Fluorosis is the deterioration of enamel mineralization due to high fluoride levels in drinking water, resulting in aesthetic defects ranging from widespread opaque white lines to deep brown pits on the surface. Enamel microabrasion, used in treatment, involves removing an average of 50 to 200 microns of tissue from the top layer of enamel by applying silicon carbide abrasive pastes with 6.6% or 10% hydrochloric acid at a low speed to the tooth surface. Transillumination (examining the depth by shining light on the tooth from behind) is used to determine the depth limit; if the stains extend deeper than one-third of the enamel, i.e., close to the dentin border, the microabrasion procedure should be stopped. Otherwise, the enamel layer will thin excessively, reflecting the underlying yellow dentin and creating a more aesthetically unappealing and sensitive surface; in this case, treatment should be supplemented with laminates or bonding.
