The oral cavity supports a rich and diverse microbial population. Oral health is dependent on the maintenance of stable microbial communities; disease occurs when this balance is disturbed and more pathogenic species outgrow the commensals. Health and disease in the mouth are active processes in which the ecology of communities, not of single organisms, is paramount. In this book, expert contributors from around the world provide an update on recent developments in the burgeoning field of oral microbial ecology. The chapters are arranged into five sections: microbial populations in oral biofilms, the structure of oral biofilms, communication and sensing within biofilms, health to disease, and new approaches for oral biofilm control.