Quantitative immunochemistry of salivary proteins adsorbed in vitro to enamel and cementum from caries-resistant and caries-susceptible human adults.

Salivary proteins adsorbed to powdered enamel and cementum from parotid and submandibular saliva (1:1) of caries-resistant (CR) and caries-susceptible (CS) subjects were examined qualitatively by polyacrylamide disc electrophoresis and quantitatively by immunochemical procedures. The electrophoretic patterns showed no consistent difference between enamel and cementum or between CR and CS samples. Quantitatively, there were no significant differences between CR and CS samples, but significant differences between enamel and cementum. On the basis of ng/mm2, enamel adsorbed five times as much acidic proline-rich protein and cysteine-containing protein as cementum and nearly twice as much lysozyme. There were no significant differences in adsorption of albumin and lactoferrin. The lack of difference in the concentration of pellicle proteins in CR and CS subjects may be related to similar findings with parotid and submandibular saliva. The influence of the major differences in surface pellicle proteins between enamel and cementum on the properties of their respective pellicles is uncertain.