Joining the USAF...but needs some expensive dental work done, should I wait?!

As long as you pass the enlistment physical itself, the AF will provide all the dental care you will need. That will include removal of your wisdom teeth, as well as other dental repairs. As far as implants, that's not done as a rule. If you need braces to correct an over or under bite, or to close gaps, they will also provide those. If the braces are just for cosmetic reasons, then you might find it a challenge. You can always go to a dentist and pay out of pocket though. While you are on active duty, the AF provides and pays for any and all dental treatment that you require. They do not pay for cosmetic things, though, and as a rule do not do implants- but that too may change in the future. I'd wait on the dental treatment if you can until you are on active duty. When you get to your first duty station, then the dental treatment will start. Of course if you need treatment before that, you can also get it done.

nurse, retired AF

I believe the USAF will take care of your teeth for you. It's one of the perks that come with serving your country. Don't know about implants though. They should take care of the root canal. I'd say wait as dental work is soooo expensive.