On Why Cavities are Contagious and How to Prevent Spreading Them

Most people consider a cavity an isolated event, a weakened tooth turned victim or a case of not brushing well enough. There’s a reason cavities also have the euphemism “sugar bugs”. Cavities are a direct result of bacteria feeding on the tooth’s defense called enamel and releasing acid as they do so. A 2011 article by Everyday Health said: “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.”
Bacteria is a microorganism that reproduces by its cells dividing, usually at a rapid rate. Oral bacteria is no exception, and over 500 species hang out in our mouths on a regular basis. Some of this bacteria is natural and necessary for your health, but others, specifically the mutans streptococci, (prominently Streptococcus mutans, Streptococcus sobrinus, and lactobacilli) are pathogens. These harmful specimens are not only hazardous to your mouth, but can also be passed from person to person in some situations.

Tooth cross section with dental caries

How Cavities Can Spread
Once a cavity takes over a tooth and if it’s not addressed fairly quickly, the infection worsens. All that bacteria and plaque production makes it’s oral environment owner a carrier. From there several situations can actually pass the bacteria to others.
Kissing is one such way. When two humans kiss, it does many things physiologically. Our heart rate accelerates, our brain temporarily shuts down “unnecessary” centers of body function to focus on the situation at hand, lowers stress by way of hormonal changes, and dilates our blood vessels for better blood flow. (Source: CNN.com) It also increases our saliva production and releases natural antibiotics. Unfortunately, if the mouth is already infected, the bodies attempt at defense is shut down by the multitude of oral bacteria.
A study published on National Center for Biotechnology Information discussed an experiment done with four couples who had advanced cases of gum disease, a condition achieved due to bad oral hygiene and usually accompanied by dental caries or the same species of bacteria. The study found that the couples had transmitted different bacteria to one another through intimacy.
Another way that oral bacteria from cavity sites can spread has been linked to mother and child. In many modern cultures, mothers test their infants’ foods for high temperatures, taste, or even chew it a little bit to soften it or break down fiber before giving it to their child. These habits are meant in love, but the food can get the mother’s oral issues into their child’s food and pass it to an oral environment for the bacteria to thrive in. (Source: NY Times)
Just as the flu or colds spread from oral or sinus fluids, bacteria from oral infections can too. This means, coughing and sneezing while you have oral infections can spread the bacteria. Granted, it is far less likely to spread than a virus as oral bacteria need a certain type of environment to thrive, you still need to be aware of this problem and keep yourself and others healthy.

 

Suggestions to Keep Your Cavities to Yourself
There are many ways you make sure not to spread oral bacteria and infections to others.
Firstly, resist sharing food or utensils. This is especially important for mothers that are prone to cavities, and their young children’s baby teeth. This also goes for toothbrushes and other tools used for oral hygiene purposes. Although we discussed kissing above, we aren’t recommending you stop the enjoyable activity entirely. Just be aware of your partner’s oral hygiene and take steps to avoid transferring bacteria when one of you has an infection.

 

Prevention is the best way to resist spreading any pathogens, including dental caries bacteria. Covering your mouth when you cough or sneeze can achieve this. Using mouth rinses or chewing sugar free gum to round up and dispose of the harmful bacteria can also keep you from overproducing them and sharing them with those around you. Drink plenty of water to keep saliva levels high and to rinse your teeth with cavity-preventing fluoride found in most U.S. tap waters. Seeing your dentist for cleanings regularly as well as a consistent regiment of brushing several times a day and flossing daily can help you maintain a healthy mouth and not give cavities to your loved ones.

About Mark C. Marchbanks, D.D.S.

Dr. Mark Marchbanks has practiced dentistry in Arlington Texas since 1983. He enjoys caring for patients young and old. You can find Dr. Marchbanks on If it's been more than 6 months since your last teeth cleaning, give us a call today to schedule your check-up.

Mark C. Marchbanks, D.D.S.
2624 Matlock Road Suite 100 Arlington, Texas 76015
Phone: (817) 261-2747 URL of Map