Before I say anything, you obviously have not been rejected yet so what I write below may not apply. But please keep it in mind.
I have witnessed so many people apply for professional school and not get accepted. Please know that you are not alone. Whether it's dental school, med school, pharm, speech pathology, or any other competitive program, sometimes the cookie doesn't crumble in your favor. It's frustrating. It is really unfair. And at this point it probably feels like there is not much you can control.
BUT THAT IS NOT TRUE - I have seen quite a few persistent, dedicated, and passionate applicants keep at it for not just 1, but MULTIPLE years. As a matter of fact, when I interviewed at a school this past year they brought in a D4 who applied to that school 5 times. FIVE TIMES.
Now, I'm not sure I would have done 5 cycles without giving up. That's pretty remarkable. But what this student and others like him have taught me is that those who really believe that dentistry is for them and desire to make it happen will stick it through until they MAKE it happen. Of course, its not that simple. Changes have to be made. Specifically, changes that will make you a competitive applicant. For instance, if you had a low DAT score, studying for many extra months and possibly taking extra courses in school to reaffirm your knowledge are a good bet. Taking practice DAT exams to monitor your progress is also a good idea. If you had a low GPA, enrolling in a post-bac program would be worth your while if you can show that you've learned from being rejected (ie, you get a better GPA in a post bac program).
You might be thinking 'woah! this sounds pretty expensive!!! And like SO much work!!' And you're absolutely right. There is no getting around that, and maybe that's why it isn't worth it for you. There is absolutely nothing wrong with that.
But to those who really want it, cost doesn't matter. They are willing to make sacrifices in order to keep striving for their dream. So really you just have to decide whether or not it is worth it for you to keep going. And not because you've come this far. But because you genuinely WANT to keep going. Too many times, people believe that there is no other way. There are many other options! But you have to decide which route is the one for you.
Good luck!