Mouthwash can be useful for rinsing away food debris and bacteria after brushing, but it's not an essential part of a good oral hygiene routine. That said, it doesn’t do any harm either, and may help fight bad breath.
Some people enjoy rinsing with mouthwash after they’ve brushed their teeth, because they feel that the mouthwash is clearing away all that loose debris left over after brushing.
While this is actually true, rinsing with water after brushing has the same effect.
Mouthwash, more than anything else, is a good addition to a proper oral hygiene routine, not a substitute. Mouthwash should never take the place of brushing, flossing, and visiting the dentist, but it can help freshen your breath, and it’s mostly harmless.
This may surprise you, if you’ve heard about the studies over the years that connect mouthwash use to things like cancer and heart disease.
One example of these alarming studies was in the journal Free Radical Biology and Medicine which found that some mouthwashes could raise blood pressure by wiping out a type of mouth bacteria that helps the body generate nitric oxide. Nitric oxide plays a critical role in protecting the cardiovascular system, including keeping blood pressure down.
It's important to note however, that this study focused on mouthwashes which contain an antibacterial agent called chlorhexidine, which is usually only available by prescription. Not only that, the Free Radical Biology and Medicine studio was very small, just 19 participants. So few participants mean that this study requires much more research to support its findings.
A number of studies the 90s have suggested mouthwashes that contain alcohol may contribute to the development of oral cancers. However, many experts say that these studies are flawed, and focus on excessive mouthwash use of three or more rinses daily.
Several review studies since then have failed to find links between alcohol rinses and cancer.
Nonetheless, it is important to note that mouthwashes with alcohol in them can dry out your mouth. People who have issues with dry mouth should be sure to choose an alcohol-free variety.
A much more complicated issue is presented by antiseptic or antibacterial mouth rinses. Only people who have periodontal disease or other harmful types of oral bacteria should use these types of mouthwashes. If you think that you should be using one be sure to consult with your dentist first.
People who have healthy teeth and mouths but who want to use mouthwash should select a mild brand without strong antibacterial agents or alcohol.
Just keep in mind, mouthwash may feel nice and refreshing to use, but it really doesn’t do much other than (possibly) help reduce bad breath. If you enjoy using mouthwash, there’s no medical reason not to rinse with it once or twice a day, but if you want to save some money, just use water instead.