Hello and thank you for your question,
One of the most common reasons for metal taste in the mouth is Acid Reflux. Some people who experience acid reflux complain of heartburn/indigestion but these symptoms are not always present.
Metal taste in the mouth is not a sign of oral cancer so you dont have to worry about that.
I would suggest that you take an over-the-counter acid blocker such as Prilosec (or generic Omeprazole - cheaper). You can take 1 tablet in the morning before breakfast and 1 tablet before dinner. You should notice a difference within a couple of days.
If symptoms persist, you can start with seeing your dentist to check the crowns.
I hope you find this information helpful. Please feel free to follow-up with any other questions you might have.
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