Re: STRUGGLING IN DENTISTRY, HELP?
I can feel for you a bit. I'm in college currently, just switched out of the pre-dental path, and have a brother who's in his first year at the U of Utah's dental school (who's an ENTP btw).
I feel like one hopeful point you have going for you is that INTPs have a (somebody correct me if I'm wrong here) love of knowledge and that'll kick in sooner or later, especially with science fields. I even got myself to sort've enjoy my Finance 201 class by the end of the semester so there's hope for you yet.
As for getting the material progressively faster, I think a lot of it just comes with time. I struggled with AP bio in high school, but found that the more and more science I learned the faster I could pick it up and I think it'll largely just take time. Most people (as you're probably well aware) go into dental school with some sort of Biology degree and so they've just had time to develop the skill of learning science faster and faster. Also, a lot of them aren't actually learning the material at light speed like it may seem, they just (and this'll hurt a little) already know it because of their background. My brother, for example, got his undergrad in Bio-Chemistry and worked as a Cell Bio and later as a general Bio tutor at our University (BYU) and so despite being in the #1 or #2 dental program in the country he already knew tons of the material already. So when they started learning Cell Bio he recognized they were going through a week's worth of material every day, it just wasn't that hard because he already knew it. He also got a 26 on the Bio portion of the DAT and took grad level Bio before going to dental school. So even just studying for the DAT meaning going backwards for him while for you it was more going forwards (I'd guess) or reviewing pre-req classes you had to take to get into dental school (Not saying that to brag, just pointing out that the people you're competing with probably have a huge head start on the whole life science thing). So the people you're competing with likely aren't learning nearly as fast as it seems, they just came knowing some of the material already and they're more just filling in gaps in their knowledge rather than starting from scratch.
As for the application of everything, and you already know this but I'll say it anyways, it's good to remember that you'll be able to prescribe medications when you're done so it's pretty important to know what they do/how they work on the body IMO. Also, Youtube and KahnAcademy are great for understanding things (KA got me through Chem 105).
So the short answer boils down to the Nike "just do it". Also on the bright side, school will easy up after your second year you know.
And if all else fails, you can say to yourself "At least I'm not in accounting". I switched from Pre-Dent to accounting and have since discovered how miserable it is (for an INTP). Literally the major is learning thousands of rules other people make up for you and then grinding out numbers. The rules are pretty sensible, but the lack of creativity etc. is total misery. I once had an executive from Disney (head of auditing I think) come guest speak at one of my classes. After class ended I went up to him and asked if there was any opportunities for creativity in accounting and he just got silent for a second like he wasn't sure what to say. After stopping for a second he suggested tax since you can look at things from multiple angles.
And props for getting into dental school. It's crazy tough to do I know.