Herbal Products for Dental and Oral Health: What They Do and Their Limits

How Much Can Herbal Products Help Oral Health?

Some herbal products can offer limited support for oral health: xylitol chewing gum can help reduce the risk of decay, and green tea and some plant extracts can contribute to easing gum inflammation. However, none of these products replaces brushing with fluoride toothpaste, cleaning between the teeth and regular dental check-ups. Oils such as coconut, sesame and St John's wort oil can moisturise and soothe the lining of the mouth; in conditions such as mouth ulcers, cold sores and oral thrush they can only play a complementary role. Products such as clove oil may ease toothache for a short time, but they do not treat its cause, and used carelessly they can also damage the tissues of the mouth.

Does Rosemary Really Contain More Calcium Than Cheese?

Dried rosemary has recently featured in the press as "a spice with more calcium than cheese". According to food composition tables, 100 grams of dried rosemary contains about 1,280 mg of calcium, which is indeed high compared with 100 grams of cheese. But spices are used by the pinch, not by the gram. A teaspoon of dried rosemary weighs about 1.2 grams and provides around 15 mg of calcium, while adults need about 1,000 mg of calcium a day. So rosemary adds flavour to food, but it does not replace dairy products or other main sources in meeting daily calcium needs.

The link between calcium and teeth is also often misunderstood. Calcium is important while teeth are forming and for the health of the jawbone. But the enamel of a tooth that has already come through cannot repair itself with calcium from food; enamel does not regenerate. Early mineral loss on the enamel surface can be partly regained with the help of saliva and fluoride. That is why what really matters in preventing decay is less calcium-rich food and more the frequency of sugar intake, fluoride toothpaste and regular cleaning.

Which Herbal Products Have Been Studied?

There are scientific studies on the products below, but most of the evidence comes from small, short studies. The effects are generally limited and should be considered in addition to standard oral care.

• Xylitol: A sugar alcohol obtained from birch or corn. The decay-causing bacteria in the mouth cannot use it to produce acid. Studies suggest that xylitol gum chewed after meals can help reduce the risk of decay by increasing saliva flow. Large amounts can cause wind and diarrhoea.
• Miswak: A traditional tooth-cleaning stick made from the twigs of the Salvadora persica tree. Studies show that, used correctly, it can remove plaque nearly as well as a toothbrush. However, it contains no fluoride and does not reach between the teeth, so it can be used alongside, not instead of, brushing with fluoride toothpaste.
• Green tea: Studies suggest that its catechins can somewhat reduce plaque bacteria and gum inflammation. It is important to drink it without sugar. Frequent consumption can stain the teeth.
• Clove (eugenol): Eugenol, released when cloves are chewed or clove oil is used, has a calming (sedative) and mildly numbing effect on the tissue near the nerve of a decayed tooth. This is why it can ease decay-related toothache for a short time; in dentistry it is also used in controlled amounts in some temporary fillings and dressings. However, eugenol is also an irritant: used often, for long periods or in concentrated form, it can cause burning and sores on the gums and the lining of the mouth, and in an open decay cavity it can irritate the tooth tissues it comes into direct contact with. Clove temporarily suppresses the pain, but the decay or inflammation causing it continues to progress, so it is not a substitute for treatment.
• Aloe vera: There are some promising studies on its use as a gel or mouthwash for gum inflammation; the evidence is still limited.
• Chamomile and sage: Traditionally used as mouth rinses for irritation in the mouth. They may be soothing, but there is no strong evidence that they treat gum disease.
• Tea tree oil: Its antibacterial effect is known, but it can be toxic if swallowed. It should only be used in diluted products made for this purpose and without swallowing, and it should not be used in children.
• Turmeric: There are small studies on the effect of its curcumin on gum inflammation. It can stain teeth and fillings yellow.

Does Oil Pulling Work?

Studies on this method, in which coconut or sesame oil is swished around the mouth for several minutes, are few, small and methodologically weak. There is no evidence that it replaces brushing, cleaning between the teeth or fluoride toothpaste. Rarely, oil accidentally entering the airway can also cause problems.

Effects of Coconut, Sesame and St John's Wort Oils on the Lining of the Mouth

The oral mucosa is the thin, delicate tissue lining the inside of the cheeks, the tongue, the palate and the gums. Herbal oils mostly act on this tissue by forming a moisturising and protective layer; some of their components are also being studied for antimicrobial or anti-inflammatory properties.

• Coconut oil: Laboratory studies have shown that lauric acid, which makes up about half of it, is effective against some bacteria and fungi, particularly the Candida species that cause oral thrush. It can be soothing as a moisturiser for a dry mouth and dry, cracked lips. Human studies, however, are few and small; current evidence does not show that coconut oil treats an infection.
• Sesame oil: One of the oils most often used in traditional oil pulling. Because of antioxidants such as sesamol and sesamin, small studies have been done on gum inflammation and plaque; the results are limited. It can bring relief in dry mouth by moisturising the lining of the mouth. It should not be used by people with a sesame allergy.
• St John's wort oil: A traditional oil made by steeping St John's wort flowers in olive oil. Its wound-healing and anti-inflammatory effects have been shown in laboratory and animal studies; human studies on its use for sores in the mouth are limited. Remember that part of an oil applied in the mouth may be swallowed: St John's wort can reduce the effect of many medicines, such as birth control pills, blood thinners, some antidepressants and medicines that suppress the immune system. People who take regular medication, pregnant women and breastfeeding mothers should not use it without consulting a doctor. Applied to sun-exposed areas such as the lips, it can cause sensitivity to sunlight.

Whatever oil is used, a pure, food-grade product should be chosen, the oil should not be used instead of brushing, and it should be stopped if burning, redness or itching occurs.

Herbal Products for Mouth Ulcers, Cold Sores and Oral Thrush

People often turn to herbal products when they notice a sore or white patches in the mouth. These three conditions have different causes, and the role of herbal products differs accordingly.

• Mouth ulcers (aphthae): Painful round sores with a white-yellow centre and a red border, appearing inside the cheek, on the inside of the lip or on the tongue; they are not contagious and most heal on their own within 7–14 days. Small studies suggest that aloe vera gel and chamomile products may somewhat reduce the pain and healing time. St John's wort oil and coconut oil can reduce irritation by covering the sore, but they have not been shown to shorten healing. Ulcers that recur several times a year, are numerous or large need a doctor's assessment, as they may be a sign of conditions such as iron, vitamin B12 or folic acid deficiency, coeliac disease or Behçet's disease, which is common in Turkey.
• Cold sores: Caused by the herpes virus and contagious, they usually appear at the edge of the lip, starting with tingling followed by small fluid-filled blisters. Herbal oils have no effect on the virus; they can only moisturise the crusting area. There is limited evidence that creams containing lemon balm (melissa) extract may somewhat support healing. The treatment with the best evidence is an antiviral cream used as soon as symptoms begin, or medication prescribed by a doctor when needed. Do not touch the cold sore or burst the blisters, and avoid kissing and sharing glasses while it is present.
• Oral thrush (oral candidiasis): Caused by an overgrowth of the Candida fungus; it can appear as white patches that leave redness when wiped off, or as redness and burning under a denture. It is more common in babies, denture wearers, people with diabetes and those using antibiotics or inhaled steroids. Although the effect of coconut oil on Candida has been shown in the laboratory, it is not sufficient as treatment; after diagnosis, the antifungal medicines recommended by a doctor are used. Cleaning dentures every day and not wearing them at night are important in preventing recurrence. If a baby has oral thrush, see a doctor rather than applying oil at home.

Herbal Toothpastes: What to Look for on the Label

Some toothpastes marketed as "natural" or "herbal" do not contain fluoride. Fluoride is the substance with the best-proven effectiveness in preventing decay. If you choose a herbal toothpaste, check whether fluoride is listed among the ingredients; 1,000–1,450 ppm fluoride is generally recommended for adults. Toothpastes containing charcoal (activated carbon) can be abrasive and usually do not contain fluoride. Details on whitening products are explained in the article teeth whitening products sold in pharmacies, and the treatment of gum inflammation on the gum treatment page.

Risks of Herbal Products

• Burns and irritation: Placing substances such as clove oil, garlic, salt or aspirin next to an aching tooth can burn the lining of the mouth.
• Acid damage: Acidic products such as lemon and apple cider vinegar erode enamel and should not be used for oral health.
• Staining: Turmeric, strong tea and some plant extracts can stain teeth and fillings.
• Allergy: Plant extracts and essential oils can cause allergic reactions.
• Delay: The most important risk is losing time with home remedies while a problem that needs treatment progresses.

When Should You See a Dentist?

• Toothache that lasts more than a few days or keeps getting worse, or pain that wakes you at night
• Swelling or a blister on the gum, a bad taste in the mouth, or swelling of the face and fever
• Gums that bleed often when brushing or on their own
• A burn, sore or whitening in the mouth after using a herbal product
• A mouth sore that has not healed after more than two weeks, or mouth ulcers that recur often, are numerous or large
• White patches that can be wiped off and leave redness or bleeding; redness and burning under a denture
• Cold sores that recur often or come with fever; a cold sore near the eye

This article is for general information and does not replace an examination by a dentist. Herbal products should be used after consulting a doctor, especially by people taking regular medication, during pregnancy and in children.