Should I tell my dentist that I have hepatitis c?

Absolutely. While we treat sterilization of instruments and operatories the same either way... It may be important for your best care for your dentist to know and properly care for you.
Hep C and dentist. The dentist should be practicing with standard precautions for you and all their patients - to protect themselves, you and the other patients. Nonetheless it is a principle to keep your health care professionals informed about all your history not an edited list... So yes you should tell your dentist.
Absolutely. Should be on your medical update. This is extremely important. If the dentist contracts this, then they may infect others, as well as lose their career.