Salivary levels of mutans streptococci and lactobacilli in dentate 80- and 85-year-old Swedish men and women

Interactions between systemic diseases and oral microbiota shifts in the aging community: A narrative review

As a gateway to general health and a diverse microbial habitat, the oral cavity is colonized by numerous microorganisms such as bacteria, fungi, viruses, and archaea. Oral microbiota plays an essential role in preserving oral health. Besides, the oral cavity also significantly contributes to systemic health. Physiological aging influences all body systems, including the oral microbial inhabitants. The cited effect can cause diseases by forming dysbiotic communities. Since it has been demonstrated that microbial dysbiosis could disturb the symbiosis state between the host and the resident microorganism, shifting the condition toward a more pathogenic one, this study investigated how the oral microbial shifts in aging could associate with the development or progression of systemic diseases in older adults. The current study focused on the interactions between variations in the oral microbiome and prevalent diseases in older adults, including diabetes mellitus, Sjögren's syndrome, rheumatoid arthritis, pulmonary diseases, cardiovascular diseases, oral candidiasis, Parkinson's disease, Alzheimer's disease, and glaucoma. Underlying diseases can dynamically modify the oral ecology and the composition of its resident oral microbiome. Clinical, experimental, and epidemiological research suggests the associations of systemic disorders with bacteremia and inflammation after oral microbial changes in older adults.

Clinically acceptable restorations may be a hotbed for cariogenic microbes

OBJECTIVE

The aim of this study was to investigate the cross-sectional association of dental restorations with salivary cariogenic pathogens among the elderly to establish effective parameters of caries risk for this population.

MATERIALS AND METHODS

Stimulated whole saliva was collected from 289 community-dwelling older adults (66.2 ± 3.9 years old) who had 20 or more teeth. Salivary levels of three cariogenic bacteria (Streptococcus mutans, Streptococcus sobrinus and lactobacilli) were estimated using quantitative polymerase chain reaction (real-time PCR) method.

RESULTS

The mean number of residual teeth was 26.4, and restored teeth with crowns, inlays and composite resin were 7.35, 3.88 and 0.68, respectively. The number of crowns correlated positively with salivary S. mutans, S. sobrinus and lactobacilli. Multiple linear regression analyses showed that the number of restored teeth with crowns was independently associated with salivary S. mutans, S. sobrinus and lactobacilli after controlling for age, gender, number of residual teeth and salivary flow rate. Salivary flow rate was independently associated with salivary S. mutans and lactobacilli.

CONCLUSION

The number of crowns had an association with salivary levels of cariogenic bacteria, suggesting that this parameter may be a caries risk indicator for the elderly population.

Effects of mucosal care on oral pathogens in professional oral hygiene to the elderly

To elucidate the effects of mucosal care on colonization of mutans streptococci and infection of Candida species, we randomized 50 functionally dependent nursing home residents, mean age 76.1 (±7.8 years), 76% females, to receive oral professional care with or without mucosal care. During 12 months of follow-up, significant reduction in the numbers of mutans streptococci in saliva and dental plaque samples were observed in both treatment groups. However, there was no reduction in the numbers of mutans streptococci in tongue samples in the non-mucosal group (p=0.150). In the comparison between the treatment with and without mucosal care, the treatment with mucosal care showed a significant inhibition effects on numbers of nutans streptococci on the tongue surface at 6 months after the treatment as compared with the treatment without mucosal care (p=0.043). Mucosal care was not associated with any significant reduction in the rate of opportunistic infection with Candida species in any of the three sites. However, more subjects without mucosal care had Candida infection in dental plaque during the follow-up (p=0.046). Professional dental care with (versus without) mucosal care had no effect on mutans streptococci colonization in saliva or plaque. Lack of mucosal care seemed to be associated with higher rates opportunistic infections with Candida species.

The role of anti-PAc (361-386) peptide SIgA antibody in professional oral hygiene of the elderly

OBJECTIVE

Measurement of salivary IgA antibody (PAc-peptide antibody, PPA) to amino acid residues 361-386 of Streptococcus mutans PAc, which possess a multiple binding motif to various HLA-DR molecules and a B-cell epitope that recognises the inhibiting antibody to S. mutans, is an indicator for the population numbers of mutans streptococci (MS) in human saliva. The purpose of this study was to clarify the role of PPA in infection control of MS after professional oral hygiene care.

MATERIALS AND METHODS

Thirty-nine dependently living institutionalised elderly subjects (75.9 +/- 7.5 years; 10 males, 29 females) participated in the study. The measurements of PPA, MS, total streptococci (TS) and lactobacilli (LB) were performed by ELISA and culture techniques from saliva, plaque and tongue samples from the elderly.

RESULTS

After treatment using professional oral care, the numbers of MS decreased significantly at 6 months in saliva and tongue samples from the group not having PPA in comparison with the primary data; whereas in the PPA-detected group, a significant decrease in MS number was shown immediately following professional care at 1-12 months in all samples. There was little difference in the numbers of LB at any of the time points. The numbers of TS decreased rapidly in PPA-not detected group in comparison with the PPA-detected group.

CONCLUSION

PPA may be more effective for controlling MS number in the oral cavity after professional treatment. The measurement of PPA may be used for preventive instruction to dental caries at the chair side in the clinical setting.

Relationship of cariogenic bacteria levels with periodontal status and root surface caries in elderly Japanese

OBJECTIVE

The relationship of the levels of cariogenic bacterial species with periodontal status and decayed root surfaces was investigated in elderly Japanese subjects.

METHODS

Three hundred and sixty-eight individuals (each 75 years old) were examined for periodontal status (pocket depth, attachment loss), root surface caries and salivary levels of mutans streptococci (MS) and lactobacilli (LB).

RESULTS

Values >4 mm of attachment loss (rAL4) and for average attachment loss (aAL) of sites measured were significantly higher in subjects with LB than those without. Multiple regression analysis also showed a correlation between aAL and rAL4 values with the presence of LB (aAL p = 0.003; rAL4 p = 0.002). Further, multiple regression analysis of interacting factors regarding decayed root surfaces showed that LB carriers had a greater incidence of decayed root surface caries (p = 0.003), while MS and LB levels were correlated to the number of decayed root surfaces (LB p = 0.010; MS p = 0.026).

CONCLUSION

Our results indicate that considerable attachment loss elevates the possibility of having LB, thus increasing the risk of root surface caries. It was also found that LB and MS measurements may be useful indicators of decayed root surfaces in elderly individuals with attachment loss.

Cariogenic Bacteria and Caries Risk in Elderly Japanese Aged 80 and Older with at Least 20 Teeth

OBJECTIVES

To assess caries risk and check the presence of four commonly found oral cariogenic bacteria in "8020" achievers.

DESIGN

Initial report based on Japan's newly implemented "8020" campaign, which aims to promote health and awareness in older people. Simply stated, the goal is, at 80 years, to maintain 20 teeth.

SETTING

Healthy community-dwelling elderly individuals of Okayama Prefecture, Japan.

PARTICIPANTS

One hundred sixty individuals aged 80 and older with 20 of their own natural teeth.

MEASUREMENTS

General and oral health conditions, caries risk assessment using the Cariostat method, and polymerase chain reaction (PCR) detection of four oral cariogenic bacteria.

RESULTS

The participants had an average of 24.7 teeth, of which 12.1 were sound, 12.2 were treated, and 0.4 were untreated. Based on Cariostat scores, 64.4% had low caries risk. Using PCR, Streptococcus mutans, S. sobrinus, Lactobacillus casei, and L. plantarum were detected in 51.3%, 23.1%, 40%, and 25% of the participants, respectively. S. mutans (P<.001), S. sobrinus (P=.002), L. casei (P<.001), and L. plantarum (P=.001) deoxyribonucleic acid band was detected more in participants with high caries risk scores.

CONCLUSION

Participants with low caries risk scores had low prevalence of cariogenic bacteria, 20 or more sound teeth, and fewer missing teeth. Incorporating caries risk assessment, using the Cariostat and PCR analysis, in the "8020" campaign in health systems worldwide will contribute to a better life for the aging society, initiate research interest regarding the program, and improve current health policies.

Longitudinal study of the influence of removable partial denture and chemical control on the levels of Streptococcus mutans in saliva

Some studies have evaluated the salivary levels of mutans streptococci (MS) in removable partial denture (RPD) users. Saliva samples (2.0 mL) were obtained from 31 patients in six periods: (T0): immediately before installation of RPD; (T8): 8 days after T0; (T48): 48 days after T0; (T92): 92 days after T0; (T140): 140 days after T0 and (T189): 189 days after T0. The samples were vortexed and serially diluted from 10(-1) to 10(-6) in 0.05 m phosphate buffer (pH 7.4). From each dilution, 0.025 mL was plated on Mitis Salivarius Bacitracin (MSB). The plates were incubated in 5% CO2 at 37 degrees C for 72 h. There was an increase (t-test, P < 0.05) in the number of MS between periods T0 and T48 (mean/s.d., CFU mL(-1) of saliva): T0: 2.26/4.43 x 10(6) and T48: 0.47/1.48 x 10(8). After this, intensive treatment with CHX was accomplished in 29 patients. Saliva samples were obtained after treatment in four periods: (T24 h): 24 h after T0; (T14): 14 days after T24 h; (T28): 28 days after T24 h, and (T63): 63 days after T24 h. The number of MS in saliva did not decrease (t-test, P > 0.05). A new CHX formulation was applied in 15 patients. Saliva samples were obtained in periods: (T0): before new CHX application; (T24 h): 24 h after T0 and (T82): 82 days after T0. The new CHX reduced MS levels in saliva: (mean/s.d., CFU mL(-1) of saliva): T0: 6.64/8.47 x 10(6) and T24 h: 3.2/4.27 x 10(5) (sign rank, P < 0.05). In conclusion, there was a significant increase in the number of MS in saliva after the installation of RPD. The intensive treatment with a properly formulated CHX was effective in the reduction of MS, between 24 h and 82 days after its application.

Saliva, salivary micro-organisms, and oral health in the home-dwelling old elderly--a five-year longitudinal study

High scores of chair-side salivary microbial tests have been found to be related to an increased prevalence and incidence of coronal and root caries. Many elderly face an increased risk of the growth of oral microbes, and previous studies have reported high salivary microbial counts in elderly populations. The aim of this follow-up study was to compare, at five-year intervals, stimulated salivary flow rates with the numbers of selected salivary micro-organisms (mutans streptococci, lactobacilli, and yeasts) in a group of home-dwelling elderly in Helsinki. A further aim was to study the influence of baseline microbial counts on five-year root caries increments and rates of tooth loss. The baseline study population was comprised of 270 subjects who were all participants in the population-based Helsinki Aging Study. Salivary flow rates and microbial conditions were determined as part of their dental examination at the Institute of Dentistry, University of Helsinki, in 1990-1991. Of these subjects, 110 underwent a follow-up examination in 1995-1996. Commercially available kits (Dentocult SM strip mutans for mutans streptococci, Dentocult LB for lactobacilli, and Oricult N for yeasts) were used for the enumeration of micro-organisms, after the collection of paraffin-wax-stimulated whole saliva. The stimulated whole saliva flow rates of the subjects were significantly lower at the follow-up than at baseline (paired t test, difference -0.16 mL/min; p < 0.05), whereas buffer capacity was higher (paired t test, difference 0.19 on a three-unit scale; p < 0.05). Apart from lower salivary lactobacilli counts at follow-up (paired t test, difference -0.44 CFUs/mL of saliva; p < 0.001), no changes were found in salivary microbial levels. Salivary microbial counts were clearly associated with the subjects' dentition types: More denture-wearers had high microbial counts than persons with natural dentitions. None of the salivary factors correlated with the root caries incidence or the number of teeth lost during the five-year follow-up.

Depressive symptoms favor abundant growth of salivary lactobacilli

OBJECTIVE

The purpose was to study the growth of lactobacilli in subjects with depressive symptoms in the total 55-year-old population of Oulu (a medium-sized town in Finland); 780 people participated.

METHODS

The dental examination included measurements of salivary lactobacillus growth with the Dentocult-LB method; measurements of salivary flow rate, pH, and buffering capacity; and assessment of oral health status. Depressive symptoms were determined with the Zung Self-Rating Depression Scale (ZSDS). Participants were also asked about their health, medication, smoking, and dietary habits.

RESULTS

The prevalence of high lactobacillus counts (> or =100,000 CFU/ml) was 22% among women and 31% among men (p = .02). Thirty-seven percent of the subjects with a high rate of depressive symptoms (ZSDS score of > or = 40) and 23% of those with an ZSDS score of < or = 39 had high counts of lactobacilli (p = .003). A logistic regression analysis with improvement of goodness of fit was made to confirm the relation between abundant lactobacilli and a high rate of depressive symptoms. After the confounding factors had been added stepwise into the logistic regression model, depressive symptoms were still significantly associated with abundant lactobacillus growth.

CONCLUSIONS

The association between high lactobacillus counts and depressive symptoms suggests that depressed subjects are at risk of having caries and possibly other dental diseases that should be recognized in the treatment of these patients.

Factors which are associated with dental decay in the older individual

OBJECTIVES

To improve reliability of salivary bacterial cultures as a surrogate for plaque levels of cariogenic bacterial species by reporting the salivary CFUs of these organisms as a function of the number of teeth.

DESIGN

Cross-sectional collection of data in a convenience sample of adults over 60 years of age.

SETTING

Hospital Dental clinic, University bacteriology laboratory.

SUBJECTS

523 older dentate subjects, average age 70, including 412 subjects who were in an independent living status and 111 in a dependent-living situation.

MAIN OUTCOME MEASURES

Subjects were examined for decay and the presence of salivary factors including the levels of S. mutans, lactobacilli, yeast and other bacteria. The salivary levels of the bacteria were adjusted for the number of teeth in the mouth, and the resultant values were entered into multivariable logistic regression models along with clinical and other salivary parameters.

RESULTS

Mutans streptococci levels reported as CFUs/ml saliva per tooth were significantly associated with coronal surface decay, and lactobacilli, reported in a similar way, were significantly associated with root surface decay. Salivary levels of yeasts, which had previously been associated with decay in this population, were no longer significant using this construct.

CONCLUSIONS

This construct of reporting salivary bacteriological data as a function of tooth number and per ml saliva could improve the reliability of bacteriological data obtained in epidemiological studies investigating the role of bacteria in dental decay in the elderly.

Caries prevalence and salivary and microbial conditions in 88-year-old Swedish dentate people

As part of a comprehensive investigation of 88-year-old people, caries prevalence, stimulated salivary secretion rate, buffer capacity, and the prevalence of lactobacilli and mutans streptococci were studied in a subsample of 92 dentate subjects. The mean number of remaining teeth was 14.1 +/- 7.3. The DMFT was 25.2 +/- 3.0, and DF surfaces 38.3 +/- 22.7. Root caries experience was found in 85% of the subjects, with a mean root caries index of 36.6 +/- 28.5%. The men had significantly higher mean values of salivary secretion rate (2.0 +/- 1.3 ml/min) than the women (1.1 +/- 0.6 ml/min) (p < 0.001). The mean final pH of buffer capacity was 6.3 +/- 1.3. High counts of lactobacilli (> 10(5)) and mutans streptococci (> 10(6)) were found in 49% and 55% of the subjects, respectively, of whom most were denture wearers. The mean number of total mutans streptococci was higher in persons harboring both Streptococcus mutans and S. sobrinus than in subjects with only S. mutans.

Factors which influence levels of selected organisms in saliva of older individuals

The most commonly measured bacterial parameters in saliva are the levels of the mutans group streptococci and lactobacilli, which have diagnostic implications for the incidence of dental decay. Diagnostic guidelines which are applicable to children and young adults in whom most, if not all, teeth are present and in whom the rate of stimulated saliva is almost always greater than 0.5 ml/min have been developed. Dental decay is a potential health problem of considerable magnitude among elderly individuals. In elderly individuals, missing teeth, the presence of dentures, and a reduced salivary flow could confound the interpretation of salivary levels of cariogenic bacteria. In the present study, in which saliva was collected from more than 560 elderly individuals (average age, 70 +/- 8 years), there was a significant positive relationship between the salivary levels of Streptococcus mutans and increased numbers of teeth. There was a positive association between the salivary levels of S. mutans and decay when the data were stratified for the presence of a complaint of xerostomia and the presence of dentures. However, a similar analysis indicated that lactobacilli and yeasts were more likely to be associated with decay. The various variables which could influence the bacterial counts per milliliter of saliva, e.g., independent or dependent living status, complaint of xerostomia, stimulated salivary flow, salivary pH, the presence of dentures, number of teeth, and decay, were analyzed simultaneously by using a multivariable linear model. In that analysis the number of decayed teeth was significantly associated with the presence of lactobacilli (P = 0.0001) and yeasts (P = 0.025) but not with the presence of S. mutans. Our findings indicate that salivary levels of lactobacilli and yeasts, as well as the salivary levels of S. mutans, should be monitored when seeking microbial indicators that might predict the incidence of caries in elderly individuals.

Influence of salivary levels of mutans streptococci on colonization of crown margins: a longitudinal study

Initial colonization of mutans streptococci in 36 crown margins of 21 patients was studied. Before cementation, salivary concentrations of mutans streptococci and Lactobacillus sp, microorganisms associated with dental caries, were determined. Within 1 week 25% of the selected crown margins in subjects with low salivary levels of mutans streptococci and 89% in subjects with high salivary levels were colonized. High salivary counts of lactobacilli seemed to reflect conditions that enhanced the risk of colonization of mutans streptococci. The results suggest that, before cementation of fixed prosthodontics, measures should be taken to control the salivary concentrations of these organisms to reduce the susceptibility to recurrent caries.