Spies are sexy, but are they sexy when they’re dead? (Do not answer this)

There is no evidence of cyanide fake teeth existing. Beyond potential to accidentally swallow the pill or crush the tooth, a cyanide capsule is prohibitively large to be realistically and securely housed in a fake tooth. Fake teeth have been used as spy tools- usually to contain Micro dots or micro film to pass to a contact. Cyanide pills have also been used-

High ranking Nazis famously killed themselves before trial. In WW2 some allied agents were given cyanide pills to use if they were captured- both to prevent a captive from “cracking” and divulging information, but also to save the user the pain and suffering assumed to be awaiting them if captured. The two have not been recorded as being combined in the real world however.

Cyanide capsules were hidden in objects like pens, pencils, glasses, cigarette filters, necklaces, etc. items that were common and innocuous, and that the owner could chew on inconspicuously, as such items are things people often chew as a “tick.” Pills could commonly be seen into clothing, and pills could be designed to be hidden in the mouth and held relatively safely for a period- but these were “hidden” in the way that you might hide any other pill etc- in a cheek or under the tongue, and inspecting the mouth would likely reveal the pill.

Most suicide pills relied on the user recognizing that capture was imminent, and quickly taking the pill before capture was made, or shortly after. While historically such pills have been used- historical records and commenters have indicated that in some cases, such pills were issued primarily or in part for the psychological advantage of easing the users fears of becoming a POW or suffering torture etc. feeling that they always had an “option” if needed.