Yes, if you itemize deductions (Schedule A) you can deduct qualifying out-of-pocket dental expenses and dental insurance premiums (but only if the insurance premiums were paid with after-tax dollars). Most dental treatments qualify for the deduction, although teeth-whitening does not. (See IRS Pub 502: Medical and Dental Expenses for more information.)
The deduction for medical/dental expenses is limited to expenses that exceed 7.5% of your adjusted gross income (AGI). See the FAQs below for more information.
[Edited 02.13.2018 I 03:03PM PST]