Overview

What is tea tree oil?

Tea tree oil is an essential oil derived from the steam distillation of the leaves of a tea tree. Tea trees are located along the southeast coast of Australia. Traditionally, the aboriginal people of Australia used tea tree oil as an antiseptic to kill harmful microorganisms, such as bacteria and viruses. However, today, tea tree oil is used around the world and is used to treat various conditions, including the following:

• Acne
• Lice
• Cuts and wounds
• Fungal nail infection
• Athlete’s foot

The properties of tea tree oil, such as killing harmful microorganisms, can, in theory, help to prevent the growth of harmful microorganisms in your mouth. In turn, this can help prevent plaque buildup on your teeth and help prevent cavity formation, which can lead to tooth decay. 

Tea tree oil is safe when applied topically to the outside of your skin. However, tea tree oil is not safe when it is ingested. This can make it difficult to utilise tea tree oil for oral health and fresh breath. Despite this, tea tree oil does show promise in supporting oral health as long as it is not consumed. (Colgate, Mayo Clinic)

Why is oral health and fresh breath important?

Oral health describes the health of the soft and hard tissues of the oral cavity. Good oral health is important as it allows you to interact and converse with those around you without feeling self-conscious. Healthy teeth and gums are essential for eating and chewing various healthy foods. 

Having bad breath and poor oral hygiene can be embarrassing and reduce your confidence. Bad breath is often attributed to certain bacterial species in your mouth, which can lead to gum disease and plaque build-up. (LISTERINE)

Tea tree oil: composition and properties

Chemical ingredients of tea tree oil

Tea tree oil consists of various chemical components; however, the main chemical is discussed in this article section.  

Antimicrobial chemicals in tea tree oil

Antimicrobials kill or reduce the harmful effects that microorganisms, such as bacteria, viruses and fungi, can cause.

The chemicals listed below are found in tea tree oil and have antimicrobial activity:^1,2,3

• Terpinen-4-ol: this is the primary chemical in tea tree oil
• Alpha-terpineol
• 1,8-cineole
• Gamma-terpinene
• Alpha-pinene and beta-pinene

Anti-inflammatory and analgesic chemical constituents of tea tree oil

In addition to antimicrobial activity, 1,8-cineole contributes to tea tree oil's anti-inflammatory and analgesic effects.^2,3 Anti-inflammatory properties mean that tea tree oil can reduce swelling and inflammation. (NHS). The analgesic properties of tea tree oil, accounted for by 1,8-cineole, allow tea tree oil to relieve pain (NHS).

Tea tree oil in oral health

Reduction of oral bacteria

One of the dental benefits of tea tree oil includes reducing the amount of harmful bacteria in your mouth. Tea tree oil contains different chemical components which have antimicrobial properties. Terpinen-4-ol can kill or reduce the harmful effect of bacteria in the mouth.^1,4 The mechanism that tea tree oil uses to reduce bacteria cells in the mouth is by lysing them (causing the bacteria cells to burst open). A study has shown that tea tree oil is particularly effective in reducing the numbers of the following bacterial species, which can be found in your mouth:⁴

• Staphylococcus aureus
• Escherichia coli
• Enterococcus faecalis

Prevention of dental plaque

A tea tree oil health study, which used tea tree oil as a mouthwash, highlighted that after using tea tree oil mouthwash, the amount of dental plaque on the teeth of patients with gingivitis was reduced. Therefore, tea tree mouthwash benefits include reducing dental plaque and reducing your risk of tooth cavities and further decay.^5,6 Interestingly, this study highlighted that compared to chlorhexidine mouthwash, tea tree oil was more effective in reducing dental plaque.⁵ This shows the potential that tea tree mouthwash offers in reducing dental plaque and improving oral hygiene.⁵ However, further research is needed into the effectiveness of tea tree oil mouthwash in preventing plaque formation.

Other studies looking at tea tree oil mouthwash benefits in children aged 8-15 found that using tea tree oil mouthwash, aloe vera mouthwash, and chlorhexidine mouthwash all saw a significant decrease in dental plaque on the teeth.⁷ There was not one particular mouthwash that was the most effective in reducing plaque on the teeth.⁷ This brings forth the question: can tea tree oil mouthwash simply do what other mouthwashes already do for plaque reduction? Research conducted in this field suggests yes.

Adults aged 18 and over have also been studied, with tea tree oil mouthwash being compared to chlorine dioxide-based and chlorhexidine mouthwash. All mouthwashes reduced the amount of dental plaque accumulation after 3 weeks and inflammation of the gums. The tea tree oil mouthwash was more effective in reducing dental plaque accumulation on the teeth than the chlorine dioxide-based mouthwash.⁷

Overall, the benefits of tea tree oil mouthwash in reducing the amount of dental plaque on the teeth have been demonstrated in various studies.^5,6,7

Management of gingivitis

Delving deeper into the study, we compare the benefits of tea tree oil mouthwash with the benefits of chlorhexidine mouthwash in individuals diagnosed with gingivitis. 

There are other benefits than simply reducing the amount of plaque on the teeth. In those individuals treated with tea tree oil, their gum health improved, the amount of bleeding was reduced, and redness in the gums decreased. This highlights the potential benefit of tea tree oil for gums.⁵ However, whilst this study shows the promise of tea tree oil in reducing plaque and improving oral health in those with gingivitis, this study looked at tea tree oil's effects in a small sample of individuals.⁵ To see if the benefits of tea tree oil in managing gingivitis extend to the wider population, further research is needed on a more global level.

Management of periodontal disease

A study has found that tea tree oil may affect periodontal health. Gels containing 5% tea tree oil were applied directly to the periodontium (the surrounding connective tissues that support your teeth) in conjunction with tooth scaling and root planning (SRP). The results of one study found that the level of a biomarker that indicates periodontitis was significantly reduced after this treatment. Another study indicated that after applying the tea tree oil gel to the periodontium (which has been affected by periodontitis), the amount of dental plaque and gingival inflammation decreased. As a result, it highlights the potential benefits of tea tree oil gel in managing periodontitis.⁷

Tea tree oil for bad breath treatment

Elimination of odour-causing bacteria

Tea tree oil has been shown to control bad breath by killing the bacterial species Solo bacterium moorei. This bacterial species contributes to having bad breath. This shows the potential benefit of tea tree oil for bad breath reduction.⁸

In addition, bad breath can be caused by proteins that contain sulphur. When broken down, bad-smelling gases are released, known as volatile sulphur compounds (VSCs), which in turn cause you to have bad breath. Some bacterial species in your mouth break down sulphur-containing proteins and release volatile, bad-smelling gases. One study demonstrated that tea tree oil reduced the number of two bacterial species, which caused VSCs to be released. Reducing the amount of these bacteria species in the mouth leads to fewer VSCs being produced and a reduction of bad breath.^9,10

Tea tree oil dental remedies

Tea tree oil dental remedies include using tea tree oil toothpaste and tea tree oil mouthwash, which both have antibacterial properties. These products can reduce the number of harmful bacteria in your mouth, which can contribute to the production of bad-smelling gases and bad breath.^1,10

Tea tree oil dental remedies are not limited to toothpaste and mouthwash. Tea tree oil mouth rinse can be used at your discretion, too, and this has been shown to have antibacterial properties as well.¹¹

Safety and considerations

Safe dilution of tea tree oil

The benefits of tea tree oil mouthwash, such as reducing the amount of dental plaque in your mouth, are typically seen when the tea tree oil is diluted to 0.2-0.5%.⁷ This means that you will need 2-5 drops of tea tree oil diluted with approximately 30 ml of carrier oil.^7,12

When using tea tree oil to treat periodontitis, a gel of 5% tea tree oil should be used to have the desired effect rather than mouthwash.⁷

Potential side effects

You should avoid swallowing tea tree oil products as they can be toxic when ingested. Potential side effects of tea tree oil ingested orally include the following:

• Confusion
• Inability to control your muscles
• Gradual loss of consciousness

Consultation with healthcare professionals

If you are interested in using tea tree oil for your dental hygiene and oral care, you should consult with your dentist, as they will be able to answer any questions and provide information on which tea tree oral care products to use. 

Summary

• Tea tree oil has antimicrobial properties, meaning that it can kill or prevent harmful microorganisms from growing in your mouth
• Tea tree’s antimicrobial properties are attributed to its chemical composition
• Tea tree is harmful when ingested but can be used as a mouth rinse, mouthwash, or toothpaste
• Tea tree oil can be used to reduce dental plaque
• Tea tree oil can be used to manage gingivitis and periodontitis
• Certain bacteria in your mouth can break down proteins, causing the release of volatile-smelling gases and bad breath. Tea tree oil can help eliminate these bacteria from your mouth
• Tea tree oil has some harmful side effects when ingested, including loss of consciousness
• Ensure tea tree is used at a safe dilution

FAQs

What is tea tree oil?

Tea tree oil is an essential oil derived from the steam distillation of the leaves of a tea tree. Tea trees are located along the southeast and east coasts of Australia.

What is tea tree oil used for?

Tea tree oil can treat acne, hair lice, fungal nail infections, athlete’s foot and cleaning cuts and wounds.

Can tea tree oil prevent tooth decay?

The properties of tea tree oil, such as killing harmful microorganisms, can help prevent the growth of harmful microorganisms in your mouth. In turn, this can help prevent plaque buildup on your teeth and help prevent cavity formation tooth cavities, which can lead to tooth decay.