I was on FaceBook earlier today and read a post from one of my non-dental friends. She was lamenting how desperate she was to chew gum, as she had just had a crown cemented and her dentist told her she had to wait twenty-four hours before she could chew gum. As I read it I began to wonder what things my team and I tell patients purely out of habit, or based on hearsay or myth versus being grounded in science.
So I started to listen in as I walked through the halls. One of the first things I heard was the instruction not to eat or drink for thirty minutes being given to a hygiene patient as they were being dismissed. I have been telling this to patients for more then a decade, and I think I remember it being the instructions after fluoride trays. We are no longer using trays for fluoride treatments and apply fluoride varnish instead. In truth I wasn’t completely certain I knew the correct post-op instructions for fluoride varnish. so I went to the web for my answer.
Low and behold the fluoride varnish I currently use from 3M, called Vanish Varnish, doesn’t have a thirty-minute wait for eating and drinking. The manufacturer instructions say the patient can eat or drink immediately after application. However, they should leave the varnish in place for a minimum of four hours. So that means no brushing or flossing during that time period and they should be careful about crunchy or hard foods. Now there’s an instruction I wouldn’t have given unless I had looked it up.
I have searched and searched the web and cannot find any recommendation to wait twenty-four hours before chewing gum after having a crown placed. Most of the current cements reach their maximum set and flexural strength in less then fifteen minutes, and if they are polymerized with light, polymerization is in the 90% range during placement. For myself, I’ll be on the lookout for where I hold onto myths from the past.