It's a sick joke played by the oral health gods when toothbrushes actually contribute to your bad breath.
In a new study published in the Journal of Dental Hygiene, power toothbrushes with hollow heads were shown to retain significantly more bacteria compared to those with solid heads. In fact, researchers found up to 3,000 times the bacterial growth on hollow-head toothbrushes.
"Toothbrushes can transmit microorganisms that cause disease and infections," lead study author Donna Warren-Morris, a professor in the department of periodontics and dental hygiene at the University of Texas Health Science Center at Houston School of Dentistry, said in a statement. "A solid-head design allows for less growth of bacteria ..."
The best way to identify if you have solid-head design is by looking at the brush's body. There will be some space to connect the body and head but a big portion may look solid or hollow in the area around the bristles. Unfortunately, the packaging on most electronic toothbrushes do not distinguish between a hollow-head and solid-head design.
The study was conducted over a three-week period during which participants brushed their teeth twice a daily with one of three randomly assigned electric toothbrushes. The subjects used nonantimicrobial toothpaste and flossed throughout the study, but they refrained using mouthwash along with other dental products.
The brush heads were exposed to five categories or oral microorganisms: yeast and mold, anaerobes and facultative microorganisms, oral streptococci and oral enterococcus anaerobes, Porphyromonas gingivalis, and Fusobacterium species. At the end of the study period, Warren-Morris and her colleagues tested the toothbrush heads.
The results showed that the solid-head power brush had fewer residual microorganisms in general than the brushes with hollow heads. When left uncleaned, these bacteria may be transferred back into the mouth, potentially causing bad breath, gingivitis, decay and other oral health problems.
Warren-Morris believes that the hollow heads provide more surface area for the formation of biofilms. This information, the researchers suggested, may be especially important for patients with a weakened immune system.
Warren-Morris added that bristles should be soft and made of nylon. In general, when people make the switch from a regular toothbrush to a powered one, they carry over the same brushing techniques. While it's essential to reach all dental surfaces, you won't have to brush as hard with a powered toothbrush. Simply guide the brush over your teeth in a gentle, circular motion.
Keep heads dry
After you brush, be sure to leave your toothbrush in a dry environment. Don't cap it or put it in a closed container. Just as mold likes to grow in the damp corners of basements, a moist environment for your brush encourages microbial growth. Store the brush in an upright position and allow it to air-dry until used again. If more than one brush is stored in the same holder, leave some space between the brushes to prevent cross-contamination.
For extra cleanliness, some people like to use a deep-cleaning system.
"Some power toothbrushes now include an ultraviolet system, or you can soak the head in mouthwash for 20 minutes," Warren-Morris told the source.
Swap heads every few months
The American Dental Association recommends ditching your old toothbrush head (or simply getting a new brush if you have a manual brush) about every three months, or sooner if the bristles become frayed with use. An oral health for kids fact: Children's toothbrushes often need replacing more frequently than adult brushes.
In short, go check your toothbrush. Your oral health's best friend may actually be a type of traitor.