shaped head cuts laterally and is used with a gentle, apically directed pressure. It has a modified safe tip i.e. non-cutting tip.

• These instruments come in sizes 1 to 6.

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SizesNo. 1 .50 mmNo. 2 .70 mmNo. 3 .90 mmNo. 4 1.10 mmNo.5 1.30 mmNo.6 1.50 mm

Speed – 750-1500 rpm.

Length- 28mm, 32mm.

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PEESO REAMER • It has long sharp flutes with a safe tip connected to a thick

shaft.

• It is most often used in preparing the coronal part of the root canal for a post and core.

• It cuts laterally and hence may cause perforation if used injudiciously.

• These instruments are also available in no.1 to 6.

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SizesNo. 1 .70 mmNo. 2 .90 mmNo. 3 1.10 mmNo. 4 1.30 mmNo.5 1.50 mmNo.6 1.70 mm

Speed – 750-1500 rpm.

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GPX gutta-percha remover

• It is a rotary instrument for the removal of compacted gutta-percha.

• This device break up and removes gutta-percha from the

canal, facilitating retreatment procedures.

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Flexogate • Flexogates (Dentsply/Maillefer; Tulsa,

Olka) are Modified gates-glidden designed for apical preparation.

• It consist of a smooth, flexible shank which is circular and is small in cross section.

• Flame shape head• Non cutting tip• Weak spot at the neck• Landed design

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Group III: engine-driven nickel titanium rotary instruments

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• The greatest innovation in endodontic instrumentation in recent times is probably the introduction of nickel titanium rotary instruments .

• These instruments are entirely fabricated by a machining process, in contrast to the twisting of tapered wire blanks that has been used for the traditional manufacturing of stainless steel instruments.

• The widespread popularity of nickel-titanium (NiTi) rotary instruments arises from the relatively low elastic modulus of the nickel titanium alloy, which permits use of these instruments in curved root canals that would present considerable difficulty for stainless steel instruments .

NICKEL-TITANIUM

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• And this super elastic property of nickel-titanium alloy (Nitinol) was discovered by Buehler and Wang at the US Naval Ordnance Laboratory in the early 1960s.

• The name Nitinol was derived from the elements that make up the alloy, nickel and titanium, and “nol” for the Naval Ordnance Laboratory.

• The alloy used in endodontics is commonly referred to as 55 NiTiNOL.

• It contains about 55 wt% Ni and 45 wt% Ti and substituting some Ni with less than 2 wt% Co, nearly the same number of Ni and Ti atoms are combined, being reflected in the term equiatomic.

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Features of Ni-Ti

a) Shape memory• The NiTi file comes back to its

original straight form without showing any sign of lasting deformation .This is called shape memory.

b) Super/Pseudo elasticity The ability of resisting stress

without permanent deformation and going back to the initial lattice form is called super elasticity.

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• Superelasticity and shape memory of NiTi alloy is because of phase transformation in their crystal structure.

• The alloy exists in two crystallographic forms i.e. parent Austenitic phase which is stronger and stable than the daughter Martensitic phase.

• On heating the alloy undergoes transformation from the Austenitic, (body-centered cubic lattice) stronger and stable phase to the Martensitic phase, (close packed hexagonal phase), i.e. weaker phase, and on cooling it reverts back to Austenitic phase. A similar phase change occurs when the alloy is stressed during root canal treatment.

• On release of stress, the structure reverts back to Austenite. Austenite Martensite Austenite

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Properties of nickel-titanium and stainless steel

PROPERTY NiTi Stainless steel

DENSITY (g/cm3) 6.45 8.03

Biocompatibility EXCELLENT FAIR

Elastic modulous Approx. 48 Gigapascal 193 Gigapascal

Recovered Elongation % 8 % 0.8%

Torqueability EXCELLENT POOR

Ultimate tensile strength Approx 1240 Megapascal Approx 760 Megapascal

Table 5 ( Breme HJ & Biehl V (1998) Metallic Biomaterials. In black: handbook of biomaterial properties

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Advantages over stainless steel:• NiTinol files have 2-3 times more flexibility then stainless

steel (Walia et al 1988).• Superior fracture resistance in clockwise and counter

clockwise torsion.• NiTinol can retain the shape of the curved canal and does

not straighten like stainless steel.• Ni-Ti undergoes large amounts of elastic deformation when

compared to Stainless steel.• Disadvantages compared to Stainless Steel:• Cutting efficiency of NiTinol is only 60% than that of

matching S.S. file.• Does not give any signs of fatigue before they fracture.• More expensive.

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Niti File: Design & Structure

• NiTi flex-files are manufactured from nickel-titanium wire that is ground to give the typical profile of a K-file.

• The tip of the instrument is non-cutting ('batt-tip') which makes the NiTiflex-file well suited for the preparation of curved canals without the risk of ledge formation.

• NiTiflex-files come in sizes 15 - 60, all with a taper of 0.02.• • K-file design is identified by the square symbol on the handle.

And NiTiflex-files can be best distinguished from normal K-files by the code that in NiTiflex-files is printed with two colors.

105

106

Files used in both hand and rotary motions

• PROTAPER FILES• PROFILES• GREATER TAPER FILES

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U-File• A new endodontic classification of instrument, for which there is

no ISO or ANSI/ADA specification as yet, is the U-File, developed by Health (May 3, 1988) and marketed as ProFiles, GT Files (Dentsply/Tulsa Dental; Tulsa, Okla.), LIGHTSPEED (LightSpeed Technology Inc; San Antonio, Tex.), and Ultra-Flex files (Texeed Corp., USA).

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• The U-File’s cross-sectional configuration has two 90-degree cutting edges at each of the three points of the blade.

• The flat cutting surfaces act as a planing instrument and are referred to as radial lands.

• The new U shape adapts well to the curved canal.

• A noncutting pilot tip ensures that the file remains in the lumen of the canal, thus avoiding transportation and “zipping” at the apex.

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PROFILE SYSTEM• Profile system was first introduced by Dr. Ben Johnson in

1994. • It was first sold as the “series 29” stainless steel hand

instruments with 0.02 taper.

• The manufacturer soon developed rotary counterparts due to the canal centering capacity and less aggressive cutting of NiTi.

• The tips of the profile series 29 rotary instruments had a constant proportion of diameter increments by 29 %.

• Further developments included rotary instruments with increasing taper (0.04 taper, 0.06 taper).

•

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Later on profile series with ISO-sized tips and orifice shaper were also marketed.

I] Series 29a) Hand instruments -0.02 taper.b) Rotary instruments -0.04, 0.06 taper.

II] ISO Seriesa) 0.04 and 0.06 taper hand and rotary instruments.

Ⅲ] Profile Orifice shaper 0.05- 0.08 taper.

IV] Profile GT rotary instruments AND hand files

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Cross-sectional geometry

U shape design with radial lands Parallel central core

BULLET shaped noncutting tip

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-ve RAKE ANGLE

Recommended speed: 150-300 rpm- Cleaning & shapingRecommended speed : 1200-1500 rpm for Retreatment

Together with a neutral or slightly negative rake angle this configuration facilitates a reaming action on dentin rather than cutting.

-ve CUTTING ANGLE

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Series 29• The rate of increment between file sizes in this series is

constant i.e. 29%.• length - 21mm, 25mm

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• Profile 0.04 Taper: o Taper- 4%o Length- 21, 25 and31mmo Available Sizes- 15 to 90 No (15, 20, 25,

30, 35, 40, 45,60 & 90)o These are also available as hand

instrumentso For preparing the terminal part of the

canal.o Identification : Presence of a single

colored ring on the shank

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Profile 0.06 Taper o Taper is 6%. For example- 20 no file will have tip diameter

0.20 and diameter at 16 mm will be 1.16.o Length is 21, 25, 31 mmo Available Sizes- 15- 40 Noo For preparing the middle part of the canal.o Identification – Presence of two colored rings on the shank.

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ProFile 0.S.( Orifice Shaper )• It is a preferred instrument for opening up the canal. • Identified by three colored rings.• Taper is 5 to 8%.• Length is 19 mm.• Sizes : NO. 20, 30, 40, 50, 60, 80• Speed - 150 – 350 rpm

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VORTEX• A recent addition to the profile system is the vortex. • The major changes lies is the non landed cross section ,

whereas tip sizes and tapers are similar to existing profile system.

• It is manufactured using NiTi M- wire , exhibiting superior cyclic fatigue resistance.

• Vortex also have varying helical angle to counteract the tendency of non-landed files to thread in to the canal.

• Taper is 0.04 , 0.06 • Sizes- 15 – 50 No

•

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Vortex blue• The distinctive colour of vortex blue rotary files is a visible

titanium oxide layer resulting from processing of NiTi wire for optimum performance.

• The standard NiTi instruments with shape memory have tendency to go back to their original straight position which is not advantageous in curved canals. The processing of vortex blue rotary files reduces shapes memory and increases the resistance to cyclic fatigue. Hence, vortex blue follows the natural curvature of the tooth within the canal.

• Increased torque strength.• Taper – 0.04, 0.06 • Size – 15 -50 No

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GT FILES • The Greater Taper file, or GT file, was introduced by Dr.

Buchanan in 1994.

• It was first produced as a set of four hand-operated files and later as engine-driven files.

• The instruments came in four tapers (#.06, #.08, #.10, and #.12), and the maximum diameter of the working part was 1 mm. The length of cutting flutes was decreased so file has short cutting portion and the taper was increased.

• Cross section of file has triple U with radial lands.

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The current set includes:• 20, 30, 40 Series – taper 4%, 6%, 8%, 10%• Size 50,70,90 - available in 0.12 Accessory Series with 12%

taper. The maximum diameter of these files is 1.5 mm, similar to that of a # 6 GG (gates-glidden)

drill

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GT Hand Files, 20-0.06 (white handle), 20-0.08 (golden handle), 20- 0.10 (red handle),20 – 0.12(blue handle)35-0.12 (green handle),50-0.12 (yellow handle),70-0.12 (green handle).

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VARIABLE PITCH

123

ROUNDED TIP AND LANDED FLUTE DESIGN

Triple U SHAPE CROSS SECTION

=

Negative cutting angleNegative rake angle

Recommended speed-

150-350 r.p.m

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The GT System includes (left to right) GT Hand File, GT Rotary File, GT Gutta Percha, GT Paper, GT Obturator, and GT Post.

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Light Speed Instruments• The LightSpeed file, developed by Dr. Steve Senia and R.

William Wildey in the early 1990s. These are also known as LSI .

• It is an engine driven version of the Ni-Ti Canal Master

'U‘ file .

The unique features include • Short anterior cutting heads• Long, thin noncutting shafts

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• Sizes :• LightSpeed /LSI set consist of totals 26 instruments with sizes

20 to 140 and in lengths of 21 mm, 25 mm, and 31 mm, 50 mm

• LightSpeed instruments also have half-sizes between 20 and 70 (22.5, 27.5, 32.5, 57.5, and 65.5)

• The half-sizes instruments are color-coded exactly as the previous sizes, but also have white or black markings or engraved rings on the instrument’s handles.

• LSX does not have half size files and set consist of size 20 – 80. It can be used with 2500 rpm because of high flexibility.

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• Cutting heads:• Light speed cutting head has three radial lands and three U-

shaped spiral grooves between the radial lands.

• LightSpeed cutting heads are 0.25 mm- 2.25 mm long.

• Size 20-30 – short noncutting pilot tips and a 75-degree cutting angle.

• Size 32.5 -slightly longer noncutting pilot tip and a 33-degree cutting angle.

• Sizes 35 through 140- longer and more slender noncutting pilot tips and a 21-degree cutting angle.

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• Thin shafts, shank and handle:• Instruments have thin, taperless, noncutting shafts. Because of

the thin shaft lightspeed instruments are very flexible thereby reduces the danger of straightening the canal.

• The shank is marked with rings that indicate distances from the instrument’s tip.

• The 21-mm instruments have only one ring on the shank, indicating distance of 20 mm from the tip.

• The 25-mm instruments have three rings indicating distances of 20 mm, 22 mm, and 24 mm from the tip.

• The 31-mm instruments have four rings on the shank, indicating distances of 24 mm, 26 mm, 28 mm, and 30 mm from the tip.

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Design of the instrument

Non cutting pilot tip, U shape design

Non cutting, flexible shaft with markings.

0.25-2.25 mm head

Recommended speed-

1500-2000 r.p.m

Size 20, 32.5, 40

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Principles Of LS Technique

Simplifill gutta percha

RPM –Constant- 1500-2000Require- 1. Straight Line access2. Coronal preparation with # 15,20,253. W.L determination.Progressive larger instruments are used i.e. smaller to larger.

Apical seal: SimpliFill is a solid, 5mm tapered gutta-percha cone attached to a stainless-steel carrier. The carrier is removed from the canal after it condenses the G.P. cone to the working length. The middle and coronal parts of the canal are obturated with the technique of choice.

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• Lightspeed Instrument fracture:

• Fractures may occur at two sites.• One is at the shaft–shank junction

and is due to excessive angulation of the instrument in the canal combined with poor access.

• The second site for fracture is a few millimeters from the cutting head and generally is caused by locking the cutting head in the canal or by excessive speed, which accelerates metal fatigue.

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HERO 642• Introduced by Daryl Green and manufactured by Micro Mega.

• It is the first rotary NiTi instrument designed without radial lands.

• HERO 642 means:

H - High

E - Elasticity

Ro – in Rotation

642 means that it is available in the 0.06, 0.04 and 0.02 taper .

A complete set consists of 12 files

with varying ISO sizes, tapers

and lengths of cutting segments.

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Design features

RECOMMENDED SPEED:

300-600 r.p.m

Triple-helix cross-section

Less negative/Positive cutting angle

Negative rake angle

Non cutting tip

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135

Hero Shaper • It is designed with the same triple-helix cross-section.

• The key modifications in this instrument involve the pitch of the blade and the length of the cutting portion, which vary depending on the taper.

• By modifying these parameters, it is possible to select the strength, efficiency, and flexibility best suited for the taper and the work required of the instrument – this is called as the ‘adapted pitch’ concept.

• Available Sizes and tapers

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4 %

6 %

12 mm

16 mm

25 no file with different taper and different length of cutting portion

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• HERO Apical® are NiTi instruments used to enlarge the apical third of the canal after the canal is prepared with HERO Shaper (ideally) following the normal sequence. Use of HERO Apical® is indicated at the end of canal preparation, with a reducing contra-angle handpiece at a speed of 300 to

600 rpm or manually.

2 instruments are offered:

• No- 30 HERO Apical® (black stop) with .06 taper

• No- 30 HERO Apical® (red stop) with .08 taper

4 mm

6 %

8 %

HERO APICAL

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Uses-• In case of root canal infection, it eliminates the dentine layers

contaminated with bacteria and enables antiseptic solution and temporary medication to be applied. It also improves the root canal sealing.

• It flares the apical third facilitating penetration of plugger and reduces the risk of extrusion of gutta percha beyond the apical limit.

• Both instruments are inserted, one after the other till the apical limit of the preparation (Working Length) . The resultant .08 tapered width ensures a uniform stop for the gutta percha.

• FIRSTLY- .06 WL • THEN .08 WL

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ENDOFLARE It is a Ni-Ti instrument used for coronal flaring.

Available as :-

• Larger Taper .12 with size # 25.

• Blade Length 15 mm

• Safe Non-Active Tip.

• Positive Cutting Angle.

• Excellent Debridement

Rotation speed: 300 - 600 rpm

Endoflare with INGET shaft

Endoflare with CLASSIC shaft

TRIPLE HELIX CROSS SECTION

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TECHNIQUE• 1. Initially open the canal with a Micromega Hand File size No

10, length 21 mm or 25 mm.• 2. Insert ENDOFLARE in the coronal third to a maximum depth

of 3 mm using a gentle back & forth motion.• 3. Irrigate generously.• 4. In complicated cases, press lightly against the chamber walls in

order to selectively debride the area.

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PROTAPER• The ProTaper system (Dentsply/Maillefer) represents a new

generation of NiTi instruments.

• This instrument was designed by Prof. Pierre Machtou, Dr. Clifford Ruddle and Prof. John West in coperation with Dentsply/Maillefer.

• Can be used at 200 to 300 rpm.

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features of protaper Progressive taper Modified guiding tip Varying tip diameters Modified cross-section Varying helical angel and pitches Shorter handle of the file

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Progressive taperProgressive taper - The unique design factor is the varying tapers along the instruments' long axes. This progressively tapered design serves to significantly improve flexibility, cutting efficiency and safety.

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VARIABLE HELICAL ANGLE

Protaper files have changing helical angle and pitch over their cutting blades which reduces the potential of an instrument from screwing into the canal.

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Cross section- Modified K file type with sharp cutting edges and no radial lands .This convex triangular cross section enhances the cutting action while decreasing the rotational friction between blade of the file and dentin. The cross section of F3 finishing file is slightly relieved for increased flexibility.

Protaper have modified non cutting guiding tip that helps in making the file centred in the canal while rotation.

convex, triangular cross-section

cross-section of F3 with a reduced core

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NEGATIVE RAKE ANGLE NEGATIVE CUTTING ANGLE

147

• The ProTaper system originally comprised of just six instruments: three shaping files for the crown-down procedure and three finishing files for apical shaping and creating a smooth transition from the middle one third of the canal.

148

The S-X Shaper is an auxiliary instrument used in canals of teeth with shorter roots or to expand the coronal aspects of the preparation. It is similar to the use of Gates-Glidden drills or orifice openers.

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Instrument design• Shaping files• The first auxiliary shaping file is Shaper X or SX.

• SX is recognized by the lack of an identification ring on its handle and its extraordinary shape, resembling “Eiffel Tower in Paris”.

• All the three shaping files have partially active tips.

• The three shaping files are characterized by increasing taper coronally and the reverse pattern is seen in the three finishing files. They have 14 mm long cutting blades .

• S1 & S2 have tip diameter of 0.17 mm and 0.20 mm respectively, diameter at D14 are 1.2 and 1.1 mm, respectively.

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• The finishing files ( Fl, F2, and F3) are marked with a yellow, red, and blue identification ring, respectively and have tip diameters of 0.20, 0.25 and 0.30 mm, respectively.

• The finishing files have noncutting tips.

F 1 finishing file (size 20) Initial taper of .07 from D1 to D3 Decreased taper of 5.5% from D4 to D14 Maximum flute diameter: 1.13 mm

• F2 finishing file (size 25) Initial taper of .08 from D1 to D3 Decreased taper of 5.5% - 6.0 % from D4 to D14 Maximum flute diameter: 1.2 mm

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• F3 finishing file (size 30) Initial taper of .09 from D1 to D3 Decreased taper of 5.0% - 7.0% from D4 to D14 Maximum flute diameter: 1.2 mm

152

RETREATMENT PROTAPER

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QUANTEC• It was introduced by McSpadden. & Manufactured by Sybron

Endo.

• The original Quantec 2000 series had a 90° tip. This sharp tip appears to predispose problems like zipping, elbow formation and perforations. So, they were replaced.

• Newer Quantec series are available in both QLX Non-cutting (LX) and QSE safe-cutting tip (SC) having 60° tip.

Quantec LX Quantec SC

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Quantec system is available as-

STANDARD HANDLE-With variable taper and constant tip: Length- 17, 21, 25mmTip diameter- 0.25mmTaper- .03, .04, .05, .06

With variable tip and constant taper Length- 21, 25mmTip- 15, 20,25….55,60.Taper- .02

AXXESS HANDLE: it results in an overall height reduction of file over 7mm.

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• Tip Geometry• LX Non-Cutting – The LX pilot tip maintains a central axis and

deflects around severe curvatures.

Ideal for: Routine cases

Severe curvatures

Delicate apical region

SC Safe-Cutting -The Quantec SC features a negotiating tip that cuts as it moves apically, following canal pathways and minimizing stress. • Ideal for: Small, tight canals

Calcified canals

Constricted canals

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• Quantec system had a positive blade angle Hence it shave the dentin rather than scraping.

Two wide radial lands are also present along

with relief behind the lands. This unique design

minimises its contact with the canal thereby –• Reduces rotational friction and torque• Prevent the crack formation • Increases the strength

157

File design

POSITIVE CUTTING ANGLE

NEGATIVE RAKE ANGLE

30 HELICAL ANGLE∘

158

INSTRUMENTS FEATURES• Graduating Tapers

Instruments come in #.02, #.03, #.04, #.05, #.06, #.08, #.10, and #.12 taper. The increasing tapers changes the point at which the file engages the canal wall.

Quantec system utilizes the ‘‘gradual taper technique’’ to prepare a canal, starting with larger tapered file first, progressing with files of lesser taper until working length is established. This technique restricts the contact area of file in contact with canal wall leading to increase efficiency of instrument because forces will be concentrated on smaller area.

159

K3The current K3 system (SybronEndo) was developed in a sequence of further development of the Quantec system by Dr. McSpadden in January 2002.

The most obvious difference between the Quantec and K3 models is the K3’s unique cross-sectional design : a slightly positive rake angle for greater cutting efficiency, wide radial lands, and a peripheral blade relief for reduced friction.

Unlike the Quantec a two-flute file, the K3 features a third radial land which prevents screwing-in of the file. A safety tip is also incorporated into the design .

160

Speed- 300-350 rpm

The instrument is available in #.02, #.04, and #;06 tapers.

A series of body shapers in #.08, #.10, and #.12 is also available.

Body shaper files

K3 canal shaping files

simple color coding to distinguish between different tip sizes and tapers

161

• This instrument has the most positive rake angle of all the instruments currently available and is considered among the most resistant to fracture because of its cross-sectional geometry.

• The third radial land on K3 files stabilizes and keeps the instrument centered in the canal and minimizes over engagement.

Positive rake angleWide radial lands• Peripheral blade relief• Third radial land

Special features

162

• Peripheral Blade • The K3 Blade Relief areas, in addition to reducing frictional

resistance helps to control the depth of cut. This aids in protecting the file from over-engagement, and separations (breakage).

• U-shaped files without such a relief have a greater potential for over-engagement, apical blocking and instrument failure.

Peripheral blade relief to reduce friction and facilitate smoother 

operation

U- FILE K3 file

163

Asymmetrically placed flutes make the k3 system with better canal tracking ability, add peripheral strength and prevent screwing.

164

Variable core diameter This may be better described as variable flute depth. The proportion of the core diameter to the outside diameter is greatest at the tip, where strength is most important. This proportion then decreases uniformly, resulting in greater flute depth and increased flexibility while maintaining strength. An additional benefit to this is that debris is also removed more efficiently.

Variable flute pitch- “Screwing-in’’ occurs as each successive flute naturally follows the path created by the one before. But K3 file hasa variabe pitch that allows debris to effectively move coronally and reduces ‘‘screwing-in’’ effect.

Variable core diameter variable flute pitch

165

Axxess handle

Safe-ended tip

Axxess handle- it allows the operator easier access to the posterior region of the mouth. The K3 files are 4mm shorter, yet the working (fluted) length is the same. 

Safe-ended non-cutting tip -follows the canal system and assists the practitioner in avoiding ledging, perforations and zipping.

166

INCREASED HELICAL ANGLE

The increasing variable helical angle from tip to handle helps reduce the “pull-down” effect and helps in pushing debris coronally. This feature allows continuous instrumentation with little or no interruption from clogged flutes.

167

RaCe• The RACE stands for reamers with alternating cutting edges.• The RaCe was manufactured by FKG and was later distributed in

the United States by Brasseler (Savannah, GA).

• A RaCe has alternating twisted and straight segments, giving a larger space for debris removal and reduces the tendency to screw in the canal.

168

Negative rake angle Negative cutting angle

Speed- 300-600 rpm

169

• Crosssection- traingle or square for small instruments (15/0.02 and 20/0.02) and triangle in remaining larger size RaCe instruments.

• The length of cutting parts vary from 9 to 16mm.

• The tips are round and noncutting.

• The instruments are marked by color-coded handles and milled rings.

170Available in size 15-40 with 0.02, 0.04, 0.06 taper.

171

• The surface quality of the RaCe has been improved by electropolishing, and the two largest files (size #35 with .08 taper and size #40 with .10 taper) are also available in stainless steel.

172

Race system has been incorporated with Safety Memo Disc for controlling NiTi fatigue. It quantifies usage and stress to minimize the overuse and metal fatigue.This disc has petals which are peeled off after every use. Once the petals are over, the file should be discarded. There are 8 petals in each disc. the SMD can be sterilised and never leave the instrument.

173

D RaCeD-Race instruments are used to remove most of the old root filling material from the canals such as gutta-percha, obturators or resin-based material. It removes a large part of the ancient filling material without solvent.

The D-Race set consists of two NiTi files – DR1 and DR2. The first instrument, DR1, has an active tip to allow engagement of the root filling material and is used in the first few millimetres of the coronal and straight part of the canal. Once the access is cleared with the DR1, the second instrument, DR2, is used to reach WL. As this instrument is highly stressed, it is intended for single use.

DR1 –ISO 030/.10L-15/8ACTIVE TIP1000 rpm

DR2 –ISO 025/.04L-25/16NON ACTIVE TIP600 rpm

174

FLEXMASTER• Manufactured by: VDW

• The cutting blades of FM instruments have no radial lands and have round, passive tip.

• Because of their convex cross-sectional profile, it has a more substantial core that reduces the risk of instrument fracture and deformation.

CONVEX TRIANGULAR CORE

round, passive tipsmilled ring markings

175

• Available in #.02, #.04, and #.06 tapers.

• The tip diameters are 0.15 to 0.7mm for #.02 taper instruments and 0.15 to 0.4mm for #.04 taper and #.06 taper files .

• In addition to the standard set, the Intro file, which has a #.11 taper and a 9 mm cutting part is also available.

INTRO FILE9mm cutting part , 11%

Taper+

SPEED- 280

(150-300 rpm)

176

• The manufacturer provides a system box that indicates sequences for narrow, medium size, and wide canals.

177

REAL WORLD ENDO SEQUENCE• Introduced by Brave and Koch.• Triangular cross-section

EndoSequence remains centered without the need for radial lands by incorporating a unique Alternate Contact Point(ACP) geometry into its design which-

• Preserves the natural flexibility of NiTi.• Reduces the torque requirement • Keeps the file centered in the canal .• Prevents self-threading / “screwing in” to canal• Enhances debris removal• Maximizes cutting efficiency

178

No radial lands-

• Flexibility is maximized

• Torque is minimized

Electropolished surface – • promote better fatigue resistance. • Eliminates surface imperfections that weaken other files• Increases file sharpness

Precision Tip- Non-active at the tip, fully

active precisely at 1mm

Works at rotational speed of 450 – 600 rpm.

PRECISION TIP

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Taper – .04 and .06 in three sizes each: small, medium and large.

Available in 0.04 and 0.06 taper having a precision tip.Come in package of four files along with Expeditor file which is

used as a guide in estimating canal size. It comes as #27 with .04 Taper and 21mm length. • Creates coronal flaring while staying centered hence expedites(speed up) the use of subsequent EndoSequence.

Expeditor File

180

Group V: Engine-driven reciprocating files

181

• Examples:• Giromatic :It accepts only latch-type instruments. In this device,

the quarter-turn motion is delivered 3,000 times per minute.• • Instruments available to be used with this handpiece are: Giro pointer -orifice opener (16 mm) Giro reamer. Giro broach. Giro-file with headstroem configuration Heli-Girofile

182

Rasps and broaches are most often used in giromatic handpiece ,but k-type and H-type instruments also can be used.

Endo-Eze file system is recently introduced addition for giromatic handpiece. The set has four instruments .The size and taper are-

0.10 # 0.025 taper,

0.13 # 0.35 taper,

0.13# 0.45 taper ,

0.13# 0.06 taper .

183

Group IV: Engine-driven three dimensionally adjusting file

184

SAF The SAF is a hollow device, designed as a

cylinder of thin-walled, delicate NiTi lattice with a lightly abrasive surface, which allows it to remove dentin with a back-and-forth grinding motion.

The SAF is operated with a KaVo handpiece that generates in-and-out vibrations about 5000 vibrations per minute and 0.4 mm amplitude.

A special irrigation device is connected by a silicon tube to the irrigation hub on the file and provides continuous flow of the irrigant during the procedure, at flow rates of 1 to 10 mL/min.

185

• The SAF is available in two diameters: 1.5 mm and 2 mm. The SAF 1.5 mm is available in 3 standard lengths (21, 25, 31 mm) whereas the SAF 2 mm is available in two lengths (21, 25 mm).

186

File is initially compressed into the canal and gradually enlarges while cleaning and shaping . This unique feature adapts the file to the shape of the canal not only longitudinally but also to the cross-section of the canal. Consequently basic shape of the root canal is preserved.

The absence of a metal core also makes the SAF extremely resistant to fracture.

187

Group VI: sonic and ultrasonic instruments

188

SONICS• These include the Sonic air 1500 and Megasonic 1400.• It impart vibrations in the frequency of between 1500 and 3000

Hz, which is imparted to the file shank.• Air pressure is adjusted to 0.4 Mpa.

• Instruments used:• Rispi files, heli-sonic files, shapers.• Rispi files are used in the coronal two third and shapers are used in

the apical third of the canals.

• These instruments have safe ended non cutting tip with 1.5 to 2 mm in length. The size of these instruments range from 15- 40.

189

• Instruments oscillate outside the canal which is converted in to vibrational up and down movement within the canal.

• The movement of the file creates a form of acoustic microstreaming around the mid shank and at the tip .It is the generation of time independent unidirectional steady circulation of fluid in the vicinity of small vibrating object(file’s tip) .This will result in large hydrodynamic shear stress around the file capable of distrupting most biological materials.

190

ULTRASONICS• There are two methods of generating ultrasonic oscilations in the file

shank:• Magnetostrictive- that converts electromagnetic energy into

mechanical energy. A stack of magnetostrictive metal strips in a handpiece is subjected to a standing and alternating magnetic field, as a result of which vibrations are produced.

• Magnetostrictive units create figures of eight (elliptical movement), which is not ideal for endodontic use and another drawback with these units is that heat is generated, so adequate cooling is required.

• Piezoelectric –this method uses a crystal which changes size when an electrical charge is applied. When the crystal deforms, it goes into mechanical oscillation without producing heat hence does not require water cooling.

• The tips of piezoelectric units work in a linear, back-and-forth, “piston-like” motion, which is ideal for endodontic treatment .

191

• Maximum movement occurs at file tip in both types. Piezoelectric• Instrument used:• modified K files and diamond impregnated file for straight part of

the canal.

• The magnetostrictive can produce a tapered canal preparation.• The piezoelectric may produce apical widening and ledges in

curved canals.

192

RECENT ADVANCES IN ROTARY FILES

C-PILOT files• Manufactured by- VDW.

• High bending strength due to a special thermal hardening process

• The inactive pilot tip conducts the instrument safely along the canal .

• Additional length marking on handle.• Intermediate size ISO 12.5 is also available • Available sizes: ISO 06 to 15 + 12.5

193

194

LIBERATOR FILES

Parallel Grinding Pattern

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• Liberator™ rotary NiTi file manufactured by: Miltex has a unique straight blade design and manufacturing process that eliminates the traditional helical flutes. Hence they have a less tendency to self-thread.

• Liberator files are manufactured with a process using electro-chemical grinding (ECG) techniques, in which a liquid chemical is used that decreases the thermal impact of grinding process. Thus the heat affected zones on the file get reduced, which usually affects surface hardness or brittleness and creates potential for file separation.

• In conventional files the direction of the grinding wheel is perpendicular to the file axis resulting in transverse micro-cracks. These micro-cracks have been attributed to file separation. Hence in liberator files the direction of grinding wheel has been changed from perpendicular to parallel to prevent crack formation.

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• Due to relatively high RPM(1,500-2,000), the abrasion of dentin results in very fine debris particles which can be easily removed by wiping.

• Roane safety tip minimizes ledging and transportation. It also helps the file to remain centered in the canal.

• Available as: • .02 taper- ISO size 15-40, 45-80.• .04 taper- ISO size 15-40, 45-70.• .06 taper- ISO size 15-40, 45-70.• Length- 21, 25 mm.

Roane safety tip

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NiTi Tee

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NiTi-TEE consists of six files with varying taper for use with crown down method.First three files (12/30, 8/30 and 6/30 ) are used as Coronal shapers. The next three files (4/30, 4/25 and 4/20) have the unique S-profile hence they shape the apical portion of the canal quickly and effectively.

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V TAPER• The V-Taper™ Rotary System is a

series of three (3) variable taper NiTi rotary files.

• Manufactured by- Guidance Endo• Safe-Core- Reduces the chance for

instrument fracture• Variable Pitch- Eliminates “screw-

in” effect• Neutral Rake Angle- Eliminates the

gouging action of positive rake angles and heat build-up and inefficiency of negative rake angles.

• No Radial Land- no dragging, friction, heat build-up which can cause breakage

Safe-Core Parabolic Cross-Section

Steps- 1) Glide path using V-Taper Glide-Path hand

files in step back tech :10(V02) 10(V04) ➞ ➞10(V06) repeat➞

2) Coronal flare - 25(V08) 30(V10) ➞ ➞Coronal Shaper :Gates-Glidden, straight, or tapered Pesso.

3) Apical shaping using crown down tech: 30(V10) 25(V08) 20(V06) repeat➞ ➞ ➞

4) Final Shape- 30(V10)-Large Canals 25(V08)-Medium Canals 20(V06)-Small Canal

Non-cutting tip prevents ledging and transportation.

Flex Shaft- Reduces torque, bending forces, and breakage.

30 25 20(V10) (V08) (v06)

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F FILE • Manufactured by: Plastic endo .• Radiopaque• Single Use Only• Size: 20• Taper: 0.04mm• Lengths Available: 21mm, 25mm, 31mm

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Uses :• Diamond coated- hence agitate sodium hypochlorite and remove

remaining dentinal wall debris without further enlarging the canal.

Additional Uses of the F File• Removal of calcium hydroxide dressing • Placement of sealer• Removal of canal debris after post preparation• Placement of post cements

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• The F File should be the last file to be used in a canal before obturation.

• Prior to placement of the F File, the canal should be filled with sodium hypochlorite.

• The F File can be used with 600-900 rpm.

• The working length is set on the F File with a rubber stopper, then the file is placed passively into the canal and circumferentially worked along the dentinal walls with cyclic axial motion (up and down).

• The F file should be used in the canal for approximately 30 seconds, then the canal is flushed with sodium hypochlorite and dried for obturation or placement of an intracanal medicament.

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S5 Rotary Files• Features

1. Short shank (13mm) for better accessibility.2. Progressive flute design - reduces "screw-in" effect.3. Unique "S" profile ensures enhanced debris removal.

• File Dimensions

Set consists of 5 files

File no 1 = .08/30             file no 2 = .06/30              file no 3 = .04/30                               file no 4 = .04/25 file no 5 = .04/20• All 23mm in length (file no1 is only 18mm

in length).

Manufactured by:Sendoline

S- SHAPED CROSS SECTION

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TWISTED FILES3 unique processes to deliver strength and flexibility.• R-phase heat treatment technology- it effects the

molecular phase and properties of Ni-Ti. Thereby resulting crystalline structure maximizes flexibility and resistance to breakage.

• Twisted design, not ground- twisting optimizes grain structure and eliminates micro-fractures formation. However grinding weakens the metal’s structure at the molecular level and creates micro-fractures on the metal surface.

• Advanced surface treatment- it increases the hardness of the file

25/0.08 30/0.06

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ENDOWAVEAdvantages of EndoWave filesFive files for preparationAnti screwing design : the unique‘‘continuous Wave design’’ ensures that file do no screw or jam in to the canal, prevents the file being automatically drawn in to the root canal and reduced the force to be applied by the operator.

Unique safety tip : rounded tip ensures maximum safety when preparing in the apex . The tips follow the canal contour perfectly and prevent canal straightening. No step formation in narrow and curved canals

Optimum cutting edges: triangular design of the files produces sharp cutting edges, which excavate the root canal quickly and efficiently.

Smooth surface texture: files are electrochemically conditioned which increases the metal fatigue resistance and resiliency and durability of the instrument.

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Kit A FOR NORMAL ROOT CANAL

Kit B FOR SEVERLY CURVED ROOT CANAL

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M TWO• Manufactured by: VDW• Simple: one sequence for all types of root canals• Single length: all instruments are brought to full

working length • Simultaneous shaping: M2 cuts automatically while

advancing apically and also laterally when using in a brushing movement.

• Each instrument creates a glide path for the next one.• Two efficient cutting edges. In addition, it is

designed with minimum radial contact as well as large and deep flutes for continuous upwards evacuation of dentine chips.

• Highly flexible due to small core and S –shaped cross section

• Tapers-.04, .05, .06, .07 Length–21,25, 31mm • Sizes- ISO No. 10- 25

BASIC SEQUENCE FILES

(10/.04 , 15/.05, 20/.06, 25/.06)

1 Ring .04 taper Bands(size)

209SPEED- 300 r.p

.m

Negative rake angle Positive cutting angle

“S” shape cross sectionNon cutting tip

Variable helical angle

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M-two Design

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CONCLUSION• From a biological perspective, root canal treatment is

directed toward the elimination of micro-organisms from the root canal system and the prevention of reinfection.

• Technological advances in the form of rotary NiTi instruments have led to dramatic improvements in the ability to shape root canals with potentially fewer procedural

complications.

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REFERENCES• Ingle’s Endodontics: 5th & 6th Edition• Torabinejad & Walton’s Endodontics Principle & Practice: 4th

Edition• Grossman’s Endodontic Practice: 11th Edition• Cohen’s Pathways Of Pulp:9th Edition• Franklin Weine’s Endodontic Therapy:6th Edition• H. R. Pitt Ford’s Problem Solving In Endodontics: 3rd Edition• Mastering endodontic instrumentation (2007) Dr. John T.Mc

Spadden