I’ve heard anything from 3 months to 6 months. But why? The bristles may be a little bent, but they haven’t fallen off. What’s the big deal? And if its bacteria, isn’t it all my bacteria that I’m already immune to?
the bristles are scrapers and stimulators, less effective when bent. people do loose wisdom teeth because of difficulty in good cleaning back there.
Marketing.
Replacing tooth brushes less regularly has results in an unpleasant condition whose primary symptom is reduced profits for tooth brush manufacturers.
I’ve had the same toothbrush for about 9 months now. No bent bristles. On the upside, you could just go to the dollar store and buy a whole crap load.
I see the dentist every six months for a checkup and he gives me a new one.
Me, too. I have about a dozen unopened toothbrushes in the drawer under the bathroom sink just in case.
And no, I have not lost all of my wisdom teeth. There’s still one left. 
I keep hearing that you should replace your toothbrush after you get over a cold so you don’t reinfect yourself. How long can a toothbrush harbor virus or bacteria? And if it came out of my mouth in the morning, is it going to hurt to put it back in that night?
Same here. I put them in my guest bathroom.
Now if I could only get him to give me refills for my Sonicare.
I’m sure toothbrush manufacturers love the fact dentists recommend replacing toothbrushes every few months, but that isn’t among the reasons dentists recommend replacing them so often, though I suppose it would be hard to convince people who like to believe physicians are all in the pockets of drug companies and dentists are all in cahoots with…um…Colgate.
Here’s the link: http://www.dentist-chicago.net/Hey-Doc-When-should-I-replace-my-toothbrush.html
And here’s the relevant information, which seems pretty reasonable and unbiased:
“Why Should You Replace Your Toothbrush So Often?
A brand new toothbrush has clean bristles with rounded edges. When used properly, new brushes can gently sweep away plaque, bacteria, and food debris without damaging your teeth, gums, or general health.
On the other hand, older toothbrushes have bristles with broken, frayed, and sometimes sharp edges. These conditions make a toothbrush less effective at removing plaque and bacteria, and the sharp edges can sometimes damage gum tissue. In addition, older toothbrushes can be contaminated with bacteria, viruses, and fungus. For this reason, it’s especially important to replace your toothbrush if you’ve had a cold, cold sores, or infection, dropped your toothbrush on the floor or other contaminated area, or shared it with someone else.
There’s some debate about whether you should replace your toothbrush more often than every three months. Millions of germs live naturally in your mouth, and when you brush your teeth, many of these bacteria and other microorganisms stay on your toothbrush. In addition, organisms that float by in the air can also be caught by toothbrush bristles. These organisms can continue to live on toothbrushes for 1 to 3 days or even more if conditions are right. And when you brush again, some of these organisms can be transferred back into your mouth. Not everyone, though, agrees that this is a problem.
In January 2002, the Centers for Disease Control noted that there was no published evidence showing that reusing a properly handled toothbrush leads to a healthy person’s becoming ill from re-infection by these germs. They suggest that you rinse your toothbrush thoroughly after brushing and let it air dry standing upright. On the other hand, other experts, such as Dr. Glass, say that these germs can indeed cause infections, such as colds and gingivitis, to recur. Dr. Glass says that older toothbrushes are especially dangerous because their sharp edges harbor bacteria and can cause very small cuts in the gum tissue, allowing these organisms enter the body more easily.
Depending on your situation, we may recommend a middle ground. You could replace your toothbrush every three months as the ADA recommends, and clean it between uses. In an article published in the Journal of the American Dental Association, Mary Zolonowski-Casey, DDS, suggests that you run your toothbrushes through the dishwasher. This doesn’t damage the toothbrushes, and the very hot water can kill many germs. Another method is to soak your toothbrush for 20 minutes in an antiseptic mouthwash. There are also toothbrush purifiers on the market made for home use.”
I don’t know how long they can harbor bacteria, but you can’t reinfect yourself with a viral disease like a cold. Once you’ve gotten over it, you’re immune to that specific bug. The reason you can get lots of colds is that there are a couple hundred different viruses that cause approximately the same disease. This is why elderly people get fewer colds – they’ve literally had them all.
Yeah, this is a silly piece of advice. First, you develop immunity to the particular cold virus, so you can’t reinfect yourself. Second, I wouldn’t expect the virus to remain viable for long once the toothbrush dries out. Third, if the viruses on your toothbrush could reinfect you, why wouldn’t the viruses in your own body reinfect you constantly - that is, how would you ever get over the cold in the first place?
Hav you ever tryed to scrub a floor using a old nasty scrub brush whose bristles are all bent over? If you have, you know that a brush like that works OK for the flat areas, but is useless for getting stuff out of crevices such as grout lines.
The same thing is likely true for a toothbrush. So …
I replace mine when the bristles are all bent over. That seems to be every couple of months. Now if they still made kinds other than soft & almost-as-soft-but-labeled-medium I’d be even happier. Better yet if I could still get a simple one for a buck intead of a uselessly more complex one for $3.
Dentists in Germany recommend 1 to 2 months. That’s because they recommend the softest brush available and advise strongly against medium- and hard bristles, since their studies have shown that people who do brush their teeth tend to overscrub with hard brushes, basically brushing away the enamel which you want to keep. (The trick is better technique and brushing every day instead of brute force. It’s also one of the reasons many dentists recommend electric toothbrushes, which have a warning sensor if you apply too much force).
And my soft toothbrush certainly lets its bristles hang outward after two months.
As for bacteria, more and more research shows how bacteria in the mouth can wander freely in the body to wreak serious havoc in the heart (causing stroke), in the joints (causing arthritis) etc.
If you still use a manual toothbrush instead of an electric one, please use one of the new environmental friendly systems where you buy one stem and only replace the heads thereafter to reduce plastic waste.
Actually, toothbrushes are a wonderful moist place usually for bacteria to breed, esp. if kept in closed cabinets.
The virus/ bacteria in your body are driven off by your immune system. The virus on the toothbrush can breed on the moist surface in great numbers and are then introduced into your blood system right close to your head, surprising your immune system with sheer numbers.
Even if your immune system has the numbers of this particular breed down from the previous encounter, sheer numbers can overwhelm it a bit before it manufactures enough counter-resources. If your immune system is busy with something else or weakened (because you didn’t sleep enough, are low on Vit. C, have stress…) then you can re-infect yourself.
General doctors don’t recommend this for kickbacks from the toothbrush manufacturers, but because of studies done, you know.
Interesting. I haven’t seen replacement brush heads sold in the US yet.
Actually, my dentist says the main problem with using too much force is not in scouring away the enamel, but in scrubbing away the gum. I have two spots in my mouth where I’ve done exactly this. I tend to think that to do a good job, I need to apply pressure, as I would when scrubbing a floor. Dentist says that’s very common and to use an electric toothbrush and just hold it to the tooth/gum for a few seconds with no pressure. Wish I’d known this 10 years ago.
A virus can’t replicate on its own, so they won’t be reproducing on your toothbrush. Bacteria could potentially do so, so it may make sense to dispose of your toothbrush after an oral bacterial infection, although it seems like you would have to use a new toothbrush every brushing until you were sure the infection was gone. Soaking your toothbrush in a 0.5% sodium hypochorite solution (1:10 household bleach:water) between brushings with a rinse off before brushing would probably be the best approach.
Colds are caused by viruses, not bacteria. As has already been mentioned, a virus needs a host to reproduce - it injects its DNA or RNA into a host cell, where it takes over the cell and uses it to make copies of itself. These copies then burst out of the cell to go infect other cells. A virus literally has no metabolism of its own.
Viruses are not “driven off” by the immune system, nor can they breed on a toothbrush (as I explained above). They are killed by antibodies which the immune system develops in response to the infection. As for the immune system being “surprised” by sheer numbers, by the time the cold is over it has already killed the same virus in far greater numbers (both absolute and by concentration) than a toothbrush would introduce, even if you used it again immediately after brushing.
There is no evidence that vitamin C prevents colds. This has been studied pretty thoroughly.
I am not accusing anyone of dishonesty, merely of being wrong. By the way, I have never heard an actual dentist or doctor recommend replacing a toothbrush after a cold. And even if one did recommend it to me, I would still question it, as it just doesn’t make any sense to me. Even professionals can believe things that are wrong. And can you cite any of the studies that you say support this belief?
Among laypeople, many do not distinguish between an influenza from virus and a normal cold from bacteria, because the effects can be similar in both. (The influenza can be more severe, yes.) But if you have to lie in bed for a week, stuffed nose, headache, fever, feeling rotten, until it’s over, people don’t much care if it’s the bacterial cold or the virus influenza, they just want to get it over with.
Actually, what Vitamin C doesn’t do is make you immune to colds if you have high levels. Yes, that has been proven.
Equally proven however is that low levels of Vitamin C make you much more susceptible to colds, because your immune system needs Vitamin C to work.
It’s like saying that because with a gas tank filled to overflowing your car can’t fly that gas is not necessary; but a car with an empty gas tank can’t drive at all.
Throwing out your toothbrush after a cold/ infection is not recommended by dentists, but by general doctors as I said, because they get to see the colds and the re-infected patients.
And no, I’ve stopped citing studies that are not believed anyway because they are in German or have been done by German doctors. Takes too much time for me to find them only to have them ignored anyway.