Tooth discolouration is caused by both external and internal stains. Professional teeth cleaning and polishing are very effective at removing these surface stains. Once the external stains have been removed and the tooth surfaces cleaned and polished the teeth whitening gels are applied and absorbed deep into the internal tooth structure breaking down the dark stains.
Any surgical or invasive procedure carries risks, and we recommend seeking a second opinion from an appropriately qualified health practitioner before proceeding.