ProTaper – System

The Pro Taper System ( Dentsply Maillefer Ballaigues, Switzerland ) represents a

new generation of NiTi instruments currently available. The system was developed by a

group of endodontists ( Prof . Pierre Machtou ,Dr. Clifford Ruddle, and Prof .Jone West.)

in corporation with Dentsply Maillefer. Compared to other systems, these files

demonstrate completely new file features it has been designed by François Aeby and

Gilbert Rota. [36]

The distinguishing feature of the ProTaper System is the progressively variable

tapers of each instrument that develop a “progressive preparation” in both vertical and

horizontal directions. Under use, the file blades engage a smaller area of dentin, thus

reducing torsional load that leads to instrument fatigue and file separation. “Taper lock”

is reportedly reduced, extending a newly found freedom from concern about breakage.

This instrument system, consisting of three “shaping” and three “finishing” files; But

very recently there was addition of 2 more Accessory finishing files to this original

ProTaper system, along with 3 retreatment files. It is being marketed as ProTaper

Universal.

According to the developers, ProTaper nickel-titanium rotary files substantially

simplify root canal preparation, particularly in curved and restricted canals. Hand

ProTaper kit is also available.

Original ProTaper file design along with ProTaper Universal [74] additional

finishing files will be elaborated in this draft. For Retreatment files design refer in Rotary

NiTi in retreatment.

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File Design Features : ProTaper instruments have a convex triangular cross-

section which reduces the contact area between the file and dentin. fig

But F-3, F-4, & F-5 has a reduced cross- sections with a U- shape to facilitate a

higher degree of flexibility. Fig

Improved cutting efficiency has been safely incorporated through balancing the

pitch and helical angles for better removal of debris out of the root canal and prevent the

instrument from screwing into canal.

Modified guiding tip and the variable tip diameters allow the files specific cutting

action in defined areas of the canal with out stressing the instrument in other sections.

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ProTaper Configurations :

1) Three shaping files ---------------------- S X, S1 & S2

2) Three + Two finishing files ------------------ F 1, F 2, F3 + Accessory finishing files

F 4 & F 5

All files are available in 21 mm ,25 mm and 31mm lengths.

Shaping Files. The Shaping Files are labeled S-X, S- 1, and S-2.

The S-X Shaper is an auxiliary instrument used in canals of teeth with shorter

roots or to extend and expand the coronal aspects of the preparation, similar to the

use of Gates-Glidden drills or orifice openers.

The Auxiliary Shaping instrument (Sx) has no identification ring on its gold-

colored handle and a shorter overall length of 19 mm. The Sx has a D0 diameter

of 0.19mm and a D14 diameter approaching 1.20 mm. The shaping instruments

have increasingly larger percentage tapers over the length of their cutting blades

allowing each instrument to engage, cut and prepare a specific area of the coronal

aspect of canal relocates canal orifices resulting in straight line access. Sx has a

much quicker rate of taper between D1 and D9 as compared with the other

ProTaper Shaping files.

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The S-1 and S-2 files start at tip sizes of 0.17 mm and 0.20 mm, respectively, and

each file gains in taper up to 1.2 mm. But unlike the consistent increase of taper

per millimeter in the ISO instruments, the ProTaper Shapers have increasingly

larger tapers each millimeter over the 14 mm length of their cutting blades. This

is what makes the instruments unique.

Shaping File S-1 is designed to prepare the coronal one-third of the canal,

whereas Shaping File S-2 enlarges and prepares the middle third in addition to

the critical coronal region of the apical third.

Finishing Files. The three finishing F-1, F-2, F-3 + 2 Accessory finishing files F-4, F-5

have been designed to plane away the variations in canal diameter in the

apical one-third.

F-1, F-2, F-3 have tip diameters (D0) of ISO sizes 20, 25, and 30, respectively.

Their tapers differ as well. Between D0 and D3, they taper at rates of 0.07, 0.08,

and 0.09 mm/mm, respectively. From D4 to D14, each instrument shows a

decreased taper that improves its flexibility.

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F-4, andF-5 Accessory files are added under the name ProTaper Universal these

files has have tip diameters (D0) of ISO sizes 40 and 50 tapers differ between D0 and

D3, they taper at rates of 0.06 and 0.05mm/mm respectively. Note:- Redaction in

taper form of these F-4 and F-5 .

ProTaper Benefits.

1. The progressive (multiple) taper design improves flexibility and “carving”

efficiency, an important asset in curved and restrictive canals.

2. The balanced pitch and helical angles of the instrument optimize cutting

action while effectively augering debris coronally, as well as preventing the instrument

from screwing into the canal.

3. Both the “shapers” and the “finishers” remove the debris and soft tissue

from the canal and finish the preparation with a smooth continuous taper.

4. The triangular cross-section of the instruments increases safety, cutting

action, and tactile sense while reducing the lateral contact area between the file and the

dentin. The modified guiding instrument tip can easily follow a prepared glide path

without gouging side walls.

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Canal Preparation.

ProTaper System: Guidelines for Use

1. Establish a smooth glide path with No. 10 and No. 15 stainless steel hand files.

2. Use maximum magnification to observe the movement of the rotary instrument.

“Seeing” rotary apical movement is safer than simply “feeling” such movement.

3. Use a torque- and speed-controlled electric motor, powering the handpiece at 200

to 300 rpm.

4. Be much gentler than with hand instruments. Always treat in a moist canal.

Irrigate frequently!

5. Slow down! Each instrument should do minimal shaping. Only two, three, or four

passes may be required for the file to engage restrictive dentin and carve the shape

to the proper depth.

6. Instruments break when flutes become loaded or when instruments are forced.

Check the flutes frequently under magnification and clean them. Cyclic fatigue

from overuse, or if the glide path is not well established, also leads to breakage.

7. ProTaper instruments are disposable and, like all endodontic files and reamers,

are designed for single- patient use. Sometimes instruments are even changed

within the same treatment (eg, in the case of a four-canal molar).

8. Irrigate with 17% EDTA or a viscous Chelator during the ProTaper shaping.

ProTaper System: Directions for Use

1. Establish proper access and a glide path with No. 10 and No. 15 stainless steel

files to the working length or the apical constriction exit.

2. Flood the canal and chamber with sodium hypochlorite and begin shaping with

the Shaper S-1 using multiple, passive-pressure passes. Go no deeper than three-

quarters of the estimated canal length. Irrigate and recapitulate with a No.10 hand

file, establishing patency to full working length. Now, with S-1, extend the

preparation to full working length. Again irrigate and recapitulate.

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3. “Brush” with the Shaper S-X to improve the straight-line access in short teeth or

to relocate canal access away from furcation in posterior teeth.

4. Shaping file S-2 is now used to full working length. Irrigate, recapitulate, and re-

irrigate.

5. Confirm and maintain working length with a hand file. (Remember, as curves are

straightened, canals are shortened.)

6. With Finisher F-1, passively extend the preparation to within 0.5 mm of the

working length. Withdraw after one second! And only one second! The F-1 has a

tip size of 0.20 mm, and if a No. 20 hand instrument is found to be snug, the

preparation is finished. With the instrument in place, radiographically verify the

exact length before final irrigation.

7. If the F-1 and the No. 20 hand file are loose, continue the preparation with the

Finisher F-2, which is 0.25 mm diameter at the tip. Confirm with a No. 25 hand

instrument and, if snug, confirm the length radiographically and irrigate.

8. If the F-2 instrument and the No. 25 hand file are loose, continue the preparation

to just short of the working length with the Finisher F-3 file, which has a 0.30

mm tip diameter, and follow with the confirming No. 30 instrument. If the No. 30

is found to be snug, the preparation is finished. Frequent irrigation and file

cleansing are imperative— irrigation and recapitulation.

9. Use F-4 and F-5 for finishing wider apical areas.

A study using micro - CT showed that the ProTaper created consistent shapes in

constricted canals without obvious preparation errors, although wide canals may be

insufficiently prepared with this system. O.A.Peters et al, concluded in an in Vitro study

that, ProTaper instruments may be more effective in shaping narrow canals than wider,

immature canals. [37]. To attend this above problem probably two more finishing files F-

4 & F-5 are added to the original instrumentation.

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In a comparison of ProTaper and K3 instruments (Sybron Endo, Glendora, CA),

Bergmans et al [38] found few differences, with the exception of some transportation by

the ProTaper into the furcation region.

J-Y Blum,et al [39] in a study by using Endographe have found that the ProTaper

shaping files are best used with lateral forces to decrease the coronal screwing effect. The

ProTaper finishing files should be used with slow penetration and be introduced only into

canals that have a confirmed smooth and reproducible glide path.

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