I realize I’m coming rather late to the party, but …
As mentioned, natural sunlight has UV, which was the purpose of wanting fluorescence in dentures. It is also the purpose in adding fluorescent dye to laundry detergent - gets that “Whiter than white” effect.
The specific activity (measure of radioactivity per gram) for natural uranium is very, very low. (Depleted uranium is even less, since the more radioactive isotopes have been removed.) A curie of natural uranium is a cube as large as a room. And since very little was used, it was essentially a no-never-mind. :o
Like a number of other uses, it was discontinued due to concern and workable alternatives, not because of significant risk. Orange Fiestaware plates and Coleman lantern mantles were a much more significant concern. Similar amounts of it may still be used in glazes for porcelain fixtures, but those are near your butt, not in your mouth.
The alleged death toll is a typical inflation created by use of assumptions and statistics; a key one is usually that every case of cancer in a denture wearer was caused by the uranium in their false teeth (See also: TMI, Chernobyl, Fukushima Daiichi for similar cases of letting a number off its leash).
The regulatory concept of linear effects with no threshold also contributes to this. This concept ignores the phenomenon of hormesis, which can be readily demonstrated for radiation, as well as other substances. This concept is that for many substances, while a lot is bad, a little is beneficial. (Too much vitamin A will kill you dead. Painfully. :eek: It happened to some Arctic explorers a while back.)
Summing up, uranium was and is used in consumer products, but was removed, and in most cases was not an actual health concern.
Some of the radium products, on the other hand …