Another tip for dental exams--I live quite far from any of the nearest dental offices listed on the website, but I used Lifebooker (a discount site similar to Groupon or LivingSocial, but focused on stuff such as haircuts) to buy a dental exam, X-ray, and cleaning package for $49. As a dentally uninsured applicant, this was a gold mine.
Luckily, I didn't have any further problems and so didn't have to have any further procedures, but those would probably have to be done at full price, and I would likely have made the drive to one of the free/low-cost dental offices then.
I highly recommend a discount site such as the ones listed above, especially if you live near a large city.
PS: Dental exams can be done within a year before staging, so get started early in case you need work done on your teeth. I actually had my exam package done before I received my invitation because I thought I was due for a cleaning, and I didn't have to do another because it was within the year.