protaper next 2

7/24/2019 Protaper Next 2

1/5

Trends & Applications DENTALTRIBUNE Asia Pacific Edition No. 7+8/201412

Prof. Peet J. van der Vyver &Dr Michael J. Scianamblo

South Africa & US

According to Bird, Chambers

and Peters,1

rotary nickel-titanium (NiTi) instrumentshave become a standard toolfor shaping root canal systems.Compared with conventionalstainless-steel instruments,these instruments offer severaladvantages. For instance, theyare more flexible and haveincreased cutting efficiency.24

They can also create centredpreparations more rapidly,5, 6 aswell as produce tapered rootcanal preparations that tend tohave less canal transportation.7, 2

However, NiTi instrumentsappear to have a high risk offracture8, 9 mainly because offlexural and torsional stresses

during rotation in the root canalsystem.10, 11

When there is a wide area ofcontact between the cutting edgeof the instrument and the canalwall during rotation, the instru-ment will be subjected to an in-crease in torsional stress.12 Thepreparation of a reproducible

glide path, a smooth passage thatextends from the canal orifice inthe pulp chamber to its opening atthe apex of the root,13 can reducethe torsional stress on root canal

instruments. This way, a continu-ous and uninterrupted pathwayfor the rotary NiTi instrumentto enter and to move freely to theroot canal terminus is provided.The main purpose of a glide pathis to create a root canal diameterthe same size of the first rotaryinstrument used or ideally a sizelarger than that.1416

Another way to reduce tor-sional stress is to incorporate mul-tiple progressive tapers into the in-strument design, as the ProTaperUniversal system (DENTSPLYMaillefer) does, for example. Ac-cording to West,17 the progressivetaper allows for only small areas of

dentine to be compromised. Thisdesign concept also contributes tomaintaining the original canalcurvature.18

The ProTaper Next system wasrecently launched on the dentalmarket. Although it comprises fiveinstruments, most canals can beprepared by using only the first

two. Each file comes with anincreasing and decreasing per-centage tapered design on a singlefile.19 This multiple progressivetaper concept helps to reduce

contact between the cutting flutesof the instrument and the dentinewall, thus reducing the possibilityof taper lock (screw-in effect).It also increases flexibility andcutting efficiency.20

The first instrument in the sys-tem is the ProTaper Next X1 (Fig.1)with a tip size of 0.17 mm anda 4 % taper. This instrument isused after a reproducible glidepath has been created by meansof hand instruments or rotaryPathFiles (DENTSPLY Maillefer).The ProTaper Next X2 (0.25 mmtip with 6 % taper;Fig. 2) can beregarded as the first finishing filein the system, as it leaves the pre-

pared root canal with adequateshape and taper for optimal irriga-tion and root canal obturation.Both the X1 and X2 have an in-creasing and decreasing percent-age tapered design over the activeportion of the instruments.

The last three finishing instru-ments are the ProTaper Next X3

(0.3 mm tip with 7 % taper;Fig. 3),ProTaper Next X4 (0.4 mm tip with6% taper; Fig. 4) and ProTaperNext X5 (0.5 mm tip with 6 % taper;Fig. 5). All three have a decreasing

percentage taper from the tip to theshank. They can be used to eithercreate more taper in a root canal orprepare larger root canal systems.

Another benefit of this systemis that the instruments are man-ufactured from M-Wire and notfrom a traditional NiTi alloy.Johnson et al.21 demonstrated thatthe M-Wire alloy can reduce cyclicfatigue by 400 % compared withsimilar instruments manufac-tured from conventional NiTi al-loys. This allows for instrumentsthat are more flexible, increasedsafety, and protection againstfracture of the instruments.22

The last major advantage ofroot canal preparation with theProTaper Next system is that mostof the instruments have a bilateralsymmetrical rectangular cross-section(Fig. 6)offset from the cen-tral axis of rotation (except in thelast 3 mm of the instrument,D0D3). The exception is the Pro-Taper Next X1, which has a square

cross-section in the last 3 mm seg-ment to give the instrument a bitmore core strength in the narrowapical part.

This design feature results ina rotational phenomenon knownas precession or swagger,23whichfurther minimises the engage-ment between the instrument andthe dentine walls for reduced taperlock, screw-in effects and stress onthe file. The removal of debris oc-curs in a coronal direction (Fig. 7)because the off-centre cross-sec-tion allows for more space aroundthe flutes of the instrument. Thisleads to improved cutting effi-ciency, as the blades remain incontact with the surrounding den-tine walls. This way, root canalpreparation is faster and requiresless effort.

The swaggering motion of theinstrument initiates the activationof the irrigation solution duringcanal preparation, further im-proving debris removal. Every in-strument is capable of cutting alarger envelope of motion (largercanal preparation size; Fig. 6)compared with an instrument ofsimilar size with a symmetrical

Fig. 2 Fig. 3Fig. 1

Fig. 5 Fig. 6Fig. 4 Fig. 7

Fig. 13a Fig. 13b Fig. 14a Fig. 14b Fig. 15a Fig. 15b

Fig. 9aFig. 8 Fig. 9b Fig. 10 Fig. 11 Fig. 12a Fig. 12b

Clinical guidelines for

the use of ProTaper Nextinstruments (Part I)


2/5

DENTALTRIBUNE Asia Pacific Edition No. 7+8/2014 Trends & Applications 13

mass and axis of rotation. Thisallows the clinician to use fewerinstruments in preparing a rootcanal, as well as adequate shapeand taper for optimal irrigationand obturation. Moreover, there isa smooth transition between thedifferent sizes of instruments asthe instrument sequence itselfexpands exponentially.

Clinical guidelines forProTaper Next instruments

The clinical technique forProTaper Next will be discussedin the following case reports. Thefirst example will outline the basicguidelines for the use of ProTaperNext instruments.

Case report 1The patient, a 64-year-old

male, presented with a previouslyconducted emergency root canaltreatment on his maxillary left firstpremolar. A periapical radiographshowed evidence of three separateroots and a large periapical lesion(Fig. 8). According to the patient,

the tooth was left open to allow fordrainage by his dentist who hadperformed the emergency rootcanal treatment.

Guideline 1:

Create straight-line access

and remove triangles of dentine

It is very important to preparean adequate access cavity that willallow straight-line access into

each root canal system. However,in this clinical case, there was stilla dentine triangle obscuring directaccess to the distobuccal rootcanal system(Figs. 9a & b). The #3Start-X tip (DENTSPLY Maillefer)was used to remove some of thisdentine on the pulp floor (Fig. 10)for more direct access to the disto-buccal root canal orifice.

A micro-opener (10.06) wasused to locate and enlarge the dis-tobuccal and mesiobuccal canalorifices (Fig. 11). For improvedradicular access, the SX instru-ment from the ProTaper Universalsystem was employed (Fig. 12a).Introducing the file into the coro-nal portion of the root canal isrecommended to ensure that thefile can rotate freely. Restrictivedentine is then removed by usinga back stroke outward brushingmotion. This step will also relocatethe canal orifices more mesially ordistally (away from furcal danger)and pre-flare the canal orificesto provide complete straight-line

access to the root canal system(Fig. 12b).

Guideline 2:

Negotiate the canal to patency and

create a reproducible glide path

The authors of the article pre-fer to negotiate the root canal withsize 08 or 10 K-files until apicalpatency is established (Fig. 13a).This is the ability to pass small

K-files (0.51.0 mm) passivelythrough the apical constrictionand beyond the minor diameterwithout having to widen it.24

Length determination should beperformed with a Propex Pixi apexlocator (DENTSPLY Maillefer).Predictable readings can beachieved by using two size 10 K-filesin the mesiobuccal and distobuc-

cal root canals, and a size 20 K-filein the larger palatal root canal.The results have to be confirmedradiographically (Fig. 13b).

After working length determi-nation, a reproducible glide pathshould be established. It is recom-mended that the stainless-steelK-files be used in an in-and-outmotion vertically with an ampli-tude of 1 mm, gradually increasingthe amplitude as the dentine wallwears away and the file advancesapically.13West also recommendsa super-loose size 10 K-file as theminimum requirement. In orderto confirm that a reproducibleglide path has been established,

the size 10 file should be taken tofull working length(Fig. 14a). Thefile is then withdrawn 1 mm andshould be able to slide back toworking length by applying lightpressure with the finger. Then, thefile is withdrawn 2 mm and shouldbe able to slide back to workinglength using the same protocol.Once the file can be withdrawn45 mm and slides back to working

length (Fig. 14b), a reproducibleglide path has been established.25

The reproducible glide pathshould then be enlarged by usingrotary PathFiles. The #1 PathFile(0.13 mm tip size) should be takento full working length while oper-ating at 300 rpm and 5 Ncm torque(Fig. 15a). Once the file has

reached working length, the au-thors recommend brushing lightlyoutwards against one side of thecanal wall. The file should then bepushed back to working lengthand brushed outwards againstanother part of the canal wall. Thisprocedure should be repeated fourtimes (touching the canal wall ina mesial, distal, buccal and lingualdirection). Then, the #2 PathFile(0.16 mm tip size) should be usedin accordance with the same pro-tocol (Fig. 15b). In most cases,it is only necessary to enlarge theglide path to the second PathFile(0.16 mm), as the X1 has a tip sizeof ISO 17. However, using the#3 PathFile (0.19 mm tip size) for

more challenging root canal sys-tems is recommended.

Guideline 3: ProTaper Next

preparation sequence

Sodium hypochlorite (NaClO)and the ProTaper Next X1 instru-ment should be introduced intothe root canal. The authors foundthat there are five scenarios withthe X1: easy root canals, more

difficult and longer root canals,very long and severely curved rootcanals, as well as large-diameterroot canals and root canals forretreatment for which the use ofthe X1 is not necessary and canalpreparation can be initiated withthe ProTaper Next X2, X3, X4 or X5.The last two scenarios will bediscussed later in the article.

In the case of easy canals(a mesiobuccal root canal in thiscase report), the X1 (operating at300 rpm and torque of 2.8 Ncm)should slide down the glide pathup to working length (Fig. 16a).If this is possible, the instrumentshould be pulled back to approxi-mately 23 mm short of workinglength, followed by a deliberateback stroke outward brushingmotion, away from any externalroot concavities, to create morespace in the coronal aspect of theroot canal (Fig. 16b). Finally, thefile should be taken to full work-ing length and touch the apex.Brushing outwards (coronally)

with the file in the apical third ofthe root canal is recommended.This touch-and-brush sequencecan be repeated up to three or fourtimes (Fig. 16c).

For more difficult and longercanals (a distobuccal root canal inthis case report), the X1 should

Fig. 18a Fig. 18b Fig. 18c Fig. 19 Fig. 20 Fig. 21a Fig. 21b

Fig. 22a Fig. 22b Fig. 22c Fig. 23 Fig. 24 Fig. 25 Fig. 26

Fig. 16a Fig. 16b Fig. 16c Fig. 17a Fig. 17b Fig. 17c

page 14DT


3/5

slide down the glide path untilit meets resistance (Fig. 17a).

A deliberate back stroke outwardbrushing motion removes restric-tive dentine at this level, awayfrom any external root concavities.

This motion will create more lat-eral space, enabling the file to slidea few more millimetres down theroot canal towards working length

(Fig. 17b). If the file ceases toprogress apically, the file should beremoved. After cleaning the flutes,the canal should be irrigated, reca-pitulated and re-irrigated beforecontinuing with the shaping. Thisprocedure should be repeateduntil the file reaches full workinglength. In order to completethe canal preparation, the fileshould be taken to full workinglength (Fig. 17c), followed by thetouch-and-brush sequence, whichshould be performed up to three tofour times.

After the use of the X1, it isrecommended that the canal beirrigated with NaClO, recapitu-lated with a small patency fileto dislodge cutting debris andre-irrigated to flush out all of thedislodged debris from the rootcanal (Figs. 18ac).

ProTaper Next X2The instrument (25.06) should

be taken to full working lengthusing the same protocol discussedabove. However, using the touch-and-brush sequence in the apicalpart of the root canal only two tothree times is recommended asa final step (Fig. 19), as excessiveuse can lead to transportation of

the root canal. The root canalshould again be irrigated, recapit-ulated and re-irrigated.

Gauging of the apical foramen

to determine whether

the preparation is complete

A 25.02 NiTi hand file(DENTSPLY Maillefer) should beintroduced to full working length(Fig. 20). If the file is snug atworking length, it indicates thatthe apical foramen has been pre-pared to ISO 25 and the canal isadequately shaped.

The palatal root canal in thepresent case report was preparedwith the X1 and X2. In this case, it

was found that the 25.02 NiTi handfile was loose at length and it couldbe pushed past working length(Fig. 21a) after canal preparationwith the X2. This indicated that theapical foramen was still largerthan 0.25 mm. In these situations,gauging the foramen with a 30.02NiTi hand file (Fig. 21b) is recom-

mended. If the 30.02 file is snug atlength, the shape is complete.

If the 30.02 instrument fitstightly but is short of full workinglength (Fig. 22a), continuing withcanal preparation with the X3(30.07; Fig. 22b) and gaugingagain with the 30.02 NiTi handinstrument (Fig. 22c) is recom-mended.

Guideline 4:

Shaping recommendations for

the ProTaper Next X3, X4 and X5

The X3, as well as X4 and X5,

if necessary, is used in the samemanner as the X1 or X2, with theexception that the apical prepara-tion is performed using the touch-and-brush sequence only onceor twice in the apical third of theroot canal. Apical gauging is per-formed according to the protocolusing a 30.02, 40.02 or 50.02 NiTiinstrument. The 30.02 instrumentfitted snugly at working length inthe palatal root canal in the presentcase report. The canals were obtu-rated with X2 gutta-percha pointsin the mesiobuccal and distobuc-cal root canals and an X3 gutta-percha point in the palatal rootcanal as master cones using theCalamus Dual obturation unit

(DENTSPLY Maillefer).Figure 23demonstrates the result aftercanal obturation.

Preparation sequence for very

long and curved root canals

In selected clinical cases,the clinician might find thatthe ProTaper Next X1 does notprogress to full working lengtheven after several coronal circum-ferential brushing motions. Theauthors then recommend creatingmore coronal shape using the X1,followed by the X2 up to two-thirds of the canal length. Thispreparation sequence will createenough lateral space in the coro-nal two-thirds of the root canal to

ensure that the X1 can be takento full working length without anydifficulty.


female, presented with pain in


The 36th Australian Dental Congress

Brisbane Convention and Exhibition Centre - an AEG 1EARTH venue

Wednesday 25th to Sunday 29th March 2015

Invitation from the Congress Chairman

On behalf of the Local Organising Committee of the 36th Australian Dental Congress,

it is with great pleasure that I invite you to attend Congress and enjoy the river city of Brisbane.

Over three and a half days, highly acclaimed International and Australian speakers supported by contemporary

research, will present a wide range of subjects relevant to practice. These presentations will be complimented

by hands on workshops, Lunch and Learn sessions, specific programmes for members of the dental team.

Social activities will be available for relaxation purposes.

The Brisbane Convention and Exhibition Centre is adjacent to the Southbank Precinct on the banks of

the Brisbane River. Nearby is the Queensland Performing Arts Complex, the Queensland Museum and

the Queensland Art Gallery and Gallery of Modern Art. A comprehensive industry exhibition will be

held alongside the Congress enabling delegates access between scientific sessions to view

the latest in equipment and materials.

Come and join us for the scientific programme, the opportunity to meet

colleagues and the experience Brisbane has to offer.

Dr David H Thomson

Congress Chairman

36th Australian Dental Congress

Educating for Dental Excellence

facebook.com/adacongress twitter.com/adacongress youtube.com/adacongress adc2015.com

Titanium sponsor:

AD

page 16DT

Fig. 30a Fig. 30b Fig. 30c Fig. 31a Fig. 31b Fig. 31c Fig. 31d

Fig. 27a Fig. 27b Fig. 27c Fig. 27d Fig. 28a Fig. 28b Fig. 29a Fig. 29b

fl page 13DT


4/5

The recognition is inspiring. Every year since

the inception of the Townie Choice awards,

doctors have voted A-dec best in class

across multiple dental-equipment categories.

Thats more than a vote of confidence. Its a

testament to A-dec quality from those whoknow best.

To learn more, call 1.503.538.7478 or

visit a-dec.com/DentistsChoose.

Honored

2014 A-dec Inc.

All rights reserved.

Best

Operatory

Lights

(2003-2013)

Best

Patient

Chairs

(2003-2013)

Best

Waterline

Systems

(2003-2013)

Best

Stools

(2003-2013)

Best

Operatory

Delivery

Systems

(2003-2013)

Best

Dental

Cabinetry

(2008-2013)


5/5

her mandibular right first molar,which had a history of emergencyroot canal treatment. The tempo-rary restoration had broken downand was leaking, possibly result-ing in coronal leakage.

A periapical radiograph re-vealed very long and curvedmesial roots. Also visible on theradiograph was evidence of den-tine triangles that preventedstraight-line access to the mesialroot canals (Fig. 24).

The defective temporaryrestoration and caries were re-moved before the tooth wasrestored with composite anda new access cavity was prepared.The dentine triangles on themesial aspect of the canal orifices(Fig. 25)were removed with theProTaper Universal SX instrument.

Figure 26shows the radiographicview of the length determination,confirming straight-line accessto the root canals.

As mentioned before, the clin-ical protocol in cases with very

long and curved root canalswould be to allow the X1 toprogress to about two-thirds ofthe canal length (Fig. 27a). Thisis followed by the irrigation, re-capitulation and re-irrigationsequence with NaClO. The X2 isused in the same manner (withcircumferential outstroke brush-

ing motions) to the same length(Fig. 27b). The canal preparationis then continued with the X1to full working length (Fig. 27c)using the previously mentionedtouch-and-brush sequence. Final -ly, the X2 is taken to full working

length (Fig. 27d) after irrigation,recapitulation and re-irrigation ofthe root canal.

The canals were gaugedaccording to the technique de-scribed before and final prepa-ration was performed up to the X2in the mesial root canals and up

to the X3 in the distal root canal.GuttaCore verifiers (DENTSPLYTulsa Dental Specialties) werefitted(Fig. 28a) to working lengthto confirm the size of the obturatorfor each canal before the canalswere obturated with the corre-

sponding GuttaCore obturators.Figure 28b shows the result afterobturation.

Shaping recommendations

for large-diameter root canals

or retreatment of root canals

If the first file to workinglength is a size 20 K-file and it is

loose up to working length, theshaping procedure can be initi-ated using the X2 (25.06). If thefirst file to length is a 25/30, 30/35or 40/45 and it is found to be loosein the canal up to working length,the shaping procedure can beinitiated with the X3 (30.07), X4(40.06) or X5 (50.06), respectively.


female, presented with pain anddiscomfort in her maxillary rightcentral incisor. The radiographicexamination revealed that pre-vious root canal treatment hadbeen conducted poorly. Therewas also evidence of a large peri-

apical area (Fig. 29a).

After removing the gutta-percha, it was possible to take asize 35 K-file to working length(Fig. 29b). Root canal preparationwas initiated by preparing theroot canal to working length withthe X4 (40.06; Fig. 30a). Apicalgauging with a 40.02 NiTi handfile established that the tip of thefile was loose at length and able totravel past the predeterminedworking length (Fig. 30b) andthat a 50.02 NiTi hand file was un-able to reach full working length,penetrating to about 2 mm shortof working length (Fig. 30c). Thisindicated that the apical foramen

size was between 0.40 and 0.50 mm.The root canal was enlarged withthe X5 (50.06; Fig. 31a) andgauged again with a 50.02 handNiTi file. It was found that the50.02 instrument fitted snuglyat working length (Fig. 31b),indicating that the shape wascomplete. The prepared canalwas obturated with a ProTaperNext X5 gutta-percha pointusing the Calamus Dual.Figures31c & d show the result afterobturation.

Editorial note: A complete list of refer-ences is available from the publisher.

Part II of this series will discuss the man-agement of complex root canal systems

with the ProTaper Next system.

DT


Prof. Peet J. vander Vyver is anex t r aor d i n ar yprofessor at theDepartment ofOdontology of theUniversity of Pre-torias School of

Dentistry in South Africa. He canbe contacted at [email protected].

Contact Info

Dr Michael J.

Scianamblo isan endodontist inthe US and thedeveloper of Crit -ical Path Tech-nology. He canbe contacted at

[email protected].

Contact Info

fl page 14DT

#1RetractionPaste

intheUSA! 2

Try it!

Say goodbye to cord! Traxodent is much easier, saves significant time,

and dramatically reduces bleeding compared to packing cord. When

used with a retraction cap, Traxodent effortlessly displaces tissue with

greater patient comfort. Traxodent is gentle, absorbent and effective for

hemostasis in restorative bonding procedures as well.

When a 1- to 2-mm-deep subgingival preparation finish line is

formed on a healthy gingival margin, the displacement paste

(Traxodent) and cap application may be the first choice, givingthe benefits of hemostasis, time saving and ease of application.1

Patient bites on retractioncap after Traxodent issyringed onto sulcus.

Prepped tooth beforerinsing

After 2 minutes, removecap and Traxodent iseasily rinsed.

Premier Dental Products Company 888-670-6100 www.premusa.com Restorative

Try it! Traxodent Starter Pack - 7 syringes and 25 FREE retraction caps!Available through your a uthorized Premier dealer.

AD

protaper next 2

Documents