Exploring the presence of oral bacteria in non-oral sites of patients with cardiovascular diseases using whole metagenomic data.

Cardiovascular diseases (CVDs) encompass various conditions affecting the heart and its blood vessels and are often linked with oral microbes. Our data analysis aimed to identify oral bacteria from other non-oral sites (i.e., gut, arterial plaque and cultured blood) that could be linked with CVDs. Taxonomic profiling identified bacteria to the species level and compared with the Human Oral Microbiome Database (HOMD). The oral bacteria in the gut, cultured blood and arterial plaque samples were catalogued, with their average frequency calculated for each sample. Additionally, data were filtered by comparison with the Human Microbiome Project (HMP) database. We identified 17,243 microbial species, of which 410 were present in the HOMD database and further denominated as "oral", and were found in at least one gut sample, but only 221 and 169 species were identified in the cultured blood and plaque samples, respectively. Of the 410 species, 153 were present solely in oral-associated environments after comparison with the HMP database, irrespective of their presence in other body sites. Our results suggest a potential connection between the presence of specific species of oral bacterial and occurrence of CVDs. Detecting these oral bacterial species in non-oral sites of patients with CVDs could help uncover the link between oral health and general health, including cardiovascular conditions via bacterial translocation.

Oral health literacy, knowledge and perceptions in a socially and culturally diverse population: a mixed methods study.

BACKGROUND: Poor oral health literacy has been proposed as a causal factor in disparities in oral health outcomes. This study aims to investigate oral health literacy (OHL) in a socially and culturally diverse population of Australian adults visiting a public dental clinic in Western Sydney. METHODS: A mixed methods study where oral health literacy was assessed using the Health Literacy in Dentistry scale (HeLD-14) questionnaire and semi-structured interviews explored oral health related knowledge, perceptions and attitudes. Interviews were analysed using a thematic approach. RESULTS: A sample of 48 participants attending a public dental clinic in Western Sydney was recruited, with a mean age of 59.9 (SD16.2) years, 48% female, 50% born in Australia, 45% with high school or lower education, and 56% with low-medium OHL. A subgroup of 21 participants with a mean age of 68.1 (SD14.6) years, 40% female, 64% born in Australia, 56% with a high school or lower education, and 45% with low-medium OHL completed the interview. Three themes identified from the interviews included 1) attitudes and perceptions about oral health that highlighted a lack of agency and low prioritisation of oral health, 2) limited knowledge and education about the causes and consequences of poor oral health, including limited access to oral health education and finally 3) barriers and enablers to maintaining good oral health, with financial barriers being the main contributor to low OHL. CONCLUSIONS: Strategies aimed at redressing disparities in oral health status should include improving access to oral health information. The focus should be on the impact poor oral health has on general health with clear messages about prevention and treatment options in order to empower individuals to better manage their oral health.

Oral health status and risk of incident diabetes: A prospective cohort study of 213,389 individuals aged 45 and over.

AIMS: To examine whether simple measures of oral health are associated with incident diabetes. METHODS: This prospective cohort study linked data from the 45 and Up Study, Australia, to administrative health records. The study participants were 213,389 men and women, aged ≥45 years, with no diabetes at baseline. The oral health of participants was assessed by questionnaire. Incident diabetes cases were ascertained based on self-report in follow-up questionnaires, linked data on medical and pharmaceutical claims, and hospitalisation data up until 2019. The association between oral health and incident diabetes were calculated using multivariable cox proportional hazards models. RESULTS: During 2,232,215 person-years of follow-up, 20,487 (9.6%) participants developed diabetes. Compared with those with ≥20 teeth, the adjusted hazard ratio (aHR) for incident diabetes was 1.12 (95% Confidence Interval (CI): 1.08, 1.17) for 10-19 teeth, 1.20 (1.14, 1.26) for 1-9 teeth and 1.15 (1.09, 1.21) for no teeth. Compared with those with excellent/very good teeth and gums, the aHR for incident diabetes was 1.07 (1.03, 1.12) for fair and 1.13 (1.07, 1.20) for poor teeth and gums. CONCLUSIONS: Simple measures of oral health were associated with risk of developing diabetes, demonstrating the potential importance of oral health screening for diabetes prevention.

Role of prebiotic dietary fiber in periodontal disease: A systematic review of animal studies.

Background: Periodontitis is a chronic inflammatory condition affecting the supporting structures of a tooth in the oral cavity. The relationship between dietary fiber and periodontitis is poorly understood. The objective of this systematic review is to investigate if an intake of dietary fiber modulates periodontal disease in animal models and any concomitant effects on systemic inflammation, microbiota and their metabolites. Methods: Animal studies using periodontitis models with any form of fiber intervention were included. Studies with comorbidities that were mutually inclusive with periodontitis and animals with physiological conditions were excluded. Search strategy with MeSH and free-text search terms were finalized and performed on the 22nd of September 2021.CINAHL Complete, EMBASE, MEDLINE, SciVerse Scopus® and Web of Science Core Collection databases were used to identify studies. SYRCLE's risk of bias tool and CAMARADES were used for quality assessment. Results were synthesized utilizing Covidence© web-based platform software to remove duplicates, and the remaining studies were manually filtered. Results: A total of 7,141 articles were retrieved from all databases. Out of 24 full-text articles assessed for eligibility, four studies (n = 4) were included. Four studies involved the use of ß-(1,3/1,6)-glucan (n = 3) and mannan oligosaccharide (n = 1) at differing dosages for different study durations. All studies utilized a ligature-induced model of periodontitis in rats, either Wistar (n = 3) or Sprague-Dawley (n = 1). A dose-dependent relationship between the increased fiber intake and decrease in alveolar bone loss and pro-inflammatory markers was observed. Conclusion: The number of included studies is limited and narrow in scope. They highlight the importance of pre-clinical trials in this field with broader dietary fiber intervention groups before proceeding to clinical trials. The use of dietary fiber as an intervention shows promise in the reduction of inflammatory conditions like periodontitis. However, further research is required to delineate the relationship between diet and its effects on microbiota and their metabolites such as short chain fatty acids in animal models of periodontitis.

Targeting the reduction of inflammatory risk associated with cardiovascular disease by treating periodontitis either alone or in combination with a systemic anti-inflammatory agent: protocol for a pilot, parallel group, randomised controlled trial.

INTRODUCTION: Cardiovascular disease (CVD) is associated with systemic inflammation. Colchicine, an anti-inflammatory drug, reduces the incidence of CVD events. Periodontitis, a chronic localised inflammatory disease of the tissues supporting the teeth, triggers systemic inflammation and contributes to inflammatory risk. Treatment for periodontitis reduces markers of inflammation, however, there is no evidence on whether an anti-inflammatory medication in combination with periodontal treatment can reduce the inflammatory risk. The aim of this trial is to investigate the effect of periodontal treatment either alone or in combination with an anti-inflammatory agent on inflammation in patients with periodontitis and CVD at 8 weeks. METHODS AND ANALYSIS: 60 participants with moderate-to-severe periodontitis, coronary artery disease and an increased inflammatory risk (>2 mg/L high sensitivity C reactive protein (hsCRP) levels) will be recruited from a tertiary referral hospital in Australia in a parallel design, single blind, randomised controlled trial. Baseline hsCRP levels, lipid profile and periodontal assessment will be completed for each participant before they are randomised in a 1:1:1:1 ratio to one of 4 arms as follows: (group A) periodontal treatment and colchicine; (group B) periodontal treatment only; (group C) colchicine only or (group D) control/delayed periodontal treatment. Periodontal treatment will be provided over three treatment visits, 0.5 mg of colchicine will be provided as a daily tablet. Participants will be followed up at 8 weeks to measure primary and secondary outcomes and complete a follow-up questionnaire. The primary outcome is the difference in hsCRP levels, the secondary outcomes are differences in lipid levels and periodontal parameters and the feasibility measures of recruitment conversion rate, completion rate and the safety and tolerability of the trial. ETHICS AND DISSEMINATION: The study has been approved by the Western Sydney Local Health District Human Ethics Committee (protocol number 2019/ETH00200). Results will be published in peer-reviewed journals and presented at conferences. TRIAL REGISTRATION NUMBER: ACTRN12619001573145.

Protein Intake and Oral Health in Older Adults-A Narrative Review.

Oral health is vital to general health and well-being for all ages, and as with other chronic conditions, oral health problems increase with age. There is a bi-directional link between nutrition and oral health, in that nutrition affects the health of oral tissues and saliva, and the health of the mouth may affect the foods consumed. Evidence suggests that a healthy diet generally has a positive impact on oral health in older adults. Although studies examining the direct link between oral health and protein intake in older adults are limited, some have explored the relationship via malnutrition, which is also prevalent among older adults. Protein-energy malnutrition (PEM) may be associated with poor oral health, dental caries, enamel hypoplasia, and salivary gland atrophy. This narrative review presents the theoretical evidence on the impact of dietary protein and amino acid composition on oral health, and their combined impact on overall health in older adults.

Periodontitis and Preeclampsia in Pregnancy: A Systematic Review and Meta-Analysis.

OBJECTIVES: A conflicting body of evidence suggests localized periodontal inflammation spreads systemically during pregnancy inducing adverse pregnancy outcomes. This systematic review and meta-analysis aim to specifically evaluate the relationship between periodontitis and preeclampsia. METHODS: Electronic searches were carried out in Medline, Pubmed, Embase, Lilacs, Cochrane Controlled Clinical Trial Register, CINAHL, ClinicalTrials.gov, and Google Scholar with no restrictions on the year of publication. We identified and selected observational case-control and cohort studies that analyzed the association between periodontal disease and preeclampsia. This meta-analysis was conducted following the PRISMA checklist and MOOSE checklist. Pooled odds ratios, mean difference, and 95% confidence intervals were calculated using the random effect model. Heterogeneity was tested with Cochran's Q statistic. RESULTS: Thirty studies including six cohort- and twenty-four case-control studies were selected. Periodontitis was significantly associated with increased risk for preeclampsia (OR 3.18, 95% CI 2.26 - 4.48, p < 0.00001), especially in a subgroup analysis including cohort studies (OR 4.19, 95% CI 2.23 - 7.87, p < 0.00001). The association was even stronger in a subgroup analysis with lower-middle-income countries (OR 6.70, 95% CI 2.61 - 17.19, p < 0.0001). CONCLUSIONS: Periodontitis appears as a significant risk factor for preeclampsia, which might be even more pronounced in lower-middle-income countries. Future studies to investigate if maternal amelioration of periodontitis prevents preeclampsia might be warranted.

Encounters and management of oral conditions at general medical practices in Australia.

BACKGROUND: Poor oral health has been widely recognised as an ongoing public health issue. Patients with oral conditions may visit either a general practitioner (GP) or a dental practitioner for management. The aims of this study are to report (i) the GP management rate of oral health conditions by patient and GP demographics, (ii) what specific oral conditions were managed, and (iii) how GPs managed oral conditions. METHODS: Data from the Bettering the Evaluation and Care of Health study (2006 to 2016 inclusive) were analysed. Descriptive statistics with 95% confidence intervals around point estimates were used to summarise data. Multivariate logistic regression was performed to determine the independent effect of patient and GP characteristics. RESULTS: A total of 972,100 GP encounters were included in the dataset, with oral condition-related encounters managed at a rate of 1.19 oral conditions per 100 GP encounters. Patients who were aged 54 years or younger, resided in a socioeconomically disadvantaged area, came from a non-English speaking background or Indigenous background were more likely to have oral conditions managed by GPs. The most commonly reported oral conditions were dental and oral mucosa-related. Over 60% of oral conditions were managed by GPs through prescribed medications. CONCLUSIONS: This study provided an overview of management of oral conditions by GPs in Australia. Patients from certain vulnerable demographic groups were more likely to attend a GP for management of oral conditions. Common oral conditions and management approaches were identified. The findings of this study contribute to public health and health policy discussions around optimising primary care provision in oral health.

THE CONSISTENT DETECTION OF ORAL BACTERIA IN ATHEROSCLEROTIC PLAQUE DOES NOT QUALIFY FOR DENTAL TREATMENT TO REDUCE CARDIOVASCULAR RISK.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Joshi, Chaitanya; Bapat, Ranjeet; Anderson, William; Joshi, Chaitanya; Bapat, Ranjeet; Anderson, William; Dawson, Dana; Hijazi, Karolin; Cherukara, George (2021). "Detection of periodontal microorganisms in coronary atheromatous plaque specimens of myocardial infarction patients: A systematic review and meta-analysis." Trends in Cardiovascular Medicine 31(1): 69-82. SOURCE OF FUNDING: None. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis of data.

WITHDRAWN: The consistent detection of oral bacteria in atherosclerotic plaque does not qualify for dental treatment to reduce cardiovascular risk.

The Publisher regrets that this article is an accidental duplication of an article that has already been published in The Journal of Evidence-Based Dental Practice, 22/2, 101718, http://dx.doi.org/10.1016/j.jebdp.2022.101718. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Are Inflamed Periodontal Tissues Endogenous Source of Advanced Glycation End-Products (AGEs) in Individuals with and without Diabetes Mellitus? A Systematic Review.

Advanced glycation end-products (AGEs) are heterogeneous compounds formed when excess sugars condense with the amino groups of nucleic acids and proteins. Increased AGEs are associated with insulin resistance and poor glycemic control. Recently, inflamed periodontal tissues and certain oral bacteria were observed to increase the local and systemic AGE levels in both normoglycemic and hyperglycemic individuals. Although hyperglycemia induced AGE and its effect on the periodontal tissues is known, periodontitis as an endogenous source of AGE formation is not well explored. Hence, this systematic review is aimed to explore, for the first time, whether inflamed periodontal tissues and periodontal pathogens have the capacity to modulate AGE levels in individuals with or without T2DM and how this affects the glycemic load. Six electronic databases were searched using the following keywords: (Periodontitis OR Periodontal disease OR Periodontal Inflammation) AND (Diabetes mellitus OR Hyperglycemia OR Insulin resistance) AND Advanced glycation end products. The results yielded 1140 articles, of which 13 articles were included for the review. The results showed that the mean AGE levels in gingival crevicular fluid was higher in individuals with diabetes mellitus and periodontitis (521.9 pg/mL) compared to healthy individuals with periodontitis (234.84 pg/mL). The serum AGE levels in normoglycemic subjects having periodontitis was higher compared to those without periodontitis (15.91 ng/mL vs. 6.60 ng/mL). Tannerella forsythia, a common gram-negative anaerobe periodontal pathogen in the oral biofilm, was observed to produce methylglyoxal (precursor of AGE) in the gingival tissues. Increased AGE deposition and activate of AGE receptors was noted in the presence of periodontitis in both normoglycemic and hyperglycemic individuals. Hence, it can be concluded that periodontitis can modulate the local and systemic levels of AGE levels even in absence of hyperglycemia. This explains the bidirectional relationship between periodontitis and development of prediabetes, incident diabetes, poor glycemic control, and insulin resistance.

Mass media campaigns for the promotion of oral health: a scoping review.

BACKGROUND: Oral diseases are highly prevalent globally and are largely preventable. Individual and group-based education strategies have been dominant in oral health promotion efforts. Population-wide mass media campaigns have a potentially valuable role in improving oral health behaviours and related determinants. This review synthesises evidence from evaluations of these campaigns. METHODS: A systematic search of major databases was undertaken to identify peer-reviewed articles reporting the evaluation of mass reach (non-interpersonal) communication strategies to address common forms of oral disease (i.e., dental caries, periodontitis, gingivitis). Studies using all types of quantitative design, published in English between 1970 and 2020 were included. Data concerning campaign objectives, content, evaluation methods and findings were extracted. RESULTS: Eighteen studies were included from the 499 identified through searching, reporting the findings of 11 campaign evaluations. Two of these used controlled quasi-experimental designs, with the remainder using pre- and post-test (N = 5) or post-test only designs (N = 4). Message recall, as a measure of exposure, was reported in eight campaigns with short-term (≤ 8 weeks) recall ranging from 30 to 97%. Eight studies examined impacts upon oral health knowledge, with four of the five measuring this at baseline and follow-up reporting improvements. From the eight studies measuring oral health behaviours or use of preventative services, six that compared baseline and follow-up reported improvements (N = 2 in children, N = 4 in adults). CONCLUSION: There are relatively few studies reporting the evaluation of mass media campaigns to promote oral health at the population level. Further, there is limited application of best-practice methods in campaign development, implementation and evaluation in this field. The available findings indicate promise in terms of achieving campaign recall and short-term improvements in oral health knowledge and behaviours.

Oral health and cardiometabolic disease: understanding the relationship.

Examination of the oral cavity can identify clinical signs indicative of underlying systemic disease. Key features to examine include the general appearance and number of the teeth, signs of inflammation of the mucosa or gingival tissues including bleeding of the gums and redness, swelling or hyperplasia. Additionally, the tongue should be assessed for any ulceration or discolouration and the presence of excessive build-up (coating). Cardiovascular disease and diabetes, together known as cardiometabolic disease have an impact on oral health. Similarly, oral health conditions, such as gum disease (periodontitis) and dryness of the mouth (xerostomia), are associated with an increased risk for both cardiovascular disease and type 2 diabetes mellitus. The aim of this narrative review is to outline both the impact of periodontitis and xerostomia on cardiometabolic disease and the impact of cardiometabolic health on these oral health conditions. Key features of periodontitis and xerostomia will be provided along with a brief discussion of current concepts in early prevention and management of these oral health conditions. The biological mechanisms linking cardiometabolic disease and periodontitis will be outlined and the evidence supporting the association between cardiometabolic disease and oral health conditions will be presented together with an identification of areas where further research is indicated. Last, guidance for general practitioners to assess and support early diagnosis and management of oral health conditions by raising awareness of the relationship between oral health and cardiometabolic disease, providing simple oral health advice and referring to a dental practitioner will be presented.

A randomized clinical trial to investigate the effect of dietary protein sources on periodontal health.

AIM: The aim was to assess two macronutrient interventions in a 2 × 2 factorial dietary design to determine their effects on oral health. MATERIALS AND METHODS: Participants (65-75 years old) with a body mass index between 20 and 35 kg/m2 of a larger randomized control trial who consented to an oral health assessment were recruited. They had ad libitum access to one of four experimental diets (omnivorous higher fat or higher carbohydrate, semi-vegetarian higher fat or higher carbohydrate) for 4 weeks. The periodontal examination included periodontal probing depth (PPD), clinical attachment level (CAL), and bleeding on probing. Oral plaque and gingival crevicular fluid (GCF) were collected before and after the intervention. RESULTS: Between baseline and follow up, the number of sites with a CAL <5 mm (mean difference [MD] -5.11 ± 9.68, p = .039) increased and the GCF amount (MD -23.42 ± 39.42 Periotron Units [PU], p = .050) decreased for the semi-vegetarian high-fat diet. For the mean proportion of sites with PPD reduction of >1 mm and CAL gain of >1 mm, significant differences were calculated between the diets investigated. The clinical parameters were not associated with changes in the oral microbiota. CONCLUSIONS: The results of this study provided evidence that a semi-vegetarian high-fat diet provides benefits to clinical parameters of periodontal health. This study is registered in ClinicalTrials.gov (ACTRN12616001606471).

Macronutrient-induced modulation of periodontitis in rodents-a systematic review.

CONTEXT: Consumption of dietary macronutrients is associated with the progression of a wide range of inflammatory diseases, either by direct modulation of host immune response or via microbiome. This includes periodontitis, a disease affecting tooth-supporting tissues. OBJECTIVE: The aim of this work was to systematically review studies focusing on the effect of macronutrient (ie, carbohydrate, protein, fat) intake on periodontitis in rodents. DATA SOURCES: Electronic searches were performed in February 2021 using the PubMed and Web of Science databases. Out of 883 articles reviewed, 23 studies were selected for additional analysis. DATA EXTRACTION: Investigators extracted relevant data, including author names; the year of publication; article title; macronutrient composition; number and species of animals and their age at the start of the experiment; intervention period; method of periodontitis induction; and primary and secondary periodontitis outcomes. Quality assessment was done using the risk-of-bias tool for animal studies. After completing the data extraction, descriptive statistical information was obtained. DATA ANALYSIS: High intakes of dietary cholesterol, saturated fatty acids, and processed carbohydrates such as sucrose, and protein-deficient diets were positively associated with periodontitis in rodents. This included greater amounts of alveolar bone loss, more lesions on periodontal tissues, and dental plaque accumulation. In contrast, high doses of milk basic protein in diets and diets with a high ratio of ω-3 to ω-6 fatty acids were negatively associated with periodontitis in rodents. CONCLUSION: This work highlights the fact that, despite the large body of evidence linking macronutrients with inflammation and ageing, overall there is little information on how dietary nutrients affect periodontitis in animal models. In addition, there is inconsistency in data due to differences in methodology, outcome measurement, and dietary formulation. More studies are needed to examine the effects of different dietary macronutrients on periodontitis and investigate the underlying biological mechanisms.

Role of PDGF-A/B Ligands in Cardiac Repair After Myocardial Infarction.

Platelet-derived growth factors (PDGFs) are powerful inducers of cellular mitosis, migration, angiogenesis, and matrix modulation that play pivotal roles in the development, homeostasis, and healing of cardiac tissues. PDGFs are key signaling molecules and important drug targets in the treatment of cardiovascular disease as multiple researchers have shown that delivery of recombinant PDGF ligands during or after myocardial infarction can reduce mortality and improve cardiac function in both rodents and porcine models. The mechanism involved cannot be easily elucidated due to the complexity of PDGF regulatory activities, crosstalk with other protein tyrosine kinase activators, and diversity of the pathological milieu. This review outlines the possible roles of PDGF ligands A and B in the healing of cardiac tissues including reduced cell death, improved vascularization, and improved extracellular matrix remodeling to improve cardiac architecture and function after acute myocardial injury. This review may highlight the use of recombinant PDGF-A and PDGF-B as a potential therapeutic modality in the treatment of cardiac injury.

The Impact of Carbohydrate Quality on Dental Plaque pH: Does the Glycemic Index of Starchy Foods Matter for Dental Health?

Sugary carbohydrate foods have long been associated with increased risk of dental caries formation, but the dental health impact of starchy carbohydrates, particularly those with a high glycemic index (GI), has not been well examined. AIM: To investigate the effect of different starchy foods varying in their GI, on acute changes in dental plaque pH. METHODS: In a series of sub-studies in healthy adults, common starchy carbohydrate foods, including white bread, instant mashed potatoes, canned chickpeas, pasta, breakfast cereals, white rice, and an oral glucose solution were consumed in fixed 25 g available carbohydrate portions. The change in dental plaque pH was assessed postprandially over 1 h and capillary plasma glucose was measured at regular intervals over 2 h. RESULTS: Higher GI starchy foods produced greater acute plaque pH decreases and larger overall postprandial glucose responses compared to lower GI starchy foods (white bread compared with canned chickpeas: -1.5 vs. -0.7 pH units, p = 0.001, and 99 ± 8 mmol/L min vs. 47 ± 7 mmol/L min, p = 0.026). Controlling for other food factors (food form and nutritional composition), lower GI versions of matched food pairs produced smaller plaque pH excursions compared to higher GI versions of the same food. Using linear regression analysis, the GI value of starchy carbohydrate foods explained 60% of the variation in maximum plaque pH nadir and 64% of the variation in overall acute dental plaque pH excursion (p < 0.01). CONCLUSION: The findings imply that starchy foods, in particular those with a higher GI, may play a role in increasing the risk of dental caries.

Periodontitis induces endothelial dysfunction in mice.

The treatment of periodontitis has numerous positive effects on established chronic health conditions, including cardiovascular disease and diabetes. However, ethical considerations do limit the establishment of human trials to investigate whether periodontitis promotes the early stages of chronic conditions. Therefore, the aim of this study was to investigate whether periodontitis induces endothelial dysfunction in hyperlipidemic apolipoprotein E gene-deficient (ApoE-/-) mice. Forty-five 8-week-old ApoE-/- mice were challenged by oral lavage with Porphyromonas gingivalis and Streptococcus gordonii for 4 weeks. A subgroup of animals (n = 15-17/group) was placed in a metabolic chamber immediately before euthanasia at 4 weeks to measure VO2/CO2 concentrations and voluntary locomotion. In infected and control animals alveolar bone levels were measured by x-ray imaging and endothelial function was determined by measuring endothelial-dependent vasorelaxation of aortic rings. The mRNA expression levels of serum amyloid A and tumor necrosis factor were determined in liver tissues by qRT PCR and protein concentrations in serum by ELISA. Caecal contents were analysed by sequencing to determine changes to the gut microbiota to investigate linkages between microbiome and systemic changes. The results showed that oral lavage of P. gingivalis and S. gordonii for 4 weeks, initiated periodontitis in ApoE-/- mice, similar to the human situation. The oral inflammation was accompanied by a significant increase in mRNA expression of pro-inflammatory mediators serum amyloid A1 and tumor necrosis factor in the liver. Mice with periodontitis also exhibited impaired endothelial-dependent vasorelaxation responses to acetylcholine. This systemic response was connected to increased energy expenditure, locomotion and respiratory quotient. No differences were detected in caecal microbiota between the infected and control animals. Overall, this is the first report that provide evidence that periodontitis induces endothelial dysfunction in mice. Other systemic responses observed in response to the local reaction need further investigation. The study suggests that early prevention of periodontitis may help limit the early stages of endothelial dysfunction that is linked to atherogenesis in humans.

Evaluation of biofilm colonization on multi-part dental implants in a rat model.

BACKGROUND: Peri-implant mucositis and peri-implantitis are highly prevalent biofilm-associated diseases affecting the tissues surrounding dental implants. As antibiotic treatment is ineffective to fully cure biofilm mediated infections, antimicrobial modifications of implants to reduce or prevent bacterial colonization are called for. Preclinical in vivo evaluation of the functionality of new or modified implant materials concerning bacterial colonization and peri-implant health is needed to allow progress in this research field. For this purpose reliable animal models are needed. METHODS: Custom made endosseous dental implants were installed in female Sprague Dawley rats following a newly established three-step implantation procedure. After healing of the bone and soft tissue, the animals were assigned to two groups. Group A received a continuous antibiotic treatment for 7 weeks, while group B was repeatedly orally inoculated with human-derived strains of Streptococcus oralis, Fusobacterium nucleatum and Porphyromonas gingivalis for six weeks, followed by 1 week without inoculation. At the end of the experiment, implantation sites were clinically assessed and biofilm colonization was quantified via confocal laser scanning microscopy. Biofilm samples were tested for presence of the administered bacteria via PCR analysis. RESULTS: The inner part of the custom made implant screw could be identified as a site of reliable biofilm formation in vivo. S. oralis and F. nucleatum were detectable only in the biofilm samples from group B animals. P. gingivalis was not detectable in samples from either group. Quantification of the biofilm volume on the implant material revealed no statistically significant differences between the treatment groups. Clinical inspection of implants in group B animals showed signs of mild to moderate peri-implant mucositis (4 out of 6) whereas the mucosa of group A animals appeared healthy (8/8). The difference in the mucosa health status between the treatment groups was statistically significant (p = 0.015). CONCLUSIONS: We developed a new rodent model for the preclinical evaluation of dental implant materials with a special focus on the early biofilm colonization including human-derived oral bacteria. Reliable biofilm quantification on the implant surface and the symptoms of peri-implant mucositis of the bacterially inoculated animals will serve as a readout for experimental evaluation of biofilm-reducing modifications of implant materials.