when to change a toothbrush?
November 24, 2005 8:19 PM   Subscribe

how often should i change my toothbrush?
posted by brandz to Health & Fitness (33 answers total) 1 user marked this as a favorite
You should get your teeth cleaned by a dental hygenist every six months. They will usually give you one there. If you don't get the tooth cleaning, at least get the new tooth brush every six months.
posted by Doohickie at 8:23 PM on November 24, 2005

Results 1 - 4 of about 12 for "change your toothbrush every 2 months".

Results 1 - 10 of about 52 for "change your toothbrush every 3 months". (0.29 seconds)

Results 1 - 5 of 5 for "change your toothbrush every 6 months".

3 months seems to be the winner. (FYI 1, 4, 5 months got no results.)
posted by Krrrlson at 8:29 PM on November 24, 2005

"When the bristles become stiff" is what I was told by my dentist.
posted by cribcage at 9:06 PM on November 24, 2005

When the bristles start falling out/breaking off.
posted by jellicle at 9:06 PM on November 24, 2005

I've got this newfangled toothbrush that has some sort of battery magic in it to make it vibrate. I haven't even come close to running the thing down yet, but I figure when it dies I'll replace it, which is as good a system as any. (If it lasts for 3 weeks or something, then I'll try another solution.)

Some of the toothbrushes out there (can't remember the brand, and I'm talking about the US here) have a set of blue bristles that gradually fade. I used to change those when the bristles were mostly faded.
posted by socratic at 9:14 PM on November 24, 2005

Conventional wisdom is every three months -- so every time you visit the dentist, and then halfway between visits.

Or you can do like I do and use Oral-B's products that have fading bristles to let you know. Here's one. And no, I don't work for them... but if they'd like to give me free stuff, let me know.
posted by SuperNova at 9:14 PM on November 24, 2005

Why would you want to change your toothbrush before it becomes painfully obvious that you need to? I wait until the bristles are so bent that they don't effectively get between my teeth.

If you're concerned about germs, splash some Listerine on it and save yourself three bucks.
posted by Geektronica at 9:15 PM on November 24, 2005

There are people who see their dentist every three months?


I see a dentist about once every seven years. I do not floss. I do brust several times a day, and I brush very well. On the whole, I do not eat junk food and do not drink sugary drinks (milk, juice, soda).

Every time I've been in, the dental assistants exclaim how I must be a frequent flosser and how wonderful my teeth are.

Disclaimer: my mother gave us flouride drops as children; we were on entirely untreated water (not even a sand filter!) I suspect the flouride is to blame for both my strong teeth and my third arm.
posted by five fresh fish at 10:30 PM on November 24, 2005

Change it after you are sick too, to prevent re-infection.
posted by fshgrl at 11:08 PM on November 24, 2005

Many toothbrushes have coloured bristles that slowly fade to white specifcally so you know when to change them.
posted by krisjohn at 11:29 PM on November 24, 2005

Every month or two and I keep mine upside down in a small cup of Listerine.
posted by Independent Scholarship at 11:36 PM on November 24, 2005

fff, that was "every time you see a dentist, and then halfway between visits." (emphasis mine) Hence the every 3 months. One is supposed to see one's dentist every 6 months. I don't think that your "every seven years" is a good example and I don't think you should be espousing this infrequent-dentist-visit philosophy to others. It may work for you; it's not recommended for just anyone, though -- it's like you're suggesting that because you only go to the gynecologist every seven years, no one else needs to go any more frequently, even if she may have a different lifestyle and different needs.

On preview (I'm slow): krisjohn is right about the brushes that fade. They are great. I was going to say that but I got carried away with combating fff.

So, brandz, ask your dentist and/or hygienist; if you haven't one, play it safe and change every 3 months. Ask your dental professional for enough brushes to last until you go in again -- if you will be in in six months, as for 2 brushes; if it'll be 2 years, ask for 4. Etc. They'll gladly give you that plus floss and probably some toothpaste as well.

Also, toothbrushes? CHEAP.

On preview again (OK, so I'm *really* slow): Independent Scholarship's suggestion is good, but running them through the dishwasher is better. If the bristles aren't bent, just disinfect them in the dishwasher and keep using them.
If the bristles are bent, you need a new brush, and you need to learn to brush less hard. Ask your dentist.
posted by librarina at 11:42 PM on November 24, 2005

My math about how many toothbrushes to ask for was probably totally wrong. I blame the Manhattans. However, I feel confident that you can figure it out.
posted by librarina at 11:45 PM on November 24, 2005

fff: how old are you? My folks did like yours did, I did like you did, and now I'm 43 and my gums have started to recede from overbrushing, which means I hurt when I cold rinse, which sucks. Just a heads-up.
posted by flabdablet at 3:05 AM on November 25, 2005

re: toothbrushes whose color fades -- doesn't that mean some of the dye is likely dissolving in your mouth? something to think about.
posted by ori at 3:31 AM on November 25, 2005

My dentist said I only have to come in for a cleaning every 9 months because my teeth (and gums) are in good shape. When she told me this she said it was because while she was cleaning my gums did not bleed (I suppose the amount of plaque was also important). This seems to be an indicator of how healthy they are.

FWIW: I brush twice a day, floss (flossing in the evening is better than in the morning), and generally use one of those electric toothbrushes with soft bristles (soft is important no matter what type of brush you use). Brushing with hard bristles could injure your gums.
posted by Taken Outtacontext at 4:32 AM on November 25, 2005

Use search engines for questions like this. Seriously.
posted by stavrosthewonderchicken at 4:40 AM on November 25, 2005

I am still not a dentist, but some people do, in fact, need to see the dentist every three to four months due to periodontal disease. (but some are allowed to show up every nine months for good behavior, but that's not an indefinite parole) Google image some photos of that periodontal disease. And while you're at it, perio surgery. Nasty. Err on the side of too many toothbrush changes, definitely any time you get sick, but also if you live with someone else it's not a bad idea to change your brush when they're done being sick.

And use soft bristles unless your dentists tell you otherwise.
posted by bilabial at 5:20 AM on November 25, 2005

Best answer: i tried using a search engine, but can't come up with anything citing original, reviewed/corroborated research. i've wondered the same thing myself, because it seems like a heck of a good business, getting people to throw away toothbrushes every few months (i'm also amazed at how "fancy" current toothbrushes are - it's just a brush!).

i'm not sure i'd trust asking a dentist. how many dentists are really going to check into such an irrelevant detail? if a brush company has one piece of sponsored "research" saying three months that could justify sufficient advertising to push the whole "3 month" thing into the collective subconscious, in my humble and somewhat cynical opinion.
posted by andrew cooke at 5:51 AM on November 25, 2005

it's a bacteria thing. bacteria lives quite happily on your toothbrush. it's also a bristle thing, if they are damaged, they are not doing the job. stop being cheap, buy a new brush.
posted by bilabial at 8:03 AM on November 25, 2005

how do you know, bilabial? if you have a reference, i'd love to hear it. otherwise, i assume you're just bullshitting. for example: why won't the bacteria population reach a stable level in days? what does "damaged" mean when it's a bristle? do you really have damaged bristles at three months?

stop being so cheap

ooo. great argument there. you seem to be gullible, unquestioning, and dismissive. in my book that's way worse than not wasting money.
posted by andrew cooke at 8:14 AM on November 25, 2005

andrew cooke (1Ker) writes "how many dentists are really going to check into such an irrelevant detail?"

They're medical professionals. They have journals and stuff, you know. It's not an irrelevant detail. It's the entire point of their profession. Other than recommending toothbrushes and good brushing technique, they have no control over your health outside of their office. And my hygienist mother has had patients who've died from gum disease; an abcess in the upper jaw can get into the brain and kill you. Bad dental hygiene (excessive plaque) has also been shown to be related to heart disease. It's not an irrelevant detail to them.

Damaged bristles means bent.

Re: dye on the toothbrushes -- I hadn't thought of that, but they are ADA approved etc etc and it's what my mother always gets me. Soft bristles, for sure.
posted by librarina at 8:50 AM on November 25, 2005

Quick PubMed and Google Scholar searches ("toothbrush replacement" or "replace toothbrush) turn up multiple studies and journal articles, like "An investigation into the effect of three months' clinical wear on toothbrush efficacy: results from two independent studies":
OBJECTIVE: Limited evidence has suggested that a worn toothbrush may be significantly less effective than a new brush with respect to plaque removal. Two independent studies, one with a manual toothbrush and one with a powered toothbrush, were undertaken to compared the ability of these toothbrushes as new and after three months' use to remove plaque. [...]

CONCLUSION: The results from these two studies provide further data in support of the hypothesis that a worn toothbrush is less efficient with respect to plaque removal than a new brush. Patients should therefore be encouraged to replace their toothbrush regularly before bristle wear becomes excessive.
posted by mbrubeck at 9:20 AM on November 25, 2005

(I'm curious how andrew cooke somehow "tried using a search engine" and didn't find any of the hundreds of articles on this topic, especially since his unsubstantiated claims got marked as "best answer.")
posted by mbrubeck at 9:26 AM on November 25, 2005

flabdablet: 38, iirc. I use an soft brush, and I typically dunk it in boiling water to make it ultra-soft, otherwise my gums do get harmed. There is some gum recession on my canines, but the dentist doesn't seem concerned (I saw him a year or so ago, to have wisdom teeth removed.)

librarina: calm down. In no way did I even remotely suggest that what I'm doing is smart, nor did I suggest others do as I do. I do not think AskMe readers are so stupid as to think they should emulate my life.
posted by five fresh fish at 10:49 AM on November 25, 2005

Teeth get me riled up, apparently. Who knew?
posted by librarina at 11:19 AM on November 25, 2005


1 - thanks for the links.

2 - i did try searching, with google. if you want to check, do it yourself. there's stuff selling toothbrushes, stuff on how it's a better invention than the car, etc etc. that's from memory, but i couldn't find any papers.

3 - why does it need someone like me to piss people off because anyone will give some evidence to back up their claims?

4 - i will change my toothbrush more often from now on. seriously - thank-you. all i want is the facts, rather than unsubstantiated opinion.
posted by andrew cooke at 1:44 PM on November 25, 2005

sigh. so now i try checking the people who implied i was making things up.

pubmed doesn't turn up useful results for "toothbrush replacement", as far i can see. google scholar turns up conflicting reports. it's not as clearcut as mbrubeck suggested. taking the hits reported in order:

1 - reports on dentist recommendations, not effects. nice quote, in the light of librarina's indignant spluttering: It appears that practicing dentists and dental hygienists may be aware of new research on toothbrush replacement but, for reasons as yet undocumented, this information is not relayed to their patients.

2 - changing toothbrushes was not listed as significant in a study on brlgian children (tooth brushing with fluoridated toothpaste, dental appointments and dental fluorosis were)

3 - behavioural study; not relevant.
4 - behavioural study

5 - [...] toothbrush wear has been shown not to be critical in ensuring optimal plaque removal (not a conclusion but part of the context of the abstract).

6 - behavioural study

7 - Each individual is capable of maintaining low PI, even if using a toothbrush that shows evidence of wear

8 - behavioural study
9 - single case study (regular replacement suggested if your immune system is failing!)
10 - dna collection

at this point i gave up and started looking at everything and started picking more relevant looking results.

The 3-month-old toothbrushes were as effective as new brushes in plaque removal.

Patients should therefore be encouraged to replace their toothbrush regularly before bristle wear becomes excessive.

having (finally, using a different search - "toothbrush replace") found the paper shown above, i'm calling it a day. make up your own mind....
posted by andrew cooke at 2:10 PM on November 25, 2005

Thanks, andrew. You're right that there's no clear-cut answer. (Even the one paper I linked is somewhat ambivalent in its conclusions.) My point was that this is indeed an area of research for dentists, and that there is some evidence that replacing worn toothbrushes can have health benefits.
posted by mbrubeck at 2:17 PM on November 25, 2005

I manage a dental office. We give away toothbrushes at the 6 month visit, so if you go to the dentist twice a year, you ought to buy about 2 brushes per year, provided you don't get sick. That's uh, 6 bucks if you get a fancy one where I live. The dentist I work for (and any dentist who hopes to keep his license) participates in continuing education courses every year. They talk about these sorts of things. The dental health studies I read are more geared toward periodontal disease and the link (not proven to be causal) of gum health to vascular health. It seems that it's all called plaque in a stunning coincidence. The bacteria that likes your teeth also likes your heart. Why take the chance?

One of the major bacterial things that people do is put those plastic toothbrush covers on. Nothing like a damp environment for protecting your health.

I will ask the doctor on monday for any pertinent studies that he's seen, but three months is the standard. And the brush companies aren't knocking down our door with free samples, so don't worry that we're shilling for anyone.
posted by bilabial at 3:09 PM on November 25, 2005

The American Dental Association has an official statement on this topic:
A toothbrush should be replaced every three or four months, or sooner if the bristles become frayed. A worn toothbrush does not do a good job of cleaning your teeth.
In the course of Googling this, I discovered that New York City generates 410 tons of toothbrush waste a year.
posted by ikkyu2 at 12:53 AM on November 26, 2005

Here's a link that might actually work.
posted by ikkyu2 at 12:50 PM on November 28, 2005

MeTa: Someone thinks this post should be tagged "toothbrush." It sounds like a good idea to me also.
posted by caddis at 6:54 AM on December 2, 2005

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