Xerostomia: Causes, Diagnosis and Treatment of Dry Mouth

The pharmacological and systemic causes of dry mouth, why saliva is much more than a simple lubricant, and the management strategies available in the practice and at home.

Xerostomia — the subjective perception of dry mouth — doesn't always coincide with objectively measurable salivary hypofunction, but in clinical practice the two conditions overlap in most cases that come to the dentist's attention. Saliva serves far from secondary protective functions: it lubricates soft tissue, facilitating chewing, swallowing and speech, buffers acids produced by plaque bacteria, contains minerals essential for enamel remineralization, and exerts direct antimicrobial action through enzymes like lysozyme.

By far the most common cause of xerostomia is pharmacological: hundreds of commonly used drugs, including antidepressants, antihistamines, antihypertensives, diuretics and anxiolytics, have dry mouth as a side effect, often dose-dependent and more pronounced in patients on multiple medications, a particularly common condition in the elderly population. Other relevant causes include head and neck radiotherapy, which can permanently damage salivary gland tissue, autoimmune conditions such as Sjögren's syndrome, uncontrolled diabetes, and dehydration.

A patient with unmanaged chronic xerostomia faces significantly elevated caries risk, often with an atypical caries pattern — localized on surfaces normally at low risk, such as cervical margins and lingual surfaces — precisely because saliva's protective action is missing. The risk of oral candidiasis, halitosis and difficulty with removable dentures (which lose retention without an adequate salivary film) also increases significantly in these patients.

Managing xerostomia works on several fronts: when possible, a shared assessment with the prescribing physician about possibly replacing xerostomia-causing medications; use of saliva substitutes and lubricating gels for symptomatic relief; stimulants for residual salivary secretion, such as sugar-free chewing gum or, in cases with some remaining glandular function, prescription sialogogue medications; and reinforced fluoride prophylaxis, given the increased caries risk, often with high-concentration products for daily home use in addition to periodic professional applications.

On Oralzon you'll find saliva substitutes, lubricating gels and high-concentration fluoride products specifically indicated for managing patients with chronic xerostomia.