The eyes may be the window to the soul, but oral health can serve as a window into our overall health. The state of our teeth and the soft tissues in our mouth can tell us a lot about how we're doing physically. In fact, experts -- including those at the University of Illinois at Chicago, College of Dentistry -- have linked oral health to general health.

That's why it's important to pay attention to the teeth. Poor oral hygiene can contribute to other health problems, like heart issues. And there's one telltale sign that your mouth isn't as healthy as it could be: a calculus bridge.

To understand calculus bridges, it helps to start with understanding the substance that makes them up. Calculus is, in short, hardened plaque.

You're probably familiar with plaque, the sticky film that can make your teeth feel fuzzy. Plaque contains bacteria that make acid, which can eat away at your enamel (the hard outer coating on your teeth).

Having plaque on your teeth is a natural result of eating. Fortunately, you can clear plaque away on your own. Your toothbrush and floss are enough to remove this film -- and the bacteria in it. In other words, plaque isn't a cause for concern, provided you have good oral health habits.

Plaque becomes a problem when it morphs into something else. Left unchecked, plaque hardens into calculus (also called tartar), and unfortunately, you can't remove this calcified plaque on your own. As it sits on your teeth, it can contribute to tooth decay and irritate your gums, encouraging the development of gum disease.

Sometimes, that hardened plaque becomes an even bigger problem because it spans several teeth. "A calculus bridge forms when the calculus around individual teeth join to form a solid 'bridge' around several teeth," Joseph Dill, DDS, the chief dental officer at Delta Dental Plans Association, explains.

Once it's formed, the calculus bridge can affect your smile. Because calculus can be yellow, brown or even black or green, it might make your teeth look stained. Over time, calculus usually darkens, which means your bridge will become more noticeable the longer it goes untreated.

When you have a calculus bridge, you may be able to see that you have a band of staining near your gum line. That discoloration might extend up your teeth, down under your gums or both.

Speaking of your gums, you might notice symptoms there, too. The calculus can irritate your gums, causing inflammation. You might notice that your gums look redder than normal. They may also bleed more easily. Left unchecked, the calculus can cause your gums to recede, leaving more of your tooth exposed and potentially causing decay or even tooth loss.

There's one more unwelcome symptom to contend with, too. Calculus bridges can cause bad breath.

The answer here is specific to you. As Dr. Alice Boghosian, consumer advisor spokesperson for the American Dental Association (ADA), explains, "Everyone's body chemistry is different, so calculus forms at different rates for different people."

That said, the clock is certainly ticking. In some cases, it only takes a day for plaque to calcify. By day 12, experts say that 60-90% of the plaque left on teeth will harden into calculus.

However, it generally takes weeks for calculus to develop to the point where it connects across several teeth.

That doesn't mean you can go weeks without flossing, though. Once the calculus develops, you can't remove it at home. You'll need a dentist to get rid of it for you. And that means that even a few days of poor brushing and flossing can be enough time for the hardened deposits on individual teeth to connect and form a calculus bridge.

Because you can't get calculus off with a toothbrush or floss, you'll need to turn to the professionals. "A calculus bridge can only be removed by a dental professional," Boghosian says.

Dill says that to get rid of the bridge, dentists use a process called scaling. "[This] is typically performed using hand instruments or ultrasonic devices to remove tartar and plaque bacteria from the tooth and root surfaces above and beneath gums."

If that sounds unpleasant, you don't need to be overly worried. While scaling can be uncomfortable, it's designed with you in mind. "The dental professional will typically use specialized tools such as scalers and ultrasonic instruments to carefully remove calculus deposits from the teeth," Michael J. Wei, DDS, FIADFE, a cosmetic dentist in New York City, explains. "These tools are designed to effectively remove hardened plaque without causing harm to the teeth or gums."

That said, the longer you let the calculus bridge go unchecked, the more involved the removal process becomes. "If the calculus extends below the gumline, a deeper cleaning called root planing may be required to smooth the tooth roots and further remove bacteria," Dill says.

While scaling usually isn't painful because it focuses on the hard exterior of your tooth, root planing can hurt because it brings your soft tissue (i.e., your gums) into play. However, your dentist should numb the area to keep you as comfortable as possible.

Since removing a calculus bridge is an involved and potentially unpleasant process, you probably want to do what you can to avoid one. Dental experts have a few specific steps they recommend here.

If you leave the calculus bridge unchecked, the deposits of hardened plaque can grow. This leads to unwelcome symptoms like tooth discoloration and bad breath.

The bigger problem, though, is the complications that can arise because of the bridge. "The longer the calculus bridge remains in place, the greater the chance of developing more severe dental problems, such as gum disease or tooth decay," Wei explains.

In other words, the calculus bridge makes you more likely to get cavities and have gum problems.

Gum disease is extremely common, affecting about half of the American adult population, per the National Institutes of Health. Like calculus bridges, this issue gets more significant if it goes untreated. If early-stage gum disease (gingivitis) progresses to periodontitis (aka a severe gum infection), it can lead to serious problems like tooth loss.

And that's not all. "It is important to remember that poor oral health is connected to specific health conditions, such as heart disease, diabetes and respiratory disease," Dill points out. "Being diligent with oral health care regimens at home and with the dentist is critical to supporting optimal oral and overall health."

Boghosian sums it up nicely, saying, "Not treating the calculus bridge can lead to gum disease. Regular dental visits will not only treat this condition, but will ensure good dental health and this will contribute positively to overall health."

Ideally, you should see a dentist well before the calculus bridge has a chance to form. Make it a habit to schedule an appointment every six months. "Regardless of whether you have a calculus bridge or not, you should visit your dentist or dental health professional regularly for examinations and cleanings," Boghosian says.

At each appointment, your dentist can remove any calculus that has developed since your last visit. This can prevent a bridge from forming.

Good at-home oral health practices and biannual dental appointments should keep calculus at bay. That said, if you see staining in your teeth or changes in your gums, it's probably time to take action. "If you notice calculus (tartar) building on your teeth, it is vital that you see your dentist as soon as possible," Dill says.

A calculus bridge develops when plaque hardens into calculus, then those hardened deposits connect across multiple teeth. At that point, you can't get rid of the issue at home.

Fortunately, dental professionals have specialized tools they can use to remove calculus. Not only does this get rid of unwanted symptoms like tooth staining and bad breath, but it also protects your overall oral health. Removing a calculus bridge lowers your likelihood of getting cavities or developing gum disease.

Since oral health directly relates to overall health, removing a calculus bridge -- and preventing it from coming back -- can protect your well-being.