40 minutes.
That's how long our teeth are left vulnerable and defenceless after eating a candy (or any quickly digested carbohydrate), according to Alexandra Sheppard, dental hygienist with the University of Alberta's Faculty of Medicine and Dentistry.
"Every time we eat a fermentable carbohydrate, those that break down fast like raisins or toffee or white bread, the pH level in our mouth drops from a 7 to 5.5. That's when the cavity process starts," said Sheppard, Assistant Director of Dental Hygiene Clinical Education.
"It takes 40 minutes before the saliva rebuffers and returns to 7-when Ph has protective effects. In the meantime, the tooth weakens, white spots can result and in general the integrity of the tooth is in peril."
So will eating one candy give you a cavity?
"No," said Sheppard. "But on occasions like Halloween, the issue is how frequently we expose our teeth to fermentable carbohydrates. We tend to graze throughout the day. You might eat a tiny Twix bar at lunch, a tiny Mars bar in the afternoon, and another one later."
Those 40 minutes of time when teeth are vulnerable to bacteria start to add up, she added.
Here are a few quick and easy tips to help kids (and adults) protect teeth while savouring the Halloween haul, and help reduce the high rates of cavities in children between 6 and 11 (57 per cent!).
•Choose sugar-free candy and chewing gum, or chocolates and powdery candy (which dissolve quickly in the mouth) over toffees, lollipops or other hard treats, according to the Canadian Dental Hygienists Association. "The less time that sugar is in contact with the teeth, the better," said Sheppard.
•Eat candy once a day. Instead of spreading out the treats, Sheppard recommends eating candy once a day, preferably after a meal that contains an apple, nuts or cheese, which helps return the saliva to its protective ph quicker.
•Brush your teeth immediately after eating fermentable carbohydrates, but wait 30 minutes to brush after drinking acidic beverages like sugary soda and juice. "Otherwise you will just be spreading the acid around on the teeth," said Sheppard.
•If there are no other options, swish water around your mouth after eating sugary foods.