Role of salivary and candidal proteins in denture stomatitis: an exploratory proteomic analysis

Denture stomatitis, inflammation and redness beneath a denture, affects nearly half of all denture wearers. Candidal organisms, the presence of a denture, saliva, and host immunity are the key etiological factors for the condition. The role of salivary proteins in denture stomatitis is not clear. In this study 30 edentulous subjects wearing a maxillary complete denture were recruited. Unstimulated whole saliva from each subject was collected and pooled into two groups (n = 15 each), healthy and stomatitis (Newton classification II and III). Label-free multidimensional liquid chromatography/tandem mass spectrometry (2D-LC-MS/MS) proteomics on two mass spectrometry platforms were used to determine peptide mass differences between control and stomatitis groups. Cluster analysis and principal component analysis were used to determine the differential expression among the groups. The two proteomic platforms identified 97 and 176 proteins (ANOVA; p < 0.01) differentially expressed among the healthy, type 2 and 3 stomatitis groups. Three proteins including carbonic anhydrase 6, cystatin C, and cystatin SN were found to be the same as previous study. Salivary proteomic profiles of patients with denture stomatitis were found to be uniquely different from controls. Analysis of protein components suggests that certain salivary proteins may predispose some patients to denture stomatitis while others are believed to be involved in the reaction to fungal infection. Analysis of candidal proteins suggests that multiple species of candidal organisms play a role in denture stomatitis.