Ask LH: Is Mouthwash Good Or Bad For Your Teeth?

Ask LH: Is Mouthwash Good Or Bad For Your Teeth?

Dear Lifehacker, Are antibacterial mouthwashes safe to use for all gum types? I’ve read conflicting reports about their benefits and want to make sure I’m not doing more harm than good. Thanks, White Smile

Mouthwash image from Shutterstock

Dear WS,

Dental health is tougher to get right than most people realise. Even if you brush your teeth often and thoroughly, there are various things that can go wrong: from brushing at the wrong times of the day to brushing too hard. To further complicate matters, the oral hygiene products on the market aren’t always suited to everybody — and mouthwashes are no exception.

Interestingly, most oral health experts advise against using mouthwash straight after brushing. The UK National Health Service suggests waiting until after lunch, for example. You’re also supposed to refrain from eating and drinking for at least 30 minutes afterward.

We presented your query to Dr. Mark Burhenne, a dentist and author with over 30 years of experience. Here’s what he had to say:

Over reliance on mouthwash is one of the biggest mistakes people make when caring for their teeth. Using antibacterial mouthwash can disrupt the normal flora (or bacteria count) in the mouth. What a lot of people don’t realize is that we rely on a healthy balance of good bacteria in the mouth to keep us healthy.   Wiping all the bacteria out — good and bad — disrupts that delicate ecosystem of living bugs in the mouth and makes us prone to issues such as bad breath, oral yeast infections and cavities. I recommend to most of my patients that they ditch the mouthwash: you don’t need it. To prevent gingivitis, focus on oral hygiene, diet and an oral probiotic supplement. The mouthwash is a dangerous short-term solution that really has no efficacy at all.

It’s worth noting that not all dentists agree with Dr Buhenne’s assessments. Also, there are mouthwash products on the market that contain additional ingredients such as fluoride which can reduce the risk of tooth decay. The harsh alcohols can also help prevent periodontal disease, cankers and bad breath. Provided you follow good oral hygiene practices, these benefits arguably outweigh the importance of “good” bacteria.

If you’re not sure that mouthwash is right for you, we suggest going down the DIY route with a saltwater rinse made from table salt and warm water. Not only does salt work as a natural disinfectant, it can also reduce swelling in the gums.

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  • It’s not good to use alcohol based mouth washes too frequently either, IIRC a report a few years ago said high usage could lead to problems. I only use listerine once a week at most and plax once in a while. I don’t suffer from bad breath so don’t find a need to use mouthwash too frequently.

  • Dental student here:

    The dentist quoted is entirely wrong on most of his statements here. There is simply no empirical evidence at all to demonstrate that broad spectrum mouthrinses “makes us prone to issues such as bad breath, oral yeast infections and cavities” nor is it “a dangerous short-term solution”.

    Mouthrinses are actually used to prevent infections (such as yeast), combat bad breath. Mouthrinses certainly don’t make us prone to cavities, to the contrary, it reduces the primary cavity causing bacteria in your mouth called s.mutans (Fine et al. 2000; Agarwal & Nagesh 2011).

    I’m very concerned that this dentist is making these unfounded statements that have no scientific validity to them. Mouth rinses have received approval from the American Dental Association and the FDA, i certainly wouldn’t call them a “dangerous short term solution”.

    His recommendation of the use of oral probiotic supplements for gingivitis is ringing every alarm bells in my head. I personally would not go near a ‘dentist’ who recommends oral probiotics for gingivitis and makes various completely unsupported and false claims about mouthrinses.

    This guy couldn’t be more wrong when he said mouthrinse “really has no efficacy at all”. Listerine and chlorhexidine mouthwashes has repeatedly shown to be an effective anti-plaque and anti-gingivitis agent but it needs to be used soon after brushing (within 2 hours) as it isn’t effective on established biofilm/plaque.

    A systematic review (Stoeken et al. 2007) of 11 papers found statistically significant differences for both plaque and gingivitis in 6‐month home-use clinical studies of listerine/essential oil mouthwashes.

    Pizzo G et al. J Periodontol 2008 showed that short term use of mouth washes is effective in significantly reducing your plaque levels.

    Charles et al. J Clin Perio 2004 showed that long term (3-6mths) use of mouthwashes is effective in significantly reducing your plaque levels.

    Albertsson KW et al. Clin Oral Invest 2010 showed that mouthwashes better protect against drops in pH after you eat.

    Azuma et al. J Dent Res 1986 showed that listerine (essential oils) mouthwashes have an anti-inflammatory effect (inflammation causes gingivitis).

    Lamster 1983; Gordon et al. 1985; Beiswanger et al. 1997; DePaola et al. 1989; Grossman et al. 1989; Lamster 1983; Gordon et al. 1985; Beiswanger et al. 1997; DePaola et al. 1989; Grossman et al. 1989; Overholser et al. 1990; Charles et al. 2001; Sharma et al. 2002; Bauroth et al. 2003; Charles et al. 2004; Sharma et al. 2004 all showed anti-plaque effects of listerine in 6 month clinical trials.

    That said, we do not recommend the use of regular mouthrinses for everyone. We will only use these when we can’t address poor mechanical plaque removal (toothbrushing). It is used when toothbrushing is not possible (after oral surgery) or as an adjunct to toothbrushing when your oral hygiene is compromised/inadequate (e.g. have braces on).

    Toothbrushing is the most important factor when it comes to plaque removal

    • You have a point, and a good one.
      But I need to ask you a question. You have clearly mentioned that mouthwash does reduces/kills the harmful bacteria in the mouth, being alcoholic in nature , doesn’t it kills the good bacteria as well?
      Or does it have a search and destroy mechanism which makes it to kill only the harmful bacteria or fungus ??

      Even antibiotics are not recommended for over a longer period of time because not only they kill the intended bacteria, they also kill the good ones from your guts. Prolonged uses can result into something even worse. Studies for that has been done. And scientifically proven as well.

      Same goes for any kind of antibacterial drug/lotion/liquid which I believe includes “Mouth Wash” as well.

      So, be careful, while it has good effect, it has some side effects as well. Alcohol in it will not discriminate while killing the microbes.

  • Mouthwash is used just to freshen breath. it is not good to use mouthwash daily as many mouthwashes have alcohol which is a big problem. It is also important to take care of health of your teeth.

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