When you think of green tea, toothpaste probably isn’t the first thing that comes to mind.
But green tea (Camellia sinensis) has been studied for years in relation to the oral environment, with researchers particularly interested in its naturally occurring plant compounds known as polyphenols.
Among these polyphenols are a group called catechins, including epigallocatechin gallate — more commonly known as EGCG.
Research has explored how these compounds may interact with dental plaque, gingival health, oral bacteria and even compounds associated with oral malodour.
It’s one of the reasons green tea extract was thoughtfully selected as an ingredient in the Restore Oral Care formulation.
So, what makes green tea interesting for oral care?
Green tea contains several catechins, with EGCG being one of the most widely researched.
These compounds have demonstrated antioxidant and antimicrobial activity in laboratory research, which has led researchers to investigate whether green tea could have a useful role in maintaining oral health.
Importantly, green tea isn’t a replacement for brushing, interdental cleaning, professional dental care or clinically indicated treatment.
Instead, the research is exploring whether green tea and its naturally occurring compounds may offer supportive benefits within an oral care routine.
Green tea, dental plaque and gingival health
One of the more researched areas is the relationship between green tea and plaque-related gingival inflammation.
A 2021 systematic review and meta-analysis examined 18 clinical studies involving 870 participants and evaluated green tea in relation to gingivitis, periodontitis and dental caries.
The researchers found encouraging results for several measures of periodontal health, including plaque index and periodontal probing depth.
However, the authors were also careful to note that the evidence was not strong enough to recommend green tea formulations as a first-choice treatment for gingivitis, periodontitis or dental caries.
That distinction is important.
The research doesn't tell us that green tea “treats gum disease.” Rather, it suggests that the compounds naturally present in green tea are interesting from an oral-health perspective and warrant further clinical investigation.
What have clinical trials found?
Several smaller randomised clinical trials have also investigated green tea preparations.
One study compared a green tea mouthrinse with other mouthrinses in people with plaque-induced gingivitis. Participants using the green tea preparation showed reductions in measures including plaque index and gingival index during the study period.
Another randomised clinical trial investigated a mouthwash containing 2% green tea and reported improvements in plaque and gingival measures compared with a placebo preparation.
More recently, a clinical study involving 112 participants with gingivitis compared mouthwashes containing green tea, white tea, essential oils and chlorhexidine. Green tea extract was associated with improvements in clinical measures during the four-week study, although chlorhexidine produced the greater clinical improvement.
Together, these studies add to the interest in green tea as an ingredient in oral care — while also highlighting that it should not be positioned as a substitute for established dental treatments.
What about the oral bacteria?
Our mouths naturally contain a diverse community of microorganisms.
The aim of good oral care isn't simply to eliminate every bacterium in the mouth. Oral health is much more complex than that.
Researchers have investigated how green tea extracts and catechins interact with specific microorganisms commonly studied in dentistry.
For example, a randomised clinical trial involving teenagers compared a green tea mouthrinse and a green tea gel. Both preparations were associated with reductions in salivary levels of Streptococcus mutans and Lactobacillus during the study period.
Other small clinical studies have similarly observed reductions in S. mutans following the use of green tea mouthrinses.
These findings are interesting, particularly because S. mutans has been extensively studied in relation to the dental caries process.
But oral health cannot be reduced to the presence or absence of one bacterial species, and these findings do not mean that green tea simply “kills bad bacteria” or that it has been proven to rebalance the entire oral microbiome.
The science of the oral microbiome is far more nuanced.
Can green tea help with mouth freshness?
This is another interesting area of research.
Oral malodour is frequently associated with volatile sulphur compounds, or VSCs, produced within the mouth.
A clinical study investigating green tea powder found an immediate reduction in certain volatile sulphur compounds after green tea was administered. However, the effect was short-lived and was no longer detected at later measurements.
Another study involving people with gingivitis and oral malodour found that a green tea mouthwash reduced measured volatile sulphur compounds compared with placebo during the study.
A systematic review examining green tea and halitosis also found some promising results, but noted the limited number of high-quality clinical trials available.
So again, the research is promising — but it isn't a reason to describe green tea as a treatment for persistent bad breath.
Persistent oral malodour can have several causes and should be assessed appropriately.
Why did we include green tea extract in Restore?
When developing Restore, we didn't want to build a toothpaste around one fashionable “hero ingredient.”
We looked at the formulation as a whole.
Green tea extract was selected alongside ingredients including:
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nano-hydroxyapatite (NanoXIM)
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xylitol
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L-arginine
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chicory root
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miswak
Green tea appealed to us because of the growing body of research investigating its polyphenols and catechins within the oral cavity.
It complements our philosophy of creating a thoughtful, modern everyday toothpaste using ingredients selected with the oral environment in mind.
A note on the research
There is an important limitation when talking about ingredient research.
The studies discussed above investigated different green tea extracts, mouthrinses, gels, beverages and concentrations.
They were not clinical trials performed specifically on Restore Oral Care toothpaste.
For this reason, we don't extrapolate those findings to claim that Restore prevents or treats gingivitis, periodontitis, dental caries or halitosis.
Instead, this research helps explain why green tea continues to be an ingredient of interest in oral-health science — and why we chose to include it as part of our formulation.
Because when you use something twice a day, every day, we believe every ingredient deserves consideration.
Restore Oral Care
Thoughtfully formulated everyday oral care.
This article is for general educational purposes only and does not replace individual dental or medical advice.
Research discussed
Mazur M, et al. Impact of Green Tea (Camellia Sinensis) on periodontitis and caries: systematic review and meta-analysis. The review included 18 clinical studies involving 870 participants and found encouraging periodontal findings while concluding that evidence remained insufficient to recommend green tea as a first-choice treatment.
Sarin S, et al. Preliminary Clinical Evidence of the Antiplaque, Antigingivitis Efficacy of a Mouthwash Containing 2% Green Tea – A Randomised Clinical Trial.
Haji Ahmadi M, et al. Comparative Evaluation of Efficacy of Green Tea Mouth Rinse and Green Tea Gel on Salivary Streptococcus mutans and Lactobacillus Colony Count.
Lodhia P, et al. Effect of green tea on volatile sulfur compounds in mouth air.