At PostalAnnex+ in Long Beach, we take professional US passport photos, accepted by passport processing agencies. Most stores accept walk-in's, so no appointment is needed, but call the phone number at the top of the screen for your passport photo needs.
This silver sulphide tarnish can be quite easily removed using polishes that contain abrasives to rub off the silver sulphide, but these have the disadvantage of also removing small amounts of silver. Handily, chemistry provides a method which sidesteps this problem.
Plaque can be removed by a toothbrush and floss. Tartar, known professionally as calculus, is solid and require the dental hygienists' instrument to be removed. All that said, you can prevent tartar by brushing a full two minutes, twice a day. Also, floss daily.