# Aluminum foil and fillings

**URL:** <https://boards.straightdope.com/t/aluminum-foil-and-fillings/32715>\
**Category:** Factual Questions\
**Created:** [September 11, 2000, 12:35am UTC](https://boards.straightdope.com/t/aluminum-foil-and-fillings/32715 "2000-09-11T00:35:48Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![El\_Kabong](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/el_kabong/32/496_2.png) [@El\_Kabong](https://boards.straightdope.com/u/El_Kabong)\
**Post date:** [September 11, 2000, 12:35am UTC](https://boards.straightdope.com/t/aluminum-foil-and-fillings/32715/1 "2000-09-11T00:35:48Z")

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I will accept my flogging like a good sailor if this question has come up before, but a cursory search indicates that it hasn’t.

This came up during a conversation with friends earlier today. Can anyone explain the precise reason for the unpleasant sensation that occurs when a bit of aluminum foil comes in contact with metal dental fillings? I seem to recall it is electrical in nature.

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**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\
**Post date:** [September 11, 2000, 12:52am UTC](https://boards.straightdope.com/t/aluminum-foil-and-fillings/32715/2 "2000-09-11T00:52:39Z")

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When you get two different metals immersed in the same acidic or salty liquid, you’re likely to get electrical action going. This is related to why you can run a clock on a potato, and why the sea will sometimes eat a boat’s propeller if there is no sacrificial piece of zinc nearby. Now, if you’ll excuse me, I’ll stand back while someone who understands chemistry explains why this stuff happens.

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**Author:** ![Arjuna34](https://avatars.discourse-cdn.com/v4/letter/a/eb8c5e/32.png) [@Arjuna34](https://boards.straightdope.com/u/Arjuna34)\
**Post date:** [September 11, 2000, 1:12am UTC](https://boards.straightdope.com/t/aluminum-foil-and-fillings/32715/3 "2000-09-11T01:12:05Z")

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Cecil has addressed this in a related column:  
[http://www.straightdope.com/classics/a1\_121a.html](http://www.straightdope.com/classics/a1_121a.html)

I found it by search for “aluminum foil teeth” in the “search the archives” section.

Arjuna34

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**Author:** ![El\_Kabong](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/el_kabong/32/496_2.png) [@El\_Kabong](https://boards.straightdope.com/u/El_Kabong)\
**Post date:** [September 11, 2000, 2:09am UTC](https://boards.straightdope.com/t/aluminum-foil-and-fillings/32715/4 "2000-09-11T02:09:01Z")

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Well, alrighty, then.

Er, is this going to sting?