Inhibitory effect of oral Lactobacillus against oral pathogens

Aims: To determine the inhibitory effect of oral Lactobacillus against putative oral pathogens. Methods and Results: Total 357 strains comprising 10 species of oral Lactobacillus, Lactobacillus fermentum (195), Lactobacillus salivarius (53), Lactobacillus casei (20), Lactobacillus gasseri (18), Lactobacillus rhamnosus (14), Lactobacillus paracasei (12), Lactobacillus mucosae (12), Lactobacillus oris (12), Lactobacillus plantarum (11) and Lactobacillus vaginalis (10) were used as producer strains. Inhibitory effect against a panel of indicators, periodontitis‐ and caries‐related pathogens, was assessed. Most oral Lactobacillus was able to inhibit the growth of both periodontitis‐ and caries‐related pathogens. The strongest inhibitory activity was associated with Lact. paracasei, Lact. plantarum, Lact. rhamnosus, Lact. casei and Lact. salivarius. Lactobacillus SD1–SD6, representing the six species with the strong inhibitory effect, inhibited growth of Streptococcus mutans ATCC 25175 in the biofilm model. Also, it was demonstrated that growth of Strep. mutans was inhibited in a mixture with Lact. paracasei SD1. The inhibition was enhanced in acidic condition and 5% glucose. Conclusions: The results have shown that oral Lactobacillus SD1–SD6 showed a strong inhibitory effect against Strep. mutans and Streptococcus sobrinus, as well as, Gram‐negative periodontal pathogens Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Significance and Impact of the Study: The results indicated that Lactobacillus may be of benefit as probiotics for the prevention of oral diseases.     

The impact of liquid-based oral cytology on the diagnosis of oral squamous dysplasia and carcinoma

OBJECTIVE: Even though diagnostic oral exfoliative cytology is a useful, economical and practical tool in the diagnosis of oral dysplasia and carcinoma, it is not yet extensively used. The results of conventional exfoliative and liquid-based diagnostic cytology in oral potentially malignant lesions (PML) are herein reported and compared with the histological diagnosis. METHODS: Either conventional (89) or liquid-based (384) exfoliative cytology was used for the diagnosis of oral dysplasia/carcinoma in 473 subjects and the results were compared with scalpel biopsy histology. Cells were collected using a Cytobrush device for conventional smears and with a dermatological curette for the liquid-based cytology. The 'curette technique' also allowed for the collection of 'accidental' tissue fragments, utilized as microbiopsies. RESULTS: Histological diagnosis was squamous carcinoma in 96 of 473 cases, high-grade dysplasia (oral intraepithelial neoplasia two to three) in 24 and other lesions in 353 cases. The smears in the conventional cytology group were inadequate in 12.4%, with an 85.7% sensitivity and a 95.9% specificity. There were 8.8% of inadequate specimens in the liquid-based cytology group; sensitivity was 95.1% and specificity was 99.0%. CONCLUSIONS: Although conventional cytology is useful when diagnosing oral PML (better sensitivity and predictive positive value if compared with the cervical smear test with similar specificity) and can improve the accuracy of histological diagnosis, liquid-based cytology gives better results, as it not only enhances both sensitivity and specificity, but also provides material for further investigation (AgNORs, DNA, microbiopsies, etc.).     

Cytometric analysis of oral scrapings of patients with oral lichen planus

A. Acha‐Sagredo, Y. Jiménez, J. V. Bagán, M. A. Echebarria‐Goicouria and J. M. Aguirre‐Utric analysis of oral scrapings of patients with oral lichen planus Objective: Aneuploidy has been associated with malignant and premalignant oral lesions. In the past few years, its application in oral precancerous lesions and its prognostic meaning have been controversial issues. The aim of our study was to characterize alterations in DNA content by automated DNA image cytometry in oral scrapings of patients with oral lichen planus. Methods: Cytological samples from 40 patients clinicopathologically diagnosed with oral lichen planus were analysed by DNA image cytometry. Results: All the cases were classified as diploid, showing a predominant population of cells with normal DNA content (DNA index, 0.85–1.15). Atrophic/erosive lesions showed a higher percentage of tetraploid cells when compared with reticular/papular lesions but this was not statistically significant (P = 0.09). Conclusions: Aneuploidy does not seem a common event in oral lichen planus lesions. However, we consider that the use of DNA image cytometry of oral scrapings may be an easy and helpful methodology in the follow‐up of patients with these lesions.     

A novel murine model of oral candidiasis with local symptoms characteristic of oral thrush

A conventional and easy method to establish a murine oral candidiasis model, which has not only a stable yeast population in the oral cavity but also symptoms characteristic of oral thrush, was developed by using a sedative agent. Mice were immunosuppressed with prednisolone and were given tetracycline hydrochloride. They were orally infected with 10(6) viable cells of Candida albicans by means of a cotton swab and enough chlorpromazine chloride had been injected to keep them in a sedative state about for 3 hr after inoculation. From day 3 to day 7 post inoculation, 10(5)-10(6) colony forming units of Candida were recovered from the oral cavity of each mouse and whitish, curd-like patches were observed on most parts of tongue. Microscopically, germ tubes had appeared on the tongue surface. This model would be a useful experimental oral candidiasis for investigating the pathogenesis of C. albicans oral infection and the efficacy of various antifungal agents microbiologically and symptomatically.     

基于微流控的生物被膜研究进展及口腔微生态系统应用展望

口腔是人体最重要的微生物储藏库之一,这些微生物通常以生物被膜的形式稳定地黏附于口腔内粘膜及牙齿表面,在病理条件下则可以深入髓腔及牙槽骨内,成为龋病、根尖周炎、牙周病等常见口腔疾病的主要病因,甚至与许多全身性疾病密切相关.在人类口腔微生态系统中,微生物种类繁多,生物被膜的构成及相互作用关系复杂,目前对其认识还十分有限;此...     

A novel rapid oral bacteria detection apparatus for effective oral care to prevent pneumonia

doi: 10.1111/j.1741‐2358.2011.00517.x A novel rapid oral bacteria detection apparatus for effective oral care to prevent pneumonia Objective: To clarify the oral environment, we evaluated the usefulness and clinical applicability of a new apparatus developed for the simple and rapid quantification of oral bacteria. Background: Professional oral health care can reduce the number of oral bacteria and days of fever and inhibit the development of pneumonia. A novel detection apparatus was developed by applying the dielectrophoretic impedance measurement method. Methods: First, to determine the accuracy of this apparatus, employing standard samples of Escherichia coli. Next, to evaluate the oral environment, samples were taken from the tongue in elderly (mean age: 86.6 years) in nursing home. Results: In the first study, a good correlation was observed between the two methods (R = 0.999). In the second study, there were significant correlations between measurement values obtained using this apparatus and those obtained by the culture method (R = 0.852), as well as those obtained by the FM method (R = 0.885). Conclusion: Our data showed that this rapid oral bacterial detection apparatus is effective in evaluating the oral hygiene to prevent pneumonia in the elderly.     

A histochemical comparison of methyl green-pyronin,and hematoxylin and eosin for detecting apoptotic cells in oral squamous cell carcinoma,oral leukoplakia,oral submucous fibrosis and normal oral mucosa

Abstract

Analysis of apoptotic cells in oral pathological states could be useful for determining the rates of tissue turnover, which would help determine prognosis. The use of histochemical stains such as hematoxylin and eosin (H & E) and methyl green-pyronin (MGP) can provide a simple and cost-effective method for detecting apoptotic cells. We compared the efficacy of MGP and H & E for detecting apoptotic cells in oral squamous cell carcinoma (OSCC), oral leukoplakia (OL), oral submucous fibrosis (OSMF) and normal oral mucosa (NOM). Ten cases each of OSCC, OSMF, OL and NOM were retrieved from the archives and two serial sections were stained, one with H & E and the other with MGP. Apoptotic cells were identified at 100 x magnification and the apoptotic index was calculated. Apoptotic cells were distinguished more readily in MGP stained sections than in those stained with H & E. Also, the apoptotic cell count was greater in OSCC compared to OL, OSMF and NOM. We concluded that MGP staining can be used as a routine, cost-effective method for detecting apoptotic cells.     

益生菌与口腔微生态调控的研究进展

口腔疾病的发生和发展与口腔微生物群落的失衡密切相关。益生菌是一类对人体健康有益的活的微生物,主要通过分泌抗菌物质、与致病菌竞争性定殖、调节毒力相关基因表达、调节宿主免疫反应、调节氧化应激反应、参与硝酸盐—亚硝酸盐—一氧化氮代谢循环通路、调整生物膜pH值等过程发挥其益生效能。研究发现,益生菌疗法能够降低龋齿的风险、改善牙周状况、提高口腔黏膜病的治疗效果,有望成为防治口腔疾病的潜在途径。本文就近年来益生菌与口腔微生态调控相关的研究情况做一综述。     

宏基因组学及其在口腔微生物研究中的应用

宏基因组是指环境中所有微生物的遗传物质总和。宏基因组学技术可以最大限度地利用环境中的微生物资源,受到了国内外微生物研究者的重点关注。口腔中寄居着大量的微生物群落,以往对口腔疾病微生物的研究大多局限于单纯的细菌培养技术,然而,由于培养技术的局限性,部分微生物很难或根本不能培养,宏基因组学技术打破了这一局限性,帮助人类发掘更丰富的口腔微生物资源。最近,以宏基因组学测序为基础的研究描绘出了口腔生态系统的图谱,越来越多的实验证明口腔微生物组在各种口腔疾病甚至全身系统性疾病中的重要作用。同时,这也为基于人类微生物组的诊断和治疗开辟了新的途径。本综述旨在说明宏基因组学是研究人类口腔疾病及全身疾病相关微生物的得力工具,而且具有广阔的发展前景,同时也讨论了宏基因组学在应用中有待克服的局限性。     

Biorhythms and tests of oral skills

The null hypothesis that there is no difference in an individuaľs level of skill on critical and non-critical days of the biorhythm cycle is tested over a 2-week period using oral stereognosis and a dysarthria assessment. No statistical evidence could be found to refute the null hypothesis proposed and it is concluded that there is no relationship between oral skills and stages of the biorhythm cycle.     

A review of the effectiveness of oral health promotion activities among elderly people

Objectives: This study aimed to review the effectiveness of oral health promotion studies conducted among elderly people between 1997 and 2007. Methods: Four electronic databases were searched and papers were rated for level of evidence and scientific quality. Key findings of the papers were summarised. Results: Thirteen thousand nine hundred and four papers were retrieved and 17 studies (18 papers) met the criteria for the review: 13 were randomised controlled studies, three were quasi‐experimental studies and one was a pre‐/post‐single group intervention study. According to the Levels of Evidence, 11 studies could be categorised as 1b and six studies could be categorised as 2b. The quality of the evidence of the 17 studies ranged from 12 to 19; 13 of the studies had a score of 15 or above; four of the studies ranged from 12 to 14. Evidence from oral health promotion activities aimed at preventing caries, improving periodontal health and altering oral health behaviours were reviewed. The use of fluoride, antimicrobial agents and health‐care provider education has important roles within oral health promotion activities for elderly people. Studies have tended to be of short‐term duration and rely on surrogate outcome measures of oral health. Conclusion: In the last 10 years, increasing attention has been paid to oral health promotion activities among the elderly population and high quality evidence has emerged. However, there is a need for even higher‐quality research to provide more definitive guidelines on oral health promotion practices for elderly people.     

Alzheimer's disease,oral function and nutritional status

Objectives: To study differences in nutritional, dental status and oral function between institutionalised patients with Alzheimer's disease and cognitively healthy elderly people living in the community. Design: Comparison was made between two groups, Alzheimer's disease sufferers and healthy controls, using established criteria for anthropometric, mental and dental state. Setting: An institution and residential area in Stockholm, Sweden. Subjects: Forty patients with Alzheimer's disease living in a nursing home and 40 age-and gender-matched control subjects living independently. Intervention: Dental status and anthropometric variables. Results: Overnutrition was less frequent among the demented than the controls and more demented were undernourished. Dental status was similar in the two groups with few edentulous subjects but only 2 of 7 edentulous subjects with Alzheimer's disease wore dentures. Having natural teeth and many functional oral zones is important for food consistency choice, but not for nutritional status. In the Alzheimer group, the stage of dementia has a strong association to the ability to eat unaided and an association with dental status. Conclusion: There are differences in nutritional status between Alzheimer's patients in institutions and cognitively healthy elderly living at home. The choice of food consistency is correlated to dental status but nutritional status is not shown to be influenced by dental status. However, the ability to eat unaided is strongly correlated to cognitive status.     

Alzheimer's disease,oral function and nutritional status

Objectives: To study differences in nutritional, dental status and oral function between institutionalised patients with Alzheimer's disease and cognitively healthy elderly people living in the community. Design: Comparison was made between two groups, Alzheimer's disease sufferers and healthy controls, using established criteria for anthropometric, mental and dental state. Setting: An institution and residential area in Stockholm, Sweden. Subjects: Forty patients with Alzheimer's disease living in a nursing home and 40 age-and gender-matched control subjects living independently. Intervention: Dental status and anthropometric variables. Results: Overnutrition was less frequent among the demented than the controls and more demented were undernourished. Dental status was similar in the two groups with few edentulous subjects but only 2 of 7 edentulous subjects with Alzheimer's disease wore dentures. Having natural teeth and many functional oral zones is important for food consistency choice, but not for nutritional status. In the Alzheimer group, the stage of dementia has a strong association to the ability to eat unaided and an association with dental status. Conclusion: There are differences in nutritional status between Alzheimer patients in institutions and cognitively healthy elderly living at home. The choice of food consistency is correlated to dental status but nutritional status is not shown to be influenced by dental status. However, the ability to eat unaided is strongly correlated to cognitive status.