Sometimes teeth have either brown or white stains which are not amenable to whitening alone. These stains are normally caused by a decalcification process of some sort (white stains) or by a defect created during tooth formation, such as fluorosis, which is too much fluoride intake during tooth development. Fluorosis can cause severe brown stains which are within the enamel layer of the tooth. Often these types of stains lighten significantly with whitening but are not eliminated without further treatment.
Micro-abrasion uses a mixture of hydrochloric acid and pumice, which is an abrasive agent. This mixture is rubbed onto the tooth surface repetitively until the outer layers of enamel containing the stains are abraded away. If the stains are in the outer layers of enamel they can be successfully removed, leaving a smooth, glassy enamel surface as the finishing result. The surface has been demonstrated to be more caries resistant than the original surface.
- The teeth are isolated with a rubber dam, which is a plastic sheet, this is in order to protect the lips and gums from coming into contact with the acid.
- The slurry of pumice and acid is applied to the tooth/teeth and rubbed in.
- The slurry is rinsed with water and the results evaluated.
- The process is repeated until the stain has gone, or is stopped if the enamel is getting too thin or if the tooth is becoming sensitive.
- The teeth are covered with fluoride gel to reduce post operative sensitivity.
- This technique can be used alone or combined with tooth whitening or bonding, this is where a tooth coloured filling material is applied to the tooth afterwards.