Take a deep breath. Your career is not ended because of this.
-Assuming that the instructor is a hardliner, and assuming that you are less than completely innocent of this (regardless of your intention),
-For now: look up your Uni policies on this. Contact your faculty advisor (and/or a faculty member whom you trust, ideally tenure track), immediately, and start an appeal IF warranted. Discuss with an independent counsel (attorney) if you feel that is a reasonable option. Accusations are not the same as convictions, and mistakes happen. Understand that Professor X might have to deal with this same old $h!t every damn semester, and now he turns it over straightaway to the University Student Spanking Committee rather than deal with it personally.
-IF you did it, accept the consequences for now. If you appeal and you're actually guilty with intent, all you did was to dig the whole deeper.
-When applying to DS: Assuming this is a worst case, ends up on your permanent record, type of situation: Do NOT attempt to hide this occurence. Be honest if asked about it, don't make excuses. Just explain the situation. To me the explanation and "what did you learn from this" mean far more than a check yes / no on the dental app. Lots of us got into DS without perfect records. A good friend of mine had multiple "big stuff" (theft, etc) that he overcame. A solid few have been arrested but lawyered out deals etc. It doesn't mean they aren't good dentists or humans or citizens, it just means we're all kind of dumn until we turn 30-something (hopefully, because I'm still no saint). Just realize that everybody gets "one" f**kup, and you just used yours, so you better keep your nose damn clean until you get that acceptance letter.
Consider this a good lesson in responsibility and the importance of contingency plans. What you intended to say in a conversation isn't always what the other person heard, or in this case, what you wrote vs what the robots read.
Your career isn't over. In fact, I'd say that you are now ahead of the 99.9% of dental students who haven't been sued before they get their degree. You now know the importance of triple-checking your note before you sign that chart, Dr.
Silver linings are golden-
Dr Kyak