R.J. Hunt, DDS, MS; C.W. Drake, DDS, MPH; J.D. Beck, PhD
Streptococcus mutam, lactobacilli, and caries experience in older adults This study Investigated salivary levels of Streptococcus mutans, lactobacllli, and caries experience in a random sample of 448 black and 362 white older dentate adults living in North Carolina. Significant proportions of the participants had stlmulated salivary flow rates less than 1.0 mL/min, salivary buffering capacity less than 4.0, S. mutans levels of 105 cfu/mL or more In stimulated whole saliva, or lactobacllli levels of 106 cfu/mL or more. Each of these factor levels could be considered, on a clinical bask, to increase caries risk. In general, people with higher levels of S. rnutans or lactobacilli had more untreated coronal and root caries, but not greater total caries experience.
any studies have linked increased salivary Streptococcus mutans and lactobacilli counts with increased caries rated4, but most of these studies have been conducted on children. Data from studies of adults are sparse. A few studies have linked S. mutans and lactobacilli with caries in selected adult groups, such as parents of young ~ h i l d r e n ~people , ~ , living in institutional settings7,*,and periodontal patients9J0. Recently, three studies in Sweden investigated the effectsof cariogenic bacteria and caries in adults, but found inconsistent results. Rask et PI." found that older adults who were classified as high caries risk because of salivary factors-such as flow rate, buffering capacity, lactobacilli, and S. mutansdeveloped significantlymore new caries lesions over five years. Klock et ~ 2 . found '~ that adults aged 45 and older had significant, although modest, correlations of 0.34 or less between DMFS caries levels and lactobacilli and S. mutans levels in the saliva. Salonen et aZ.13found that salivary S. mutans levels were not related to caries experience in adults ranging in age from 20 to 70 or older, except for decayed surfaces among subjects aged 70 or older. The relationships between these potentially cariogenic organisms and caries among adults are unclear. The purpose of this study was to provide additional data on these relationships by investigating levels of salivary S. mutans and lactobacilli and their correlations with caries experience in a sample of older adults living in North Carolina.
Materials and methods Subjects
The data for this analysis were taken from the Piedmont 65+ Dental Study, which is a dental substudy of the Piedmont Health Study of the Elderly. The parent study is a longitudinal study of the health status of a random stratified cluster sample of over 4,000 people aged 65 and older and living in five contiguous counties in North Carolina. Blacks were oversampled to permit comparisons to be made between blacks and whites. The dental substudy, which is also longitudinal in design, included 818 dentate and 200 edentulous subjects randomly selected (66%response rate) from the parent study. The investigation of salivary bacteria and caries experience described here used data from the 448 dentate blacks and the 362 dentate whites who participated in the baseline assessment of the dental substudy. Data from the other dentate participants, who were members of other racial groups, were not included. The edentulous subjects did not participate in the saliva collection. Clinical examinations
The participants were examined in their homes by one of five trained and calibrated dentist examiners. All existing teeth were scored, including third molars. The examiners used mirrors, explorers, and light-intensified headlamps. No compressed air or radiographs were used. Well-defined criteria developed by RadikeX4 were used for coronal caries detection. The dental explorers had
Speclal Care In DentSdtry, Vol12 No 4 1992 149
Table 1. Distributionof selected sallvary measures among older dentate adults in North Carolina, by race. % of Blacks % of Whites
< 0.50
14
16
0.5-0.99
19
19
1.O-1.49
26
28
1.5-1.99
17
19
2.0 or more
24
18
N
Streptococcus mutam, lactobacilli, and caries experience in older adults This study Investigated salivary levels of Streptococcus mutans, lactobacllli, and caries experience in a random sample of 448 black and 362 white older dentate adults living in North Carolina. Significant proportions of the participants had stlmulated salivary flow rates less than 1.0 mL/min, salivary buffering capacity less than 4.0, S. mutans levels of 105 cfu/mL or more In stimulated whole saliva, or lactobacllli levels of 106 cfu/mL or more. Each of these factor levels could be considered, on a clinical bask, to increase caries risk. In general, people with higher levels of S. rnutans or lactobacilli had more untreated coronal and root caries, but not greater total caries experience.
any studies have linked increased salivary Streptococcus mutans and lactobacilli counts with increased caries rated4, but most of these studies have been conducted on children. Data from studies of adults are sparse. A few studies have linked S. mutans and lactobacilli with caries in selected adult groups, such as parents of young ~ h i l d r e n ~people , ~ , living in institutional settings7,*,and periodontal patients9J0. Recently, three studies in Sweden investigated the effectsof cariogenic bacteria and caries in adults, but found inconsistent results. Rask et PI." found that older adults who were classified as high caries risk because of salivary factors-such as flow rate, buffering capacity, lactobacilli, and S. mutansdeveloped significantlymore new caries lesions over five years. Klock et ~ 2 . found '~ that adults aged 45 and older had significant, although modest, correlations of 0.34 or less between DMFS caries levels and lactobacilli and S. mutans levels in the saliva. Salonen et aZ.13found that salivary S. mutans levels were not related to caries experience in adults ranging in age from 20 to 70 or older, except for decayed surfaces among subjects aged 70 or older. The relationships between these potentially cariogenic organisms and caries among adults are unclear. The purpose of this study was to provide additional data on these relationships by investigating levels of salivary S. mutans and lactobacilli and their correlations with caries experience in a sample of older adults living in North Carolina.
Materials and methods Subjects
The data for this analysis were taken from the Piedmont 65+ Dental Study, which is a dental substudy of the Piedmont Health Study of the Elderly. The parent study is a longitudinal study of the health status of a random stratified cluster sample of over 4,000 people aged 65 and older and living in five contiguous counties in North Carolina. Blacks were oversampled to permit comparisons to be made between blacks and whites. The dental substudy, which is also longitudinal in design, included 818 dentate and 200 edentulous subjects randomly selected (66%response rate) from the parent study. The investigation of salivary bacteria and caries experience described here used data from the 448 dentate blacks and the 362 dentate whites who participated in the baseline assessment of the dental substudy. Data from the other dentate participants, who were members of other racial groups, were not included. The edentulous subjects did not participate in the saliva collection. Clinical examinations
The participants were examined in their homes by one of five trained and calibrated dentist examiners. All existing teeth were scored, including third molars. The examiners used mirrors, explorers, and light-intensified headlamps. No compressed air or radiographs were used. Well-defined criteria developed by RadikeX4 were used for coronal caries detection. The dental explorers had
Speclal Care In DentSdtry, Vol12 No 4 1992 149
Table 1. Distributionof selected sallvary measures among older dentate adults in North Carolina, by race. % of Blacks % of Whites
< 0.50
14
16
0.5-0.99
19
19
1.O-1.49
26
28
1.5-1.99
17
19
2.0 or more
24
18
N
