Oral defense factors in the elderly

Age-related changes in immune function (immune senescence) in caries and periodontal diseases: a systematic review

AIM

To systematically review the evidence regarding immune senescence in the pathogenesis of periodontitis and dental caries.

METHODS

A systematic search of electronic databases utilizing medical subject headings (MeSH terms) supplemented by screening of review articles and other relevant texts was undertaken.

RESULTS

Seventy-three articles were included (43 for periodontitis, 30 for caries). Study results were found to be generally heterogeneous. Regarding periodontitis, human studies suggest evidence for altered neutrophil function and increased production of pro-inflammatory mediators (e.g. interleukin-1β, interleukin-6 and prostaglandin E₂ ) in older compared to younger subjects, and animal experiments suggest increased expression of genes that contribute to a pro-inflammatory state in older compared to younger animals. Regarding dental caries, research relating to changes in immune functioning and the impact of ageing is in its infancy. A small number of studies have reported components of innate and adaptive immunity that affect the composition of saliva and dental biofilms with possible impacts on caries progression.

CONCLUSION

There is evidence that immune functioning related to periodontitis and (less investigated) dental caries alters with increasing age. In both conditions, age-associated mechanistic changes in immune functioning are complex and incompletely understood and it is not clear how these relate to disease susceptibility.

Minor salivary gland secretion rates and immunoglobulin A in adults and the elderly

Previously published data are conflicting about the effect of various factors on secretions from minor salivary glands. The aim of the present study was to investigate the secretion rate from palatal, buccal, and labial glands, and to analyze the immunoglobulin A (IgA) concentrations in relation to age, gender, circulatory disease, diabetes, medication, smoking, and pregnancy. Resting and stimulated whole-saliva secretion rates, as well as IgA concentration in stimulated whole saliva, were also examined. One-hundred and forty two individuals (96 women and 46 men), 18-82 yr of age, participated. The results did not suggest any effect of aging on the secretion capacity of minor salivary glands, but the IgA concentration seemed to increase with age. Women had lower buccal and labial saliva secretion rates, and lower levels of IgA in buccal saliva, than men. For whole saliva, resting, but not stimulated, saliva secretion rates were reduced with age, and the secretion rate of stimulated whole saliva was lower in women than in men. The IgA concentration in buccal saliva showed a positive correlation with IgA in stimulated whole saliva, and the IgA concentration decreased with increased flow rate in both salivas.

Salivary sIgA and cortisol: markers for functional dependence in older adults

Elderly persons with health problems and physical limitations have reduced independence. Since poor functional ability is a known risk factor for disease among older populations, including oral disease, this study was undertaken to assess whether salivary defense factors and the stress hormone cortisol are significant markers for functional dependence. Oral examinations; salivary and microbial analyses; and interviews using the Activities of Daily Living (ADD index, the Mini Nutritional Assessment (MNA) and the Perceived Life Stress Questionnaire (PLSQ) were conducted for 123 dentate subjects. Of the subjects, 80 lived independently in the community or in apartments at the Baycrest Centre for Geriatric Care in Toronto, Canada, and 43 resided in the Baycrest nursing home or the Baycrest Hospital. Whole saliva samples were assayed for total secretory immunoglobulin A (sIgA), sIgA1, sIgA2, total protein and cortisol using ELISA. Dependent residents in the nursing home/hospital scored significantly lower in the nutritional assessment, had higher mean PLSQ scores, increased total protein and cortisol concentrations, and reduced salivary flow rates in comparison to ambulatory residents in the community/apartments. In multivariable logistic regression, factors associated with functional dependence were: being male, perceiving income as inadequate, having low salivary flow rate and drinking less than 5 cups of water per day. These results indicate that salivary flow and cortisol may be useful markers of functional dependence; however, the ability of these markers to predict functional decline cannot be confirmed until longitudinal studies are conducted.

Evaluation of a computer-based caries risk assessment program in an elderly group of individuals

The aim of this study was to evaluate a caries risk assessment computer program, the Cariogram, by comparing the risk assessment of the program with the actual caries increment in a group of elderly individuals over a period of 5 years. The participants were examined and interviewed at baseline about their general health and dietary habits. Data on oral hygiene and use of fluoride were obtained and saliva analyses included mutans streptococci, lactobacilli, buffering capacity, and secretion rate. Based on the baseline recordings, the individuals were divided into 4 risk groups according to the Cariogram. Where the program predicted 0% 20% (high risk), 21%-40%, 41%-60%, and 61%- 100% (low/rather low risk) "chance of avoiding caries", 13, 32, 23, and 48% respectively, had no new DFS over 5 years and 18, 40, 72, and 84%, respectively, had no new lesions at the 5th year. The mean DMFS increment over 5 years was 12.8 in the high/rather high risk group (0% 40% "chance of avoiding caries"), which included 43% of the individuals. In the low/rather low risk group (61%-100% "chance of avoiding caries"), the corresponding value was 5.2%, and 21% of the participants were sorted to this group. The mean DMFS increment for the whole group of elderly individuals was 9.5. In this particular study the Cariogram was able to sort the elderly individuals into risk groups that reflected the actual caries outcome.

Xerostomia and hyposalivation: causes, consequences and treatment in the elderly

Xerostomia and salivary gland hypofunction (SGH) are prevalent in elderly populations, causing much discomfort and even difficulties in eating. SGH also increases the occurrence and severity of oral diseases and makes the patient susceptible to candidiasis. The principal causes of SGH and xerostomia are systemic diseases and drugs used daily. The diagnosis of SGH and xerostomia is based on simple methods, of which measuring both unstimulated and stimulated salivary flow rate is the most important. Treatment calls for proper management of underlying disease, avoidance of all unnecessary medications, and topical remedies such as artificial saliva substitutes. However, good hydration is essential in the elderly with SGH and xerostomia, and water is the drink of choice. In extremely difficult cases, for instance in patients receiving radiotherapy for cancer of the head and neck regions, parasympathomimetic drugs may be administered if no contraindications exist.

Caries activity and associated risk factors in elderly hospitalised population--15-months follow-up in French institutions

Only a few studies have been published concerning hospitalised elderly disabled people.

OBJECTIVES

1) to investigate the oral health status of elderly French patients hospitalised in the two main geriatric hospitals of Paris. 2) to describe the respective influences of general parameters (type of hospitalisation, pathologies and medication) on oral environment parameters. 3) to analyse the influences of these oral parameters on caries activity in Long-Term Care (LTCF) and in rehabilitation facilities (RF) patients and to study the incidence and the time-course of caries in these specific population.

SUBJECTS

117 subjects (mean age = 83.0 years, SD = 7.8, range = 64 to 102 years) were examined at baseline and 32 of the 50 LTCF subjects were reexamined 15-months later.

METHODS

The general parameters recorded were age, gender, type of hospitalisation, period of stay, removable prosthesis, general diseases, number of diagnoses, medications with hyposalivary side-effects. The oral environment parameters recorded were flow rate, buffer capacity, mutans streptococci and lactobacilli counts, measured at baseline by tests on stimulated saliva, and plaque index. Crown and root surfaces were recorded according to a modified caries activity index.

RESULTS

Among the polypathological subjects (85.5% of the population), the number of diseases ranged from 2 to 8. The LTCF patients had a significantly higher mean number of diagnoses (3.5; SD = 1.5) than the RF patients (2.8; SD = 1.4). 76.9% of patients were taking medications with hyposalivary side-effects. The stimulated flow rate ranged from 0.02 ml/min to 5 ml/min. Its mean was significantly lower for LTCF patients (0.67 ml/min; SD = 0.51) than for RF patients (1.12 ml/min; SD = 0.89). The plaque index was significantly higher in LTCF subjects and in patients with mental diseases. At baseline, 17,442 crown and root surfaces were examined. Flow rate was related to crown caries and buffer capacity to root caries. During the 15-months follow-up, the mean number of active root surfaces was significantly increased: from 0.148 (SD = 0.116) at baseline vs. 0.250 (SD = 0.174) at the second examination.

CONCLUSIONS

The strongest relationship in the present study between oral parameters and caries activity was the negative relationship between buffer capacity and active root caries. This study confirms an association between the type of hospitalisation and both salivary parameters flow rate and plaque index. This investigation illustrates the critical need for hygiene and oral care, in this elderly disabled population.

Antimicrobial function of human saliva--how important is it for oral health?

Human saliva contains a number of physical physicochemical, and chemical agents that protect oral tissues against noxious compounds, in particular those produced by various microorganisms. Among such protective factors, the flushing effect of saliva flow is the most important one, not only because it so effectively removes exogenous and endogenous microorganisms and their products into the gut but also because a steady supply of saliva guarantees continuous presence of both non-immune and immune factors in the mouth. A great number of studies with controversial results have been published regarding various individual agents and their possible association to oral health, particularly to dental caries. It appears that no single chemical agent is far more important than the others. For example, patients with selective IgA deficiency have normal levels of non-immune defense factors and often display a compensatory increase in the other immunoglobulin isotypes. The concerted action of all agents in whole saliva, both saliva- and serum-derived, provides a multifunctional protective network that is collapsed only if salivary flow rate is substantially reduced. In this mixture of defense factors, many show additive or even synergistic interactions against oral pathogens. Increased knowledge of the molecular functions of various agents has made it possible to prepare oral hygiene product that include host-derived antimicrobial agents instead of synthetic agents. Although the clinical efficacy of such products is still unsatisfactory and poorly described, new technologies, for example in the production of specific antibodies against oral pathogens, may considerably improve the antimicrobial power of these products.

Active and inactive caries lesions in a selected elderly institutionalised French population

Various epidemiological investigations have shown the high prevalence and incidence of caries in geriatric populations. The aim of the present study was to evaluate the dental status and some salivary parameters of elderly French subjects institutionalised in a geriatric hospital. The study population included 117 subjects (31 males and 86 females) who were neither demented nor edentulous, with a mean age of 83.0 years (SD = 7.8). Crown and root caries were recorded according to a modified caries activity index on 17,442 surfaces (9 surfaces per tooth: 5 crown surfaces and 4 root surfaces). The 17,442 surfaces examined corresponded to 1,938 teeth. The mean number of teeth per subject was 16.6 (SD = 7.6), more teeth remaining in the mandible than in the maxilla. The 2,985 unsound root surfaces showed a high percentage of active lesions (31.2 per cent) and a low percentage of filled root surfaces (4.5 per cent). Crowns and roots also presented a high percentage of destroyed surfaces: 1,446 destroyed surfaces, 8.3 per cent of the examined surfaces. Salivary parameters (flow rate and buffer capacity) were also recorded. Stimulated salivary flow rate had a relationship with crown caries (linear regression and analysis of covariance), and buffer capacity with root caries (analysis of variance and covariance). The data illustrate critical treatment needs in French geriatric institutions. This situation, which appears to differ from previous reports in European and US elderly people, may be related to French specificities concerning oral health status and/or care policy, but also to the usually very old population.

Periodontal effects of a biobehavioral prevention program

The present study tested preventive regimens in older subjects using dental services sporadically. 297 persons aged 60-90 (mean age 72.8; 43% ethnic minorities), were randomly assigned to either a control group or four interventions with incrementally more complex preventive strategies; behavioral training (group 2), added weekly chlorhexidine rinse (group 3), added semi-annual fluoride varnish (group 4), and added semi-annual prophylaxis (group 5). The control group received dental care as they preferred, primarily emergency care. All subjects were re-examined annually for 3 years. At baseline, 190 (64%) of the subjects were considered at risk for future periodontal disease progression. At baseline there were no group differences for any clinical parameter studied. Gingival bleeding varied between 19% and 23% over time and with no group differences. After 1 year, the greater decrease in probing depth for group 5 approached significance compared to the control group (p<0.06). Clinical attachment levels (CAL) improved in group 5 compared to the control group (p<0.01 for mesio-buccal, p<0.05 for mid-buccal tooth surfaces). The group differences did not persist at year 3. At year 3 in group 1, 9.2% and in group 5, 4.9% subjects lost > or =2.0 mm CAL. 310 teeth (6.5%) were extracted during the study period. A 21% increased risk for tooth loss was found in group 2, a 15% reduced risk in group 3, a 28% reduced risk in group 4, and a 44% reduced risk in group 5 compared to the control group (Wald-statistics robust p-value 0.12). At year 3, the tooth mortality rate in groups 3, 4 and 5 combined was reduced to 59% and significantly lower than groups 1 and 2 together (p<0.04). Self-efficacy was the best predictor of periodontal disease progression (F=7.02, p<0.01). Thus older persons benefited from a preventive oral health care program.

Oral microbial ecology and the role of salivary immunoglobulin A

In the oral cavity, indigenous bacteria are often associated with two major oral diseases, caries and periodontal diseases. These diseases seem to appear following an imbalance in the oral resident microbiota, leading to the emergence of potentially pathogenic bacteria. To define the process involved in caries and periodontal diseases, it is necessary to understand the ecology of the oral cavity and to identify the factors responsible for the transition of the oral microbiota from a commensal to a pathogenic relationship with the host. The regulatory forces influencing the oral ecosystem can be divided into three major categories: host related, microbe related, and external factors. Among host factors, secretory immunoglobulin A (SIgA) constitutes the main specific immune defense mechanism in saliva and may play an important role in the homeostasis of the oral microbiota. Naturally occurring SIgA antibodies that are reactive against a variety of indigenous bacteria are detectable in saliva. These antibodies may control the oral microbiota by reducing the adherence of bacteria to the oral mucosa and teeth. It is thought that protection against bacterial etiologic agents of caries and periodontal diseases could be conferred by the induction of SIgA antibodies via the stimulation of the mucosal immune system. However, elucidation of the role of the SIgA immune system in controlling the oral indigenous microbiota is a prerequisite for the development of effective vaccines against these diseases. The role of SIgA antibodies in the acquisition and the regulation of the indigenous microbiota is still controversial. Our review discusses the importance of SIgA among the multiple factors that control the oral microbiota. It describes the oral ecosystems, the principal factors that may control the oral microbiota, a basic knowledge of the secretory immune system, the biological functions of SIgA, and, finally, experiments related to the role of SIgA in oral microbial ecology.

Salivary flow and composition in elderly patients referred to an acute care geriatric ward

OBJECTIVE

The purpose of this investigation was to study oral health and salivary aspects of the frail elderly. The study hypothesis was that elderly patients with many concomitant diseases and drugs would have different salivary secretion rates and biochemical constituents than healthier patients.

STUDY DESIGN

The stimulated flow, pH buffering capacity, and biochemical constituents were analyzed from salivas of 169 elderly subjects (51 men and 118 women, mean age 81.2 years, range 69 to 96 years) admitted to an acute geriatric ward because of sudden worsening of their health. Common statistical methods were used to analyze the differences among patient groups. The patients were grouped according to the number of concomitant diseases and daily used drugs and on the basis of salivary flow rate values.

RESULTS

Reduced salivary flow (< 0.7 ml/min) was found in 48% of the men and 62.5% of the women, and a low buffering capacity was found in 31.9% of the men and 36.7% of the women. Age did not significantly affect the salivary flow rate. The factors that showed the strongest influence on salivary flow were endocrinologic diseases, ophthalmologic and respiratory drugs, and potassium chloride. Salivary immunoglobulin A and immunoglobulin M concentrations were significantly higher in older patients. Immunoglobulin A, lysozyme, and amylase concentrations were significantly higher in older patients taking many drugs. Patients with many concomitant diseases had significantly higher salivary urea concentrations than healthier patients. Edentulous patients had significantly higher salivary immunoglobulin A, immunoglobulin M, lysozyme, and amylase concentrations.

CONCLUSIONS

In this study, hyposalivation was a frequent observation, and the elderly who took many drugs and had several systemic diseases had higher concentrations of most of the analyzed biochemical constituents.

Effects of oral hygiene products containing lactoperoxidase, lysozyme, and lactoferrin on the composition of whole saliva and on subjective oral symptoms in patients with xerostomia

This study evaluates the effects of two oral hygiene products containing nonimmunoglobulin antimicrobial agents on whole saliva and on subjective oral symptoms in patients with xerostomia. Twenty patients used a lactoperoxidase-system-containing toothpaste (Biotene) combined with the use of a mouthrinse (Biotene), comprising also lysozyme and lactoferrin, for 4 weeks. Saliva samples were collected at base line, after 4 weeks' use of the products, and at the end of a 4-week washout period. Samples were analyzed for selected biochemical and microbiologic factors. The effects on subjective oral symptoms were also recorded. A 4-week daily use of toothpaste and mouthrinse relieved the symptoms of oral dryness in 16 patients. The levels of salivary hypothiocyanite, lysozyme, lactoferrin, or myeloperoxidase activity did not change, but there was a significant decrease in salivary pH (P < 0.05), total peroxidase activity (P < 0.05), and total protein content (P = 0.01). In patients with the lowest salivary flow rates (n = 5) a significant (P > or = 0.04) increase was detected in salivary hypothiocyanite concentrations. No major changes occurred in salivary microflora. The products relieved subjective oral symptoms in most xerostomic patients, but this was not necessarily related to the presence of antimicrobial agents.

Xerostomia and associated factors in a community-dwelling adult population

Xerostomia is the subjective sensation of dry mouth. Estimates on the occurrence of xerostomia in community-dwelling adults have ranged from 10% among persons over age 50 to 40% for persons over age 65. Virtually no data are available for persons under age 50. To begin to establish a database on the occurrence of xerostomia and factors associated with it, a cross-sectional assessment of self-reported symptoms and salivary function was conducted across a broad age-range of generally healthy community-dwelling adults. A convenience sample of 710 adults who ranged from 19 to 88 years of age was drawn from various sources in the greater-Rochester, New York area. Study volunteers were administered a standardized questionnaire on general and oral health, which included questions on the symptoms of xerostomia, and were provided an oral screening examination, which included measurement of unstimulated and stimulated whole saliva flow rates. Overall, the observed prevalence of xerostomia was 24% among females and 18% among males. While xerostomia was more commonly observed in women than men, this association was only clear after age 50. Xerostomia was associated with: use of medications with hyposalivatory side-effects; difficulty with dry foods; cracked lips; dry eyes; difficulty swallowing; and, among males, current cigarette smoking. Results indicated a tendency for salivary flow rates to be lower for older persons, particularly the stimulated flow rate. There was a tendency in the younger cohorts for flow rates to be lower among individuals who reported sensation of dry mouth than among those who did not. This tendency was not apparent among older persons, suggesting that younger persons may be more likely to experience symptoms of oral dryness when salivary flow was low while older persons may relate symptoms of dry mouth to a more complex constellation of factors where salivary flow is only one component. These findings need to be examined further.

Salivary IgA secretion rate in young and elderly persons

Immunoglobulin A (IgA) is the dominant immunoglobulin isotype on all mucosal surfaces where it acts as a first line of defense against microbial invasion. Recent investigations suggest that secretory IgA (sIgA) concentrations vary over the day due to a range of variables including dietary factors, daily mood, and exercise. In this study, salivary IgA was determined by ELISA in samples of 48 persons grouped as "young" (20-30 years old) and "elderly" (60-80 years old). Unstimulated, stabilized morning and afternoon saliva was collected during 7 consecutive days. Saliva flow, total proteins, sIgA concentrations, and sIgA secretion rates were determined. The main finding was that saliva flow and sIgA secretion rate were significantly lower in the elderly than in the young. Salivary IgA secretion rate was found to be independent of total proteins secreted in all samples. There is individual variability within a particular age group. It was also found that stress and daily events influence the sIgA secretion rate.

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.

The burning mouth syndrome

The burning mouth syndrome is characterized by burning and painful sensations of the mouth in the absence of significant mucosal abnormalities. For patients in whom no causative factor can be identified, empiric antifungal, nutritional, and estrogen replacement therapy can be initiated. If these fail, long-term therapy with antidepressants, benzodiazepines, and clonazepam can be considered. Topical capsaicin and laser therapy have been reported beneficial in a few patients.

Does variability in salivary protein concentrations influence oral microbial ecology and oral health?

Salivary protein interactions with oral microbes in vitro include aggregation, adherence, cell-killing, inhibition of metabolism, and nutrition. Such interactions might be expected to influence oral ecology. However, inconsistent results have been obtained from in vivo tests of the hypothesis that quantitative variation in salivary protein concentrations will affect oral disease prevalence. Results may have been influenced by choices made during study design, including saliva source, stimulation status, control for flow rate, and assay methods. Salivary protein concentrations also may be subject to circadian variation. Values for saliva collected at the same time of day tend to remain consistent within subjects, but events such as stress, inflammation, infection, menstruation, or pregnancy may induce short-term changes. Long-term factors such as aging, systemic disease, or medication likewise may influence salivary protein concentrations. Such sources of variation may increase the sample size needed to find statistically significant differences. Clinical studies also must consider factors such as human population variation, strain and species differences in protein-microbe interactions, protein polymorphism, and synergistic or antagonistic interaction between proteins. Salivary proteins may form heterotypic complexes with unique effects, and different proteins may exert redundant effects. Patterns of protein-microbe interaction also may differ between oral sites. Future clinical studies must take those factors into account. Promising approaches might involve meta-analysis or multi-center studies, retrospective and prospective longitudinal designs, short-term measurement of salivary protein effects, and consideration of individual variation in multiple protein effects such as aggregation, adherence, and cell-killing.

Antimicrobial factors, sialic acid, and protein concentration in whole saliva of the elderly

Concentrations of salivary antimicrobial factors are well documented in children and young adults, but little information is available on such defense factors in healthy elderly persons. We determined the levels of total IgA, total IgG, lysozyme, lactoferrin, myeloperoxidase, salivary peroxidase, amylase, sialic acid, and total protein in a group of 71 subjects aged 76, 81, and 86 yr, as well as their correlations to paraffin-wax-stimulated salivary flow rate. Participants were either unmedicated (n = 67) or using medicines with no oral significance (n = 4). Statistically significant negative correlations existed between flow rate and total IgA, lysozyme, lactoferrin, sialic acid, and total protein. Concentrations of sialic acid and salivary peroxidase were highest in the oldest age group. Total IgA concentration was higher in women than in men, although men showed higher concentrations of sialic acid and higher sialic acid/total protein ratios. Subjects with poor gingival health had higher concentrations of total protein than did those with no need for periodontal treatment. Edentulous subjects with complete dentures showed significantly lower concentrations of IgG, lactoferrin, and myeloperoxidase than did dentate subjects. Our results suggest that, when compared with data from previous studies, concentrations of salivary antimicrobial agents do not decline with age in unmedicated elderly people. However, defense factors which are derived also from gingival crevicular fluid are decreased in the absence of teeth.

Mutans streptococci and lactobacilli in the elderly

The prevalence of salivary mutans streptococci and lactobacilli, salivary flow rate, and the type of dentition were studied in connection with a medical survey of 76-, 81-, and 86-yr-old inhabitants of Helsinki living at home. High bacterial counts were associated with low salivary flow rates. High counts of mutans streptococci (> 10(6) CFU/ml) were found in 68% of wearers of full dentures, as compared with 53% of subjects having natural teeth. High counts of lactobacilli (< 10(6) CFU/ml) were found in 44% of subjects having removable partial dentures and in 39% of subjects having natural teeth. The bacterial counts correlated neither with medicines taken daily nor with diseases among this population.