Relationship between the ability of oral streptococci to interact with platelet glycoprotein Ibalpha and with the salivary low-molecular-weight mucin, MG2

The oral streptococci Streptococcus sanguinis, Streptococcus gordonii and Streptococcus oralis are common aetiological agents of infective endocarditis, and their ability to adhere to and induce the aggregation of platelets is thought to be a virulence trait. The platelet glycoprotein GPIbalpha has been implicated as the adhesion receptor for S. sanguinis and S. gordonii, but it is not known if this is the case for S. oralis and other species. The aim of this study was to determine the GPIbalpha-interactive capability of a range of oral streptococci and to determine the relationship between this capability and their ability to interact with the salivary constituents that they would encounter in their normal habitat. All platelet-adhesive S. sanguinis strains and most S. gordonii strains adhered in a GPIbalpha-dependent manner, but strains of S. oralis, Streptococcus cristatus, Streptococcus parasanguinis and Streptococcus mitis had no direct affinity for platelets. Those strains that were able to bind GPIbalpha also bound to the low-molecular-weight submandibular salivary mucin, MG2, and this interaction was sialic acid-dependent. The data suggest that S. sanguinis and S. gordonii may be efficient colonizers of platelet vegetations because of their adaptation to recognize sialylated salivary mucins. In contrast, S. oralis does not interact with platelets and so is likely to colonize vegetations through an as yet unidentified mechanism.     

A lacticin 3147 enriched food ingredient reduces Streptococcus mutans isolated from the human oral cavity in saliva

AIMS: To isolate and characterise Streptococcus mutans from Irish saliva samples and to assess their sensitivity to a food-grade preparation of the lantibiotic, lacticin 3147, produced by Lactococcus lactis DPC3147. METHODS AND RESULTS: Saliva samples collected from children with varying oral health status were screened on Mitis Salivarius agar for the presence of pathogenic streptococci. Following selective plating, 16S rDNA sequencing and Pulsed Field Gel Electrophoresis (PFGE), 15 distinct strains of Strep. mutans were identified. These were grouped according to their relative sensitivity to lacticin 3147 which ranged from 0.78 to 6.25%; relative to a sensitive indicator strain, Lactococcus lactis ssp. lactis HP. Inhibition of indicator Strep. mutans strains from sensitive, intermediate and tolerant groupings were assessed in microtitre plate assays with increasing concentrations of lacticin 3147. The concentration of lacticin 3147 required to give 50% growth inhibition correlated with their relative sensitivities (as assayed by well diffusion methodology) and ranged from 1280 to 5120 AU ml(-1). Concentrated preparations of lacticin 3147 caused a rapid killing of Strep. mutans strains in broth. Moreover, in human saliva deliberately spiked with Strep. mutans, the pathogen was eliminated (initial inoculum of 10(5)) in the presence of 40,000 AU ml(-1) of lacticin 3147. Furthermore, a food-grade lacticin 3147 spray dried powder ingredient was assessed for the inhibition of Strep. mutans in human saliva, spiked with a strain of intermediate sensitivity, resulting in up to a 4-log reduction in counts after 20 min. CONCLUSION: A food grade preparation of lacticin 3147 was effective in the inhibition of oral Strep. mutans. SIGNIFICANCE AND IMPACT OF THE STUDY: The inhibition of oral streptococci by food grade preparations of lacticin 3147 may offer novel opportunities for the development of lacticin 3147 as an anti-cariogenic agent particularly in the area of functional foods for the improvement of oral health.     

Principal component analysis and artificial neural network analysis of oral tissue fluorescence spectra: classification of normal premalignant and malignant pathological conditions

Pulsed laser-induced autofluorescence spectroscopic studies of pathologically certified normal, premalignant, and malignant oral tissues were carried out at 325 nm excitation. The spectral analysis and classification for discrimination among normal, premalignant, and malignant conditions were performed using principal component analysis (PCA) and artificial neural network (ANN) separately on the same set of spectral data. In case of PCA, spectral residuals, Mahalanobis distance, and scores of factors were used for discrimination among normal, premalignant, and malignant cases. In ANN, parameters like mean, spectral residual, standard deviation, and total energy were used to train the network. The ANN used in this study is a classical multiplayer feed-forward type with a back-propagation algorithm for the training of the network. The specificity and sensitivity were determined in both classification schemes. In the case of PCA, they are 100 and 92.9%, respectively, whereas for ANN they are 100 and 96.5% for the data set considered.     

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

doi: 10.1111/j.1741‐2358.2011.00562.x
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.     

Relationship between oral impacts on daily performance and chewing ability among independent elders residing in Daejeon City, Korea

doi: 10.1111/j.1741‐2358.2011.00504.x
Relationship between oral impacts on daily performance and chewing ability among independent elders residing in Daejeon City, Korea Objective: The aim of this study was to assess the association between oral health‐related quality of life (OHRQoL) measured by the oral impacts on daily performances (OIDP) inventory and chewing ability. Methods: The cluster sampling method was used to select a sample of 634 socially active independent community‐dwelling elders. An oral examination was conducted and a questionnaire was implemented. After bivariate comparisons, a multivariable two‐level logistic model was developed for the dichotomous OIDP indicator using the generalised linear mixed model. Results: The mean age of the participants was 74 years and 56.6% were women. Eight percent were edentulous, and the mean number of teeth was 17.7. Overall, 39.3% of participants had one or more oral impacts on daily performance. Elders with chewing ability of 0–49, 50–74 and 75–99% were approximately 120, 20 and seven times more likely to have oral impacts compared with those with full chewing ability, respectively. Elders reporting their oral health as ‘fair’ or ‘better’ were 68% less likely to have oral impacts than those with poor or very poor self‐reported oral health. Conclusion: Among independent elders, amelioration of chewing ability including delivery of appropriate prosthodontic care might independently contribute to improving OHRQoL of elders by improving their physical, psychological and social wellbeing.     

Relationship of stimulated whole saliva cortisol level with the severity of a feeling of dry mouth in menopausal women

doi: 10.1111/j.1741‐2358.2010.00403.x Relationship of stimulated whole saliva cortisol level with the severity of a feeling of dry mouth in menopausal women Objectives: To evaluate the relationship of stimulated whole saliva cortisol level with the severity of a feeling of dry mouth (DM) in menopausal women. Background: A feel of DM is a major complaint for many elderly individuals and strongly associated with the menopause. The exact mechanisms that mediate sensation of DM in menopausal women have not been firmly established. Methods: A case–control study was carried out on 104 selected menopausal women with/without a feeling of DM, conducted at the Clinic of Oral Medicine, Tehran University of Medical Sciences. Xerostomia Inventory (XI) score was used as an index of DM severity. Stimulated whole saliva cortisol concentration (stimulated by chewing standard‐sized paraffin for 60 s) was measured by ELISA. Statistical analysis by Student’s t‐test and Spearman correlation was used. Results: The mean cortisol concentration of saliva, but not saliva cortisol output, was significantly higher in the cases than in the controls. There was significant positive correlation between XI score and concentration (r = 0.357, p = 0.000) or output (r = 0.223, p = 0.017) of stimulated whole saliva cortisol. Conclusions: It appears that stimulated whole saliva cortisol is high in menopausal women with a feeling of DM.     

Salivary immunity in elderly individuals presented with Candida-related denture stomatitis

doi: 10.1111/j.1741‐2358.2011.00476.x
Salivary immunity in elderly individuals presented with Candida‐related denture stomatitis Objectives: Elderly individuals with Candida‐related denture stomatitis (DS) present with a reduced defence against Candida albicans. This study evaluated levels of antimicrobial mediators in the elderly DS saliva and salivary neutrophils’ activation characteristics compared with elderly and young without DS. Methods: Salivary peroxidases (SPO) and elastase activities (ELA), nitric oxide (NO), transforming growth factor beta (TGF‐β), IL‐6 and CCL3 production were determined in saliva from elderly with or without DS, and young control individuals. TLR4, CXCR1, CD11b, CD16 and CD32 expression on salivary neutrophils were evaluated. Correlations between number and apoptosis rate of salivary neutrophils, enzymatic activities and cytokine levels were determined. Results: Elderly DS individuals exhibited the lowest SPO and ELA activities. Also, the activity of both enzymes was low in elderly without DS. Although both elderly groups showed higher salivary NO and TGF‐β levels compared to young control groups, elderly DS presented the highest salivary NO, TGF‐β, IL‐6 and CCL3 levels. Decreased percentages of salivary TLR4⁺ and CD16⁺ neutrophils were detected in both elderly groups. Although these damages could influence the establishment and persistence of DS, the highest levels of salivary IL‐6 and CCL3 in elderly DS could be preventing more serious complications.     

Edentulism and dental caries in Victorian nursing homes

doi: 10.1111/j.1741‐2358.2011.00510.x Edentulism and dental caries in Victorian nursing homes Objectives: The aim of this project was to investigate edentulism and dental caries in nursing home residents in Victoria, Australia. Background: The Australian population is ageing with a growing number of people living in nursing homes. These residents are at increased risk for dental caries, have more teeth present now than at any time in the past 50 years and often have difficulty maintaining adequate oral hygiene. Materials and methods: Clinical dental examinations were conducted at 31 nursing homes in Melbourne and regional Victoria between May 2005 and June 2006. A total of 510 residents were examined out of 1345 eligible participants. Socio‐demographic and medical history was collected via questionnaire. Results: Just over half of the residents were dentate (53.9%), and dentate residents had a mean of 14.4 teeth present and 2.66 untreated decayed teeth. Residents who required total assistance with oral hygiene had more decayed teeth and fewer filled teeth than residents who did not require assistance. Conclusions: Nursing home residents in Victoria are retaining an increasing number of natural teeth and have more tooth surfaces at risk for dental caries. Untreated dental caries was a significant problem for residents, particularly for those who are dependent on others for their daily oral hygiene care.     

A 3-year longitudinal study of quality-of-life outcomes of elderly patients with implant- and tooth-supported fixed partial dentures in posterior dental regions

doi: 10.1111/j.1741‐2358.2011.00592.x
A 3‐year longitudinal study of quality‐of‐life outcomes of elderly patients with implant‐ and tooth‐supported fixed partial dentures in posterior dental regions Background: Clinical studies have mainly been focused on oral health‐related quality‐of‐life (OHRQoL) outcomes of removable dentures. Objective: To evaluate therapy of elderly patients with implant‐supported fixed partial dentures (IFPD) and tooth‐supported fixed partial dentures (FPD) in the posterior dental regions. Patients and methods: The OHIP49 was used to measure OHRQoL in 64 patients with IFPD and 38 patients with FPD, before, 3 weeks and 3 years after rehabilitation. A control group (CG) consisted of 62 individuals. Results: The Oral Health Impact Profile questionnaire (OHIP) follow‐up scores of the patients with FPD and the patients with IFPD were significantly smaller in comparison with the baseline scores (p < 0.01). The OHIP scores were further reduced at the 3‐year follow‐up. The patients with IFPD had significantly higher scores than the patients with FPD and the CG at the baseline and at the follow‐ups. In the patients with FPD, both age groups (≤60 and >60) showed equal improvement of the OHRQoL. In the IFPD group, patients older than 60 years showed better improvement (p < 0.05). There were no significant differences dependent on gender and antagonistic teeth (p > 0.05). Conclusion: The FPD and the IFPD treatment showed significant improvement of OHRQoL. The FPD treatment improved OHRQoL equally in both age groups, while the IFPD treatment improved OHRQoL better in older patients.