Starchy foods can play havoc with your teeth and gums by promoting plaque.
Plaque is a thin, invisible film of sticky bacteria and other materials that covers your teeth. When sugars or starches come in contact with plaque, the acids that result can attack teeth for 20 minutes or more after you finish eating. Repeated acid attacks can lead to tooth decay, and plaque buildup can result in gum disease. Plaque also produces toxins that attack gum tissues and bone support teeth.
While some foods invite tooth decay, others help fight plaque buildup.

The good guys

• Fiber-rich fruits and vegetables. Foods that contain fiber can help reduce plaque by scrubbing against it and dislodging it from teeth and gums. They also tend to stimulate the flow of saliva, which is your best natural defense against cavities and gum disease – although it's not nearly as effective as flossing your teeth once a day and brushing them daily in the morning and at night.

• Cheese, milk, plain yogurt and other dairy products. The calcium in cheese (another saliva generator) and the calcium and phosphates in milk and other dairy products help put back minerals your teeth might have lost due to other foods.

• Green and black teas. Both contain polyphenyls that kill or suppress plaque bacteria.

• Sugarless chewing gum. This great saliva generator removes food particles from your mouth.

• Foods with fluoride. Fluoridated drinking water, or any product made with it, helps your teeth.

The longer plaque triggered bacteria remains in your mouth, the more damage they can do. it's not so much the amount of sweets you eat, but how often you consume them. Eating one piece of candy per hour will cause more damage than eating 10 of them at the same time.

The bad guys

• Sugary candies and sweets that stick in your mouth. Go for sweets that clear out of your mouth quickly. So it's thumb down for lollipops, caramels and cough drops that contain refined sugar. Surprisingly, it's thumbs up for chocolate, which – because its sugars are coated in fat – slides easily away from gums and teeth.

• Carbonated soft drinks. Besides being laden with sugar, most contain phosphoric and citric acids that erode tooth caramel.

• Sports drinks, energy drinks and highly sugared teas and lemonades. Their high sugar levels promote tooth decay.

• Items that dry out your mouth, including alcohol and many medicines. Drink plenty of water, and do not forget to visit your dentist every six months for a checkup and cleaning that will help keep plaque bacteria at bay.