Objective: The composition of the salivary interface (pellicle) between dental restorations and oral mucosa may be critical to the biocompatibility of the restoration. The purpose of this study was to examine the molecular composition of the salivary pellicle on nickel-chromium alloy in vivo. Method and materials: The molecular components of nickel-chromium pellicle was examined with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analyses. Results: Only limited numbers of salivary proteins were found to participate in the formation of nickel-chromium pellicle in vivo. Salivary amylase and secretory immunoglobulin A were among the proteins identified in the pellicle. Conclusion: In vivo, nickel-chromium pellicle consists of selectively adsorbed salivary proteins. Because both salivary amylase and secretory immunoglobulin A are antimicrobial proteins, it is possible that they play a role in modulating the microbial flora on the nickel-chromium prosthesis.