You can learn all of those procedures during years 3 and 4 of your dental school if you go to a good dental school. If you don't go to a good one, then yes there are GPR residencies and CE available for that.
You can also pretend like you're interested in residencies like Endo, OMFS, etc. and try to do externships while you're in dental school, then pretend like you changed your mind and want to do GP, but that's REALLY REALLY mean since you'll be wasting those residents time, so not advisable at all. Also, your dental school GPA has to be comperable to what that specialty typically accepts, otherwise they won't waste their time considering your application. So if your GPA isn't high enough for OMFS, they'll just ignore your application, and I don't know how good of an idea it is to be so forthcoming with them about your true motives. Maybe an OMFS resident can comment about that. But practically speaking, you want to get into private practice without needing any additional training after graduation, and what better way to do that than to extern at a residency program where all they do all day is just that one specialty.