Pacemaker Ultrasonic Scaler — ORE Part 1 MCQ
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Correct answer: D — Ultrasonic scaler
Ultrasonic scalers are the primary dental equipment of concern in patients with pacemakers. In-vitro studies have demonstrated that magnetorestrictive ultrasonic scalers can produce electromagnetic interference capable of inhibiting pacemaker pacing function at distances up to 37.5 cm. However, recent in-vivo clinical investigations found no functional interference with modern pacemakers or ICDs under routine clinical use conditions. Current UK practice guidance (NHS/Medtronic) recommends caution with ultrasonic equipment in pacemaker patients, advising awareness and appropriate distance/monitoring, rather than absolute contraindication. The other options are all safe: high-speed handpieces (pneumatic, no electromagnetic output), dental mirrors and cotton wool rolls (passive, non-electronic), and composite curing lights (in modern designs, do not interfere). This question tests understanding of which electronic dental equipment carries recognized electromagnetic risk and requires prudent clinical judgment in pacemaker patients.
Reference: In-vivo compatibility between pacemakers and dental equipment. PubMed PMID 29972599 (2018); NHS Manchester Specialist Equipment: Pacemaker and ICD patients guidance (2025); Selective interference with pacemaker activity by electrical dental devices. PubMed PMID 9474611 (1997). https://pubmed.ncbi.nlm.nih.gov/29972599/ and https://www.mse.nhs.uk/pacemaker-and-icd-patients