The dentine on the inside of a tusk is what is carved out and called Ivory. The value of Ivory was because it could be carved easily and looked nice, and increasingly because of its rarity. The Ivory inside a tusk has no more value than the dentine inside your teeth - that is, it is a mundane part of the body. Why would someone call their product dentine? Is it a mundane, hidden part of a larger organism? Or is it because, once carved out, Ivory is rare and expensive? Please try to find a reason that it makes sense of an application to be called Ivory that is not because it still has connotations of value.
The Ivory trade is disgusting. Anything that continues to promote Ivory as a positive is disgusting.
Update: I think the two folks replying are making my point for me. If your product is a sugar-free gum that is good for teeth, then for sure call it Dentyne.