Dental biofilm or plaque is a causative factor for caries and periodontal disease.

Dental biofilm is an almost colourless sticky bacterial film, which adheres to the tooth surface. It is not removed by rinsing with water.

The accumulation of dental biofilm or plaque around the gum margin leads to the development of gingivitis in most people. The longer the plaque is left, the greater the risk of developing gingivitis. Thus, daily careful plaque removal is required to prevent gingivitis. The most important plaque control method is toothbrushing, and should be established as a daily routine from early childhood. Plaque is also involved in causing dental decay. When foods containing sugars are eaten, the bacteria in plaque break down the sugars and acid is produced. This acid then dissolves the surface of the enamel under the plaque, causing dental decay
(caries). Plaque is difficult to see, which makes it difficult to remove. A special dye in the form of a disclosing tablet can be used to stain the plaque making it easier to see. These tablets are available in most pharmacies and are an aid to plaque removal. A more detailed discussion of the factors influencing the decay process and methods for the control of plaque is given here.