Are Mouth Rinses Good For Me?

Are Mouth Rinses Good For Me?

Many of us have seen advertisements promoting all sorts of mouth rinses, to a point where many get the impression that mouth rinses are absolutely essential.

Misleading Mouth Rinse Ad

Misleading Mouth Rinse Ad


With advertisements like these, it is easy to assume that using mouth rinse is superior to toothbrushing and flossing. However, mouth rinses are only effective if used as an adjunct to proper toothbrushing and flossing. (Adjunct means as a side kick. Think of mouth rinses as Robin. As great as he is, he cannot replace Batman.)

Fundamentally, mouth rinses CANNOT replace toothbrushing or interdental cleaning.

Mouth Rinse is NOT superior to tooth brushing and flossing, and CANNOT replace good oral hygiene.

The concept of BIOFILM

The greatest enemy is ever present as a coating on our teeth and gums – Plaque.

If you own a fish tank, or used a water bottle frequently enough without washing, you will notice that after a while, a sticky film will form on the surfaces, and no amount of rinsing will get rid of it. But with a good scrub, this scrummy layer will come off.

Biofilm is the same concept – our teeth is the smooth surface on which this sticky film will form. This biofilm consists mainly of salivary proteins and bacteria. With exposure to food, the biofilm matures into plaque – which looks yellow and smells. Plaque consists of up to 70% bacteria, and is the cause of gum inflammation and dental decay.

Dental plaque

This patient has not been brushing his teeth and as a result, there is now a thick yellow sticky coating on it – dental plaque (yucks!) – which can be scraped off. No amount of rinsing with water or mouth rinse will get rid of this plaque.

Toothbrushing and flossing disrupts this layer of mature plaque, but the biofilm forms back almost immediately. The whole idea of brushing and flossing is to continuously disrupt and remove the layer of biofilm on our teeth, so that it does not thicken and mature into harmful plaque, and eventually cause tooth decay and gum disease.

Mouth rinses, even when used vigorously, cannot disrupt this biofilm. Even if the manufacturer claims the active ingredient has effect, but penetrating the thick biofilm in the form of plaque is extremely difficult to exert any significant effect. So does that mean mouth rinses are completely useless? No! Mouth rinses are beneficial, especially those with certain active ingredients, but only if used together with toothbrushing and flossing that first removes the layer of plaque in order to allow better penetration of the active ingredients.

Read more: Why Must I Brush My Teeth Well?

Know the Active Ingredients in Your Mouth Rinse

With so many types of mouth rinse on the market, it can get very overwhelming to choose. Our advice is to look at the label to know the contents of the mouth rinse, specifically the active ingredients. Manufacturers are required by law to list their active ingredients, so that consumers can be aware of what type of mouth rinse they are purchasing.

supermarket aisle with mouthrinses

That’s a lot of mouth rinses to choose from!

Here, we will help you decide on the right mouth rinse, by choosing the right active ingredients:

  • Fluoride (F) – strengthens the enamel, reduces risk for tooth decay
  • Cetylpyridinium Chloride (CPC) – antibacterial, inactivates Covid-19 virus
  • Chlorhexidine (CHX) – disinfectant, reduces gum inflammation, reduces risk of wound infection after extraction or surgery
  • Hydrogen Peroxide (H2O2) – for faster healing of oral ulcers or wounds
  • Essential Oils (EO) – antibacterial, reduces gum inflammation, freshens the breath
  • Povidone-iodine (PVP-I) – for sore throats, reduces Covid-19 virus load


Fluoridated mouth rinses
Ingredients to look out for:
  • 0.05% Sodium Fluoride (NaF) = 225ppm of fluoride
  • 0.11% Sodium Fluoride (NaF) = 500ppm of fluoride
  • 0.2% Sodium Fluoride (NaF) = 900ppm of fluoride
  • 0.31% Sodium Fluoride (NaF) = 1400ppm of fluoride
  • Stannous Fluoride (SnF2) – additional benefit of having antibacterial properties, but stains teeth, therefore less common in Singapore
Good for:

Daily rinsing, and to compliment the use of a fluoride toothpaste

Do you really need it?
  • Yes – If you want to prevent cavities and reduce the risk of tooth decay.
  • No – If you are at low risk of developing cavities (no new cavities in the last 12 months, as checked by the dentist).
  • However, if you enjoy using mouth rinse to provide fresher breath, choose a fluoride-containing mouth rinse for added benefit.
What does it do?

Fluoride is also found in toothpastes, and helps to strengthen the tooth’s enamel, in a process known as remineralization. This helps to prevent cavities by making enamel more resistant to acid attacks from bacteria in the mouth. This can be especially beneficial for people who are at high risk of cavities, such as those who have a history of tooth decay or who consume sugary or acidic foods and drinks on a regular basis.

Do take note that while fluoride toothpastes usually contain 1000ppm of fluoride, mouth rinses usually contain only 200-500ppm of fluoride. As such, fluoride mouth rinses should not be used to replace fluoride from toothpastes, but rather to complement it.

After brushing, it is advisable to not rinse out the toothpaste completely, in order to leave the fluoride in the mouth for maximum effect. Since many people do rinse out their toothpaste completely anyway (because it can feel quite icky with the toothpaste foam left over), rinsing after toothbrushing with a fluoride mouth rinse may help to replenish the lost fluoride.

Read more: Which Toothpaste is Best for Me?


High fluoride mouth rinses

High fluoride mouth rinses are very effective in preventing tooth decay and promoting oral health. These are mainly for patients at high risk of decay, such as those who have new cavities every year or have had multiple fillings done in the past.

It is important to note that high fluoride mouth rinses must be prescribed by a dentist, as these contain a higher concentration of fluoride than over-the-counter mouth rinses. This higher concentration can be more effective in preventing tooth decay, but it can also be potentially harmful if not used correctly.

Typically, high fluoride mouth rinses are used at night, usually 2-3 times a week, as a final rinse just before sleeping. This allows the fluoride to remain in contact with the teeth for an extended period, providing additional protection against decay.

When using a high fluoride mouth rinse, it is important to follow the instructions provided by your dentist carefully. Swish the rinse around your mouth for the recommended amount of time, then spit it out. Do not swallow the rinse, and do not rinse out your mouth with water right after.

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Mouth rinses with CPC

Ingredient to look out for:

Cetylpyridinium Chloride, usually in 0.05% or 0.1% concentration

Good for:
  • Daily rinsing, with antimicrobial properties which may help to reduce gum inflammation and bad breath, and sore throat.
  • Safe for use during pregnancy
Do you really need it?
  • Yes – If you want a daily mouth rinse to reduce the amount of microorganisms in the mouth and to freshen your breath
  • No – If you’re afraid of tooth staining
What does it do?

Cetylpyridinium Chloride (CPC) is an antimicrobial compound widely used in mouth rinses to prevent bacterial, fungal, or viral infections in the oral cavity. The compound is known to exert antimicrobial effects by disrupting the membrane of bacteria, viruses, or fungi cells.

CPC has been shown to be effective in reducing plaque accumulation and gingival inflammation, and helps with bad breath. Additionally, recent studies have found that rinsing with CPC-containing mouth rinses can reduce the viral load of the SARS-CoV-2 virus (also known as the COVID-19 virus) in saliva. This may help to reduce the transmission of the virus, especially in dental clinics.

During the Phase One and Phase Two Post-Circuit Breaker of Singapore’s COVID measures, dental clinics were advising every patient to rinse with 0.05% – 0.1% cetylpyridinium chloride (or 1% hydrogen peroxide or 0.2% – 1% povidone-iodine) for 1 minute before treatment. This pre-procedural rinse helped to ensure the safety of both patients and dental professionals during the pandemic.

Many mouth rinses in the market combine both CPC with Sodium Fluoride, to strengthen tooth enamel and to help prevent tooth decay.

However, it is important to note that CPC may cause staining in a minority of patients, albeit much milder than Chlorhexidine. CPC is generally safe and effective when used as directed, and is also safe to be used during pregnancy.

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chlorhexidine mouth rinses
Ingredients to look out for:

Chlorhexidine Gluconate or Chlorhexidine Digluconate, usually 0.2% concentration.

Good for:
  • Use after dental extractions or surgery, to reduce risk of wound infection
  • Bleeding and swollen gums
  • Safe for use during pregnancy
Do you really need it?
  • Yes – If you are prescribed to one by the dentist
  • No – If you’re afraid of tooth staining

Do not use continuously for more than 2 weeks

What does it do?

Chlorhexidine (CHX) is a disinfectant and antiseptic commonly used in healthcare to sterilize surgical equipment and disinfect surfaces and the skin of doctors and patients.

CHX mouth rinses are prescribed by the dentists to reduce post-extraction infections, and for the treatment of gum disease. The compound has a positive charge which causes it to bind to negatively charged surfaces in the oral cavity, including the oral mucosa, salivary pellicles on teeth, titanium surfaces, and various components of biofilm including bacteria. Thus, it can stay longer in the mouth to exert its antimicrobial and antifungal effects.

It is well-researched that CHX can reduce plaque formation, reduce gum bleeding and gingival inflammation. It also reduces the incidence of dry socket (alveolar osteitis), and painful condition which occurs a few days after a tooth is removed.

However, use of CHX is limited to 2 weeks as it can cause some adverse reactions, mainly brownish discolouration of teeth, increased calculus formation, and altered taste perception (loss of taste, bitter metallic taste, dry or numb feeling of the tongue).

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Hydrogen Peroxide mouth rinse by Colgate
Ingredient to look out for:

Hydrogen Peroxide, usually 1.5% concentration.

Good for:
  • Daily rinsing
  • Promoting healing for chronic ulcers, extraction wounds etc
  • May be effective for sore throats
Do you really need it?
  • Yes – If you suffer from frequent and chronic ulcers in the mouth
  • No – If you do not enjoy the bubbling effect in your mouth
  • No – If you are hoping to whiten your teeth
What does it do?

Hydrogen peroxide (H2O2) breaks down to produce oxygen, and has many uses as a disinfectant as it works well against bacteria and viruses. Hydrogen peroxide, at low concentrations of 1.5%, has been shown to promote wound healing in the mouth, as such can be useful for those who suffer constant chronic ulcers. Since it breaks down to form water and oxygen only, it is considered very safe, but will lose its effectiveness if stored too long in a warm and bright environment.

Hydrogen peroxide is also used as a whitening agent to bleach or whiten teeth, usually in the form of whitening gels, but at much higher concentrations. At the low concentration of 1.5% found in mouth rinses, the whitening effect may be very limited1. However, there are studies that suggest using 1.5% hydrogen peroxide mouth rinse right after 0.2% chlorhexidine mouth rinse can reduce the staining of teeth without decreasing the efficacy of chlorhexidine2.

There are higher concentrations of hydrogen peroxide being sold elsewhere, such as 3% solutions for cleaning wounds, and even up to 19% concentration for gardening uses. We DO NOT recommend using such high concentrations as mouth rinses, as they may cause burns on the sensitive oral mucosa (the pinkish-red “skin” in your mouth).

1: Greenwall, L. Tooth whitening techniques: Second edition. Tooth Whitening Techniques (CRC Press, 2017). doi:10.1201/9781315365503.
2: Jhingta, P. et al. Effect of hydrogen peroxide mouthwash as an adjunct to chlorhexidine on stains and plaque. J. Indian Soc. Periodontol. July 2013. 17(4), 449–453 (2013). doi: 10.4103/0972-124X.118315.
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Listerine mouth rinse range
Ingredients to look out for:

Eucalyptol, Thymol, Menthol, and Methyl Salicylate. Found only in Listerine® mouth rinses.

Good for:
  • Non-alcohol ones are safe for daily use
  • Those who are looking to improve their overall oral health
  • Freshening one’s breath during the day, maybe for a meeting, or after having lunch
What does it do?

The proprietary combination of 4 essential oils – eucalyptol, menthol, methyl salicylate, and thymol – are the active ingredients found in all types of Listerine® mouth rinses. This combination of ingredients is specifically designed to penetrate biofilm and kill bacteria that can lead to gingivitis3. Essential oils have also been shown to have anti-inflammatory properties, which can help reduce inflammation in the gums.

However, it has been shown that the essential oils require alcohol for better penetration into the biofilm. This explains why despite the trend towards alcohol-free preparations, Listerine still offers alcohol-containing mouth rinses, specifically the Original and Healthy White range.

3: Alex Nogueira Haas, Tassiane Panta Wagner, Francisco Wilker Mustafa Gomes Muniz, Tiago Fiorini, Juliano Cavagni, Roger Keller Celeste. Essential oils-containing mouthwashes for gingivitis and plaque: Meta-analyses and meta-regression, Journal of Dentistry, Volume 55, 2016, Pages 7-15, ISSN 0300-5712.
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Povidone Iodine (PVP-I) Mouth rinses
Ingredient to look out for:

Povidone-Iodine, in 1% concentration

Good for:
  • Sore throat
  • Alternative to chlorhexidine if suffering from an oral infection

Do not use if you are pregnant or have thyroid problems.

What does it do?

Povidone-iodine (PVP-I) is an antiseptic agent that has been used for decades in healthcare settings for wound care, surgical hand scrubbing, and disinfection of medical equipment. It has a very strong antimicrobial and higher anti-viral activity compared to other antiseptic agents, and works by the release of iodine molecules which penetrates into the microbes to cause microbial death. More recently, povidone-iodine has gained attention for its potential use as a mouth rinse to prevent and treat viral infections, particularly of the COVID-19 virus, SARS-COV-2.

Povidone-iodine has also been shown to be particularly effective in killing viruses such as rhinoviruses (which causes the common cold), influenza (which causes flu), herpes simplex virus, and SARS-CoV-2. As such, it was recommended and used in many dental clinics worldwide as a pre-procedural rinse to reduce the viral load of the COVID-19 virus, in the mouth, thus potentially reducing the risk of the spread of COVID-19.

Viruses like the rhinovirus or SARS-COV-2 primarily targets the cells lining the soft tissues of the throat. The virus binds to these cells and starts to replicate, causing inflammation and irritation in the throat, leading to a sore throat, which is often one of the first symptoms of a cold. As the virus continues to replicate, it can spread to other areas of the upper respiratory tract, including the nose and sinuses. This can lead to additional symptoms such as congestion, runny nose, and sinus pressure.

Sore throat

Sore throat caused by inflammation of the airway tissues (tonsils, pharynx and larynx).

PVP-I can be used when experiencing sore throat. By gargling with a PVP-I mouth rinse, the viral count in the mouth especially at the throat is significantly reduced and may help to delay or even prevent the progression to an upper respiratory tract infection (URTI).

It is important to note that povidone-iodine mouth rinses should be used as directed and not swallowed. Ingesting povidone-iodine can be harmful, particularly for individuals with thyroid problems, due to the iodine content. PVP-I is also not recommended for use by pregnant ladies.

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Alcohol-Free Mouth Rinses

In previous years, most mouth rinses available are formulated with alcohol, or specifically ethanol. Ethanol is used as a solvent or carrier for the active ingredients, has antiseptic and antimicrobial properties, and also acts as a preservative for the mouth rinse.

In recent years, there have been some studies which suggest that frequent use of alcohol-containing mouth rinses may predispose the user to oral cancer, especially in the presence of other risk factors for oral cancer, such as poor oral hygiene, smoking and frequent alcohol consumption4.

The alcohol content in the mouth rinse can also cause issues such as drying of the oral soft tissues, burning sensation or pain, cell destruction and softening of dental fillings (composites).

By and large, the consensus is, having alcohol in the mouth rinse offers little additional benefit when compared to alcohol-free mouth rinses5. As such, most mouth rinses today are alcohol-free.

4: McCullough, M. and Farah, C. (2008), The role of alcohol in oral carcinogenesis with particular reference to alcohol-containing mouthwashes. Australian Dental Journal, 53: 302-305.
5: Werner, C., Seymour, R. Are alcohol containing mouthwashes safe?. Br Dent J 207, E19 (2009).

How do you ensure your mouth rinse is alcohol-free? Look out for the label “Alcohol-free” or check the list of ingredients to make sure “Ethanol” is not included.

mouth rinse label containing alcohol and essential oils

Always check the label to know what are the ingredients – for this mouth rinse, it contains alcohol (Ethanol) and essential oils (Eucalyptol, Thymol, Methyl Salicylate, Menthol).

Examples of alcohol-containing mouth rinses:

Listerine® Original, Oral-B® Extra Fresh, Betadine®, Difflam®, Orasol®.

Our Tips For Using a Mouth Rinse

  • Use after brushing and flossing
  • Use undiluted unless instructed otherwise
  • Do not rinse out with water after using a mouth rinse
  • Avoid food and drinks for at least 30 minutes after using a mouth rinse
  • Do take note that some mouth rinses are not meant for long term daily use: chlorhexidine, povidone-iodine, alcohol-containing mouth rinses
Mouth rinses available in our clinic:

High Fluoride: Pearlie White® Fluorinze Max
Chlorhexidine: Pearlie White® Chlor-Rinse Plus
Hydrogen Peroxide: Colgate® Peroxyl

Disclosure: We are not sponsored by any dental product companies and this article serves as a guide to the various types of mouth rinses available in the Singapore market. The opinions expressed in this article are based on evidence available at the current moment. If you have any specific oral health concerns, it is highly recommended to see a dentist who can advise on the appropriate mouth rinse for you.

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