The 1 Unfair Reason Your Teeth Decay Despite Following Your Dentist's Advice

I can't believe I didn't know this.
Serhii Prystupa via Getty Images

Let’s say you’re an absolute dreamboat of a dental patient. You floss every day (before you brush, taking care to go the extra couple of mm into your gums pros recommend). You brush your teeth a minimum of twice a day and don’t rinse the paste out. You even avoid sugar, for the most part.

So why are your teeth still bothering you?

Well, according to Dr. Ellie Philips, a doctor of dental surgery who specialises in preventative dental care, the answer could lie in XX chromosomes.

In a recent TikTok, she shared that ”[cis] women’s teeth are very different from [cis] men’s” ― and the variations could lead to more cavities and other dental issues among fellow wombmates.

Why are cis women’s teeth so different to cis men’s?

It’s all because those with XY chromosomes are a bit more basic (in terms of saliva acidity, anyway).

“I hear all the time... [cis] women telling me, ’Hey, I take so much care of my teeth, I always attend dental cleanings, I floss, I brush, I do everything I’m told to with my teeth, [but] I have cavities, I have gum disease I have gum recession,” the dentist revealed.

Meanwhile, she says, their cis male counterparts have perfect teeth without as much effort. So ― why?

“Let’s take a step back,” Dr. Philips said. “I was at dental school in the ’60s. And it was fascinating, because I was trained to believe the pH of our saliva was seven.”

“It took me years, and it took me to get a pH meter and actually test all the people I could find in my environment, to discover that [cis] women’s pH level is not [typically] seven,” she added. “It’s frequently six. It’s frequently 5.5.”

A 2016 study seems to back her up ― “salivary pH values were significantly lower in [cis] females than that in [cis] males” both before and after participants’ mouths were exposed to citric acid, the research found. The lower the pH, the higher the acidity.

And as Dr. Philips points out, “an acidic saliva in your mouth... can be the very reason your teeth are weakening, that you are promoting plaque in your mouth, that you’re getting gum disease ― acidic saliva is really damaging to oral health.”

Why do we think saliva has a pH of seven?

Well, basically because the studies tended to be done by, and on, cis men, Dr. Philips suggests.

After all, “who was a dental student in the ’50s [when many of these studies were conducted]? Not [cis] women,” the doctor said.

For those who fall outside that outmoded study group, Dr. Philips suggests that “you need to understand that your salivary pH fluctuates. [AFAB people] have cycles” when it comes to our saliva.

What can we do about it?

“The dream is that xylitol is easy to obtain these days,” Dr. Philips says.

“And when you put xylitol ― even a tiny, one-gram amount ― on the tip of your tongue, you will stimulate a flow of saliva into your mouth.”

This results in “stimulated saliva,” which Dr. Philips says has “all the minerals you need, all the things in the cells you need to fix your gums. It’s your repair system.”

A 2014 paper found that “xylitol, a five-carbon sugar polyol, has been found to be promising in reducing dental caries disease and also reversing the process of early caries.”

It’s a sweet substance found naturally in foods like strawberries, plums, oats, mushrooms and lettuce. It’s also used as an artificial sweetener in foods like chewing gum and even toothpaste ― though be careful to keep it away from dogs, as it’s poisonous to them.

Healthline also advises avoiding black coffee, waiting a while after consuming acidic foods before you brush your teeth, skipping the sugary drinks, and staying hydrated in order to keep your saliva’s pH on the more alkaline side.