Clinical Consequences of Hyposalivation

Qualitative and quantitative changes in saliva lead to reduced lubrication of the lips and oral tissues. The dryness affects taste, swallowing, and speech. The oral mucosal tissues become atrophic, the tongue fissured. Reduced lavage and cleansing of oral tissues promotes plaque accumulation and lead to gingivitis, periodontitis, and dental caries.24 Reduced concentration of growth factors lead to further loss of mucosal integrity. Reduced lysozyme, secretory leukocyte protease inhibitor, secretory IgA, and histatin activity predispose to bacterial, viral, and fungal infections.25

Mucositis and secondary infections may interfere with the wearing of tissue-borne prostheses and lead to further impaired chewing and swallowing. Impaired chewing and swallowing and/or the loss of taste may cause patients to alter their diet increasing the risk of dehydration, malnutrition, and weight loss. Decreased retention of even well-fitting prostheses may lead to the development of traumatic ulcers, which may provide additional portals to oral microorganisms and in susceptible patients such ulcers may lead to osteonecrosis.26,27

Decreased salivary immunoglobulin levels lead to a highly cariogenic oral microflora (S. mutans, lactobacillus and Actinomyces). In addition, the lack of saliva promotes the availability of sugars and other substrates essential for microbial survival. The loss of salivary buffering capacity, loss of the insoluble pellicle, and reduced concentrations of salivary calcium and phosphate ions interfere with normal remineralization of teeth and lead to caries on plaque forming surfaces, areas of exposed dentin, and on cusp tips and incisal edges of teeth.28

Reduced antibacterial and antifungal activity associated with hyposalivation also contributes to an increased risk of both acute and chronic infection by the Candida species, which under homeostatic conditions are inhibited by the normal bacterial flora and salivary gland function.29 Alteration of the normal flora may also increase the potential for aspiration pneumonia and colonization of the lungs with Gram-negative anaerobes from the gingival sulcus.30,31