Why do some people get "red wine teeth" and others don't?

Image: iStock.

Those of us who suffer from ‘red wine teeth’ are easy to spot in a bar. We’re the ones contorting our lips to avoid direct wine-to-tooth contact; swishing water around our mouths between sips and trying to be subtle about it; or sporadically rubbing our fingers across our front teeth.

Yes, a night out is hard when your favourite drop turns your smile a weird shade of bluey-purple. According to Dr Peter Alldritt, Chairman of the Oral Health Committee at the Australian Dental Association, the reason some of us get more dramatic red wine teeth than others comes down to our enamel, which is slightly porous.

“The tannins, which are chemicals in the red wine, are actually absorbing into the surface of the enamel and they tend to take on this bluey, horrible colour,” he explains.

"Some people seem to be prone to it and others aren't. That would be a reflection of varying degrees of porosity in tooth enamel — in general, younger people are going to have more porous enamel than older people."

The good news: enamel gets harder as you get older, so it's likely to also become less porous over time (hurrah!). The bad news: if you've done any kind of tooth whitening recently, it could make your teeth more vulnerable to staining. Kind of ironic, wouldn't you say?

"Whitening toothpaste wouldn’t do it because they're not concentrated enough, but whitening strips or dentist-applied whitening gels tend to be strong enough to open up the porosity in your tooth enamel," Dr Alldritt explains.

"This does settle down after you've finished the whitening process, but during that period it's a shocker. If you're a bride whitening your teeth before your wedding, don't drink red wine on the day. You might be disappointed."(Post continues after gallery.)

Red wine can also cause more longer-lasting discolouration of the teeth in the form of extrinsic stains, similar to those linked to tea, coffee and smoking. Fortunately, Dr Alldritt says these can be polished off the surface and your tooth will look normal underneath.

Another factor that can affect wine's staining powers is the pellicle, a thin, clear coating on your teeth that's made from glycoproteins in saliva and protects your enamel from acid. Brushing your teeth removes this coating, but it will reform within minutes.

"So if you brushed your teeth right now and then drank red wine, your teeth are going to be more likely to stain as there's no pellicle on them. But who's going to do that? The wine would taste shocking," Dr Alldritt says.

The obvious way to prevent red wine teeth is to banish the culprit from your life, but that's no fun. Instead, Dr Alldritt advises you choose your drop carefully; heavy-bodied wines like Cabernet and Shiraz have a higher concentration of tannins than lighter reds like San Genovese and Pinot Noir. (Post continues after video.)

Drinking water will also help to wash away the tannins, especially if you swish it around your mouth.

Unfortunately, Dr Alldritt says white spirits and wines won't have the same effect because alcohol in all forms is acidic, and the aim here is to dilute and neutralise the acidity in your mouth. So no, alternating between red and white (or vodka) won't save you here.

A sly piece of gum can also come in handy, as chewing promotes the production of saliva which then combats the staining.

More generally, Dr Alldritt recommends having your teeth regularly cleaned by a dentist to keep the surface clean.

"A clean and smooth surface is going to be less attractive to staining as opposed to a rough surface. If your teeth have a lot of plague and tartar build-up, they're going to be more prone to staining, so a professional scale and clean will help to minimise the problem."

Does red wine wreak havoc on your teeth? Are you bothered by it?