They don’t use it when they absolutely need images to diagnose a problem in your mouth. They use it the moment your insurance company will allow them to make a new set of images.

It’s pretty easy money: Push button, cash check.

Meanwhile, you get exposed to radiation and all the risks that come with it — including brain tumors, as a new study finds that dental images can double your risk or more.

Researchers from Yale, Harvard, and several other institutions interviewed 1,433 people with a type of tumor called a meningioma as well as 1,350 people without the condition matched for age, gender, income, race, and more.

They found that people who had annual “bitewing X-rays” had double the tumor risk, while regular “panorex dental exams” starting before the age of 10 caused that risk to shoot up by 500 percent.

The panorex exam is when a single image of all teeth is taken from outside the mouth, and even starting after the age of 10 boosted the risk. In fact, patients of any age who received annual panorex exams had triple the risk of meningioma.

But is this really a surprise? A dental X-ray is basically a blast of radiation aimed right at your noggin — and while meningioma is still pretty rare and often non-fatal, you certainly don’t want to boost your odds of getting one.

Besides, the risks don’t end there — because dental X-rays can also increase your chance of getting thyroid cancer. A 2010 study, for example, found that people who have 10 or more dental X-rays over the course of a lifetime have 5.4 times the risk of thyroid cancer of people who’ve never been X-rayed.

Throw in the fact that many dentists still work with fluoride and mercury along with all that radiation, and your annual exam could quickly become one of the riskiest things you’ll ever do in the name of “health.”

I won’t say don’t ever visit the dentist. Clean teeth and gums are important to your overall health, and people with bad oral hygiene and gum disease have a higher risk of heart problems.

But when you do visit the dentist, set some ground rules: No fluoride… no mercury… and no X-rays unless they’re absolutely necessary and your dentist has a good reason.

Your best approach is to see a holistic dentist, sometimes referred to as a biological dentist, who is sensitive to these issues.

I’m not done with dental health yet — and if you or anyone you love wears dentures, keep reading for a warning you don’t want to miss.

Simple enough, I know, but too many people skip out on oral hygiene — and that’s especially true when they’re sick.

Big mistake — because that’s exactly when you don’t want to let your guard down: A small study of 37 patients on ventilators found that pneumonia often begins with a dramatic shift in oral bacteria.

And that’s a shift that can be prevented with a toothbrush.

The study didn’t look at how this change in oral bacteria leads to the misery of pneumonia, but other studies have already mapped out the route: Nasty little critters build up in the mouth… and then drip right into your lungs, where they can wreck havoc.

Some studies have even shown that people with deep pockets in the their gums are more likely to die of pneumonia — and that’s another sign of the role these bacteria play, since they just love to hide in those pockets.

In fact, gum pockets are about as cozy a home as a germ could ask for: warm, wet and sheltered.

The Yale University researchers behind the new study say you can minimize your own risk by brushing twice a day with a fluoride toothpaste — and I’d say they got that half right.

Brush twice a day — but skip the fluoride.

Despite what you’ve heard, fluoride isn’t all that great for your teeth. And along with not doing much to prevent cavities, this toxic substance can actually damage your brain and weaken your bones.

Try an all-natural fluoride-free toothpaste instead — and don’t forget to floss, because there’s a lot more than gum disease and pneumonia on the line here.

Just last month, I told you how gum infections can raise your risk of heart attack and stroke. Poor periodontal health has also been linked to everything from obesity to dementia to pre-term births and underweight babies.

Along with brushing and flossing, there’s another simple way to keep your mouth clean and protect your heart at the same time: give up sugar.

Sugar serves as fuel for the bacteria that can damage your teeth and boost your risk of disease. Take away their fuel, and they die.

One more note here: If you do get sick, throw away your toothbrush once you recover. The same bacteria that caused your illness can hide in your toothbrush — getting a free ride back into your body, twice each day.

While that connection has been confirmed by repeated studies over the years, the reason for it hasn’t always been well understood… until now.

Researchers say they’ve found the missing link between dental health and cardiovascular risk–and it turns out the same bacteria responsible for toothaches and gum disease are making their way right into your cardiovascular system.

The problem is the common Streptococcus, the same bacteria that put the “strep” into “strep throat.”

These bacteria are present in the mouth more often that you might want to believe… in fact, they’re almost certainly in your mouth right now.

Don’t panic–because in most cases, they’re harmless.

The problems begin when you let your dental health go to pieces. Bleeding gums offer these bacteria easy access to your insides. In fact, you can think of bloody gums as the entrance ramp to the superhighway of your circulatory system.

And these bacteria are only too happy to hop on and make a beeline for the express lanes.

Anyone who’s seen what too many big trucks do to a highway can appreciate what then starts happening in your arteries: traffic jams. The researchers say the bacteria use a protein on their surface to force the platelets in your blood to clump, creating the clots that can lead to strokes and heart attacks.

And just to show you how clever these guys are–and why they’re so hard to beat–the researchers also found that by causing the clots, the bacteria also create a suit of armor out of platelets, covering them completely and protecting them from antibiotics.

If that doesn’t have you reaching for the floss and mouthwash, I don’t know what will.

Streptococcus isn’t the only oral bacteria that can put a stop to your heart. One study last year found that people with Tannerella forsythensis had a 53 percent increased risk of heart attack, while the presence of Prevotella intermedia led to a 35 percent increase in that risk.

That same study also found that people with the most bacteria in the mouth–any type of bacteria at all–have the highest risk, so the message is pretty clear: Keep your mouth clean and you’ll have a healthier heart.

And that means bleeding gums and painful scaling sessions with the dentist might actually be the least of your worries if you’re suffering from periodontal problems.

New York University researchers looked at 20 years of data on 152 participants in Denmark’s Glistered Aging Study. These subjects were followed for 20 years, starting when they were 50 and ending when they were 70, and they underwent cognitive tests at the beginning and end.

They also had their periodontal inflammation levels measured, and, as it turned out, those who suffered from that inflammation at the age of 70 were nine times more likely to score on the lower end of the cognitive tests than those with no inflammation–putting them at risk for Alzheimer’s, according to the study presented at an International Association for Dental Research meeting in Barcelona, Spain.

A lower dementia risk should be good enough… but of course, that’s not the only reason to make sure you have good oral hygiene.

Repeated studies have found a strong link between healthy teeth and gums and overall cardiovascular health. One study last year found that heart attack victims had higher levels of bacteria in their mouths.

A study earlier this year also found that people who brush their teeth the least had a 70 percent increased risk of problems such as heart attack and stroke compared to those who brush at least twice a day.

But brushing isn’t the only way you can keep the taint off your teeth. Another recent study found that omega-3 fatty acids can help lower your risk for gum disease, so make sure you eat more fish–or at least take a good fish oil supplement.

And of course, skip the sugar–there’s no place for it in a healthy diet anyway, and sugar is the fastest way to dental decay. It’s like soaking your teeth in cola.

If a lower risk for heart problems and Alzheimer’s disease isn’t enough, think about this: Clean teeth and healthy gums will also mean that your visits to the dentist will be shorter… and a lot more pleasant.