There are two TV shows that we are following right now that have mercury-as-a-cure-for-syphilis embedded in the story line. The first is The Alienist; the second is The Frankenstein Chronicles. Both are set in the 19th century.
It is a fact that, for centuries, syphilis was treated with mercury either by ingesting it, by rubbing it on sores or by inhaling it. It is, of course, toxic and many patients died from the treatment rather than from syphilis.
In The Alienist, the serial killer was described as a man with a “silver smile” in earlier episodes. It was theorized that the silver teeth might be the result of mercury treatment for syphilis. In Episode 5, the face of the serial killer was revealed and his teeth were indeed silver.
Do the teeth turn silver as a result of mercury treatment for syphilis?
I searched and searched for information but found nothing to support that proposition. I did find references, however, to the use of a mixture of mercury, silver, tin and copper as dental amalgam—with about 50% of the mixture consisting of elemental mercury. “Dental amalgam” is the term for the filling for tooth cavity.
It might be more reasonable to suppose that since mercury treatment often resulted in tooth decay and loss, the serial killer in The Alienist had lost his teeth, partially or wholly, and had been replaced by dental amalgam.
In The Frankenstein Chronicles, Inspector John Marlott notices a sore on his hand and goes to a doctor who gives him mercury pills. He has taken them before, he says, and he did not like its side effects of bad dreams and visions. The doctor says it gets worse than that but Marlott does not really have a choice.
The mercury is shown as round blue pills—an accurate depiction—which Marlott takes orally. Although I have been unable to find references to bad dreams and visions as side effects of mercury treatment, it does seem reasonable to assume that they were manifestations of mercury poisoning.