Talk:Hi-Fi Gilligan/@comment-141.193.16.151-20191003133011

Actually, though it's highly improbable, receiving a radio signal in a tooth filling is theoretically possible due to the piezo-electric effect. That's what causes certain crystalline structures to be stressed due to an applied voltage (it works the other way too, stressing certain crystals will create a voltage). This effect is used for ultrasonic instrumentation and bar-b-cue lighters.

On a microscopic level, metals used for fillings have a crystalline structure that could be piezo-electric in nature. If the filling, combined with the tooth, is just the right size and shape to resonate with the carrier wave of the radio signal, then the filling will vibrate with that radio signal.

Now, in the very unlikely circumstance that this would ever happen, the filling could only pick up one radio station, it wouldn't be tunable. Also, it could never get so loud that anyone other than the person with the filling could detect it. Finally, although this is theoretically possible, I'm not aware of any case where this has actually happened. I also don't think it would be testable due to the difficulty of determining the resonant frequency of something as geometrically irregular as a tooth with a filling.