Los Angeles, California - From flossing possibly getting the kibosh to getting cavities on a sugar-free diet, it is easy to get confused when it comes to dental care.

USC News spoke with experts from the Herman Ostrow School of Dentistry of USC to get their take on your teeth.

We want to know: Does flossing work?

A 2011 systematic review — meaning researchers combed applicable research to come up with a report — came to a startling conclusion: There was limited evidence showing flossing works.

But, USC dentists say, do not toss the floss.

• "When there’s not enough evidence, one needs to ask: Is it because there weren’t enough studies?" ~ Mahvash Navazesh

“When there’s not enough evidence, one needs to ask: Is it because there weren’t enough studies?” said Mahvash Navazesh, a professor at the Ostrow School and an expert on clinical research.

The study didn’t examine how effective the flossing was, whether people were flossing correctly or using the best method for their teeth. There’s also a limited amount of research on flossing, Assistant Dentistry Professor Yaara Berdan points out.

The biggest thing to remember about dentistry, like all medicine, is that it’s personal, said Navazesh.

Someone with crowding, or limited space between teeth, would need to floss to get debris out and prevent tooth decay, inflammation or infection, Navazesh said. But for another patient with gaps between their teeth, the dentist might advise brushing alone to get remove debris and bacteria.

Going to the dentist

Dental care is primarily preventive so there’s a built-in incentive to go to those twice-yearly appointments.

But, interestingly enough, dentists didn’t come up with that timetable. In the 1950s, Pepsodent ran an ad, urging folks to pick up their toothpaste along with a bit of advice. “They said, ‘See your dentist twice a year,’ and it stuck,” Berdan said.

How often you go should be determined by your dentist, Navazesh said. Dentists take into consideration your health, nutrition and your propensity to tooth decay.

Patients who have medical issues, are prone to cavities or have poor nutrition may be advised to visit the dentist more often — perhaps a few times a year. But patients who present few issues might be told to pop in once a year.

Generally, two visits a year is a good rule of thumb. For one, dentists are looking for a lot more than just plaque and cavities.

“Most patients don’t even know they just had an oral cancer screening,” Navazesh said.

Dentists are trained to screen for autoimmune disorders, such as Sjogren’s syndrome, heart disease, diabetes and skin cancer.

“In reality, there are medical conditions that may affect your mouth before you even have been diagnosed with it,” she said.

A visit to the dentist might catch issues like decay early on, perhaps solving it with fluoride and staving off fillings or even root canals.

No sugar, no cavities? No

It’s true that sugar is the big culprit with cavities. But what about folks who don’t have a sweet tooth and still get them?

Navazesh said genetics may be at play. Certain people have proteins in their saliva that act as a protectant, keeping sugar from sticking to the enamel of the tooth. Those lacking the proteins might get decay, even if they avoid sugar.

In fact, some research shows moms could even pass them on to their babies, Navazesh said.

Regardless, there are a few ways to keep tooth decay at bay.

For one, if you do consume sugar, consume it quickly, Berdan said.

“Let’s say you have a Coke and take sips throughout the day,” she said. “That person who is continually exposing themselves to sugar is going to have a higher incidence of decay.”

Fluoride, found in most toothpaste, can turn back the clock on early signs of decay, Berdan said. To let it set in, spit after brushing your teeth, rather than swishing out with water.

Also, make sure to brush before bed.

• "I tell kids to brush after every meal but if you’re going to only brush once, brush before you go to bed." ~ Yaara Berdan

“I tell kids to brush after every meal but if you’re going to only brush once, brush before you go to bed,” Berdan said.

During the day, saliva and talking moves debris around the mouth and keeps it from sticking on teeth. At night, salivary glands slow down and bacteria gets to hangout, undisturbed.

To whiten or not to whiten?

Head into any big-box retailer and the toothpaste aisle is littered with one glittering word: whitening.

Whether whitening products bother your teeth is entirely personal, Navazesh said. Some people might use them all the time with zero issues while another patient might experience sensitivity.

An important place to start is to make sure the product has the ADA seal of approval, which means it was approved by the American Dental Association, seen as the gold standard for dental safety and efficacy.

Berdan advises not using whitening products for prolonged periods.

“Some whitening toothpastes may be too abrasive and long-term use may damage the enamel,” she said.