Salivary yeasts, saliva, and oral mucosa in the elderly

Yeasts are commensals in the oral cavity and may not cause disease unless there are predisposing host factors, such as other disease, or when medication is being taken. The elderly are at increased risk of yeast infection. In this paper, prevalence of salivary yeasts in a group of 368 inhabitants of Helsinki aged 76, 81, and 86 years is reported. Salivary yeasts were counted by the Oricult-N dip-slide method, salivary secretion rate and buffering capacity were measured, type of dentition was noted, and signs of yeast infection and the occurrence of subjective symptoms were determined. There was no growth of yeasts in 25% of the subjects. From one to 20 colonies/slide were observed in 21%, 21-50 colonies in 21%, and over 50 colonies (a high count) in 33%. Subjects with low salivary flow rates and low buffering capacities had significantly higher yeast counts than did subjects with normal salivary flow rates and buffering capacities. High yeast counts were found in 19% of subjects with natural teeth. The corresponding percentages in those wearing partial or complete dentures were 32 and 41, respectively. High salivary yeast counts were associated with oral mucosal lesions but not with subjective complaints of oral symptoms.