Effect of Electronic Apex Locators on Cardiac Pacemaker Function

doi:10.1097/00004770-200212000-00009

Journal of Endodontics

Volume 28, Issue 12, December 2002, Pages 831-833

https://doi.org/10.1097/00004770-200212000-00009 Get rights and content

The purpose of this study was to assess the effects of five electronic apex locators on pacemaker function in vitro. A Biotronik Actros DR+ pacemaker was evaluated at maximum sensitivity on a flat bench top. The pacemaker lead, electronic apex locator, and oscilloscope were connected across a 150-ohm resistor. Pace monitoring was carried out with a Biotronik EPR 1000 programmer and a Tektronix TDS 220 2-channel digital real-time oscilloscope. Four of five electronic apex locators tested did not cause inhibition or interfere with normal pacemaker function. It seems that electronic apex locators can be used safely in patients with pacemakers.

Section snippets

MATERIALS AND METHODS

Five EALs were tested for pacemaker interference, including the Root ZX (J. Morita Co., Tustin, CA, U.S.A.), Justwo (Toei Electric Co., Kanagawa, Japan), EIE (Analytic Endodontics, Orange, CA, U.S.A.), Neosono (Amadent, Cherry Hill, NJ, U.S.A.), and Bingo-1020 (Dent Corp, White Plains, NY, U.S.A.). A Biotronik Actros DR+ pacemaker (Biotronik, Berlin, Germany) with an atrial lead (model PX45JBP) was set to 60 pulses/min and evaluated at maximum sensitivity (unipolar: AAI mode, 0.1 mV) on a flat

RESULTS

The negative control showed a normal pacing pattern; the positive control showed pace inhibition (Fig. 2). The Root ZX device caused no interference with pacemaker activity (Fig. 3). Telemetric recordings for the Justwo and the EIE apex locators both showed the absence of two paced beats within the test period, whereas the Neosono showed that five paced beats were not registered. However, all three devices showed normal pacing on the oscilloscope. The Bingo-1020 device produced an irregular

DISCUSSION

There have been dramatic improvements in pacemaker technology over the last few decades. Pacemakers manufactured before 1975 used discrete electronic components encapsulated in a clear epoxy case. Electromagnetic interference (EMI) could easily penetrate the pacer and affect the electronic circuits. Modern pacemaker electronics are shielded in a hermetically sealed metal case with capacitors that effectively filter out EMI signals (14, 15). Because newer pacers are less susceptible to

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Cited by (43)

Safety concerns of Piezoelectric Units in Implantable Cardioverter Defibrillator
2018, Journal of Oral and Maxillofacial Surgery
Citation Excerpt :
Pzs are used in the oral cavity, located some 25 to 30 cm from an ICD; thus, these units would never come in to close proximity to an ICD in a clinical setting. In addition, human body tissue might shield the device from EMI by reflecting or absorbing the interference.11,24 Given the absence of strict guidelines for the safe use of electrical dental units in patients wearing an ICD, the authors strongly recommend that the dental clinician should consult the patient's cardiologist before performing any dental treatment involving the use of Pzs.
Evidence-based research appears to conflict on the potential risk of electromagnetic interference (EMI) between piezoelectric units (Pzs) and implantable cardioverters and defibrillators (ICDs). The purpose of this study was to observe whether the EMI produced by Pzs is hazardous for ICDs.
A cross-sectional study of 6 Pzs was conducted in vitro for EMI using an ICD system. To simulate the human body's electrical resistance, electrographic recordings were made of the ICD and lead that were immersed in a bath of saline solution. The variables investigated were the presence of EMI, the distance between the ICD and the Pz, and signal intensity, damage, and type of damage to the ICD and lead. Each series of tests was repeated 3 times, beginning with a 15-second baseline recording (control), until all recording conditions had been covered. Each Pz was recorded under the following conditions: less than 2 cm from the tip of the ICD lead; less than 2 cm from the ICD; less than 2 cm from the lead body and coils; and 15 cm from the lead or the ICD (R4).
In the positive control (direct contact between the lead or the ICD with the Pz switched on), the ICD detected electrical activity as false heart activity. However, after covering all test conditions, no EMI was produced by the Pzs.
No EMI or permanent changes in the functioning of the ICD were detected in vitro.
Evaluation of interference of cellular phones on electronic apex locators: An in vitro study
2016, Journal of Endodontics
Citation Excerpt :
Experiment 2 was conducted in a polyclinic with good signal strength where Wi-Fi, GPRS, and Bluetooth networks were activated, and the dental personnel carried cellular phones, mimicking a dental operatory in a realistic scenario. Because the distance between 2 electronic devices can influence EMI (16, 24), different distances between the cellular phone and the EAL were tested in this study. The recommended safety distance between a cellular phone and medical device for a Global System for Mobile Communication (GSM) 900 MHz cellular phone is 70 cm, for a GSM 1800 MHz cellular phone the safety distance is 5 cm (16), whereas for GPRS cellular phones, a safety distance of 1 m is recommended between the cellular phones and medical devices (25).
Use of mobile phone has been prohibited in many hospitals to prevent interference with medical devices. Electromagnetic radiation emitted from cellular phones might interfere with electronic working length determination. The purpose of this in vitro study was to evaluate the effect of a smart phone (Samsung Galaxy Note Edge) on working length determination of electronic apex locators (EALs) Propex II and Rootor.
Fifteen intact, non-carious single-rooted teeth were decoronated at the cementoenamel junction. Visually, working length was determined by using a #15 K-file under stereomicroscope (×20). The effect of cellular phones on electronic working length (EWL) was determined under 2 experimental settings: (1) in a closed room with poor signal strength and (2) in a polyclinic set up with good signal strength and 5 conditions: (1) electronically, without cellular phone in room; (2) electronically, with cellular phone in physical contact with EAL; (3) electronically, with mobile phone in physical contact with EAL and in calling mode for a period of 25 seconds; (4) electronically, mobile phone placed at a distance of 40 cm from the EAL; and (5) electronically, mobile phone placed at a distance of 40 cm and in calling mode for a period of 25 seconds. The EWL was measured 3 times per tooth under each condition. Stability of the readings was scored from 1 to 3: (1) good stability, (2) stable reading after 1 attempt, and (3) stable reading after 2 attempts. The data were compared by using analysis of variance.
The EWL measurements were not influenced by the presence of cellular phone and could be determined under all experimental conditions.
Within the limitations of this study, it can be concluded that mobile phones do not interfere with the EWL determination.
Electromagnetic interference of endodontic equipments with cardiovascular implantable electronic device
2016, Journal of Dentistry
Citation Excerpt :
Results regarding other equipments, such as electric scalpel [5,7] and light-curing unit [5,7,9], remain controversial, possibly owing to the different brands of dental equipments tested and variations in the type and sensitivity setting of CIEDs. In endodontics, the literature is controversial regarding the effect of electric pulp test [5,7–10] and apex locators [11–15], whereas some equipment such as rotary motors [9,15], gutta-percha heat carrier [9,6] and gutta-percha gun [9] remain understudied and others had never been investigated, such as laser devices and optical microscope. Moreover, the occurrence of EMI depends on the characteristics of the CIED, such as brand, type of stimulation and polarity[1,17].
Assess the electromagnetic interference (EMI) of endodontic equipment with cardiovascular implantable electronic devices (CIEDs) and related factors.
The laser device, electronic apex locators (EAL), optical microscope, endodontic rotary motors, gutta-percha heat carrier (GH), gutta-percha gun and ultrasonic device were tested next to CIEDs (Medtronic and Biotronik) with varied sensitivity settings and distances. CIEDs were immersed in a saline solution to simulate the electrical resistence of the human body. The endodontic equipment was tested in both horizontal and vertical positions in relation to the components of the CIED. The tests were performed on a dental chair in order to assess the cumulative effect of electromagnetic fields.
It was found no EMI with the Biotronik pacemaker. EALs caused EMI with Medtronic PM at a 2 cm distance, with the NSK^® EAL also affecting the Medtronic defibrillator. GH caused EMI at 2 cm and 5 cm from the Medtronic defibrillator. EMI occurred when devices were horizontally positioned to the CIED. In the majority of the cases, EMI occurred when the pacemaker was set to maximum sensitivity. There was cumulative effect of electromagnetic fields between GH and dental chair.
EALs and GH caused EMI which ranged according to type and sensitivity setting of the CIEDs and the distance. However, no endodontic equipment caused permanent damage to the CIED. The use of GH caused a cumulative effect of electromagnetic fields. It suggests that during the treatment of patients with CIEDs, only the necessary equipments should be kept turned on.
Patients with CIEDs may be subject to EMI from electronic equipment used in dental offices, as they remain turned on throughout the treatment. This is the first article assessing the cumulative effect of electromagnetic fields.
Do cell phones affect establishing electronic working length?
2015, Journal of Endodontics
Patients often keep their cell phones on and nearby during root canal therapy. Cell phones release electromagnetic interference, which might disturb electronic working length measurements. The purpose of this ex vivo study was to determine the effect of a cell phone (Apple iPhone 5 [Apple, Cupertino, CA] or KP100 [LG, Seoul, Korea]) placed into direct contact with an electronic apex locator (EAL) (Dentaport Root ZX module [J Morita Corp, Tokyo, Japan] or Propex II [Dentsply Maillefer, Ballaigues, Switzerland]) on working length determination.
Twenty-six human premolars without fractures or carious lesions were used; previously cleaned; and observed under magnification (×15) in order to check for the presence of only 1 apical foramen, the absence of apical resorption, an “open” apex, and accessory canals. The working length measurement was performed with a #15 K-file in the presence of 2.6% sodium hypochlorite under 4 conditions: (1) visually, under the microscope until the file tip reached the canal terminus; (2) electronically, without the cell phone in proximity; (3) electronically, with the cell phone in standby mode placed in physical contact with the EAL; and (4) electronically, with the cell phone activated by a call in the same position. The experimental model for electronic working length determination was a screw top plastic container filled with a saline solution. The measurements were repeated 3 times per canal under each condition. Scores of 1 to 3 categorized the stability of the readings as follows: (1) good stability; (2) unstable reading with minor difficulties determining the working length; and (3) major difficulties or impossible to determine the working length. A 2-way repeated measures analysis of variance (way 1: cell phone type and way 2: EAL model) was performed, and a second repeated measures analysis of variance was performed to seek a difference among the 4 working length determination conditions.
Neither the cell phone type nor the EAL affected the measurements (not significant). The electronic working length measurements gave the same results as the visual examination, and this length was not influenced by direct contact with a cell phone (not significant). It was also possible to determine the electronic working length under all the experimental conditions.
Within the limitations of the present study, it can be concluded that patients can keep their cell phones on during root canal therapy without any adverse effect on electronic working length determination.
Evaluating the Effects of Different Dental Devices on Implantable Cardioverter Defibrillators
2015, Journal of Endodontics
The implantable cardioverter defibrillator (ICD) is an electronic device that emits electrical signals to the heart via lead wires and electrodes. It is used for cardiac rhythm monitoring and treatment. Because electronic dental devices have been shown to produce electromagnetic fields, we hypothesize that they may interfere with ICD function.
Nine dental devices (heat carrier, electronic apex locator, electric pulp tester, unipolar electrosurgery unit, electric motor, curing light, and 3 gutta-percha guns) were tested in this study for their ability to interfere with the function of 4 ICDs (2 single-chambered and 2 dual-chambered ICDs). ICD activity was monitored for 30 seconds using an ICD programmer (Medtronic 2090; Minneapolis, MN) and evaluated through an electrogram test strip printout.
Electromagnetic interference was detected with the electric motor, curing light, electric pulp tester, and electrosurgery unit although no electromagnetic disturbances were detected with these devices. No electromagnetic interferences were observed for the gutta-percha guns, heat carrier, and apex locator. However, the electrosurgery unit affected the dual-chambered ICD (Consulta CRT-D, Medtronic) and delivered therapies for fibrillation when no ventricular fibrillation was present.
Our results suggest that the electrosurgery unit produces electromagnetic disturbances with unwanted therapy delivery shock and potentially clinically significant outcomes.
Interference between dental electrical devices and pacemakers or defibrillators: Results from a prospective clinical study
2015, Journal of the American Dental Association
The authors aimed to determine whether electrical dental devices would interfere with the function of cardiac pacemakers or implantable cardioverter defibrillators (ICDs) in humans.
The authors exposed asymptomatic nonpacemaker-dependent patients to commonly used electrical dental equipment (for example, battery-operated curing lights, ultrasonic baths, ultrasonic scalers, electric pulp testers, and electric toothbrushes) in an outpatient cardiology clinic. The authors operated dental devices at various distances and programmed cardiac devices to sense and pace. The authors obtained cardiac tracings using a cardiac programming unit and a cardiac provider who noted any interference interpreted the results in real time.
The authors enrolled 32 consecutive patients and tested 12 pacemakers and 20 ICDs. They did not observe any significant clinical interference in sensing and pacing functions in any patient; however, they noted minor interference without clinical impact in the telemetry from the cardiac programming unit during use of the ultrasonic scaler and bath.
The findings of this prospective study suggest that electrical devices commonly used in dental practices do not interfere with the sensing and pacing of contemporary cardiac patients’ pacemakers or ICDs. However, they do interfere with the telemetry from the cardiac programming unit, without any clinical impact on patient safety. These findings should help in the development of clinical guidelines regarding dental management of patients with pacemakers or ICDs.
Electrical dental devices (for example, ultrasonic baths, ultrasonic scalers) induced minor interference with programmers that interrogate cardiac devices implanted in patients; however, overall, dental devices do not appear to interfere with pacemakers’ and defibrillators’ pacing and sensing function.

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CLINICAL ARTICLESEffect of Electronic Apex Locators on Cardiac Pacemaker Function

Section snippets

MATERIALS AND METHODS

RESULTS

DISCUSSION

Oral Surg

J Am Dent Assoc

J Am Dent Assoc

Oral Surg

J Endodon

Med Clin North Am

Cardiol Clinics

CLINICAL ARTICLES
Effect of Electronic Apex Locators on Cardiac Pacemaker Function