Maude Wikström

Electrolytes in stimulated whole saliva in individuals with hyposalivation of different origins

There are reasons to believe that changes in the secretion rate of saliva as well as changes in its protein and electrolyte composition promote the growth of micro-organisms associated with oral disorders. Knowledge of the electrolytes in the saliva of those with hyposalivation might therefore be of value in designing oral health-promoting measures. In this study, electrolytes in stimulated whole saliva were analysed in individuals with hyposalivation due to radiation therapy in the head and neck region (RT group), primary Sjögrens syndrome (pSS group), neuroleptic treatment (Neuro group), and to medication or of unknown origin (Unknown group). The bicarbonate concentration was significantly lower in all four hyposalivation groups compared with controls. The bicarbonate concentration, which in normal conditions is positively correlated with the salivary secretion rate, was lower in the Neuro group than in the RT and Sjögrens groups despite a stimulated secretion rate about twice as high. Furthermore, the Neuro group had the highest phosphate concentration. The RT and Sjögrens groups tended to have increased sodium concentrations. For potassium and calcium, the RT group had significantly higher concentrations than the other hyposalivation groups and the controls. The substantial increase in calcium and decrease in bicarbonate suggest that the function of the parotid glands is more affected than that of the other salivary glands. The results also indicate a contribution of plasma to the electrolyte concentrations determined in whole saliva in the RT and Sjögrens groups. In conclusion, in individuals with hyposalivation the concentrations of electrolytes in stimulated whole saliva seem to be more related to the reason for the hyposalivation than to the salivary secretion rate.

Microflora in oral ecosystems in subjects with radiation-induced hyposalivation

AIM To analyse the microbial flora in specific oral sites in 13 dentate subjects, 6-8 months after completed radiation therapy (RT group) and in 13 matched controls. MATERIAL AND METHODS The microflora on the tongue, buccal mucosa, vestibulum, supragingival plaque and subgingival region was analysed using duplicate sampling and cultivation technique. A clinical examination was also performed. RESULTS Candida albicans was found in one or more sites in 54% of the RT subjects and in 15% of the controls. In three RT subjects, C. albicans was found at all four sites analysed. An unexpected finding was that enterococci were found in all RT subjects and in high number in 38%. None of the controls harboured enterococci. In supragingival plaque, Lactobacillus spp. were detected in 92% of the RT subjects and the number and proportion of Lactobacillus spp. were extremely high compared with the controls. Mutans streptococci were detected in high numbers in 31% of the RT subjects, while they were not detected in 23%. CONCLUSION The microbial results explain why some RT subjects have an increased susceptibility to oral diseases and stress that site-specific microbial analysis is an important diagnostic tool when planning oral health preventive care for RT subjects.

Attitudes to and knowledge about oral health care among nursing home personnel – an area in need of improvement

BACKGROUND In 1999, a dental reform became law in Sweden that regulated both dental care to dependent individuals and training in oral health care for nursing home personnel. Substantial resources have been channelled into these efforts, but the outcome of these efforts has not been evaluated. The aim of this study was to explore attitudes to and knowledge about oral health care among nursing home personnel more than 5 years after the law was adopted, that being 2005. METHODS A total of 454 individuals employed at nursing homes answered a questionnaire of 16 multiple-choice items concerning attitudes to and knowledge about oral health care. RESULTS Eighty-nine per cent considered oral health care to be an important part of good nursing. The answers indicated problems, however, when it came to its implementation and knowledge, and 35% stated that they had had no formal education in oral health care. CONCLUSIONS Despite generally positive oral health care attitudes, it is important that oral health care education is available to and made of interest for all nursing home personnel, especially in light of the increase in number of natural teeth and frequency of crowns and bridges among dependent elderly.

Dental Plaque pH and Micro-organisms during Hyposalivation

We have previously reported that minor gland and whole saliva flow rates and salivary proteins showed differences in individuals with primary Sjögren’s syndrome or head and neck radiation therapy, compared with controls (Eliasson et al., 2005). We now hypothesize that pH and number of acidogenic micro-organisms in dental plaque as well as saliva buffering capacity also differ in these individuals. Plaque pH was measured by the microtouch method up to 60 min after a sucrose rinse. Plaque collected from the same sites was analyzed for counts of total and acidic micro-organisms. Compared with their controls, the irradiated group but not the Sjögren’s syndrome group displayed significantly lower plaque pH, increased numbers of lactobacilli and Candida species, as well as reduced buffering capacity. Stepwise regression tests suggested that the buccal minor-salivary-gland secretion rate in the test groups and counts of mutans streptococci in the controls were of significant importance for dental plaque pH.

Reflectometry in kinetic studies of immunological and enzymatic reactions on solid surfaces

Abstract An optical method is described, by means of which immunological and enzymatic reactions can be followed at a primary level on a solid surface, without labelling procedures. When plane-polarized light is reflected at a solid surface, there is a minimum in reflectance at a certain angle of incidence, the pseudo-Brewster angle. For example, a layer of protein adsorbed on a silicon surface increases the reflectance with increasing amount of adsorbed material. High sensitivity is obtained because of the large difference in refractive index between silicon and organic material; about 0.1 μg cm −2 adsorbed protein can be detected. In a model system of human IgG and anti-human IgG, the primary adsorption of IgG on a hydrophobic surface is first measured, and on this IgG-coated surface the binding kinetics of anti-IgG could be measured. The kinetics of proteolytic degradation of IgG-coated surfaces by trypsin was also investigated.

Modification of cystatin C activity by bacterial proteinases and neutrophil elastase in periodontitis

AIM: To study the interaction between the human cysteine proteinase inhibitor, cystatin C, and proteinases of periodontitis associated bacteria. METHODS: Gingival crevicular fluid samples were collected from discrete periodontitis sites and their cystatin C content was estimated by enzyme linked immunosorbent assay (ELISA). The interaction between cystatin C and proteolytic enzymes from cultured strains of the gingival bacteria Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans was studied by measuring inhibition of enzyme activity against peptidyl substrates, by detection of break down patterns of solid phase coupled and soluble cystatin C, and by N-terminal sequence analysis of cystatin C products resulting from the interactions. RESULTS: Gingival crevicular fluid contained cystatin C at a concentration of approximately 15 nM. Cystatin C did not inhibit the principal thiol stimulated proteinase activity of P gingivalis. Instead, strains of P gingivalis and P intermedia, but not A actinomycetemcomitans, released cystatin C modifying proteinases. Extracts of five P gingivalis and five P intermedia strains all hydrolysed bonds in the N-terminal region of cystatin C at physiological pH values. The modified cystatin C resulting from incubation with one P gingivalis strain was isolated and found to lack the eight most N-terminal residues. The affinity of the modified inhibitor for cathepsin B was 20-fold lower (Ki 5 nM) than that of full length cystatin C. A 50 kDa thiol stimulated proteinase, gingipain R, was isolated from P gingivalis and shown to be responsible for the Arg8-bond hydrolysis in cystatin C. The cathepsin B inhibitory activity of cystatin C incubated with gingival crevicular fluid was rapidly abolished after Val10-bond cleavage by elastase from exudate neutrophils, but cleavage at the gingipain specific Arg8-bond was also demonstrated. CONCLUSIONS: The physiological control of cathepsin B activity is impeded in periodontitis, owing to the release of proteinases from infecting P gingivalis and neutrophils, with a contribution to the tissue destruction seen in periodontitis as a probable consequence.

Determination of proteolytic activity: A sensitive and simple assay utilizing substrate adsorbed to a plastic surface and radial diffusion in gel

Abstract A method to determine proteolytic activity using radial diffusion in agar gel in combination with protein adsorbed to a polystyrene surface as substrate is developed. After the agar gel is removed, the effect of enzyme activity is demonstrated by condensation of water vapor on the protein-coated surface. Wettability of the enzyme-affected surface is decreased compared to that of the unaffected protein surface. The method is tested with two enzymes, trypsin and pronase. The sensitivity of the method is on a par with other highly sensitive methods. With bovine serum albumin (BSA) as substrate, the activity in 1 ng of enzyme is detected in a 10 μl test volume. A linear relationship is found between the enzyme-affected surface and the logarithmic value of the enzyme concentration from 0.1 μg/ml to 1 mg/ml. With 5 μg/ml BSA in distilled water, the polystyrene surface is sufficiently coated for use in the assay. The method also permits quantitative protease determination in crude and contaminated samples. This sensitive and simple technique has a high degree of accuracy and reproducibility without several of the disadvantages associated with other types of methods.

Oral Care and Mortality in Older Adults with Pneumonia in Hospitals or Nursing Homes: Systematic Review and Meta‐Analysis

The objectives of the study were to compare the effect of intensified oral care interventions given by dental or nursing personnel on mortality from healthcare‐associated pneumonia (HAP) in elderly adults in hospitals or nursing homes with the effect of usual oral care. Systematic literature searches were conducted in PubMed, the Cochrane Library, and the Health Technology Assessment database of the National Health Service Centre for Reviews and Dissemination (August 2015). Randomized controlled trials (RCTs) were considered for inclusion. Data were extracted and risk of bias was assessed independently and agreed on in consensus meetings. Five RCTs, with some or major study limitations, fulfilled the inclusion criteria. Based on meta‐analyses, oral care interventions given by dental personnel reduced mortality from HAP (risk ratio (RR) = 0.43, 95% confidence interval (CI) = 0.25–0.76, P = .003), whereas oral care interventions given by nursing personnel did not result in a statistically significant difference in mortality from HAP (RR = 1.20, 95% CI = 0.97–1.48, P = .09), in elderly adults in hospitals or nursing homes from usual oral care. Oral care interventions given by dental personnel may reduce mortality from HAP (low certainty of evidence, Grading of Recommendations Assessment, Development and Evaluation (GRADE) ⊕⊕○○), whereas oral care interventions given by nursing personnel probably result in little or no difference from usual care (moderate certainty of evidence, GRADE ⊕⊕⊕○) in elderly adults in hospitals or nursing homes.

Proteins adsorbed to a hydrophobic surface used for determination of proteolytic activity

Abstract Wettability of a thin layer of protein adsorbed to a hydrophobic surface is reduced after proteolytic digestion. Reduced wettability is demonstrated by condensation of water vapour on the surface. The condensation patterns of enzyme-treated and untreated protein layers give different light-scattering properties which can be observed by the naked eye. Based on these principles, a new simple and inexpensive method, thin layer enzyme assay (TEA), for determination of proteolytic activity, was developed. Fibrinogen, gammaglobulin (IgG), bovine serum albumin (BSA), haemoglobin, ovalbumin and gelatin were used as substrates. The proteolytic activity in 1 ng trypsin (EC 3.4.21.4) and in 1 ng pronase (EC 3.4.24.4) was reproducibly detected.

Microflora in oral ecosystems and salivary secretion rates – A 3-year follow-up after radiation therapy to the head and neck region

OBJECTIVE Results indicate that late improvements of radiation therapy (RT) in the head and neck region may diminish the long-term effects on salivary glands and oral microflora. The aim was therefore to analyze salivary secretion rates and oral microflora over time in RT subjects. DESIGN Twelve dentate subjects (28±2 teeth) and 12 controls were included. A clinical examination was performed and the salivary secretion rates were determined. Microbial samples, analyzed using cultivation technique, were collected from the soft tissues, supragingival plaque and gingival crevice region. RESULTS Compared with the controls, the RT group (n=11) had 3 years post RT higher numbers and proportions of lactobacilli (p<0.001 and p<0.01) and Candida albicans (p<0.01 and p<0.05) in the supragingival plaque, higher numbers of enterococci in the vestibulum in the molar region and on the tongue (p<0.05 for both), a lower total count (p<0.001) and lower numbers of streptococci, Streptococcus salivarius and Fusobacterium nucleatum (p<0.01) on the tongue. Although both stimulated and unstimulated salivary secretion rates were increased over time, the proportion of microorganisms associated with oral health decreased, and microorganisms associated with oral disorders increased. Despite a comparable oral hygiene, it was only the 27% who had a stimulated salivary secretion rate ≥1.0ml/min and a buffering capacity ≥6.0, where a recovery of the flora could be seen. CONCLUSION The results indicate that regaining a normal, stimulated salivary secretion rate and buffering capacity are prerequisites to regaining an oral flora associated with good oral health.