To make it very clear: the use of mouthwash can by no means replace a proper mechanical tooth cleaning; it is just an additional tool for your mouth hygiene and cannot replace tooth brushing and dental flossing!

What is mouthwash?

Mouthwash is an antibacterial solution to reduce the growth of bacteria in your mouth and your throat. Mouthwash can reduce bad breath (halitosis) and can greatly help with your mouth hygiene. Mouthwash is also called mouth rinse, mouth bath, or oral rinse. The first documented use of mouthwash dates back to about 2700 BC. It was used in Ayurveda, Chinese medicine, and later in Greek and Roman periods. Independently, Native North American and Mesoamerican cultures, like the Aztec, used mouthwashes based on plant extracts or salt water.

Benefits of mouthwash

Some mouthwashes can reduce the formation of dental plaque and thus gum inflammation (gingivitis) and dental caries. Furthermore, almost all commercially available mouthwashes claim to reduce a bad breath (halitosis). Dental plaque arises from the hardening oral biofilms that consist of bacteria. Once formed, dental plaques are difficult to penetrate and require mechanical disruption by using professional brushes and abrasive paste.

Types of mouthwash

Today, there are more than 100 different types of mouthwash available, which consist of about 30 different chemical substances.

The two most effective mouthwashes are based on:

  • Essential oils (EO) or
  • Chlorhexidine digluconate (CHX)

Although chlorhexidine-based mouthwashes are more effective in reducing plaque formation, essential oil-based mouthwashes tend to cause fewer side effects (see below).

Mouth rinsing technique

Be aware that mouth rinsing usually follows mechanical cleaning with tooth brush, dental floss, interdental brushes, or dental sticks! It can only complement, but never replace a proper mechanical tooth cleaning.

Mouthwash should not be used immediately after brushing the teeth so as not to wash away the beneficial fluoride residue left from the toothpaste. That means it´s good to wait 10 minutes after using fluoride-containing toothpaste before you use mouthwash!

  • Usually you use about 20-50 ml of mouthwash for a mouth rinse, depending on the size of your mouth of course.
  • Mouthwash is held in the mouth and can also be swilled around the mouth. It may also be gargled to decrease bad breath.
  • After the mouth rinse, spit out the mouthwash. Don´t drink it!

To ensure a good action, you should not drink (water) immediately after using mouthwash.

Essential oil-based mouthwash

Essential oils used in mouthwashes are for example menthol, eucalyptol, and thymol. Mouthwash containing essential oils can reduce the formation of dental plaque and gum inflammation (gingivitis), according to clinical studies1.

Mouthwash containing essential oils always uses alcohol to dilute the oils in water. But it is actually not the alcohol killing the bacteria, but the essential oils that are penetrating the oral biofilm and destroying the bacteria.

The concentration of alcohol in mouthwashes is only below 30%, which is not enough to kill bacteria. The issue with alcohol-based mouthwashes is that alcohol is a drying agent and can actually increase bacterial activity in the mouth leading to a worse bad breath (halitosis).

Chlorhexidine-based mouthwash

Chlorhexidine digluconate (CHX) is a chemical substance that is used as a disinfectant and antiseptic to sterilise surgical instruments and for skin disinfection. Chlorhexidine is a positively charged cationic substance and can bind to negatively charged bacterial cell walls. This results in the disruption of the bacterial membrane, thereby killing the bacteria. Chlorhexidine also has low anti-fungal activity.

Benefits of Chlorhexidine-based mouthwash

Chlorhexidine (digluconate) is used in is used as a 0.12-0.2% solution in mouthwash. It can reduce the formation of dental plaque and gum inflammation (gingivitis), according to clinical studies1. In the long term, chlorhexidine is slightly more effective in reducing plaque formation than essential oil-based mouthwashes, but equally effective in reducing gum infections1.

In contrast to most other substances used in mouthwashes, Chlorhexidine stays in the mouth for hours after using mouthwash. It adheres to surfaces in the mouth, especially gums and soft tissues. Afterwards, it is slowly released into the mouth in effective concentrations and can exert its antibacterial action (8-12 hours).

Side effects of Chlorhexidine-based mouthwash

The side effects of using chlorhexidine-based mouthwash are various.  Chlorhexidine can stain teeth and gums, especially in people who drink coffee, tea, and red wine. Tooth crowns made of resin or composite are particularly prone to staining. This staining changes the colour of the teeth towards yellow, brown, or black. Fortunately, your dentist can easily brush away these stains with brushes and abrasive paste, during a professional dental cleaning!

Chlorhexidine mouthwash can also change the way you taste food and drinks, can irritate your gums, can temporary render your tongue numb, and lead to throat burns. These are reasons not to use mouthwash every day. Mouthwash rather is a good tool when you feel your oral flora is out of balance.

Read more about tongue scrapers and how to use them here