Here is an article about the connection between nicotine and gum disease.
Nicotine and periodontal tissues
I found it using a simple search on Google, something you could have done before proclaiming " I have yet to see any such study" blah blah blah.... It just shows your bias when you create facts to fit your view point. A case in point is where you ignored the first part of your own reference article mentioning the dangers of Nic, and jumped to the last part consistent with your view point. Studies involve statistics with large margins of error, so that could possibly explain the discrepancy.
There is no arguing with some of you nic-heads, so I give up. Good luck and happy holidays