Quantitative determination of salivary components in the pellicle on PMMA denture base material

The formation of a salivary pellicle is a protective mechanism of the body for all surfaces in the oral cavity. The nature of the substrate may influence the composition of the pellicle. The aim of this study was to investigate the quantitative composition and individual variation of the salivary pellicle formed on denture base material (PMMA). Cylindrical specimens of PMMA were carried in the mouth and then desorbed with a 0.5-M sodium chloride solution. The solution was analysed for total protein, alpha-amylase, total proteases, protease inhibitors, secretory immunoglobulin A, immunoglobulin G, peroxidases, thiocyanate, lysozyme, and calcium content. All investigated salivary components could be found unequivocally in the desorption solution, indicating that a salivary pellicle had formed on the surface of the PMMA. Large coefficients of variation indicate large individual variations in the adsorbed amounts. The data also point to large intraindividual variations for the bound salivary components. Only the protease inhibitors revealed a strong positive correlation of the bound activity to the salivary activity. It is hypothesised that differences in the bound amounts of antimicrobial components might influence the microbial colonisation of denture bases and that protease inhibitors could be meaningful for the spread of the yeast Candida albicans from denture base material to the oral mucosa and thus might be an explanation for different susceptibility to denture base stomatitis.