Point of Care December 2008/January 2009

Background Restorative dentists and orthodontists have described severely fluorotic teeth as the most difficult surface for bonding.1,2 The difficulty arises from the composition of the enamel of such teeth, which has an acid-resistant, hypermineralized outer layer. As a result, it is very difficult to mechanically treat the surface with conventional 37% phosphoric acid to allow for effective bonding.3 Further, the subsurface of the fluorotic enamel has defects that exacerbate the difficulty of etching the surface. Fluorosis manifests as irregular and unsightly brown or white opaque lines, pits, striations or cloudy areas (Fig. 1). The esthetic appearance of the dentition is often a concern for patients with fluorosis, and they frequently receive composite or laminate veneers, or they undergo microabrasion or bleaching. Scanning electron microscopy has been used to compare fluorotic and nonfluorotic teeth previously treated with 37% phosphoric acid. These studies confirmed that the fluorotic teeth had fewer irregularities from the etchant; they also demonQ u E s t i o n 1