Going by these lines (which I think you are quoting)from the NHS Website,I would have said YES
You are also entitled to free NHS dental treatment if you or your partner (including civil partners), receive either:
Income Support
Income-based Jobseeker�s Allowance
Income-related Employment and Support Allowance
Pension Credit Guarantee Credit; or
you are named on, or entitled to (use your award notice as evidence), an NHS tax credit exemption certificate, or
you are named on a valid HC2 certificate.
However,I would ask your Dentists receptionist to clarify it for you.