I don't believe this is really about the wisdom teeth, now that I think about it. That's a proxy complaint for something else that's bothering her.

Three years is a good solid amount of time to have been living together. The two of you now know each other about as good as you're going to. Is there a reason you haven't made a legally binding commitment to her (as in "marriage")? If she gives any indication of wanting to be married, and you are not responding with much enthusiasm, then that's the issue between you two right there. After 3 years, I would say it's time to formalise the commitment, or else realize that you're hanging back, and she has every right to resent that.