What is meant by "professional prophylaxis " to treat tooth discoloration. my teeth are cleaned every 6 months but brown stain remains.?

Cleaning: A prophylaxis is a teeth cleaning. Most of the extrinsic stain can be removed with this procedure. Tooth whitening procedures may help diminish internal staining

DDS or Hygienist: If the stain remains after the cleaning it is intrinsic (coming from within the tooth) rather than extrinsic ( on the surface of enamel).

In case: Of decalcification, the enamel becomes weakened and become porous, therefore, it is susceptible to take in color from foods and drinks, e.g., tea, coffee, soy sauce, etc... Nicotine and heat from smoking cannot only damage teeth but bone and gum tissues as well. It cannot simply be polished away in this condition but bleaching and flouride will help if the surface is still smooth.

Professional Clean: Your dentist is more than likely going to use a combination of pumice and some type of acid or peroxide to try and scrub your stains away. I have seen great success with this technique. Follow up with bleaching for your best result.