Going off of your previous thread, it sort of seems like this switch has stemmed from having to retake your first "premed" class and people telling you to consider other career choices. Unfortunately, getting into dental* school is pretty competitive too. You'll have to keep your GPA as high as possible, score as well as you can on the DAT, be involved in volunteering and shadowing, and hopefully have other ECs that separate you from all the other applicants you'll be competing against.
But, since you're only a freshman, please go and shadow a general dentist for a little bit to see what it entails and make sure you won't be miserable if you had to do that kind of stuff for the rest of your life- don't be hasty in this switch. Orthodontists/OMFS/Pediatric Dentists/etc are all after you complete dental school and require their own kinds of crazy things to get in, and you're going to dental school to essentially be a general dentist. After shadowing, you may find that you don't like it as much as you thought you did and may decide to pursue something else instead 🙂 But, nonetheless, for any career in the healthcare field, you'll need to keep your grades up or else it'll be a tough road ahead for you.