In one of my threads, we discussed on sharing a 'Toothbrush' wit a partner. https://www.nairaland.com/1227960/u-share-tooth-brush-wit.
But 2day we wud b lukn at hw long a toothbrush shld b used.
Your toothbrush is a breeding ground for germs. But fear not, say experts — just know when it's time to give yours a kick.
By Beth W. Orenstein.

Do you know how many bacteria live on your toothbrush ? Brace yourself! Researchers have found that a single toothbrush can be loaded with as many as 10 million germs and bacteria. In fact, recent studies even found that your toothbrush could be a breeding ground for tiny microorganisms.
But before you swear off brushing, know this: These bacteria aren’t a big threat to your pearly whites. According toRichard Price, DMD, a dentist in Newton, Mass. and a consumer adviser for the American Dental Association, the researchers who discovered those toothbrush-dwelling microorganisms found that theydidn’t make people sick — toothpaste has an anti-germ component built into it, and the microbes need moisture to survive. So as long as your toothbrush is given time to dry after you use it, it should be safe.
¤Squeaky-Clean Toothbrush Tips¤
To take care of your teeth and your toothbrush, it’s important to use your toothbrush the way you’re supposed to, rinse it in tap water, and then let it air dry, Price says.
This starts with storing your toothbrush in an upright position. Most people don’t need to worry about storing it away from other toothbrushes — germs are airborne, but they don’t hopscotch from one brush to another. However, if someone in the household has an immune deficiency, you can't be too careful, says Price.
If you’re really fastidious about dental care , you can soak your toothbrush in alcohol to kill the germs, Price adds. Mouthwash is also an antiseptic, so it works as a "toothbrush soak," too, as does a solution of half water and half hydrogen peroxide. Another option is to dip it in boiling water for about five to 10 seconds.
Interestingly enough, toothbrush sanitizers haven’t shown to have much effect. And you should never put your toothbrush in the dish washer or microwave: You’ll just end updamaging it.
Time for a New Toothbrush?
The American Dental Association recommends getting a new toothbrush (or brush head, if you use an electric type ) about every three (3) months — more because of the wear on the bristles than germs.
And that depends on the brusher and not the brush, Price emphasizes. If you have a heavy hand, the bristles might wear out sooner. Remember that the key determinant is not the calendar but the shape the bristles are in. “You need to replace your toothbrush when the bristles spew in different directions,” Price says. Check your children’s toothbrushes regularly because they probably will need to be replaced more frequently.
http://m.everydayhealth.com/dental-health/how-often-should-you-replace-your-toothbrush