Yeasts are occasionally seen in oral biofilms, most often Candida albicans. They are pathogenic and can cause the same inflammatory reactions as bacterial pathogens, even in their absence. Yeasts are pleomorphic, the hyphal and bud or cyst forms having distinctly different morphologies. They are easily identified via Phase Contrast Microscopy of oral biofilms. These images were captured with a BioScan Phase Contrast Video microscope from OraTec Corporation.