I've also been working as an assistant without certification. I was luckily offered the job after shadowing a dentist for a few weeks. The other dental assistants have been happy enough to train me on certain things. I'm also not paid much though, but then again, I don't do as much as the other DA's since I'm still a beginner. If you really want to work in the dental office, perhaps you could see if the dentists you've shadowed are hiring. If not, Craigslist is great to sift through.