Regular brushing, flossing and dental cleanings help rid your mouth of plaque — that gritty, sticky substance that’s deadly for your teeth.

The American Dental Association explains what plaque is and what it can do:

• Plaque is made up of bacteria that stick to your teeth and release acids after you eat. These acids eat away at tooth enamel and contribute to tooth decay and the formation of cavities.
• Plaque buildup creates
  tough-to-remove tartar, which attaches to tooth enamel and the gum line.
• Tartar buildup can lead to gingivitis, an early-stage gum disease that causes inflammation of the gums, irritation and redness. This can progress to a full-fledged gum disease called periodontitis.

Source: HealthDay