SURFACE-MORPHOLOGY AND CHEMICAL CHARACTERIZATION OF ABRASION EROSION LESIONS

Purpose: To describe the dentin surface morphology of abrasion/erosion lesions and to chemically characterize in vivo samples of sclerotic d entin. Materials and Methods: Baseline polyvinylsiloxane impressions o f eight in vivo caries-free lesions were taken. Dentin was collected f rom retention grooves for FTIR photoacoustic spectroscopic analysis. T he cavity preparation was etched for 30 seconds with 37% phosphoric ac id, rinsed, and dried. Impressions were taken of the etched surfaces. Epoxy resin dies were made of baseline and etched impressions, sputter -coated and examined at x1000 with the SEM. Results: Lateral dentin tu bule orientation was observed at gingival margins and on occlusal wall s. Open cross-sectional tubules were seen at the depth of the groove. The mineral/protein ratio in the FTIR/PAS spectra of in vivo unetched sclerotic dentin samples suggested an increased mineral content.