Foreword: I ask this only for mouthwashes with no alcohol; so please omit alcoholic mouthwashes (which may hurt the mouth and may have been claimed to cause cancer).

My grandmother uses the Crest Pro-Health Rinse which contains 'anti-microbial agent, cetylpyridinium chloride'. Yet USA Today in 2008 and CTV News in 2012 reported complaints that the mouthwash browns and stains teeth, and also numbs taste. From the CTV article:

The parent company of Crest, Proctor and Gamble, told CTV News that the ingredient Cetyl Pyridinium Chloride is what causes some people’s teeth to turn brown.

Dentist Shaireen Lalani says the stains are not permanent and can be removed with professional cleaning.

In some cases, Crest has reimbursed consumers to have their teeth professionally cleaned.

What are the risks to using such mouthwashes? Most mouthwashes recommend two rinses daily, but is this advice safe and correct? How often should they really be used?

  • 6
    Where are you getting your information on alcoholic mouthwash causing cancer? A quick Google search showed results that say that is debatable and that other factors need to be considered. Is the use of mouthwash considered excessive? Articles list more then 3 times in a day as excessive. Is it being used as a substitute for proper oral care such as brushing and flossing? More articles list that as a major issue for people. I have seen in your posts about wanting to avoid something for some reason but not going into detail as to why and showing evidence.
    – Joe W
    Commented Apr 12, 2015 at 17:19
  • 5
    @Law People here don't have to back up their claims in questions. However yours is a big one and I don't like to see it - someone could come along and see it, without any evidence to back it up. I have edited it out until you have strong evidence for it. We don't need to spread rumours on this site.
    – Tim
    Commented Apr 12, 2015 at 17:29
  • @Tim Thanks for your concern. I've tempered my OP. Better now? I use the auxiliary verb 'may'.
    – user14
    Commented Apr 12, 2015 at 17:37
  • @JoeW Better now? I apologise for any offense caused.
    – user14
    Commented Apr 12, 2015 at 17:37
  • @Tim That gladdens me. Thanks for the feedback again.
    – user14
    Commented Apr 12, 2015 at 17:40

1 Answer 1


You don't need at all to use any mouthwash. A healthy mouth is full of bacteria, almost all of them beneficial for our health, and

  1. There is no evidence so far of any long term preventive effect of any kind of mouthwash, only trials with transient effects (< one year) or 6 months in surrogate clinical endpoints as number of bacteria and gingivitis. The only one with some evidence are fluoridated-based mouthwashes, but you get the same effect if you don't spit after brushing with fluoridated toothpaste;
  2. If you still decide to use, the only risk is the staining and metallic taste from chlorhexidine-based mouthwashes. There is no evidence so far of risk of oral cancer associated with the use of essential oil–containing mouthrinses.

Instead, you may invest your money in cheese for your oral health.

Lastly, if you are interested in joining a study to increase our limited knowledge about mouthrinses for oral health, there are some trials recruiting.

So, in brief: daily use of fluoridated toothpaste without spitting after using it is enough if you already are eating enough fruits and vegetables and limiting the consumption of sugar.

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