idzahi 2014 journal of endodontics

8/11/2019 Idzahi 2014 Journal of Endodontics

1/4

Interference of Electronic Apex Locators with ImplantableCardioverter DefibrillatorsKarim Idzahi, DDS,*Carel C. de Cock, MD, PhD,

Hagay Shemesh, DDS, PhD,*

and Henk S. Brand, PhD

Abstract

Introduction: The purpose of this in vitrostudy wasto evaluate the potential electromagnetic interferenceof electronic apex locators (EALs) on implantable cardi-overter defibrillators (ICDs). Methods: Four differentEALs were tested for their ability to interfere with thecorrect function of 3 different ICDs. Each ICD was placedin a plastic container with 1.5 L physiological saline, andthe EAL unit was placed at a distance of 2.5 cm from theICD. The file electrode and lip clip were placed directly

against the ICD. The EAL was turned on for 30 secondswhile continuously showing the APEX mark. Asa negative control, the ICD was tested without EAL for30 seconds. An electrosurgical unit served as a positivecontrol. During each test, the ICD output was monitoredcontinuously by real-time telemetry, and after comple-tion of the experiment, intracardiac electrocardiogramswere printed. The tests were repeated 3 times foreach device. The electrocardiograms were examinedfor interference on ICD ventricular activity. Results:All EALs tested and the negative control failed toproduce electromagnetic interference in each of theICDs tested. The electrosurgical unit induced interfer-

ence in the ICDs, which were detected as episodes ofventricular tachycardia and led to the initiation of elec-trical shocks in all ICDs. Conclusions: The 4 EALs testeddid not interfere with the correct functioning of ICDsin vitro. (J Endod 2014;40:277280)

Key WordsElectromagnetic interference, electronic apex locator,implantable cardioverter defibrillator

Pacemakers and implantable cardioverter defibrillators (ICDs) are small lithiumbatteryoperated electronic devices that are surgically placed under the skin usuallynear the left clavicle. They have flexible insulated wires (leads) that run through theveins to the heart and monitor the heart rate continuously to detect heart rhythm disor-ders (arrhythmias). There are 2 basic kinds of arrhythmias: the heart rate could eitherbe too slow (bradycardia) or too fast (tachycardia).

A pacemaker is implanted in patients with symptomatic bradycardia. It gener-ates an electrical impulse to the heart muscle to maintain an adequate heartrhythm. The ICD is similar to a pacemaker, but it can also detect and restore

a tachycardia. It uses electrical pulses or shocks to prevent sudden death fromcardiac arrest caused by life-threatening abnormal heart rhythms. When a ventric-ular tachycardia or ventricular fibrillation is detected, the ICD delivers a preciselycalibrated electrical shock to terminate the arrhythmia and restore the normalheart rhythm.

Pacemakers and ICDs are both potentially sensitive to electromagnetic interfer-ence (EMI) from external sources. These electromagnetic signals have the potentialto be interpreted by an implanted pacemaker as electrical noise, resulting in inhi-bition of pacing or asynchronous pacing. In case of an ICD, the electromagneticinterference may result in the inappropriate delivery of a shock. This inappropriatetherapy has a major influence on quality of life and is even associated withincreased mortality(1). Therefore, patients with an ICD are recommended to avoidthe use of cellular phones, metal detectors, and electrocautery devices close to their

ICD(2, 3).Over the last decades, there has been a debate whether dental equipment could

interfere with the correct functioning of pacemakers and ICDs. Some authors statethat electronic dental equipment can interfere with correct functioning (47),whereas others conclude that dental equipment has no significant effect(810).

An electronic method for root length determination during root canal treatmentwas first described by Custer in 1918(11). In 1962, Sunada(12)introduced a simpledevice that used direct current to measure the root canal length.

A few studies have investigated the potential EMI of electronic apex locators(EALs) on pacemakers. Beach et al (13) published a case report that showedthat an EAL could be used safely in a patient with a pacemaker. Garofalo et al(14) tested 5 EALs for potential interference of pacemakers in vitro. Because 4of the 5 EALs tested showed no effect on cardiac pacemaker function, they suggested

that EALs can be used safely in patients with a pacemaker. A recent article by Gomezet al (15) assessed the effects of 6 EALs on pacemaker function in vitro. Theyconcluded that there was some EMI when the EAL was placed close to tip of thepacemaker electrode or close to the pacemaker itself. However, no EMI was de-tected when EALs were placed under 2 cm and at 15 cm from the sensing arc.In 2006, Wilson et al (16) studied the interference of 2 EALs and an electricpulp tester (EPT) on 4 patients with a pacemaker and 23 patients with an ICD.No periods of abnormal detection were observed in the pacemakers and no inter-ference was detected in the ICDs. Despite this limited scientific evidence for potentialEMI by EALs on pacemakers, manufacturers of EALs warn against the use of an EALin patients with an implanted pacemaker (17, 18).

From the Departments of *Endodontology, Oral Biochem-istry, and Oral-Maxillofacial Surgery, Academic Centre of

Dentistry Amsterdam, University of Amsterdam and VU Univer-sity, Amsterdam, The Netherlands; and Department of Cardi-ology and Institute for Cardiovascular Research VU, VUUniversity Medical Center, Amsterdam, The Netherlands.

Address requests for reprints to Dr Karim Idzahi,Department of Endodontology, Academic Centre of DentistryAmsterdam (ACTA), University of Amsterdam and VUUniversity, Gustav Mahlerlaan 3004, 1081 LA Amsterdam,The Netherlands. E-mail address:[email protected]/$ - see front matter

Copyright 2014 American Association of Endodontists.http://dx.doi.org/10.1016/j.joen.2013.07.027

Basic ResearchTechnology

JOEVolume 40, Number 2, February 2014 Interference of EALs 277
mailto:[email protected]://dx.doi.org/10.1016/j.joen.2013.07.027http://dx.doi.org/10.1016/j.joen.2013.07.027mailto:[email protected]


2/4

To our knowledge, only a single study(16)investigated the effectof EALs on ICDs. Until now, no in vitrostudy has been conducted onpossible EMI of EALs on ICDs. Therefore, the aim of the present studywas to evaluate the potential electromagnetic interference of electronicapex locators on ICDsin vitro.

Material and MethodsFour different EALs (Table 1), the Root ZX Mini (Morita Corp,

Irvine, CA), Apit 11 (Osada Electric Co, Ltd, Tokyo, Japan), Root ZXII (Morita Corp), andVDW Gold (VDW, Munich, Germany), were testedfor their ability to interfere with the correct function of 3 commonly

used ICDs. The ICDs selected (Fig. 1) for testing were the BiotronikLumax 540 VR-T (Biotronik SE & Co KG, Berlin, Germany), BostonScientific Cognis 100-D (Boston Scientific Co, Natick, MA), andMedtronic Protecta XT CRT-D (Medtronic Inc, Minneapolis, MN).

TheICDs and connected leads were placed individually in a plasticcontainer with 1.5 L physiological saline to simulate the electrical resis-tance of the human body(9). The ICDs were programmed to maximumsensitivity (Table 2).

EALunitswereplacedatadistanceof2.5cmfromtheICD.Thefileelectrode and lip clip of the EAL were placed directly against the ICD.EALS were turned on for 30 seconds while continuously showing theAPEX mark.

A motor (VDW Gold) was also used to simulate the preparation of

a root canal while using the EAL at the sametime. An endodontic file wasplaced in a contra-angle 6:1 handpiece and, together with the lip clip,placed directly against the ICD.

As a negative control, ICDs were operated without any other elec-tric equipment in the vicinity. These data served as baseline values fornormal device function.

An electrosurgical unit, VIO 300 D (Erbe USA, Marietta, GA),served as a positive control for EMI of the ICDs (2, 5). The electricalsurgical pencil was placed in the physiological saline 5 cm from theICD and was turned on coagulation for 30 seconds. All devices weretested 3 times.

The ICD output was monitored continuouslyby real-timetelemetryduring the experiment. After completion of the experiment, an intracar-diac electrocardiogram was printed and examined for interference onthe ICD ventricular activity.

The results were categorized as follows:

EMI-0 = No presence of EMIEMI-1 = The presence of EMI without shock deliveryEMI-2 = The presence of EMI with shock delivery

Results

All 4 different types of EALs and the negative control failed toproduce EMI in each of the ICDs tested (Fig. 2A) and in all repetitivetests (Table 3). These results were categorized as EMI-0. This is incontrast to the results with the electrosurgical unit that served as a posi-tive control. Duringthe operationof thesurgical unit, each ICDdetectedinterference in all repeated tests that were misdiagnosed as episodes ofventricular tachycardia and resulted in the delivery of shocks in all ICDstested (Fig. 2B). These results were categorized as EMI-2. In all testswith the electrosurgical unit, there was shock delivery, so no EMI-1was detected.

DiscussionPacemakers and ICDs are an effective treatment for life-threatening

arrhythmias,andICDsreduce mortality caused by sudden cardiacdeath inhigh-risk patients(19). In the United States, 2.9 million patients receiveda permanent pacemaker between 1993 and 2009, and the number ofpacemakers implanted per year is still increasing (20). More than66.000 ICDs are implanted annually in the United States(21). In Europe,the number of new implants of pacemakers ranged from 1211,134 permillion and from 1.18226 for ICDs in 2005(22). This increased use ofpacemakers and ICDs means that the number of patients with such an im-planted device visiting the dental office will increase.

ICDs are sensitive to EMI from external sources, which have thepotential to simulate an arrhythmia. EMI could result in inhibition of

TABLE 1. Characteristics of the 4 EALs Tested

EAL1 EAL2 EAL3 EAL4

Device name Root ZX Mini Apit 11 Root ZX II VDW GoldMeasurement voltage (mV) 80 Unknown 80 mV UnknownMeasurement current (maximum) 10 mA 2 mA 10 mA UnknownFrequency 0.5 and 0.6 KHz 15 kHz 0.82 KHz 4763 HZPower supply 4.5 V DC 6 V DC 9.6 V DC 6 V

Figure 1. The 3 different ICDs tested.


278 Idzahi et al. JOEVolume 40, Number 2, February 2014


3/4

pacing, asynchronous pacing, or inappropriate delivery of a shock(1).EALsare electronic devices thatpotentially could cause EMI,resulting inthe undesiredtriggering of a shock that is unpleasant or even life threat-ening for a patient. Therefore, the current instruction manuals for EALsadviseagainsttheuseofthesedevicesonpatientswhohaveapacemaker(17, 18).

In previous studies, different types of dental devices have beentested on their capacity to induce EMI in pacemakers or ICDs. Brandet al(8) tested 10 different electrical dental devices for their abilityto interfere with the function of 3 types of ICDsin vitro. Only 1 typeof ultrasonic bath cleaner interfered with 2 of the ICDs. All the otherequipment failed to produce interference, even at the minimum

distance of 2.5 cm. They concluded that normal clinical use of dentalelectrical equipment does not have any significant effect on the ICDstested.

Two studies reported that electric pulp testers (EPTs) did notaffect pacemaker function(9,10). In contrast,Woolleyet al(4) showedthat electrical pulp testers were able to cause interference on pace-makers implanted in dogs.

Miller et al(5) tested 14 electrical dental devices in vitro fortheir ability to interfere with 2 different pacemakers. They showedthat certain electrosurgical and ultrasonic instruments interferedwith pacemaker activity, whereas the other dental devices had noeffect. Another in vitro study also reported that the use of an ultra-sonic scaler and composite curing light within 923 cm and 310

cm of pacemakers and ICDs, respectively, interfered with the perfor-mance of those devices in vitro (6). However, the results of thatstudy have been questioned by several authors (23, 24). Carlson(23) tested an ultrasonic scaler on his own pacemaker and noEMI occurred. Crossley and Poole(24)pointed out that the interpre-tation of the data was incorrect because there was no interference on

the pacemaker function, but there was telemetry interference.Anotherin vivostudy(7)showed that the operation of an ultrasonicscaler did interfere with intracardiac telemetry pacemaker record-ings, but the electrocardiogram and pacemaker function remainedunchanged. Because not all pacemakers tested were affected, theyconcluded that the ultrasonic scaler only caused interference withreal-time telemetry by interfering with wand function at a closedistance to the patient. The use of 7 dental instruments tested,including the Root ZX Apex locator, appeared to be safe in that pop-ulation.

To our knowledge, this is the firstin vitrostudy to investigate thepotential effect of EMI by an EAL on an ICD. Beach et al(13)published

a case report in which an EAL was used safely in a patient with a pace-maker.The same conclusion wasdrawn by an in vitro study by Garofaloet al(14). A recent article by Gomez et al(15)assessed the effects of 6EALs on pacemaker functionin vitro. They concluded that there wassome EMI when the EAL was placed close to tip of the electrode andoccasionally when close to the pacemaker. However, no EMI was de-tected when the EALs were placed near 15 cm from the sensing arcin thisin vitromodel.

In thecurrent study,all 4 EALs testeddid notproduce EMIthat wasdetected by the ICDs. This observation is in agreement with a previousin vivostudy. In 2006, Wilson et al(16)studied the interference of anEAL and EPT on 27 patients with pacemakers and ICDs. They did notobserve interference when these dental devices were used in this group

of patients.Within the limitations of this study, the present data suggest thatEALs can be used safely in patients with an ICD, especially when generalprecautions are followed to keep electrical appliances at least 1015cm away froman ICD and its lead (8). However, consulting the patientscardiologist remains advisable.

TABLE 2. Technical Specifications of the 3 ICDs Tested

Biotronik Lumax Boston Scientific Medtronic

Output (mV) 2.4 2.5 2.4RV sensitivity (mV) 0.8 0.15 0.15Mode VVI DDI DDDType of lead Bipolar Bipolar BipolarDetection threshold 9/12 beats 1 second 9/12 beats

Figure 2. (A) Two intracardiac electrocardiograms showing no EMI by the Root ZX Mini of the Medtronic Protecta XT CRT-D (upper panel) and the BostonScientific Cognis 100-D (lower panel). (B) Two intracardiac electrocardiograms showing interference of ICD function caused by the electrosurgical unit that servedas a positive control, showing the inappropriate delivery of ICD shocks (Shk) (upper panel: Medtronic Protecta XT CRT-D,lower panel: Boston Scientific Cognis100-D).


JOEVolume 40, Number 2, February 2014 Interference of EALs 279


4/4

Acknowledgments

The authors thank Noortje Bijvoet and Mariska de Blaauw fortheir technical assistance with this experiment and to Arjen vanWijk for his valuable advice.

The authors deny any conflicts of interest related to this study.

References1. Dental equipment and implantable pacemakers and defibrillators. Boston Scientific;

2009.

2. Pinski SL, Trohman RG. Interference in implanted cardiac devices, part II. PacingClin Electrophysiol 2002;25:1496509.

3. Misiri J, Kusumoto F, Goldschlager N. Electromagnetic interference and implantedcardiac devices: the medical environment (part II). Clin Cardiol 2012;35:3218.

4. Woolley LH, Woodworth J, Dobbs JL. A preliminary evaluation of the effects of elec-trical pulp testers on dogs with artificial pacemakers. J Am Dent Assoc 1974;89:1099101.

5. Miller CS, Leonelli FM, Latham E. Selective interference with pacemaker activity byelectrical dental devices. Oral Surg Oral Med Oral Pathol 1998;85:336.

6. Roedig JJ, Shah J, Elayi CS, et al. Interference of cardiac pacemaker and implantablecardioverter-defibrillator activity during electronic dental device use. J Am DentAssoc 2010;141:5216.

7. Patel D, Glick M, Lessard E, et al. Absence of in vivo effects of dental instruments onpacemaker function. Oral Surg Oral Med Oral Pathol 2005;99:430.

8. Brand HS, Entjes ML, Nieuw Amerongen AV, et al. Interference of electrical dentalequipment with implantable cardioverter-defibrillators. Br Dent J 2007;203:5779.

9. Simon A, Linde B, Bennette G. The individual with a pacemaker in the dental envi-ronment. J Am Dent Assoc 1975;91:12249.

10. Luker J. The pacemaker patient in the dental surgery. J Dent 1982;10:32632.11. Custer C. Exact methods for locating the apical foramen. J Natl Dent Assoc 1918;5:

8159.12. Sunada I. New method for measuring the length of the root canal. J Dent Res 1962;

41:37587.13. Beach CW, Bramwell JD, Hutter JW. Use of an electronic apex locator on a cardiac

pacemaker patient. J Endod 1996;22:1824.14. Garofalo RR, Ede EN, Dorn SO, et al. The effect of electronic apex locators on

cardiac pacemaker function. J Endod 2002;28:8313.15. Gomez G, Duran-Sindreu F, Jara Clemente F, et al. The effects of six electronic

apex locators on pacemaker function: an in vitro study. Int Endod J 2013;46:

399405.16. Wilson BL, Broberg C, Baumgartner JC, et al. Safety of electronic apex locators and

pulp testers in patients with implanted cardiac pacemakers or cardioverter/defibril-lators. J Endod 2006;32:84752.

17. Morita J. Root ZX mini [operation instructions]. Irvine, CA: Morita Corp; 2011 .18. VDW Gold [operation manual]. Munich, Germany: VDW; 2010.19. Buxton AE, Lee KL, Fisher JD. A randomized study of the prevention of sudden death

in patients with coronary artery disease. N Engl J Med 1999;341:188290.20. Greenspon AJ, Patel JD, Lau E, et al. Trends in permanent pacemaker implantation

in the United States from 1993 to 2009. J Am Coll Cardiol 2012;60:15405 .21. Zhan C, Baine WB, Sedrakyan A, et al. Cardiac device implantation in the United

States from 1997 through 2004: a population-based analysis. J Gen Intern Med2008;23:139.

22. Ector H, Vardas P. Current use of pacemakers, implantable cardioverter defibrilla-tors, and resynchronization devices: data from the registry of the European HeartRhythm Association. Eur Heart J Suppl 2007;9:I449.

23. Carlson BK. Pacemakers and dental devices. J Am Dent Assoc 2010;141:10523 .24. Crossley GH, Poole JE. More about pacemakers. J Am Dent Assoc 2010;141:1053.

TABLE 3. EMI of the EALs on the ICDs Tested

Devices

Biotronik Boston Scientific Medtronic

1 2 3 1 2 3 1 2 3

Root ZX Mini EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0Apit 11 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0Root ZX II EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0VDW Gold EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0Negative control EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0 EMI-0

Positive control EMI-2 EMI-2 EMI-2 EMI-2 EMI-2 EMI-2 EMI-2 EMI-2 EMI-2

EMI-0 refers to the absence of EMI. EMI-1 refers to the presence of EMI but without shock delivery. EMI-2 refers to the presence of EMI but with shock delivery. The results of 3 repetitive tests are shown.


280 Idzahi et al. JOEVolume 40, Number 2, February 2014
http://refhub.elsevier.com/S0099-2399(13)00648-1/sref1http://refhub.elsevier.com/S0099-2399(13)00648-1/sref1http://refhub.elsevier.com/S0099-2399(13)00648-1/sref2http://refhub.elsevier.com/S0099-2399(13)00648-1/sref2http://refhub.elsevier.com/S0099-2399(13)00648-1/sref3http://refhub.elsevier.com/S0099-2399(13)00648-1/sref3http://refhub.elsevier.com/S0099-2399(13)00648-1/sref4http://refhub.elsevier.com/S0099-2399(13)00648-1/sref4http://refhub.elsevier.com/S0099-2399(13)00648-1/sref4http://refhub.elsevier.com/S0099-2399(13)00648-1/sref5http://refhub.elsevier.com/S0099-2399(13)00648-1/sref5http://refhub.elsevier.com/S0099-2399(13)00648-1/sref6http://refhub.elsevier.com/S0099-2399(13)00648-1/sref6http://refhub.elsevier.com/S0099-2399(13)00648-1/sref6http://refhub.elsevier.com/S0099-2399(13)00648-1/sref7http://refhub.elsevier.com/S0099-2399(13)00648-1/sref7http://refhub.elsevier.com/S0099-2399(13)00648-1/sref7http://refhub.elsevier.com/S0099-2399(13)00648-1/sref8http://refhub.elsevier.com/S0099-2399(13)00648-1/sref8http://refhub.elsevier.com/S0099-2399(13)00648-1/sref9http://refhub.elsevier.com/S0099-2399(13)00648-1/sref9http://refhub.elsevier.com/S0099-2399(13)00648-1/sref10http://refhub.elsevier.com/S0099-2399(13)00648-1/sref10http://refhub.elsevier.com/S0099-2399(13)00648-1/sref11http://refhub.elsevier.com/S0099-2399(13)00648-1/sref11http://refhub.elsevier.com/S0099-2399(13)00648-1/sref12http://refhub.elsevier.com/S0099-2399(13)00648-1/sref12http://refhub.elsevier.com/S0099-2399(13)00648-1/sref13http://refhub.elsevier.com/S0099-2399(13)00648-1/sref13http://refhub.elsevier.com/S0099-2399(13)00648-1/sref14http://refhub.elsevier.com/S0099-2399(13)00648-1/sref14http://refhub.elsevier.com/S0099-2399(13)00648-1/sref15http://refhub.elsevier.com/S0099-2399(13)00648-1/sref15http://refhub.elsevier.com/S0099-2399(13)00648-1/sref15http://refhub.elsevier.com/S0099-2399(13)00648-1/sref15http://refhub.elsevier.com/S0099-2399(13)00648-1/sref15http://refhub.elsevier.com/S0099-2399(13)00648-1/sref16http://refhub.elsevier.com/S0099-2399(13)00648-1/sref16http://refhub.elsevier.com/S0099-2399(13)00648-1/sref16http://refhub.elsevier.com/S0099-2399(13)00648-1/sref16http://refhub.elsevier.com/S0099-2399(13)00648-1/sref17http://refhub.elsevier.com/S0099-2399(13)00648-1/sref18http://refhub.elsevier.com/S0099-2399(13)00648-1/sref18http://refhub.elsevier.com/S0099-2399(13)00648-1/sref19http://refhub.elsevier.com/S0099-2399(13)00648-1/sref19http://refhub.elsevier.com/S0099-2399(13)00648-1/sref20http://refhub.elsevier.com/S0099-2399(13)00648-1/sref20http://refhub.elsevier.com/S0099-2399(13)00648-1/sref20http://refhub.elsevier.com/S0099-2399(13)00648-1/sref20http://refhub.elsevier.com/S0099-2399(13)00648-1/sref21http://refhub.elsevier.com/S0099-2399(13)00648-1/sref21http://refhub.elsevier.com/S0099-2399(13)00648-1/sref21http://refhub.elsevier.com/S0099-2399(13)00648-1/sref22http://refhub.elsevier.com/S0099-2399(13)00648-1/sref23http://refhub.elsevier.com/S0099-2399(13)00648-1/sref23http://refhub.elsevier.com/S0099-2399(13)00648-1/sref22http://refhub.elsevier.com/S0099-2399(13)00648-1/sref21http://refhub.elsevier.com/S0099-2399(13)00648-1/sref21http://refhub.elsevier.com/S0099-2399(13)00648-1/sref21http://refhub.elsevier.com/S0099-2399(13)00648-1/sref20http://refhub.elsevier.com/S0099-2399(13)00648-1/sref20http://refhub.elsevier.com/S0099-2399(13)00648-1/sref20http://refhub.elsevier.com/S0099-2399(13)00648-1/sref19http://refhub.elsevier.com/S0099-2399(13)00648-1/sref19http://refhub.elsevier.com/S0099-2399(13)00648-1/sref18http://refhub.elsevier.com/S0099-2399(13)00648-1/sref18http://refhub.elsevier.com/S0099-2399(13)00648-1/sref17http://refhub.elsevier.com/S0099-2399(13)00648-1/sref16http://refhub.elsevier.com/S0099-2399(13)00648-1/sref16http://refhub.elsevier.com/S0099-2399(13)00648-1/sref16http://refhub.elsevier.com/S0099-2399(13)00648-1/sref15http://refhub.elsevier.com/S0099-2399(13)00648-1/sref15http://refhub.elsevier.com/S0099-2399(13)00648-1/sref15http://refhub.elsevier.com/S0099-2399(13)00648-1/sref14http://refhub.elsevier.com/S0099-2399(13)00648-1/sref14http://refhub.elsevier.com/S0099-2399(13)00648-1/sref13http://refhub.elsevier.com/S0099-2399(13)00648-1/sref13http://refhub.elsevier.com/S0099-2399(13)00648-1/sref12http://refhub.elsevier.com/S0099-2399(13)00648-1/sref12http://refhub.elsevier.com/S0099-2399(13)00648-1/sref11http://refhub.elsevier.com/S0099-2399(13)00648-1/sref11http://refhub.elsevier.com/S0099-2399(13)00648-1/sref10http://refhub.elsevier.com/S0099-2399(13)00648-1/sref9http://refhub.elsevier.com/S0099-2399(13)00648-1/sref9http://refhub.elsevier.com/S0099-2399(13)00648-1/sref8http://refhub.elsevier.com/S0099-2399(13)00648-1/sref8http://refhub.elsevier.com/S0099-2399(13)00648-1/sref7http://refhub.elsevier.com/S0099-2399(13)00648-1/sref7http://refhub.elsevier.com/S0099-2399(13)00648-1/sref6http://refhub.elsevier.com/S0099-2399(13)00648-1/sref6http://refhub.elsevier.com/S0099-2399(13)00648-1/sref6http://refhub.elsevier.com/S0099-2399(13)00648-1/sref5http://refhub.elsevier.com/S0099-2399(13)00648-1/sref5http://refhub.elsevier.com/S0099-2399(13)00648-1/sref4http://refhub.elsevier.com/S0099-2399(13)00648-1/sref4http://refhub.elsevier.com/S0099-2399(13)00648-1/sref4http://refhub.elsevier.com/S0099-2399(13)00648-1/sref3http://refhub.elsevier.com/S0099-2399(13)00648-1/sref3http://refhub.elsevier.com/S0099-2399(13)00648-1/sref2http://refhub.elsevier.com/S0099-2399(13)00648-1/sref2http://refhub.elsevier.com/S0099-2399(13)00648-1/sref1http://refhub.elsevier.com/S0099-2399(13)00648-1/sref1

idzahi 2014 journal of endodontics

Documents