My brother was told that they were fine and he ended up with a gigantic abscess in his mouth. The kid goes to the dentist every six months like clock work, and they still missed it.
One thing you can look into it going to a University that has a dentistry/periodontal school. They are generally a lot cheaper or free. They may not be the very best, but they are a heck of a lot more qualified than you are, and they can actually give you antibiotics to help with the infection.

Also, every procedure is over seen by a professor who is a well qualified dentist.