Be sure to read the instructions carefully. You might look to see if there are any resources on the Web (youtube, perhaps?) for videos on how best to use it so that you don't injure your gums or drive food and plaque under the gum line. Oh, and don't be surprised if you end up spraying yourself and your bathroom with water!

My parents have had a nightmare with their teeth and I know for my mom, it's a source of much shame. She has dentures now, but when I noted how nice her smile looked a few years ago (prior to that, it honestly and sadly looked pretty horrible), she flat out that she'd had anything done. I left it at that, and have never brought it up again.