The effects of six electronic apex locators on pacemaker function: an in vitro study

Area of Science:

• Biomedical Engineering
• Medical Devices
• Electrophysiology

Background:

• Pacemakers are critical for regulating heart rhythm.
• Electronic apex locators (EALs) are used in endodontics to determine root canal length.
• Potential electromagnetic interference (EMI) between EALs and pacemakers requires investigation.

Purpose of the Study:

• To evaluate the in vitro effects of six different EALs on the function of a single-chamber pacemaker.
• To identify specific EALs or operating conditions that may cause EMI with pacemakers.

Main Methods:

• Six EALs were tested for EMI with a pacemaker in a saline bath simulating human body resistance.
• Pacemaker activity was recorded under various conditions with EALs placed at different distances (<2 cm, 15 cm) from the electrode, generator, and sensing arc.

Main Results:

• Most EALs produced only background noise when placed near the electrode tip.
• One EAL, the Mini Apex Locator, caused EMI detected as false heart activity near the electrode tip.
• No significant EMI was detected when EALs were placed near the pacemaker generator or at a distance from the sensing arc.

Conclusions:

• EMI from EALs can occur when placed close to the pacemaker electrode tip or occasionally near the generator.
• No EMI was observed when EALs were positioned near or 15 cm from the pacemaker's sensing arc in this in vitro model.
• Clinical evaluation is recommended to confirm these findings and ensure patient safety during endodontic procedures.