XPS Characterization of Dentin and Dentin Treated with Bonding Conditioners

Samples of smear layer dentin prepared with #600 grit paper and treated with various conditioners (Gluma Conditioner, Scotchprep or Tenure Dentin Conditioner) were analyzed using XPS to determine the changes in surface composition as compared with controls of the smear layer or fractured dentin. Dentin treated with phosphoric acid liquid or gel was also analyzed. All of the conditioners lowered the Ca and P on the dentin. While phosphoric acid treated dentin exhibited similar reduction in Ca and P, Si was adsorbed onto the dentin when phosphoric acid etching gels were employed. Surface behavior diagrams were used to illustrate these changes. Micro ATR FTIR was used to confirm both the loss of Ca and P from the phosphoric-acid-etched dentin and the adsorption of the silica from the etching gel. These data are compared with other XPS studies of dentin conditioners and primers.