Oral defense factors in the elderly

Continuously increasing proportion of elderly people in the human population creates new challenges for the dental care. Because the microbial etiology of the most common oral diseases, dental caries, endodontal and periodontal diseases, is not substantially different in different age groups, the altered host response during aging may modify the progression of these diseases. Most prevalent and severe change in the oral defense is hyposalivation or xerostomia but aging as such does not seem to reduce neither parotid nor whole salivary flow rate. However, submandibular and minor salivary glands produce less saliva at old age which may be the reason for the frequently reported symptoms of oral dryness even if the stimulated flow rate is normal. Concomitantly to the changes in the flow rate the daily output of many saliva-mediated defense factors declines but age-related impairment has been described only for specific IgA response to external antigens, for salivary opsonic activity, and for T-lymphocyte function. The non-immunoglobulin defense factors seem to act with full capacity over the entire life-span. Therefore, elderly people with normal salivary flow rate possess no special risk group for the development of oral diseases.