The Stephan Curve

The impact of saliva in neutralising plaque pH was illustrated as early as 1940 by Dr. Robert Stephan, who measured the changes in plaque acidity following sugar intake.

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Clinical evidence

In this section, clinical evidence is presented to you all in one place, so you can refresh your memory in the easiest, most time-efficient way possible.


KCL systematic review

A 2019 landmark systematic review by KCL found that chewing sugarfree gum could significantly reduce the incidence of dental caries, comparing it favourably to other preventive interventions such as oral health education and supervised tooth brushing alone.

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Eat, Drink, Think report

This report reveals that current public health guidelines for oral health are not aligned with our eating and drinking habits. The gap between what and when we eat and drink, and the measures we take to protect our teeth may be a contributing factor to the high prevalence of tooth decay.

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New research from Frontier Economics has estimated cost savings to the NHS and patients of rolling out oral health measures to prevent tooth decay. Learn more about this research through our Value of Good Oral Health infographic.

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FAQs and figures

FAQ’s for both you and your patient. Click to find out more.

Are the claims regarding the oral care benefits of chewing sugarfree gum supported by clinical research?

Yes. Research supported by many organisations has established the relationship between the use of sugarfree chewing gum and oral care benefits.

The Oral Health Foundation and the Irish Dental Association (IDA), along with more than 25 national dental associations have recognised the strength of the scientific evidence supporting chewing sugarfree gum, and the Oral Health Foundation has granted the use of its logo on Wrigley's  EXTRA® sugarfree gum  packs.

In 2009, the European Food Safety Authority (EFSA) positively assessed claims that sugarfree chewing gum can help - neutralise plaque acids, remineralise tooth enamel and reduce or improve dry mouth. And in 2011, the EFSA positively assessed additional claims which noted a relationship between two of the oral care benefits of chewing sugarfree gum – the neutralisation of plaque acids and the maintenance of tooth mineralisation – to a reduction in risk factors in the development of caries.

How can chewing gum help your patients maintain oral health?

As you know, immediately after eating or drinking, plaque acids can attack teeth and initiate the demineralisation of the tooth surface, which can weaken teeth and lead to decay over time.

Chewing sugarfree gum increases the production of saliva, which can help neutralise plaque acid, wash away food particles and remineralise tooth enamel to strengthen teeth. In fact, chewing sugarfree gum for 20 minutes after meals and snacks has been proven to help protect teeth.

How does chewing gum increase saliva in the mouth?

The action of chewing stimulates the salivary glands to increase their flow rate by up to ten times the resting state during the first few minutes of chewing, and keeps it significantly elevated throughout prolonged chewing.

What are the benefits of increased saliva flow?

Increased saliva flow can accelerate the clearance of food debris and dietary carbohydrates from the mouth, as has been documented by several researchers.

Stimulated saliva also has a high bicarbonate concentration that enhances the capacity to neutralise acid. It is supersaturated with minerals that consist of the same components that make up teeth, such as calcium, phosphate and hydroxyl ions.

These components shift the equilibrium from demineralisation to remineralisation, building back mineral density in teeth.

Is there a link between chewing gum and stomach acid?

There is no evidence that saliva stimulates gastric juices from the stomach. It is generally accepted that only medication will cause the artificial activation of gastric juices. During the chewing of gum there is a sharp rise in saliva volume. Saliva contains bicarbonate, and when swallowed an acid-neutralising effect occurs in the stomach.

Research into this issue has been conducted on patients who have a duodenal ulcer, or X-ray negative dyspepsia. It was concluded that even for these people gum chewing is harmless. If this potentially sensitive group can chew gum without exacerbating their stomach problems, then it would seem reasonable to conclude that chewing gum should not cause stomach problems for others.

When should sugarfree gum be chewed?

Following the consumption of fermentable carbohydrates, the teeth’s plaque pH level falls rapidly before gradually returning to pre-consumption values after 30 to 60 minutes. Chewing gum produces a rapid increase of plaque pH to minimize the risk of damage that may be caused by plaque acids to the teeth.

Are Wrigley’s chewing gum products suitable for specific diets such halal, kosher, vegan and vegetarian?

The vast majority of our products are suitable for halal, kosher, vegan and vegetarian diets. However, to check specific product suitability please visit

Do Wrigley’s products contain any of the six colours contained in the ‘Southampton Study’?

All Mars Wrigley products are completely free of the colours identified in the Southampton Study. Since 2010 we have not manufactured any products containing these colours across our entire range.

What ingredients do Wrigley’s products contain?

All the ingredients of Wrigley products are listed on the pack. You can also find details of ingredients by product by visiting 

How much mint does Mars Wrigley need?

To grow all the mint Mars Wrigley needs for its mint-flavoured gums requires 53 square miles of farmland (137 million metres2) - about 33,890 football pitches!

How long have people been chewing gum?

The answer to that question is not known exactly, although we do know that the ancient Greeks chewed a gum-like substance called mastic that came from the bark of a tree.

What’s the UK’s gum consumption?

Over 28 million people in the UK regularly chew gum for the enjoyment and variety of benefits it brings. On average, Brits chew 125 pieces of gum a year.

Is it true that if you swallow chewing gum it takes seven years to digest?

No. Although chewing gum is not designed to be swallowed, it passes through the body’s digestive system after a few days in much the same way as roughage.

How can I remove chewing gum from my clothing?

Whilst there are no ‘guaranteed methods’ for gum removal, below are some suggestions you might want to try.

For washable clothes, you might first try scraping off any excess gum with a dull knife and then rubbing the area with ice until the remaining gum rolls off into a ball. Another method is to seal the dry garment in a plastic bag and place it in your freezer. After the garment is frozen, remove and gently scrape off the gum with a dull knife.

There are also natural solvents extracted from citrus peels which are environmentally safe and work quite well in removing chewing gum from various surfaces, including cloth. You can find these citrus-based solvents in supermarket and chemists as well as health food stores.

You can also use an extra strength heating rub to remove chewing gum from clothing. First, turn the garment inside out and spread approximately half a teaspoon of the deep-heating rub evenly on the opposite side of the gum residue. Heat the area covered with the rub with a blow dryer set on ‘high’ for thirty seconds. Immediately after turning off the dryer, the gum residue should peel off.

Next, spread approximately half a teaspoon of the extra strength deep-heating rub evenly over all of the gum residue. Heat with the blow dryer set on ‘high’ for thirty seconds. If you do not have a blow dryer, simply let the rub set for five minutes before peeling off the gum. Your garment should then be laundered as usual.

It is important that you try a small amount of the citrus-based solvent or the extra strength heating rub on an inconspicuous area of your garment before use to ensure colour fastness. Also, when using any type solvent of over-the-counter remedy, always be sure to follow directions carefully and apply all safety precautions as recommended, including keeping those items out of reach of children.

Is there a problem if my dog accidently chews gum?

EXTRA® sugarfree gum contains xylitol, which is a safe, even beneficial, additive which has been used in food, confectionery and other products - like toothpaste - as a sweetener and flavour enhancer for over 30 years and has been widely approved by regulatory authorities all over the world.

Although chewing gum products are not intended for use by dogs, cats or other pets, the Veterinary Poisons Information Service (London) has reported that xylitol may be toxic for dogs.

In fact, in addition to food products containing xylitol, the Veterinary Poisons Information Service recommends that many foods that are perfectly safe for humans be kept away from pets because of potential harm - including grapes/raisins/sultanas, chocolate, onions, yeast, dough, salt, macadamia nuts, coffee grounds, tea leaves, alcohol, fatty foods, avocadoes and garlic.

For more information regarding Xylitol or other foods that may be potentially harmful for pets to consume please contact your local vet.