Cover photograph (Courtesy of Manfred Rohde, HZI Braunschweig; reprinted with permission): Biofilm comprised of two pathogens that are found in the oral cavity, the fungus Candida albicans (red) and the caries-promoting bacterium Streptococcus mutans (light brown). A Merlin field emission scanning electron microscope (Zeiss, Oberkochen, Germany) was used. Color was added through Adobe Photoshop CS5. (See related article on page 1047.)