Publication date: 10 March, 2021
Millions of Americans are putting their health at risk by using unhygienic toothbrushes, according to a new report from national dental provider Express Dentist. Up to ten million micro-organisms can be found on a single toothbrush, including germs such as staph, yeast, E. coli-like bacteria and Pseudomonas.
Fecal matter can travel up to six feet through the air when you flush the toilet. Express Dentist recommends you keep the seat cover down before you flush to prevent the dispersal of germs into the air, and additionally you keep your toothbrush as far away from the toilet bowl as possible.
Express Dentist recommends that toothbrushes should be replaced every 3-4 months or earlier if the bristles appear frayed or matted. It’s also a good idea to change out your toothbrush if you’ve been sick with a flu-like illness. Viruses and bacteria can linger on the brush and potentially lead to a re-infection.
The report from Express Dentist provides a range of other tips to help you keep your toothbrush as hygienic as possible, including:
- Handle your toothbrush with clean hands to avoid transferring bacteria from your hands to your toothbrush
- Store your toothbrush upright to avoid contaminating with germs from the counter surface
- Rinse your toothbrush thoroughly with tap water before and after use
- Let your toothbrush air dry completely between uses and store it in a well-ventilated, sunlit environment
- Never share your toothbrush with anyone else, and make sure your family’s toothbrushes don’t touch if they’re stored in the same cup
- Clean your toothbrush holder regularly with soap and water
- Avoid cross-contamination from toothpaste to toothbrush – one person’s germs can transfer from their toothbrush to the toothpaste tube
- If you use a cup to rinse your mouth after you brush, do not share the cup with others
- Clean a new toothbrush before you use it for the first time – toothbrushes that come out of a package can sometimes be contaminated with germs
How Dirty is Your Toothbrush?
Virtually everyone owns one. Most people use it at least once a day. It is regularly ranked as the number one thing people say they can’t live without, ahead of automobiles and cell phones. We’re talking about a toothbrush, of course.
Now, let’s cut to the chase – there could be up to 10 million bacteria lurking on your toothbrush – that’s just as many germs as a public bathroom floor! But before you start gagging, remember, your mouth also has hundreds of types of bacteria at any given time. While some bacteria can make you sick with gum disease and other oral conditions, not all bacteria are bad. Some mouth bacteria play a specific role in keeping you healthy. They fight bad breath, help in food digestion, and reduce oral disease by stimulating saliva production. Problems arise when there’s an unhealthy balance between good and bad bacteria in your mouth.
So, although your mouth is home to some bacteria, you need to practice good oral and toothbrush hygiene to prevent the overgrowth of bad bacteria. This is important to keep your mouth healthy. Regularly cleaning and replacing your toothbrush is critical to removing harmful bacteria and preventing them from being introduced into your mouth and multiplying there. Keep reading to learn more about how dirty your toothbrush can get and what you should do to avoid jeopardizing your oral health.
What kinds of germs can be found on a toothbrush?
A study by researchers at the Manchester Metropolitan University in the United Kingdom found that up to 10 million micro-organisms can be isolated from a single toothbrush. 1 The most common germs they found were Staph (64%), E. coli-like bacteria (57%), yeast (39%), and Pseudomonas (28%).
Studies have found that toothbrushes used by people with existing oral infections can quickly become contaminated. Also, repeated use of a contaminated toothbrush can lead to the introduction of germs into the mouth in sufficient quantities to cause illness. 2Even normal use of a toothbrush can result in heavy contamination with harmful micro-organisms. However, the use of an oral antiseptic or mouthwash to clean the toothbrush immediately before brushing can reduce the risk of contamination.
Can bacteria from the toilet reach a toothbrush?
Dentists advise that you shouldn’t brush where you flush. In most homes, the toilet bowl is pretty close to the sink where the toothbrush usually sits uncovered. Every time you flush the toilet, it sends a spray of germs into the air, some of which can settle on your toothbrush. So yes, bacteria from the toilet can get onto your toothbrush. You can avoid fecal contamination by carefully storing your toothbrush (see below on how to accomplish this).
What’s the best way to use and store a toothbrush?
There are a few things you can do to prevent contamination of your toothbrush:
- Cover the toilet bowl (keep the seat cover down) before you flush to prevent the dispersal of germs into the air.
- Fecal (poop) particles can travel up to 6 feet in the air. Keep your toothbrush as far away from the toilet bowl as possible.
- Handle your toothbrush with clean hands to avoid transferring bacteria from your hands to your toothbrush.
- Store your toothbrush upright. Do not keep it lying flat because your toothbrush can be potentially contaminated with germs from the counter surface.
- Rinse your toothbrush thoroughly with tap water before you use it. Also, rinse it after use to remove all toothpaste residue which can potentially harbor bacteria.
- Let your toothbrush air dry completely between uses. Store it in a well-ventilated, sunlit environment so it dries naturally after use. Don’t stash it in the medicine cabinet. Bacteria love moist environments. Studies have shown that bacterial growth on a toothbrush can increase by up to 70% in a moist environment. Toothbrush covers are not recommended because they can prevent the toothbrush from drying completely. If you do use a cover or protector for your toothbrush to protect it from airborne germs, always place the cover on a completely dry toothbrush.
- Never share your toothbrush with anyone else. Make sure your family’s toothbrushes don’t touch if they’re stored in the same cup, as this can lead to the swapping of germs.
- Don’t forget to clean your toothbrush holder regularly with soap and water.
- Be aware that cross-contamination can occur from toothpaste to toothbrush. Meaning, if you share a tube of toothpaste with family members, one person’s germs can transfer from their toothbrush to the toothpaste tube and from there to others who use the same tube.
- If you use a cup to rinse your mouth after you brush, do not share the cup with others.
- Clean a new toothbrush before you use it for the first time. Studies have found new toothbrushes that came out of a package can sometimes be contaminated with germs.
How long can bacteria live on a toothbrush?
As noted, a toothbrush can be home to millions of bacteria. Germs on a toothbrush can originate from the user’s mouth and also from the environment where the toothbrush is stored. Contaminated toothbrushes can be a source of re-infection in a person who is recovering from an illness such as the common cold or Strep throat. Germs can survive on a toothbrush for a few hours to a few days, longer on wet bristles.
Do toothbrush sanitizers work?
There are many products available in the market that claim to clean your toothbrush. Besides germ-killing rinses and sprays, there are devices use ultraviolet light to kill bacteria. Some toothbrushes even claim to have antibacterial bristles.
Evidence suggests that some of these toothbrush sanitizing products work reasonably well. 3 Soaking a toothbrush in chlorhexidine mouthwash and subjecting it to UV light for about 7 minutes can both significantly reduce the number of germs on a toothbrush. Studies have shown that UV rays are particularly effective in killing micro-organisms. But UV devices are not cheap, and they don’t sterilize your toothbrush, they only sanitize it, i.e., they don’t get rid of all the germs. You can’t be sure your toothbrush is completely germ-free, which means a UV sanitizer may not be worth it. If you do buy a toothbrush sanitizer, look for a device that has been cleared by the U.S. Food and Drug Administration and has the ADA Seal of Acceptance which is given by the American Dental Association to products that demonstrate safety and efficacy.
Soaking your toothbrush in mouthwash can work quite well and is a much less expensive option. The American Dental Association does not recommend microwaving your toothbrush or putting it in the dishwasher because the high heat can damage the bristles and make them less effective. 4
Can your toothbrush make you sick?
It is unlikely that your toothbrush will make you sick. The human body is designed to fight infections quite effectively. If some germs get into the body through your mouth because you used a dirty toothbrush, the body’s natural defenses will take care of it. It is unlikely that you will fall sick simply from brushing your teeth.
Even though toothbrush germs do not usually cause you any harm, it doesn’t mean you can overlook hygiene while using and storing your toothbrush. The germs on your toothbrush can be easily transferred to your mouth and can potentially cause short- and long-term health problems. This is especially true for vulnerable individuals such as those who are critically ill or have weak immunity.
What happens if you accidentally use someone else’s toothbrush?
It is not an emergency if you accidentally use someone else’s toothbrush. However, routinely using another person’s toothbrush is not recommended. In other words, sharing a toothbrush is not a habit that you should form.
If you use a toothbrush that belongs to someone else, your mouth is exposed to bacteria that are new, against which your body may not have developed an immunity. Therefore, using another person’s toothbrush, no matter how clean it is, increases your chances of catching a flu-like illness from the germs on that person’s toothbrush, even if they are very good about dental hygiene.
Besides germs found in the mouth, shared toothbrushes can lead to the spread of serious blood-borne infections like hepatitis C. This is because the gums can sometimes bleed while brushing, transferring the virus to the person’s toothbrush and into the body of the person who shares the toothbrush.
If you live with a partner, you can, of course, potentially spread germs in many other ways, such as kissing, holding hands, and sharing food, and these behaviors are unavoidable. However, you can minimize your risk of spreading infections by not sharing a toothbrush.
How to clean a toothbrush?
It’s important to disinfect your toothbrush between uses. Here are some easy ways to do it:
Store-bought mouthwashes are specially formulated to provide optimal oral care. They contain powerful ingredients that reduce plaque, replenish calcium, and prevent cavities and gingivitis. Over-the-counter antibacterial mouthwashes also contain alcohol that will kill most bacteria. To clean your toothbrush, stir the head of your toothbrush in a cup of mouthwash to loosen food particles and hardened toothpaste. Then let the head soak in mouthwash for 20 minutes to reduce the number of germs that may be contaminating it.
Baking soda has antibacterial properties and can be mixed in a cup of water to clean your toothbrush. It can also help to reduce stains, whiten teeth, and minimize plaque acidity when used as a mouth rinse. Using baking soda to clean your toothbrush is a gentler approach than using commercially available mouthwashes. However, baking soda may be ineffective against some bacteria like Staph, E. coli, and Salmonella. It is also worth remembering that too much baking soda can be toxic, so if you’re using it as a mouth rinse, be careful not to ingest it.
Other options to clean your toothbrush include vinegar, which is an effective disinfectant against some germs but not all. You can also clean your toothbrush with 3% hydrogen peroxide by mixing 1 teaspoon in a cup of water and soaking the head of your toothbrush in this solution daily. A denture cleaner tablet in a cup of water is another effective toothbrush cleaner. This is a safer option than using self-formulated solutions like hydrogen peroxide or vinegar.
How to brush your teeth effectively?
According to the American Dental Association, you should brush your teeth twice a day for two minutes each time using fluoride toothpaste. Two minutes of brushing is needed to effectively remove plaque from tooth surfaces. Fluoride from the toothpaste increases fluoride levels in the saliva, reducing the risk of cavities.
The technique is important. You should aim to place the toothbrush at a 45-degree angle against your gum line to remove plaque from both above and below the gum margin. Use a gentle back and forth and circular motions, making short strokes to clean the front surfaces of your teeth. Tilt the toothbrush vertically and move it up and down to clean the back surfaces. Don’t forget to clean the chewing surfaces. A toothbrush with soft bristles is recommended to avoid gum injury.
Dentists also recommend that you clean between the teeth once a day. Food particles can get stuck here, leading to the growth of decay-causing bacteria. Toothbrush bristles may not be able to reach between the teeth, so flossing is important.
When to replace a toothbrush?
Studies have shown that toothbrushes with a lot of wear are less effective than those with light to no wear. When researchers compared toothbrushes in the laboratory, the ones with extreme wear belonged to people with a significantly higher amount of plaque. 5Therefore, toothbrushes should be replaced periodically. It is usually time to change out your toothbrush out when the tufts start to splay beyond the base of the brush.
The expert consensus is that toothbrushes should be replaced every 3-4 months or earlier if the bristles appear frayed or matted. It’s also a good idea to change out your toothbrush if you’ve been sick with a flu-like illness. Viruses and bacteria can linger on the brush and potentially lead to a re-infection. Another reason to change out your toothbrush regularly is that frayed bristles tend to trap and retain more bacteria.6
Manual vs powered toothbrushes
Both manual and electric powered toothbrushes can effectively remove plaque and prevent gingivitis (gum inflammation). Powered toothbrushes are more expensive but offer convenience. They may be necessary for people who have manual dexterity problems, for example, due to arthritis of the hands. Also, individuals with dental devices like braces may find powered toothbrushes are easier to use.
Some studies have shown that powered toothbrushes are more effective than manual brushing with or without flossing, producing a greater reduction in plaque, gingivitis, and the level of gum bleeding.7
If you choose a manual toothbrush, try to pick one with angled bristles or multi-level bristles because they are better at removing plaque than toothbrushes with flat-trimmed bristles. Soft bristles are advisable to minimize the risk of gum injury. Solid handles tend to retain fewer bacteria.
If you love the convenience of a powered toothbrush, be sure to choose one with a solid-head design. According to the findings of researchers at the University of Texas in Houston, hollow-head powered toothbrushes can have 3,000 times more bacterial growth compared to solid-head designs.
When to see a dentist?
If you’ve been good with toothbrush hygiene but are having problems in your mouth, do not delay seeing a dentist. Even if you don’t have any symptoms, regularly scheduled dental appointments and cleanings can help prevent gum disease, tooth decay, and other oral problems. You should see a dentist as soon as possible if you have any of the following signs and symptoms:
- Pain while chewing.
- Bleeding from the gums when you brush your teeth or floss.
- Gums that are starting to pull away from the teeth.
- Red or swollen gums.
- Permanent teeth that are coming loose.
- Constant bad breath or unusual taste in your mouth.
- Sensitivity to hot or cold.
Early detection of problems with your teeth and gums, eating a healthy diet with limited amounts of high-sugar foods, and good toothbrush and mouth hygiene can ensure a lifetime of optimum oral health for you and your family.
About the author
Dr. Greg Grillo
Dr. Greg Grillo DDS studied at the University of Washington where he received a bachelors degree with Honors and later attended dental school on the same campus. Following school Dr. Greg served in the United States Navy as a dental officer. During this time he received advanced training in specialty areas of dentistry while also treating families of members of the military.
As well as sharing valuable information on dentistry and oral health, Dr. Greg remains a practicing dentist to this day. He works with families in the Okanogan Valley where he lives with his wife and three children.
- Verran J, Leahy-Gilmartin AA. Investigations into the microbial contamination of toothbrushes. Microbios. 1996;85(345):231-8. PMID: 8699965.
- Frazelle MR, Munro CL. Toothbrush contamination: a review of the literature. Nurs Res Pract. 2012;2012:420630. doi:10.1155/2012/420630.
- Tomar P, Hongal S, Saxena V, Jain M, Rana K, Ganavadiya R. Evaluating sanitization of toothbrushes using ultra violet rays and 0.2% chlorhexidine solution: A comparative clinical study. J Basic Clin Pharm. 2014;6(1):12-18. doi:10.4103/0976-0105.145769.
- ADA. Oral Health Topics… Toothbrushes.
- Van Leeuwen MPC, Van der Weijden FA, Slot DE, Rosema MAM. Toothbrush wear in relation to toothbrushing effectiveness. Int J Dent Hyg. 2019 Feb;17(1):77-84. doi: 10.1111/idh.12370. Epub 2018 Nov 19. PMID: 30326176; PMCID: PMC7379636.
- Frazelle MR, Munro CL. Toothbrush contamination: a review of the literature. Nurs Res Pract. 2012;2012:420630. doi:10.1155/2012/420630.
- Rosema NA, Timmerman MF, Versteeg PA, van Palenstein Helderman WH, Van der Velden U, Van der Weijden GA. Comparison of the use of different modes of mechanical oral hygiene in prevention of plaque and gingivitis. J Periodontol. 2008 Aug;79(8):1386-94. doi: 10.1902/jop.2008.070654. PMID: 18672987.