Another episode of our occasional feature, Science Fact or Science Fiction. From time to time, we present a commonly held idea or popular saying - and ask a Canadian scientist to set us straight on whether we should believe it or not. And a week after Halloween, with lots of leftover candy still lying around, we have a very topical belief to put to the test: - "More sugar leads to more cavities".

To get at the root of this idea, we contacted Dr. Ferne Kraglund, an Assistant Professor in the Faculty of Dentistry at Dalhousie University in Halifax. She says it depends on how long the sugar is in your mouth.