The extra fruit we get from smoothies may be good for us, but it isn't so good for our teeth, dental care experts warn.

A recent survey conducted by the British Dental Health Association revealed that 30 per cent of people think that fruit smoothies are good for their teeth.

However, dentists warn that if the drinks are consumed slowly, the sugar and acid in smoothies and fruit juices can cause acid erosion of the tooth enamel.

"It's the smoothie or the other acidic beverages and the more prolonged exposure -- the half-hour sugar bath or acid bath that you're exposing your teeth to -- that causes the damage," Canadian Dental Association president Dr. Deborah Stymiest told CTV.ca.

Smoothies can be a source of fruit and people do not have to avoid drinking them, Stymiest said.

However, they should be consumed relatively quickly, or while eating food, which can help neutralize the acid in the mouth.

"They shouldn't be sitting at their desk with a beverage like that over long periods of time," Stymiest said.

Saliva helps rinse the mouth and keep it at a neutral pH level. But once someone starts eating or drinking, the mouth becomes a more acidic environment, which is made worse by consuming highly acidic foods and drinks.

The mouth can stay acidic for up to an hour, and the tooth enamel can start to slowly break down.

Studies have shown that oral health can have an impact on a variety of health conditions, such heart disease, respiratory illnesses and diabetes.

A study released this week indicated that people with gum disease have an increased risk of getting many common types of cancer.

But Stymiest said that if people are going to the dentist regularly for check-ups, any tooth or gum damage would be noticed early enough to intervene.

The Canadian Dental Association offers tips to avoid tooth decay and gum disease:

• choose sugar-free snacks
• avoid sugar-sweetened soft drinks
• look for fruit juices and drinks that don't contain added sugar
• look for other names for sugar on ingredient labels, such as molasses, liquid invert sugar, glucose and fructose
• avoid eating sticky sweets that cling to teeth
• eat sweets as part of a meal so the increased saliva flow can clean teeth and dilute sugar
• brush your teeth after eating sweets and after each meal, or at least rinse your mouth with water, eat raw vegetables or chew sugarless gum