Saliva, chewing gum and oral health


  Posted by: Dental Design      18th March 2020

Saliva plays a critical role in oral health and function. From aiding digestion and taste, washing away food debris, to protecting teeth and gums, salivary flow is an often overlooked but invaluable component in a patient’s oral health.

A multifunctional fluid

Saliva is primarily composed of water, but is rich in calcium, phosphate and nitrate, as well as a large number of physiologically active substances that we are still in the process of understanding. As well as helping to maintain the pH balance of the mouth, the presence of calcium and phosphate in saliva naturally facilitate the remineralisation of caries lesions.[1],[2]

Saliva serves a vital function as a lubricant, particularly for the soft tissues of the mouth and mucous membrane, as well as the teeth. This helps protect them from damage and critically, helps them maintain a hydrated state.1 Saliva provides a degree of antibacterial and fungal protection by inhibiting adhesion to oral surfaces, buffering and clearing. These effects are most active and efficient when saliva levels are high (usually during and just after eating), with buffering and clearing actions dropping to barely effective levels when unstimulated.[3]

Saliva also plays a role in taste. While much of an individual’s perception of flavour actually depends on the olfactory system, saliva is essential for breaking down and transporting molecules from substances placed in the mouth to the taste buds.[4] Additionally, a protein found in saliva (gustin) is believed to be necessary for the growth and development of taste buds.[5]

Dry mouth

Xerostomia (commonly known as “dry mouth”) is a symptom of salivary gland hypofunction – though either condition can occur separately. It is associated with numerous chronic conditions, medications and treatments (particularly radiotherapy of the head and neck). Persistent xerostomia increases the risk of caries, demineralisation, mucositis, ulcers, tooth sensitivity and oral candidiasis.[6] It can also further reduce quality of life for the patient by causing halitosis or coughing; as well as difficulty and discomfort when attempting to eat, speak, swallow or use dentures.[7],[8]

There are a number of treatments for xerostomia, yet their efficacy depends upon the cause of the condition, which is not always apparent. Chewing gum can help, various types of mouthwash (avoiding those containing alcohol), artificial saliva, drinking more water, ceasing consumption of caffeine and of course, treating the underlying cause if possible. These measures can help with symptoms, but will not necessarily arrest the condition. As patients with dry mouth receive less protection than those with normal range saliva levels, avoiding acidic food is advisable[9] but most imperatively, their oral hygiene must be given adequate attention.[10],[11]

Patients with decreased salivary flow need to take particular care of their oral health. The Waterpik® Complete Care 7.0 combines a high-end Sonic Toothbrush with a state-of-the-art Water Flosser, making it perfect for patient’s daily oral hygiene routine. With both devices integrated into one convenient unit, your patients will have all the help they need to brush and floss easily and effectively.

Chewing gum and xylitol

While some people still view chewing gum as an unpleasant habit, sugar free gum is readily available and offers a considerable range of oral health benefits.

When the mouth is at rest, saliva flow drops to around 0.25-0.5 mL per minute (though this can vary quite substantially between individuals).5 Chewing gum boosts this rate more than tenfold, to approximately 5-6 mL a minute. This effect drops after the first five minutes to 2 mL/minute, then gradually reduces to 1.2-1.5 mL/minute at around the twenty-minute mark, at which level it can be sustained for the duration the gum continues to be chewed.[12],[13]

Xylitol is a naturally occurring sugar alcohol found in low amounts in various fruits and vegetables and can also be refined from birch and beech wood. It is sweeter than sugar but non-nutritive, meaning that it does not contribute to the patient’s caloric consumption. Xylitol has a number of beneficial effects on oral health. As with other sweeteners, it increases salivary flow with the benefits that confers; however, unlike other sugars and sweeteners it is for most intents and purposes ingestible by numerous strains of harmful bacteria.[14] Crucially, xylitol reduces the level of mutans streptococci found in plaque and saliva, a bacteria widely recognised as highly cariogenic.[15] Essentially, when S. mutans attempts to metabolise xylitol not only does it fail, the cell has to then expel the chemical by-product at a cost to its stored energy. This effectively starves S. mutans, leading to a substantial reduction in the levels found in the plaque and saliva of individuals who habitually chew xylitol gum, which in turn, protects against caries.14

Use of xylitol chewing gum by mothers during pregnancy and in the early months following birth has been observed to inhibit and delay transmission of S. mutans to their children, helping to protect them from caries.14

In addition to being used for certain sugar free chewing gums, xylitol is also available as a sugar substitute that can be used as a sweetener in beverages and baking. For patients with conditions that make using gum difficult or dangerous, xylitol sweets have also been successfully used instead.14 However, patients should note that its beneficial effects are diminished if combined with other sweeteners as they can fuel bacterial growth, preventing the xylitol from disrupting and starving bacteria. Furthermore, excessive consumption of sugar free gum, particularly in patients who have not built up a tolerance, can have a laxative effect.

Another useful alternative is the Waterpik® Whitening Water Flosser. As well as helping patients to floss effectively, this outstanding dental device is supplied with Waterpik® Whitening Tablets that contain xylitol to starve S. mutans and protect the teeth from caries. Whitening infuser technology mixes the tablets with water to produce a gentle whitening agent that naturally brightens the teeth by removing stains.

The take away from this is that chewing gum can help boost salivary flow and by ensuring that patients choose a gum that uses xylitol as its sweetener, these beneficial effects can be further enhanced.


For more information on Waterpik® products please visit Waterpik® products are available from Amazon, Asda, Costco UK, Boots and Superdrug online and in stores across the UK and Ireland.


[1] Kumar B., Kashyap N., Avinash A., Chevvuri R., Sagar M., Shrikant K. The composition, function and role of saliva in maintaining oral health: a review.  International Journal of Contemporary Dental and Medical Reviews. 2017; 011217: 1-6. January 24, 2019.

[2] Doel J., Hector M., Amirtham C., Al-Anzan L., Benjamin N., Allaker R. Protective effect of salivary nitrate and microbial nitrate reductase activity against caries. European Journal of Oral Sciences. 2004; 112(5): 424–428. January 24, 2019.

[3] Humphrey S., Williamson R. A review of saliva: normal composition, flow, and function. The Journal of Prosthetic Dentistry. 2001; 85(2): 162-169. January 24, 2019.

[4] Stevenson R., Oaten M., Mahmut M. The role of taste and oral somatosensation in olfactory localization.  Quarterly Journal of Experimental Psychology.  2011; 64(2): 224-240. January 24, 2019.

[5] De Almeida P., Gregio A., Machado M., de Lima A., Azevedo A. Saliva composition and functions: a comprehensive review. The Journal of Contemporary Dental Practice. 2008; 9(3): 72-80. January 24, 2019.

[6] Plemons J., Al-Hashimi I., Marek C. Managing xerostomia and salivary gland hypofunction: executive summary of a report from the American Dental Association Council on Scientific Affairs. The Journal of the American Dental Association. 2014; 145(8): 867-873. January 24, 2019.

[7] Greenspan D. Xerostomia: diagnosis and management. CancerNetwork. 1996; 10(3). January 24, 2019.

[8] Joanna N., Thomson W. Dry mouth – an overview. Singapore Dental Journal. 2015; 36: 12-17. January 24, 2019.

[9] Joanna N., Thomson W. Dry mouth – an overview. Singapore Dental Journal. 2015; 36: 12-17. January 24, 2019.

[10] Altamimi M. Update knowledge of dry mouth- a guideline for dentists. African Health Sciences. 2014; 14(3): 736-742. January 24, 2019.

[11] Gil-Montoya J., Silvestre F., Barrios R., Silverstre-Rangil J. Treatment of xerostomia and hyposalivation in the elderly: a systematic review. Medicina Oral, Patología Oral y Cirugía Bucal. 2016; 21(3): e355-e366.

[12] Dodds M., Roland S., Edgar M., Thornhill M. Saliva: a review of its role in maintaining oral health and preventing dental disease. BDJ Team. 2015; 2: 15123. January 24, 2019.

[13] Javaid M., Ahmed A., Durand R., Tran S. Saliva as a diagnostic tool for oral and systemic diseases.  Journal of Oral Biology and Craniofacial Research. 2016; 6(1): 66-75. January 24, 2019.

[14] Nayak P., Nayak U., Khandelwal V. The effect of xylitol on dental caries and oral flora. Clinical, Cosmetic and Investigational Dentistry. 2014; 6: 89-94. January 24, 2019.

[15] Banas J. Are the mutans streptococci still considered relevant to understanding the microbial etiology of dental caries? BMC Oral Health. 2018; 18: 129. January 24, 2019.

No Comments

No comments yet.

Sorry, the comment form is closed at this time.