My son’s chavrusah is doing that after 6 years in kollel. His program required 2 years of sciences( he was still able to go to first seder during that time) and then 4 years dental school. Note, however, that during a depressed economy many people have cut back on going to the dentist as a luxury.
The academic requirements are similar to medical school, though with a different test. You need an undergraduate degree. A dubious yeshiva degree will work provided you take the required science courses at a reputable school – though a bechelors with premeds from a reputable school certainly help with admission.
And do you really want to spend your life cutting up other people’s mouths.
Being a dentist is a great profession for someone who doesnt mind doing such type of work. Its also a very well paying job. If you want to do it, go for it! Lots of luck
My timeline assumed you would get a new undergrad degree from like touro which I think could be done in two intense years if you transfer yeshiva credits and include all three summers.
If using yeshiva degree (is that ever done for dental school?), then you can do a postbac program in like a year and half.