Root caries is one of the main dental problems among the dentate old
elderly. The aim of our study was to evaluate the occurrence of root
caries in 196 dentate elderly (mean age 79.3) in relation to their
salivary flow rate, buffering capacity and salivary microbial counts.
These subjects participated in the oral health component of the Helsinki
Aging Study in 1990-1991. Clinical oral examinations included
assessment of the state of root surfaces and salivary flow rates, both
paraffin-wax-stimulated and unstimulated. Salivary buffering capacity
and the growth of salivary mutans streptococci, lactobacilli and yeasts
were determined by means of commercially available kits. Root caries
occurred in 52% of men and in 35% of women (p < 0.05). Number of
decayed (DRS) and decayed or filled (DFRS) root surfaces correlated (r =
0.16 to 0.26) with salivary microbial counts. No correlation appeared
between DRS and subjects' salivary flow rates. Basic estimates on the
association between DRS and salivary findings showed that microbial
counts only produced significant odds ratios, from 2.0 to 3.5. However,
in a log-linear model high salivary mutans streptococci and yeast counts
together with male gender were associated with greater occurrence of
root caries