microleakage of amalgam restorations after exposure to electromagnetic fields of a commercial hair dryer: an ex-vivo study

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.