Humans excrete about 1 to 1.5 litres of saliva per day, but the variations in saliva secretion vary a lot. A person’s age, general health condition, smoking, alcohol use, using medicines, and many other things affect salivation.
Saliva has many functions for human well-being. Saliva cleanses and rinses the mouth and throat. Saliva and compounds in saliva prevent microbes from adhering to mucous membranes, and saliva has antimicrobial properties. Thus, saliva protects the mucous membranes from inflammation and continuous rinsing of the tooth surface prevents the teeth from cavities. Saliva also plays a major role in food digestion because saliva moisturizes and slips food before swallowing. In addition, saliva contains a lot of enzymes that break down nutrients and start digestion.
Typical symptoms of a dry mouth include pain and tingling in the mouth, especially on the mucous membranes. Eating or speaking problems may occur as salivation decreases. With eating problems people may also observe e.g. changes in taste and swallowing dry food can be difficult. A dentist may observe cavities in teeth and usually, the cavities are seen especially in the neck of the tooth.
Many medicines or ageing may reduce salivation. The symptoms of dry mouth are thus very familiar for elderly people. In addition to xylitol, dry mouth symptoms can be relieved by drinking water regularly and avoiding alcoholic beverages and mouthwashes. In the treatment of dry mouth, regular teeth brushing with fluoride toothpaste, regular dental check and other dental home care is very important.
The symptoms of dry mouth can also be alleviated by swishing an aqueous solution of canola oil in the mouth for one minute. The oil-water mixture moisturizes the oral mucous membranes. The symptoms of a dry mouth can be relieved, e.g. by sucking on ice cubes. The ice cube cools and moisturizes the mouth and thus relieves a dry mouth. All kind of chewing activates the salivary glands to secrete saliva. Food should be chew-able and not soup-like. In some cases, chewing gum preparations also activate the salivary glands to secrete more saliva.
Some habits, such as snoring with an open mouth, will dry the oral mucous. Adequate water drinking and good dental hygiene are the main things in the treatment of dry mouth. People with dry mouths should stop or reduce smoking, alcohol, and coffee consumption.
Some diseases such as rheumatism, diabetes, stroke, Parkinson's, Alzheimer's and many autoimmune diseases can cause dry mouth. Radiation therapy and chemotherapy, some cardiovascular medicines, some antihistamines, and anticholinergic drugs may induce dry mouth. There are currently about 400 different drug substances on the market which decrease salivation. The biggest problems in reducing salivation are usually experienced with urology drugs (e.g., drugs used for urinary incontinence), antidepressants, and antipsychotics (Tan et al., 2017). However, it is usually possible to find a suitable drug for the patient, which does not cause a decrease in salivation. The possible dry mouth problems due to medication can be discussed with pharmacy staff, nurses, doctors and other healthcare professionals.
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Tan ECK, Lexomboon D, Sandborgh‐Englund G, Haasum Y, Johnell K (2017) Medications That Cause Dry Mouth As an Adverse Effect in Older People: A Systematic Review and Metaanalysis. JAGS, 66(1)76-84.
Kuiva suu - Finnish Dental Association, 2018.