Tooth decay is something many people associate with forgetting to brush their teeth or indulging in sugary treats. But did you know if it’s true when they say, ‘Can tooth decay spread?’ It might not be contagious in the same way a cold is, but there’s more to the story than most realise. In this blog, we’ll explore the fascinating science behind tooth decay, whether it can really be passed from one person to another, and how to stop it from spreading, both inside your own mouth and between loved ones.
Let’s Start with the Basics: What Exactly Is Tooth Decay?
Tooth decay, also called dental caries, begins when harmful bacteria in the mouth produce acid that slowly breaks down the tooth enamel, which is the strong and protective outer layer of your teeth. These bacteria thrive on sugary foods, and without good oral hygiene, they create a sticky film called plaque. As plaque builds up, it eats away at the tooth’s structure, leading to small holes called cavities.
Once a cavity forms, it doesn’t get better on its own. Left untreated, it can result in infection, gum disease, or even require treatments like root canals. Worse still, tooth decay can spread, affecting other areas of your mouth and potentially the mouths of others.
So, Can Tooth Decay Spread? Are Cavities Contagious After All?
In short yes, it can.
Tooth decay is caused by cavity causing bacteria, particularly Streptococcus mutans, which feed on sugar and produce acid as a byproduct. These bacteria aren’t just confined to one tooth. Once established in the mouth, they can migrate, creating new tooth cavities on neighbouring teeth, especially if oral hygiene is poor or decay is left untreated.
What’s more surprising is that these oral bacteria can be transferred from one person to another. This happens through saliva. So, sharing utensils, kissing, or even testing a child’s food can lead to the spread of cariogenic bacteria, the bacteria that cause cavities.
How Does Tooth Decay Spread Inside Your Mouth?
Tooth decay doesn’t only spread between people; it can easily spread within your own mouth. This is particularly common when:
- One cavity is left untreated for a long time.
- You neglect certain areas during brushing, especially the chewing surfaces and gum lines.
- You frequently snack on acidic foods or sugary treats, fuelling the bacteria.
- There’s reduced saliva production, which would otherwise help neutralise acid and kill germs.
Once a tooth is affected, the bacteria that cause cavities can thrive and reproduce, affecting nearby teeth and damaging more of your tooth enamel.
Can Tooth Decay Be Contagious Between People?
Although we don’t typically think of cavities as something you can “catch,” the bacteria that cause them can absolutely be shared. In fact, studies show that parents often pass Streptococcus mutans to their children during the early years of life.
This transmission often happens through everyday behaviours like:
- Sharing a spoon with a child
- Blowing on their food
- Kissing on the lips
Since a child’s immune system and oral hygiene habits are still developing, their child’s teeth are especially vulnerable. That’s why it’s so important for parents and caregivers to maintain excellent oral health themselves.
Spotting the Early Signs of Tooth Decay Before It Gets Worse
It can be difficult to detect tooth decay in its early stages. But being able to identify them can help you stop the spread before it gets worse. Look out for:
- White or brown spots on the teeth
- Sensitivity to hot or cold
- Pain when chewing
- Bad breath or a persistent bad taste
- Visible holes or pits
Early cavity care is essential. If you catch decay early, it’s often possible to stop tooth decay in its tracks using non-invasive treatments like fluoride treatments or dental sealants.
What Increases the Risk of Spreading Tooth Decay?
Several factors can increase the risk of decay spreading within your mouth or to others:
- Poor oral hygiene: Failing to brush and floss consistently
- Frequent sugary snacks: Especially sticky or hard candies
- Low saliva production: Saliva naturally washes away bacteria
- Not using fluoride toothpaste: Fluoride strengthens enamel
- Existing cavities: An untreated tooth cavity is a hub for bacteria
How to Stop Tooth Decay from Spreading
Now that you know the answer to “Can tooth decay spread?”, the next step is prevention. Here are some effective methods to keep decay at bay:
1. Brush Your Teeth Twice Daily Using Fluoride Toothpaste
Fluoride strengthens tooth enamel and fights off bacteria that cause decay. Make sure you brush for two minutes, covering all surfaces, especially along the gum line and between teeth.
2. Floss Daily
Flossing eliminates food and plaque from places your toothbrush can’t reach. It’s essential for preventing decay between teeth.
3. Limit Sugary and Acidic Foods
Cutting down on sugary drinks, lollies, and citrus fruits helps starve the harmful bacteria of their food source. Try snacking on cheese, nuts, or vegetables instead.
4. Stay Hydrated and Chew Sugar-Free Gum
A dry mouth can increase the risk of tooth decay. Drinking water and chewing sugar-free gum can boost saliva production, which helps protect your teeth.
5. Regular Dental Check-Ups
Professional cleanings remove plaque you can’t get rid of at home. Your dentist can also catch early signs of decay and provide preventive treatments like fluoride treatments and dental sealants.
6. Don’t Share Utensils or Toothbrushes
Avoid activities that might pass oral bacteria from one person to another. That includes sharing spoons, cups, or even kissing someone on the mouth if they have active cavities.
What Can Happen if Tooth Decay Is Left Untreated?
Untreated tooth decay can cause a host of problems, including:
- Larger cavities that are harder to treat
- Infections that spread to the tooth’s enamel, dentin, and eventually the root
- Severe tooth pain or abscesses
- Tooth loss or the need for root canal treatment
- Gum inflammation and gum disease
Worse still, the longer decay is left unaddressed, the more likely it is to spread to other teeth and possibly to other people.
How Tooth Decay Affects Children
Children are especially at risk of developing dental caries because:
- Their tooth enamel is thinner
- They often consume more sugary foods
- Their oral hygiene routines may not be consistent
- Their teeth are frequently touched or cleaned by caregivers, increasing the chance of bacterial transfer
Teaching kids to brush with fluoride toothpaste and establishing a regular dental routine early can go a long way in preventing cavities.
Can You Reverse Tooth Decay?
In the early stages, yes. When decay is limited to enamel demineralisation, you can often stop tooth decay with:
- Improved oral hygiene
- Switching to fluoride toothpaste
- Fluoride treatments from your dentist
- A healthier diet low in acidic foods
But once a hole forms in the enamel, it’s no longer reversible. At that point, treatment is needed to restore the tooth.
FAQs About Tooth Decay and How It Spreads
Can cavities spread from tooth to tooth?
Yes, bacteria can move from one decayed tooth to nearby healthy ones, especially if left untreated.
Is it possible to catch cavities from someone else?
Yes. While you can’t catch a cavity like the flu, the cavity-causing bacteria can transfer through saliva.
What kills the bacteria that cause cavities?
Fluoride, regular brushing, flossing, and dental cleanings can reduce and control oral bacteria.
Should I avoid kissing if I have a cavity?
To minimise the risk of sharing bacteria, it’s wise to delay kissing until after dental treatment.
What can I do to help prevent tooth decay in my child’s teeth?
Use fluoride toothpaste, teach proper brushing techniques, avoid saliva-sharing behaviours, and book regular check-ups.
Final Thoughts: Preventing and Containing Tooth Decay
Tooth decay is more than just a personal issue; it’s a shared one. The answer to “Can tooth decay spread?” is a clear yes, both within your own mouth and between people. But with awareness, good habits, and regular dental care, you can take control.
If you’re concerned about tooth cavities, have spotted early signs of decay, or want help improving your oral health, don’t wait until it worsens. Prevention is always better and easier than a cure.
If you want personalised advice or a check-up to stay ahead of cavities, schedule an appointment with Advanced Dental Care Dubbo at (02) 6188 7103. Taking small steps now can make a notable difference to your oral health for years to come.
References
- Cleveland Clinic. (n.d.). Cavities/tooth decay. Retrieved from https://my.clevelandclinic.org/health/diseases/10946-cavities
- Healthline. (n.d.). Best practices for healthy teeth. Retrieved from https://www.healthline.com/health/dental-and-oral-health/best-practices-for-healthy-teeth
- Colgate. (n.d.). Tooth sensitive to hot or cold: What it means and how to help. Retrieved from https://www.colgate.com/en-ca/oral-health/tooth-sensitivity/tooth-sensitive-to-hot-or-cold-what-it-means-and-how-to-help
