I recall reading (I do a lot of that) an article in some science magazine about a possible link between tungsten and aggressive tumor growth. I haven't a clue if tungsten is truly carcinogenic or not, but a web search will yield several government and news sites that are making implications. Of course, news sites love making implications. ;) Personally, I'd want just a little assurance before using tungsten on my face.
Here's just one government site linking tungsten to cancer (however, long-term internal exposure):
http://ehp.niehs.nih.gov/press/011505.html
However, I am interested in the alternative metal angle...