Xerostomia is a subjective dry mouth sensation due to decreased saliva caused by an alteration in salivary gland function.

The presence of saliva in the oral cavity is very important because it keeps oral tissues moist, facilitating speech, chewing, swallowing, etc. Saliva also plays a role in cleaning the mouth as well as regulating bacterial accumulation. An adequate level of saliva can prevent an imbalance of microorganisms in the oral environment which can lead to caries, gum disease, halitosis or bad breath, etc.

 Xerostomia occurs in one out of five adults, which represents 20% of people between the ages of 18 and 30 years and 40% of people over 50 years of age. It is worth noting that it affects women twice as much as it does men. Statistics show that xerostomia is taking on an ever growing importance in our society. It is a condition that alters overall health and quality of life.


Although it causes great discomfort in the oral cavity of those who have it, xerostomia is not a disease, but rather a clinical condition that is caused by many factors.

To understand this complex condition, we will consider two types of xerostomia, depending on the level of gland activity:

Reversible xerostomia is characterised by residual gland activity, where salivary secretion can be stimulated or regulated. This type of xerostomising effect is produced by certain drugs, chemotherapeutic agents, smoking, etc.

In irreversible xerostomia, irreparable gland damage that prevents it from functioning. This clinical sign can be found in patients with a diagnosis of Sjögren’s syndrome or patients with head and neck cancer who have received large doses of radiation therapy.


The causes of xerostomia are diverse, the most common being the following:

  • Speaking in public usually increases our need to salivate for better word articulation, and because this activity normally occurs over an extended period of time, it sometimes causes a lack of saliva and the need for extra liquid intake.
  • Stress, anxiety and depression all affect the central nervous system, in turn affecting organs and glands all over the body, including the salivary glands.
  • Diabetes and other systemic diseases affect the entire body, altering gland function.
  • Treatment with certain drugs, such as antihistamines, antihypertensives, diuretics and cancer drugs cause side effects including a decrease in saliva and even mucous gland atrophy.
  • The absence of teeth can also cause a reduction of stimuli in the mouth, and as a consequence, less saliva production.
  • An unbalanced diet with an excess of carbohydrates and a deficit of fruits and vegetables can alter saliva production. 
  • Smoking and alcohol consumption can reduce salivary secretion by blocking the transmission of nervous impulses.


A lack of moisture in the oral cavity can cause several different clinical signs and symptoms that hamper the quality of life of patients that suffer from xerostomia. 

The most common complications are related to: chewing, swallowing, phonation, an alteration of taste perception (dysgeusia), pasty morning mouth, and burning mouth sensation.

A decrease in saliva makes the soft tissues more susceptible to dryness, redness, irritation and cracking, facilitating the attack of opportunistic microorganisms. This in turn promotes inflammation of the mucosa (mucositis), inflammation of the gums (gingivitis), presence of painful ulcerations and local fungal infections such as candidiasis, lip fissures, halitosis. It is often related to pharyngitis, laryngitis, dyspepsia or constipation.

The main effects of reduced salivary flow on dental tissues include an increase in carious lesions and tooth sensitivity.

In patients with xerostomia who wear dental prostheses, rubbing causes erosion on oral mucosa.


Several tests exist, but the most popular ones for examining salivary flow include sialometry (measures the amount of saliva), salivary gland biopsy (detects the presence of inflammation and destruction of glandular tissue) ultrasound, MRI and CT scan. These tests are useful for the diagnosis of salivary gland diseases. All this without ignoring medical history and clinical intra and extraoral examinations.


The general measures that should be considered include controlling systemic diseases, of which the most important are Sjögren’s syndrome and the side effects from radiotherapy in the treatment of head and neck cancer.

In these patients with dry mouth, it is essential to change, remove or reduce xerostomising drugs that they are taking. It is important to consider the psychological factors that are increasingly prevalent in the development of xerostomia, particularly chronic anxiety and excessive stress.

When planning the treatment, first we must identify if the process that dry mouth generates is reversible or irreversible. This way we will know if the altered factor can be corrected and if there is any residual gland activity that can be restored.

It is important to know if gland activity can still be stimulated mechanically, chemically or by taste. Substances that promote saliva secretion are called sialogogues. Depending on their level of action, they can be classified into systemic (pharmacological substances) and topical agents (gustatory stimulants). Then there are the moisturising agents or salivary substitutes, which through the use of formulas containing Betaine, Xylitol, Allantoin, Aloe vera and Sodium fluoride as part of daily oral hygiene, help to moisten oral mucosa.

Xylitol has beneficial oral effects: bacteriostatic and moisturiser, while it boosts the anticaries and remineralising effects of Sodium fluoride. Betaine, Allantoin and Aloe vera, thanks to their anti-irritant, regenerative and healing effects on tissues, prevent tongue, lip and palate cracking, improving the symptoms of patients with xerostomia.

Some formulas exist that contain Malic acid as a stimulating agent for salivary secretion without an erosive effect on tooth enamel.

Oral hygiene is essential in cases of dry mouth; oral hygiene techniques should be reinforced using toothbrushes with soft filaments, specific toothpastes and mouthwashes and moisturising gels to help keep mucosa lubricated.

It is also recommended to visit the dentist regularly.




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