Dental bacteria. Animation showing a man lying in a dentist's chair. He opens his mouth and the view zooms in to show the surface of one of his teeth, where bacteria are multiplying. Poor dental hygiene allows the build-up of plaque, which consists of a film of bacteria embedded in a matrix of glycoprotein. If left untreated, bacteria in the plaque produce acids which erode dental enamel, leading to decay and infection.