If you had health insurance through the Healthcare Marketplace, TurboTax will automatically put the deduction where it needs to be when you enter your 1095-A. Don't enter it again elsewhere, or it will be double-entered.
Dental premiums are not reported on the 1095-A, so you can report those in the 'usual' place to report them (in the Medical Expenses section, UNLESS you are self employed).
