A new technique for the controlled removal of mottled enamel: measurement of enamel loss

Abstract

Aim: To describe and investigate a simple, effective new method for controlled removal of unsightly, malformed surface enamel. Subjects and methods: 22 mottled incisor teeth were chosen from a group of 12 patients, aged 9-15 years. One half of the labial surface of the tooth was covered with a layer of unfilled bis-GMA resin so that it remained unaffected by the procedure. The other half was treated by etching the enamel with 35% phosphoric acid for 30 seconds, washing and drying. The frosted, etched enamel was removed with a composite finishing bur (Jet 7901) running dry in an air turbine, until a shiny enamel surface reappeared. The enamel was then smoothed with a pumice and water slurry in a slow-rotating rubber prophylaxis cup. The bis-GMA resin was peeled off, and an elastomeric impression of the tooth (now with one half of its labial surface treated, and the other untreated) was taken. The treatment of the remainder of the labial aspect was then completed. The thickness of the mid-labial enamel removed was measured directly from the impression by surface imaging, using a confocal microscope. Results: The mean thickness of enamel removed was 164 microns (SD +/− 85 microns). Conclusions: This technique results in equivalent amounts of enamel removal to that claimed for other more complex and time-consuming methods