What Is Plaque? How Dental Plaque Forms and What It Does to Teeth and Gums

Plaque is a biofilm: a community of bacteria that attach to the tooth surface and wrap themselves in a sticky layer. Saliva proteins coat a clean tooth within minutes, bacteria settle on that coating, and the community thickens as more arrive. That is why teeth feel fuzzy or rough by the end of the day.

You cannot rinse it off. The sticky layer holds it to the tooth, so it has to be broken up mechanically, with a brush and with floss or interdental brushes. Mouthwash alone does not do this.

A thin film of plaque is present in every mouth. The problem is plaque left in place for days, because it thickens and changes in character.

On the teeth, bacteria feed on sugars and starches and release acid. Each acid attack dissolves a little mineral from the enamel. Repeated often enough, that becomes a cavity. Eating or sipping sugary things all day gives plaque more feeding time than a sweet taken with a meal.

At the gum line, plaque irritates the gum and the body responds with inflammation. Gums turn red, swell and bleed, which is gingivitis. It is reversible once the plaque is cleared.

If plaque stays for longer, it hardens into tartar, which cannot be brushed off and gives plaque a rough surface to grow on.

Plaque is pale and hard to see. Run a fingernail across a tooth near the gum and a creamy layer may come away, or the teeth may feel furry. Gums that bleed when you brush are often a sign that plaque is sitting along the gum line.

Control means disturbing it every day: brushing twice daily with a fluoride toothpaste, paying attention to the gum line, and cleaning between the teeth once a day, where a brush does not reach. Our guide on how to remove plaque from teeth walks through the technique.

Professional cleaning clears what home care misses. If you are unsure about your gums, the gum treatment page explains what a dentist looks for.