Can tooth decay spread

Tooth Alert: Are Cavities Contagious?

Friday, April 1, 2011 — Colds, chickenpox, and even yawns are contagious. But did you know that cavities can be catchy too?

Despite your mother’s finger-wagging, sugar-laden candy bars aren’t the only cause of cavities. Tooth decay actually results when bacteria in your mouth feed on food debris (starchy, sticky foods are a primary culprit) and produce acid as a byproduct. This mix of food, acid, saliva, and germs clings to your teeth as a filmy substance called plaque, which can erode teeth enamel and cause cavities to form.

No matter what you eat, cavities won’t form without the help of such bacteria. These germs can spread from mouth to mouth via shared food and utensils, sneezing, kissing, and more, according to Edward “Trey” Wilson, DDS, a dentist in private practice in New York City and New Hope, Pa. — making cavities contagious.

One study in the Australian Dental Journal pegged tooth decay as one of the most common infectious oral diseases. Researchers found that 30 percent of 3-month-olds, 60 percent of 6-month-olds, and nearly 80 percent of 2-year-olds were infected with cavity-causing Streptococcus mutans bacteria, a strain that’s especially likely to cause cavities.

Researchers believe that children “caught” the germs from their mothers; those with a history of cavities were more likely to pass the bacteria along to their children.

So does this mean you should avoid smooching with someone who has a horrible track record at the dentist? Not for dental health reasons, at least: As an adult, you’re far less susceptible to bacteria spread than children because they haven’t built up immunity yet, says Dr. Wilson.

Here are Wilson’s tips for preventing cavity spread in your family:

  1. Go to the dentist. Nearly half of adults skipped the dentist in 2009, according to the U.S. Centers for Disease Control and Prevention (CDC). But to keep from passing on a cavity, your first step should be to schedule a dental check-up. “Every adult needs to be screened for tooth decay,” says Wilson. While warning signs such as tooth sensitivity, pain, or visible holes in teeth are cavity clues, one of the biggest mistakes patients make is to avoid the dentist until they’re in pain. Regular cleanings (every six months) can help prevent decay from turning into cavities and reduce levels of cavity-causing (and cavity-spreading) bacteria in your mouth. According to CDC data, 23 percent of adults have untreated cavities.
  2. Use a heavy-duty mouth rinse. If a cavity has formed, you’ll need a filling. But for early-stage decay, your dentist can prescribe mouth rinse with chlorhexidine, a powerful antiseptic that fights off bacteria and can prevent decay from developing into cavities.
  3. Chew sugar-free gum between meals. Pick a brand with the artificial sweetener xylitol, and chew it three times a day for at least five minutes, Wilson advises. Xylitol boosts saliva production, which helps fight off bad bacteria.
  4. Don’t overshare. If you have young kids, avoid sharing utensils with them or tasting food before serving it to them. Cover your mouth when you sneeze, and if you’re really concerned, “maybe kiss your kid on the cheek instead of the lips,” says Wilson.
  5. Be a good dental patient. This time, heed the hygienist’s advice: Brush frequently (in the morning, at night, and after meals), floss daily, and put a cap on sugary drinks and snacks — and instill the same tooth-friendly habits in your kids. With infants, clean your baby’s teeth with a soft cloth or gauze pad as soon as they start to come in; you can switch to a soft toothbrush when more teeth emerge.
  6. Forgo fancy water. You may also want to consider switching your family from bottled water to tap. Most tap water contains fluoride, which helps teeth build up resistance to plaque.

Related: 10 Bad Habits That Can Harm Your Teeth

The bottom line: “We’re not talking about a fatal disease here,” says Wilson. “But tooth decay is a communicable disease, and it can be prevented.”

The Tooth Decay Process: How to Reverse It and Avoid a Cavity

Information for Parents of School-Age Children

You probably know that a dental cavity is a hole in a tooth. But did you know that a cavity is the result of the tooth decay process that happens over time? Did you know that you can interrupt and even reverse this process to avoid a cavity?

This web page explains how the tooth decay process starts and how it can be stopped or even reversed to keep your child from getting cavities.

What’s inside our mouths?

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Our mouths are full of bacteria. Hundreds of different types live on our teeth, gums, tongue and other places in our mouths. Some bacteria are helpful. But some can be harmful such as those that play a role in the tooth decay process.

Tooth decay is the result of an infection with certain types of bacteria that use sugars in food to make acids. Over time, these acids can make a cavity in the tooth.

What goes on inside our mouths all day?

Throughout the day, a tug of war takes place inside our mouths.

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On one team are dental plaque–sticky, colorless film of bacteria–plus foods and drinks that contain sugar or starch (such as milk, bread, cookies, candy, soda, juice, and many others). Whenever we eat or drink something that contains sugar or starch, the bacteria use them to produce acids. These acids begin to eat away at the tooth’s hard outer surface, or enamel.

On the other team are the minerals in our saliva (such as calcium and phosphate) plus fluoride from toothpaste, water, and other sources. This team helps enamel repair itself by replacing minerals lost during an “acid attack.”

Our teeth go through this natural process of losing minerals and regaining minerals all day long.

How does a cavity develop?

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When a tooth is exposed to acid frequently — for example, if you eat or drink often, especially foods or drinks containing sugar and starches — the repeated cycles of acid attacks cause the enamel to continue to lose minerals. A white spot may appear where minerals have been lost. This is a sign of early decay.

Tooth decay can be stopped or reversed at this point. Enamel can repair itself by using minerals from saliva, and fluoride from toothpaste or other sources.

But if the tooth decay process continues, more minerals are lost. Over time, the enamel is weakened and destroyed, forming a cavity. A cavity is permanent damage that a dentist has to repair with a filling.

How can we help teeth win the tug of war and avoid a cavity?

Use fluoride

Fluoride is a mineral that can prevent tooth decay from progressing. It can even reverse, or stop, early tooth decay.

Fluoride works to protect teeth. It . . .

  • prevents mineral loss in tooth enamel and replaces lost minerals
  • reduces the ability of bacteria to make acid

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You can get fluoride by:

  • Drinking fluoridated water from a community water supply; about 74 percent of Americans served by a community water supply system receive fluoridated water. (If you have well water, see “Private Well Water and Fluoride” from the Centers for Disease Control and Prevention.)
  • Brushing with a fluoride toothpaste

If the dentist thinks your child needs more fluoride, he or she may –

  • Apply a fluoride gel or varnish to tooth surfaces
  • Prescribe fluoride tablets
  • Recommend using a fluoride mouth rinse

About Bottled Water

Most bottled water does not contain enough fluoride to prevent tooth decay. If your child drinks only bottled water, talk with a dentist or doctor about whether your child needs additional fluoride in the form of a tablet, varnish, or gel.

Keep an eye on how often your child eats, as well as what she eats.

Your child’s diet is important in preventing a cavity. Remember . . . every time we eat or drink something that contains sugar or starches, bacteria in our mouth use the sugar and starch to produce acids. These acids begin to eat away at the tooth’s enamel.

Our saliva can help fight off this acid attack. But if we eat frequently throughout the day — especially foods and drinks containing sugar and starches — the repeated acid attacks will win the tug of war, causing the tooth to lose minerals and eventually develop a cavity.

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That’s why it’s important to keep an eye on how often your children eat as well as what they eat.

Tooth-friendly tips:

  • Limit between-meal snacks. This reduces the number of acid attacks on teeth and gives teeth a chance to repair themselves.
  • Save candy, cookies, soda, and other sugary drinks for special occasions.
  • Limit fruit juice. Follow the Daily Juice Recommendations from the American Academy of Pediatrics.
  • Make sure your child doesn’t eat or drink anything with sugar in it after bedtime tooth brushing. Saliva flow decreases during sleep. Without enough saliva, teeth are less able to repair themselves after an acid attack.

Make sure your child brushes

Brushing with fluoride toothpaste two times each day is important for preventing cavities.

Be sure to supervise young children when they brush. Here’s what you should know:

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  • For children aged 3 to 6, you put the toothpaste on the brush. Use only a pea-sized amount of fluoride toothpaste. (In children under age 2, dental experts recommend that you do not use fluoride toothpaste unless a doctor or dentist tells you to.)
  • Encourage your child to spit out the toothpaste rather than swallow it. Children under 6 tend to swallow much of the toothpaste on their brush. If children regularly consume higher-than-recommended amounts of fluoride during the teeth-forming years, their permanent teeth may develop white lines or flecks called dental fluorosis. Fluorosis is usually mild; in many cases, only a dental professional would notice it.
  • Until they are 7 or 8 years old, you will need to help your child brush. Young children cannot get their teeth clean by themselves. Try brushing your child’s teeth first, then let them finish.

Talk to a dentist about sealants

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Dental sealants are another good way to help avoid a cavity. Sealants are thin, plastic coatings painted onto the chewing surfaces of the back teeth, or molars. Here’s why sealants are helpful: The chewing surfaces of back teeth are rough and uneven because they have small pits and grooves. Food and bacteria can get stuck in the pits and grooves and stay there a long time because toothbrush bristles can’t easily brush them away. Sealants cover these surfaces and form a barrier that protects teeth and prevents food and bacteria from getting trapped there.

Since most cavities in children and adolescents develop in the molars (the back teeth), it’s best to get these teeth sealed as soon as they come in:

  • The first permanent molars called – “6 year molars” – come in between the ages of 5 and 7.
  • The second permanent molars – “12 year molars” – come in when a child is between 11 and 14 years old.

Take your child to the dentist for regular check-ups

Visit a dentist regularly for cleanings and an examination. During the visit the dentist or hygienist will:

  • Remove dental plaque
  • Check for any areas of early tooth decay
  • Show you and your child how to thoroughly clean the teeth
  • Apply a fluoride gel or varnish, if necessary
  • Schedule your next regular check-up

NIDCR would like to thank Dr. Margherita Fontana, an expert in cariology at the University of Michigan School of Dentistry, for scientific review of this material.

You might be surprised by the answer! Most of us believe cavities are the result of sugar and lack of oral hygiene. While these things contribute to cavities, the true source is something that actually can be “contagious”. Today, our pediatric dentist from Katy, TX explains how cavities come to be and what we can do to avoid them.

In a way, cavities are “contagious” because they are caused by a bacteria called mutans streptococcus, which can be transmitted by saliva. The bacteria consume sugar that’s left in the mouth and turn it into acid that damages the hard enamel of the teeth.

Plaque is a combination of sugar, food debris, bacteria, and acid. When children do not remove plaque by brushing and flossing, it can harden into tartar. This can result in extreme tooth decay and eventually, cavities!

While genetics do play a part in how strong our teeth are, the bacteria that are passed from parents to children are a much more likely cause of cavities. So what’s a parent to do? Here are four easy ways to keep your children from getting the cavity-causing bacteria:

1. Avoid sharing utensils

Families share everything. Bathrooms, clothes, food, you name it! But maybe it’s time to stop that habit, especially with your eating utensils… You wouldn’t share a toothbrush with your child, so why would you share a fork? These items carry bacteria from our mouths and they can spread them to other members of our family. Next time you want to share a bite of your mac n’ cheese with your little ones, tell them to grab their own fork!

2. Clean pacifiers in the sink, not your mouth.

If your child has left some banana or milk on their pacifier from a prior meal, you’ll want to clean that under the faucet with water and soap. Many parents get in the habit of cleaning their kid’s pacifier by sucking on it themselves, but this is a major no-no. Not only can you contaminate the pacifier with your own bacteria, you might get sick from wherever your child dropped their binky earlier, too!

3. Keep a clean mouth.

Say as many cuss words as you want, but make sure to wash that mouth after! No, we may not live in the most sterile environment, but that doesn’t mean we shouldn’t at least try to be clean! Show your child how to take good care of their teeth by brushing and flossing regularly. Not only will you reduce the risk of spreading bacteria, you’ll be a great role model for your kids.

To learn more about cavities and oral care, talk to our pediatric dentist in Katy today! She’s a pro at explaining complicated topics like this to her younger patients. You can also book an appointment at Kids Healthy Teeth for a checkup and dental cleaning if your child does have cavities.

WE ALL KNOW it’s possible to catch a cold from someone who’s under the weather. Did you know cavity-causing bacteria can be passed from person-to-person too?

Bacteria Is At The Root Of Cavities

While sugary treats often take the blame for causing cavities, the real culprits for tooth decay are bacteria. Streptococcus mutans and Streptococcus sobrinus are bacteria which stick to our teeth and eat food particles left behind from our last meal, producing acids which threaten gum health and cause tooth decay.

And just like cold-causing bacteria, these bacteria like to travel.

Bacteria Travels From Person-to-Person

Whether it’s through sharing a drink or kissing a loved one, cavity-causing bacteria can be passed from person-to-person the same way many other bacterial infections can. Studies have shown that “catching a cavity” is not only possible, it happens far more often than you might think.

One of the most common transmissions is from parent and child. Cavity-causing bacteria is commonly passed along to a child when a mother or father tastes food to ensure it’s not too hot or when he or she “cleans” a pacifier by sucking on it before handing it over.

Take Simple Steps To Stop The Spread of Bacteria

What can you do to reduce your risk of transmitting these cavity-causing bacterias to someone else?

  • Floss and brush frequently.
  • Chew sugar-free gum—this promotes saliva production and washes away plaque and bacteria).
  • Be mindful of drinks and eating utensils you’re sharing and the risks that are involved.
  • Be aware of other behaviors which may spread these bacteria.

Trust Our Practice For Solutions

Nobody wants to inadvertently “catch a cavity.” Our practice is committed to providing you with the best information possible to help you create a healthy and resilient smile. If you have any questions about this, be sure to ask us! We love visiting about your oral health. You can also comment below and reach out to us on social media.

Thank you for reading our blog! We value our relationship with you as our patients and friends!

Top image by Flickr user bigbirdz used under Creative Commons Attribution-Sharealike 4.0 license. Image cropped and modified from original.
The content on this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.


The health of your mouth can say a lot about the overall health of your body. Because the mouth acts as a portal to the rest of the body, what happens in your mouth can determine how the rest of your body feels and whether you are at risk of developing certain diseases and infections.

If you’re like most people, you probably don’t give your oral health too much thought other than to brush and floss regularly. And while you’re probably familiar with tooth decay, cavities, and gum disease, you might not realize what other types of bacteria can live in your mouth. As your premiere general dentist in Louisville CO, the dentists and staff at Louisville Dental Associates work hard to make sure you have the best information on mouth and oral health

The average person has several billion bacteria in their mouth at any given time, and possibly more bacteria than people on the planet depending on how recently you brushed. Researchers have identified over 700 different kinds of bacteria species that dwell in people’s mouths. While most of this bacteria is harmless, this staggeringly high number helps to underscore the complexity of your mouth.

Humans are actually not alone when it comes to the number of bacteria that live in our mouths. The mouths of both dogs and cats contain just as many bacteria, and the old notion that a dog’s mouth is cleaner than a human’s is simply untrue. In fact, there are roughly 100 different types of germs that live in the mouths of our favorite household pets that can make people sick.

Here are some other myths about the health of your mouth that many people mistake as true.

Five Second Rule

As the old adage goes, any piece of food that falls on the floor that’s picked up in under five seconds is okay to eat. While this might sound good to germaphobes, the five second rule is actually arbitrary. Food beings to pick up germs immediately upon hitting the floor, and considering the types of bacteria that can live on hard surfaces, your better off just throwing it way and eating something else.

Kiss Connection

Another popular rumor is that a person can get gum disease by kissing someone who already has the condition. Fortunately, periodontal disease is not contagious, and the conditions that cause the disease take time to develop. However, someone who has periodontal disease probably doesn’t take very good care of his or her oral health. If the person doesn’t brush and floss regularly, their mouth is teaming with harmful bacteria, called plaque, that causes tooth decay and gum disease. Plaque can be transferred through exchanging saliva, so kissing someone who suffers from periodontal disease will increase your need to brush and floss regularly.

It’s Okay to Share

The Centers of Disease Control and Prevention recommends that you should never share a toothbrush with someone else. The CDC claims that exchanging bodily fluids by sharing a toothbrush places each person at greater risk for infections. It’s not just sharing toothbrushes that can spread disease. Sharing lipstick, drinking glasses, band instruments, and any other item that goes near your mouth can also freely pass along germs.

Keep Your Brush Covered

While it might make sense to keep your toothbrush covered while not in use, you’re actually potentially making your brush dirtier than if you leave it out in the open. Placing a wet brush away in a covered space prevents air for from reaching the brush. This causes the brush to stay damp longer. Cool, damp spaces allow germs to fester and grow. So leave your brush out to air dry in your medicine cabinet.

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