Future caries vaccine

Role of Chronic Systemic Diseases and Impaired Host FactorsChronic systemic disease Of the systemic diseases, by far the greatest caries risk is associated with rheumatoid conditions, particularly Sjogren's syndrome, because of its severe depressive effect on the salivary secretion rate as well as the quality of the saliva. The most severe xerostomia is seen in patients with Sjogren's syndrome. Other systemic and chronic diseases that cause salivary gland hypofunction and xerostomia and are thereby regarded as risk factors and prognostic risk factors are listed in Box 9.

Preventive programs for patients with hyposalivation and xerostomiaFor such high-caries-risk patients, most preventive measures, self-administered as well as professional, must be optimized. The following regimens are recommended. Plaque control and self-administered fluoride Patients with impaired salivation are extremely fast plaque formers (Plaque Formation Rate Index scores 4 and 5). Therefore, not only the frequency but also the quality of combined mechanical and chemical plaque control by self-care has to be optimized, and all tooth surfaces must be targeted.

Symptomatic therapyIn the absence of natural salivation, it is essential to try to protect the oral hard and soft tissues by salivary substitution. Saliva substitutes, also called artificial salivas, are frequently recommended for patients complaining of dry mouth (xerostomia).  Although many studies suggest that saliva substitutes are useful in the management of xerostomia, clinical experience has shown that these products are not well accepted by patients. Most patients do not continue to use the substitutes regularly, relying instead on water or other fluids to relieve their symptoms.

Salivary stimulation and substitution in patients with hyposalivation and xerostomia - Stimulation of salivaRecognition of the key role of saliva in maintaining normal oral function has stimulated research on its protective properties against caries and on the treatment of xerostomia and salivary hypofunction. Salivary clearance, buffering power, and degree of saturation with respect to tooth mineral are the major protective properties (for review, see Sreebny et al, 1992; Tenuvuo, 1997), their effect increasing with salivary stimulation: The saliva stimulated by consumption of fermentable carbohydrates reduces the fall in plaque pH that could lead to demineralization andincreases the potential for remineralization.

Formation and functions of pellicleSaliva is seldom in direct contact with the tooth surface but is separated from it by the acquired pellicle, defined as an acellular layer of salivary proteins and other macromolecules, approximately 10 um thick, adsorbed onto the enamel surface. It forms a base for subsequent adhesion of microorganisms, which under certain conditions may develop into dental plaque. The pellicle layer, although thin, has an important role in protecting the enamel from abrasion and attrition, but it also serves as a diffusion barrier.