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. 2025 Jun 1;15(3):263-270.
doi: 10.31661/jbpe.v0i0.2210-1551. eCollection 2025 Jun.

Microleakage of Amalgam Restorations after Exposure to Electromagnetic Fields of a Commercial Hair Dryer: An Ex-Vivo Study

Maryam Paknahad  1 , Ali Dehghani  2 , Iman Khaleghi  3 , Mahsa Eghildespour  4 , Ghazal Mortazavi  5 , Seyed Mahammad Javad Mortazavi  6
Affiliations

Microleakage of Amalgam Restorations after Exposure to Electromagnetic Fields of a Commercial Hair Dryer: An Ex-Vivo Study

Maryam Paknahad et al. J Biomed Phys Eng. .

Abstract

Background: Dental amalgam is a popular restorative material used in posterior teeth. Hair dryers can emit electromagnetic fields (EMFs) that may affect the microleakage of the amalgam-tooth interface.

Objective: The aim of this experimental study was to investigate whether the EMFs produced by commercial hair dryers could cause microleakage in amalgam restorations.

Material and methods: In this experimental study, a total of 100 human extracted teeth without cavities were selected and prepared for class V preparations on their buccal aspects. The teeth were divided into five groups (G1-G5), each containing 20 teeth. Group 1 served as the control group and was not subjected to any treatment. Groups 2 to 5 were exposed to EMFs of a hair dryer (2000 W, 220 V, and 50 Hz). Groups 2 and 3 were exposed to "EMFs +Hot Air" for 20 min at 10 cm and 30 min at 5 cm, respectively. Groups 4 and 5 were exposed to "EMFs +Cool Air" for 20 min at 10 cm and 30 min at 5cm, respectively. After preparation, the sectioned teeth were evaluated for microleakage using dye penetration measurement.

Results: The microleakage scores showed a significant difference among the three exposure groups (G2, G3, and G5) and the control group (P=0.001, 0.002, and 0.01, respectively). However, there was no significant difference between G4 and G1. The microleakage score in G2 was higher than that in G4.

Conclusion: This study suggests that the common use of hair dryers can lead to damage in amalgam restorations.

Keywords: Dental Amalgams; Dental Leakage; Electromagnetic Fields.

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Conflict of interest statement

SMJ. Mortazavi, as the Editorial Board Member, was not involved in the peer-review and decision-making processes for this manuscript.

Figures

Figure 1
Figure 1
Microleakage evaluation under stereomicroscope shows a dye penetrating the enamel and spreading through the dentine-enamel junction (DEJ) to the dentin (score 3)
Figure 2
Figure 2
A sample control tooth under stereomicroscope microleakage evaluation reveals no dye penetration (Score 0)
See this image and copyright information in PMC

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