Prevention of white spot lesions during orthodontic treatment

The most frequent iatrogenic problem in orthodontics is white spot lesions (WSLs). Maintenance of an adequate and constant presence of fluoride ions in the vicinity of the enamel on the periphery of bracket bases helps protect against the development of WSLs. Resin-modified glass ionomer cements (RMGICs) minimize the development of WSLs due to their continuous fluoride uptake from the environment and re-release, but the perception that orthodontic brackets bonded with RMGICs frequently fail due to low initial bracket shear bond strength persists. This perception is correct if the clinician were to bond these materials as recommended by the manufacturers, which includes conditioning the enamel with an extremely weak 10% polyacrylic acid instead of the traditional 37% phosphoric acid etch. In order to successfully use RMGICs, it is recommended to first deproteinize the enamel surface by applying 5.25% sodium hypochlorite for 1 min to remove the acquired dental pellicle (which impedes proper etching of the enamel surface), followed by a 15- to 30-s etching with 37% phosphoric acid (so the resulting etch patterns on the enamel surface are types I and 2, not type 3, thereby increasing bracket bond strength), and followed by moistening the enamel surface to further increase this strength. In following these recommendations, the clinician will minimize the risk to patients of developing lifelong WSLs and their consequences. In the final analysis, the degree of damage provoked by WSLs is vastly more significant on the health of the enamel than the bonding and debonding process. It is the author's hope that this review of the scientific literature will help clinicians achieve the best results for their patients.