Comparison of the detection of periodontal pathogens in bacteraemia after tooth brushing by culture and molecular techniques

Association between cardiovascular diseases and periodontal disease: more than what meets the eye

Cardiovascular diseases (CVDs) are inflammatory diseases of coronary arteries accompanying atheroma formation that can spawn impairment and, in severe cases, death. CVDs are the leading cause of death in the world. In recent decades, investigators have focused their impact on CVD by periodontal disease (PD). PD is a risk factor that can trigger the formation, maturation, and instability of atheroma in the arteries. Two mechanisms have been proposed to explain this relationship: periodontopathic pathogens explicitly invade the circulation or indirectly increase systemic levels of inflammatory mediators. It has been suggested that improvement in disease state has a positive effect on others. This review summarizes evidence from epidemiological studies as well as researches focusing on potential causation channels to deliver a comprehensive representation of the relationship between PD and CVD.

Fusobacterium nucleatum mediates endothelial damage and increased permeability following single species and polymicrobial infection

BACKGROUND

Numerous lines of evidence link periodontal pathobionts and their virulence factors with endothelial damage. Most research has been conducted using single species infections at the exclusion of other periodontal microorganisms that have been identified in vascular tissue. Here, we assessed endothelial infection with either single or mixed periodontal species infection and examined their effect on endothelial damage and permeability.

METHODS

Cell surface abundance of platelet endothelial cell adhesion molecule-1 (PECAM-1) or endothelial permeability following infection with Porphyromonas gingivalis, Fusobacterium nucleatum subspecies (ssp) nucleatum, ssp polymorphum or Tannerella forsythia as single or mixed species infection was determined by flow cytometry and a fluorescent dextran permeability assay. Zebrafish embryos were infected systemically with either single or mixed species with mortality and disease measured over time.

RESULTS

F. nucleatum ssp nucleatum, ssp polymorphum and P. gingivalis significantly reduced PECAM-1 abundance in single species infection, whereas T. forsythia had no effect. F. nucleatum ssp polymorphum caused considerable mortality and morbidity in a zebrafish systemic infection model. Polymicrobial infection underscored the virulence of F. nucleatum ssp polymorphum in particular with increased endothelial cell death and reduced PECAM-1 abundance in co-infection studies with this organism. When injected systemically into zebrafish in polymicrobial infection, fluorescently labeled bacteria were distributed throughout the vasculature and cardiac region where, in some instances, they co-localized with each other.

CONCLUSIONS

These data provide further evidence on the effects of F. nucleatum on endothelium adhesion molecule abundance and permeability while also highlighting the importance of performing polymicrobial infection to study the molecular mechanisms associated with periodontal pathogen-induced vascular damage.

The impact of a needs-oriented dental prophylaxis program on bacteremia after toothbrushing and systemic inflammation in children, adolescents, and young adults with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) still leads to high mortality rates, mainly due to cardiovascular disease. One important influencing factor is persisting low-grade chronic inflammation partly maintained by gingivitis that favors transient bacteremia during daily activities such as toothbrushing.

METHODS

To examine whether intensive dental prophylaxis can restore oral health, reduce the prevalence of bacteremia and degree of systemic inflammation indicated by CRP levels, we conducted this pilot study examining 30 CKD patients aged 6-26 years, 15 receiving intensive prophylaxis (IP), 15 receiving treatment as usual (TAU) serving as control group. There were three appointments for examination, each 10 ± 1 weeks apart (at baseline, after intervention periods one and two, when TAU also received IP, and the IP group stopped prophylaxis).

RESULTS

The gingival index (GI) in the IP group decreased by 90% (GI 0.09; p=0.001), resulting in almost healthy gingiva. There was no significant change in CRP or prevalence of bacteremia. General prevalence of bacteremia after toothbrushing was 9.5% affecting 7 (26%) of the participants. In three participants, bacteremia dissolved after IP, in one after TAU. Two patients developed bacteremia ≥ 10 weeks after ending IP. We identified eight different bacterial species.

CONCLUSIONS

We were able to show that IP can effectively treat gingivitis. It might be a promising approach to reduce systemic inflammation and subsequently lower premature cardiovascular disease, despite the lack of statistical significance. Future research requires a larger patient cohort to enable matched treatment groups with long-term follow-up and molecular detection methods for bacteremia. A higher resolution version of the Graphical abstract is available as Supplementary information.

Oral microbiome and pregnancy: A bidirectional relationship

The oral cavity contains the second most complex microbial population within the human body, with more than 700 bacterial organisms. Recent advances in Next Generation Sequencing technology have unraveled the complexities of the oral microbiome and provided valuable insights into its role in health and disease. The human oral microbiome varies dramatically during the different stages of life, including pregnancy. The total viable microbial counts in pregnant women are known to be higher compared to non-pregnant women, especially in the first trimester of pregnancy. A balanced oral microbiome is vital for a healthy pregnancy, as perturbations in the oral microbiome composition can contribute to pregnancy complications. On the other hand, physiological changes and differences in hormonal levels during pregnancy, increase susceptibility to various oral diseases such as gingivitis and periodontitis. A growing body of evidence supports the link between the composition of the oral microbiome and adverse pregnancy outcomes such as preterm birth, preeclampsia, low birth weight among others. This review aims to summarize the dynamics of oral microbiome during pregnancy and to discuss the relationship between a dysbiotic oral microbiome and pregnancy complications.

Influence of periodontal treatment on blood microbiotas: a clinical trial

Objective

To investigate the effects of periodontal treatment on the abundance and diversity of blood microbiota.

Methods and Materials

Twenty-seven periodontitis patients were randomly allocated to a control group (A) and two test groups (B1 and B2). Group A patients received full-mouth scaling and root planing (SRP), group B1 patients received subgingival glycine air polishing (GAP) right after SRP, and group B2 patients received subgingival glycine air polishing right before SRP. Peripheral blood samples were obtained at the baseline, the day after periodontal treatment, and 6 weeks after treatment and evaluated using nested polymerase chain reaction and 16SrRNA Gene Sequencing (Miseq platform).

Results

All participants exhibited significant improvements in the clinical parameters evaluated at the 6-week follow-up visit compared to the values at the baseline, but no significant differences were observed between the three groups. The total bacterial count was lowest in group B2. The bacterial species diversity (α-diversity) in group B1 was significantly higher (Chao-1 index, P = 0.03) and Porphyromonas and Pantoea were the dominant genera (linear discriminant analysis (LDA > 2)) in this group the day after treatment compared to the baseline. No significant difference was detected in the relative abundance and α-diversity of blood microbiota between the baseline and 6 weeks after treatment.

Conclusion

Local periodontal treatment merely disrupts the stability of blood microbiota in the short term. Periodontitis treatment using full-mouth SRP followed by adjunctive GAP is a promising approach to reduce the introduction of bacteria into the bloodstream during the procedure.

Association Between Periodontal Disease and Atherosclerotic Cardiovascular Diseases: Revisited

Atherosclerotic cardiovascular disease (ACVD) is an inflammatory disease of the coronary arteries associated with atheroma formation, which can cause disability and often death. Periodontitis is ranked as the sixth most prevalent disease affecting humans affecting 740 million people worldwide. In the last few decades, researchers have focused on the effect of periodontal disease (PD) on cardiovascular disease. The aim of this review was to investigate the association between these two diseases. PD is a potential risk factor that may initiate the development, maturation, and instability of atheroma in the arteries. Two mechanisms were proposed to explain such association, either periodontal pathogens directly invade bloodstream or indirectly by increasing systemic level of inflammatory mediators. Interestingly, it has been suggested that improvement in the condition of one disease positively impact the condition of the other one. Highlighting the association between these two diseases, the importance of early diagnosis and treatment of PD and its impact on cardiovascular status may be of great value in reducing the complications associated with ACVDs. Further in vitro and in vivo studies with longer follow up are necessary to confirm the causal relationship between PD and ACVDs.

Mechanisms underlying the association between periodontitis and atherosclerotic disease

Atherosclerosis is central to the pathology of cardiovascular diseases, a group of diseases in which arteries become occluded with atheromas that may rupture, leading to different cardiovascular events, such as myocardial infarction or ischemic stroke. There is a large body of epidemiologic and animal model evidence associating periodontitis with atherosclerotic disease, and many potential mechanisms linking these diseases have been elucidated. This chapter will update knowledge on these mechanisms, which generally fall into 2 categories: microbial invasion and infection of atheromas; and inflammatory and immunologic. With respect to the invasion and infection of atheromas, it is well established that organisms from the subgingival biofilm can enter the circulation and lodge in most distant tissues. Bacteremias resulting from oral interventions, and even oral hygiene activities, are well documented. More recently, indirect routes of entry of oral organisms (via phagocytes or dendritic cells) have been described for many oral organisms, into many tissues. Such organisms include the periodontal pathogens Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Tannerella forsythia, and Fusobacterium nucleatum. Intracellular survival of these organisms with dissemination to distant sites (The Trojan Horse approach) has been described. Their relative contribution to atheroma formation and progression has been studied mainly in experimental research, with results demonstrating that these organisms can invade endothelial cells and phagocytic cells within the atheroma, leading to pathogenic changes and progression of the atheroma lesion. The second category of mechanisms potentially linking periodontitis to atherosclerosis includes the dumping of inflammatory mediators originating from periodontal lesions into the systemic circulation. These inflammatory mediators, such as C-reactive protein, matrix metalloproteinases, fibrinogen, and other hemostatic factors, would further accelerate atheroma formation and progression, mainly through oxidative stress and inflammatory dysfunction. Moreover, direct effects on lipid oxidation have also been described. In summary, the evidence supports the concept that periodontitis enhances the levels of systemic mediators of inflammation that are risk factors for atherosclerotic diseases.

Periodontal diseases and adverse pregnancy outcomes: Mechanisms

Adverse pregnancy outcomes (APOs) have been defined as (a) pre-term birth, when there is a delivery before 37 completed weeks (<259 days); (b) pre-eclampsia, which is a multisystem disorder of pregnancy characterized by maternal hypertension and proteinuria after the 20th gestational week; (c) low and very low birthweight, depending on whether the weight of the baby is less of 2500 g or <1500 g and (d) the spontaneous death of the fetus with <20 weeks (miscarriage) or between 20 and 36 weeks (stillbirth). In 2012, during the Consensus Report from the Joint EFP/AAP workshop on periodontitis and systematic diseases the role of periodontal diseases on APOs was reviewed. Some years later, this evidence has grown, and an update on the literature regarding the mechanisms related to this potential association (APOs and periodontal diseases) needs to be presented. The two major pathways (direct and indirect) already accepted in 2012 are still valid nowadays. Most evidence published in the last 5 years deals with a strong and solid evidence coming from the direct pathway while there is as scarce new evidence regarding indirect pathway. In this direct pathway, the haematological dissemination of oral microorganisms and their products, would later induce an inflammatory/Immune response in the foetal-placental unit. The most plausible route for this direct pathway is the hematogenous transmission through dental bacteremia, although not many new studies dealing with bacteremia has been performed lately.

Periodontal diseases and association with atherosclerotic disease

Cardiovascular diseases still account for the majority of deaths worldwide, although significant improvements in survival, after being affected by cardiovascular disease, have been achieved in the last decades. Periodontal diseases are also a common global burden. Several studies have shown a link between cardiovascular disease and periodontitis, although evidence is still lacking regarding the direct cause-effect relation. During the 2012 "Periodontitis and systemic diseases" workshop, the available evidence on the association between cardiovascular and periodontal diseases was discussed, covering biologic plausibility and clinical studies. The objective of the present narrative review was to update the previous reviews presented at the 2012 workshop, following similar methodological approaches, aiming to critically assess the available evidence. With regard to biologic plausibility, two aspects were reviewed: (a) for microbiologic mechanisms, assessing periodontal bacteria as a contributing factor to atherosclerosis based on seven "proofs," substantial evidence was found for Proofs 1 through 6, but not for Proof 7 (periodontal bacteria obtained from human atheromas can cause atherosclerosis in animal models), concluding that periodontal pathogens can contribute to atherosclerosis; (b) mechanistic studies, addressing five different inflammatory pathways that could explain the links between periodontitis and cardiovascular disease with the addition of some extra pathways , suggest an association between both entities, based on the presence of higher levels of these inflammatory markers in patients with periodontitis and cardiovascular disease, vs healthy controls, as well as on the evidence that periodontal treatment reduces serum levels of these mediators. When evidence from clinical studies was analyzed, two aspects were covered: (a) epidemiologic studies support the estimation that the incidence of atherosclerotic disease is higher in individuals with periodontitis than in individuals with no reported periodontitis, irrespective of many common risk factors, but with a substantial variability in the definitions used in reporting of exposure to periodontal diseases in different studies; (b) intervention trials have shown that periodontal therapy can reduce serum inflammatory mediators, improve the lipids profile, and induce positive changes in other cardiovascular disease surrogate measures, but no evidence is available to support that adequate periodontal therapy is able to reduce the risk for cardiovascular diseases, or the incidence of cardiovascular disease events in periodontitis patients.

Absence of bacteria in intracranial aneurysms

OBJECTIVE

This study aimed to detect the presence of bacteria in the walls of both unruptured and ruptured aneurysms in a French population.

METHODS

Patients treated between January 2018 and July 2018 were included in a prospective study when specimens from ruptured or unruptured aneurysm walls were obtained intraoperatively. Samples from superficial temporal artery, dura mater, and middle meningeal artery were obtained from each patient during the same surgical procedure to be used as a negative control. Direct bacterial analysis, aerobic and anaerobic bacterial culture, and bacterial DNA detection were performed on each sample.

RESULTS

There were 21 women and 9 men with a mean age at treatment of 54 years (range 31-70 years). Eighteen patients were smokers. Hypertension was present in 18 patients and hyperlipidemia in 5 patients. Chronic alcoholism was found in 6 patients. Polycystic kidney disease was present in 1 patient. Fifteen patients had multiple intracranial aneurysms. Ten patients had a ruptured aneurysm and 20 had an unruptured aneurysm. The mean diameter of all aneurysms was 8.5 mm (range 2.5-50 mm). No presence of bacteria was detected with direct bacterial analysis and culture in any of the samples. No bacterial DNA was detected in any of the samples.

CONCLUSIONS

Unlike in Finnish patients, no bacterial presence was found in the wall of aneurysms in French patients. This absence of bacterial infection might explain the lower risk of aneurysm rupture in the French population compared to the Finnish population.

Impact of antibiotic prophylaxis on the incidence, nature, magnitude, and duration of bacteremia associated with dental procedures: A systematic review

BACKGROUND

Antibiotic prophylaxis (AP) is used routinely in high-risk groups of patients to reduce bacteremia and the risk of developing infective endocarditis (IE). In this systematic review, the authors evaluated the efficacy of AP on the incidence, nature, magnitude, and duration of post-dental procedure bacteremia.

METHODS

The authors conducted a systematic search of the literature using MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials up to and including May 2019. They included randomized clinical trials in which researchers compared antibiotics with a placebo or no treatment (as the control). They undertook random-effects meta-analyses to evaluate the incidence of bacteremia after dental procedures.

RESULTS

The authors included 12 studies in the review. The studies evaluated the incidence of bacteremia after AP with American Heart Association (AHA) protocol antibiotics (amoxicillin, clindamycin, cephalosporin, and azithromycin) or non-AHA protocol antibiotics (moxifloxacin and intravenous [IV] amoxicillin-clavulanic acid). The pooled analysis revealed that antibiotics significantly reduced the bacteremia incidence, but their effectiveness was moderate (risk ratio, 0.50; 95% confidence interval, 0.38 to 0.67). IV amoxicillin-clavulanic acid promoted a considerable reduction in bacteremia. However, in patients with penicillin allergies, antibiotics (that is, clindamycin and cephalosporin) had lower efficacy.

PRACTICAL IMPLICATIONS

Oral amoxicillin is still the antibiotic of choice to reduce bacteremia. IV amoxicillin-clavulanic acid could be used for patients at high risk of developing IE who require invasive dental procedures, have high levels of dental infection, and are to be treated under general anesthesia. In patients with penicillin allergies, oral azithromycin showed a higher efficacy for the reduction of bacteremia and the use of clindamycin should be reviewed. Antibiotic premedication should be limited to patients at high risk of developing IE, according to the indications of the AHA guide.

Omega-3 fatty acids suppress Fusobacterium nucleatum-induced placental inflammation originating from maternal endothelial cells

Fusobacterium nucleatum is an oral anaerobe prevalent in intrauterine infection associated with a wide spectrum of adverse pregnancy outcomes. We demonstrate here that F. nucleatum triggers placental inflammation through maternal, rather than paternal, TLR4-mediated signaling. Elimination of TLR4 from maternal endothelial cells alleviated placental inflammation and reduced fetal and neonatal death, while elimination of TLR4 in the hematopoietic cells had no effect. The placental inflammatory response followed a spatiotemporal pattern, with NF-κB activation observed first in the maternal endothelial cells and then in the decidual cells surrounding the endothelium, followed by induction of inflammatory cytokines and chemokines. Supplementation of pregnant mice with fish oil as a source of omega-3 fatty acids suppressed placental inflammation, reduced F. nucleatum proliferation in the placenta, and increased fetal and neonatal survival. In vitro analysis illustrates that omega-3 fatty acids inhibit bacterial-induced inflammatory responses from human umbilical cord endothelial cells. Our study therefore reveals a mechanism by which microbial infections affect pregnancy and identifies a prophylactic therapy to protect against intrauterine infections.

Detection and quantification of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans in bacteremia induced by interdental brushing in periodontally healthy and periodontitis patients

OBJECTIVE

This study was aimed to compare the presence and amounts of bacteremia induced by interdental brushing in periodontally healthy (H) and periodontitis (P) individuals using culture based (direct culture [DC]) and molecular based techniques (real-time quantitative polymerase chain reaction [qPCR]) in a cross-sectional study model.

MATERIALS AND METHODS

After a full mouth periodontal evaluation, blood samples were taken before and 1 min after professionally-administered interdental brushing. These samples were analyzed by DC and qPCR, targeting Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Subgingival samples were also collected and analyzed. Student t-test, chi-squar tests and correlations were used for analyzing the data.

RESULTS

Thirty individuals per group were included. P. gingivalis and A. actinomycetemcomitans were detected with qPCR methods, but not with DC. At baseline, bacteremia was observed in 5 P patients (16.7%) and in 2 H individuals (6.6%) (p = 0.421). After interdental brushing, bacteremia was only observed in 2 P patients (6.6%) (p = 0.901). A positive correlation between subgingival and blood levels of A. actinomycetemcomitans was observed (r = 0.3; p = 0.013).

CONCLUSION

Bacteremia related to A. actinomycetemcomitans and P. gingivalis did not significantly increase after a single session of use of interdental brushes.

Effects of chlorhexidine preprocedural rinse on bacteremia in periodontal patients: a randomized clinical trial

OBJECTIVE

Single dose of systemic antibiotics and short-term use of mouthwashes reduce bacteremia. However, the effects of a single dose of preprocedural rinse are still controversial. This study evaluated, in periodontally diseased patients, the effects of a pre-procedural mouth rinse on induced bacteremia.

MATERIAL AND METHODS

Systemically healthy individuals with gingivitis (n=27) or periodontitis (n = 27) were randomly allocated through a sealed envelope system to: 0.12% chlorhexidine pre-procedural rinse (13 gingivitis and 13 periodontitis patients) or no rinse before dental scaling (14 gingivitis and 15 periodontitis patients). Periodontal probing depth, clinical attachment level, plaque, and gingival indices were measured and subgingival samples were collected. Blood samples were collected before dental scaling, 2 and 6 minutes after scaling. Total bacterial load and levels of P. gingivalis were determined in oral and blood samples by real-time polymerase chain reaction, while aerobic and anaerobic counts were determined by culture in blood samples. The primary outcome was the antimicrobial effect of the pre-procedural rinse. Data was compared by Mann-Whitney and Signal tests (p<0.05).

RESULTS

In all sampling times, polymerase chain reaction revealed higher blood bacterial levels than culture (p<0.0001), while gingivitis patients presented lower bacterial levels in blood than periodontitis patients (p<0.0001). Individuals who experienced bacteremia showed worse mean clinical attachment level (3.4 mm vs. 1.1 mm) and more subgingival bacteria (p<0.005). The pre-procedural rinse did not reduce induced bacteremia.

CONCLUSIONS

Bacteremia was influenced by periodontal parameters. In periodontally diseased patients, pre-procedural rinsing showed a discrete effect on bacteremia control.

The Influence of Toothpaste Containing Australian Melaleuca alternifolia Oil and Ethanolic Extract of Polish Propolis on Oral Hygiene and Microbiome in Patients Requiring Conservative Procedures

The study was based on the use of a toothpaste with antiphlogistic activity, containing Australian Melaleuca alternifolia oil (tea tree oil—TTO) and ethanolic extract of Polish propolis (EEP). Fifty-one patients with varying conditions of the gingiva were divided into two groups. The study group received the toothpaste with TTO and EEP, while the control group received the same toothpaste but without TTO and EEP. Approximal plaque index (API), simplified oral hygiene index (OHI-s) and modified sulcus bleeding index (mSBI) were assessed in three subsequent stages. During each examination, swabs were employed for microbiological inoculation. During the period of use of toothpastes with TTO and EEP, a significant reduction of the API was observed, as assessed upon the control visit after 7 days and after 28 days, compared to baseline. A statistically significant reduction of mSBI was observed after 7 and 28 days of using the toothpaste with TTO and EEP, as compared to the value upon the initial visit. Statistically significant differences in the OHI-s value were observed in the study group, which was using the active toothpaste. The use of a toothpaste containing TTO and EEP helps to maintain microbiome balance. The observed stabilisation of bacterial microflora confirms the beneficial activity of toothpaste containing EEP and TTO compared to the control group, where the lack of these substances contributed to the emergence of qualitative and quantitative changes in oral microbiome.

Prevalence of and factors associated with fewer than 20 remaining teeth in Taiwanese adults with disabilities: a community-based cross-sectional study

OBJECTIVES

To examine the prevalence of and the factors associated with a number of remaining teeth (NRT) <20 among adults with disabilities.

DESIGN

A community-based, cross-sectional descriptive study.

SETTING

This study was part of a health promotion programme designed for community-dwelling adults with disabilities.

PARTICIPANTS

A total of 549 adults with disabilities, aged 20-80 years, living in the community in Chiayi County in Taiwan.

OUTCOME MEASURES

Various parameters, including NRT, oral health behaviours (ie, oral hygiene, dietary habits and substance use), comorbidities, disability classification and capability for performing activities of daily living, were measured. Data were statistically analysed using descriptive statistics and multivariate logistic regression analysis.

RESULTS

The mean NRT was 18.1 (SD=10.9); 44.8% of participants had NRT <20 (including 13.7% edentulous participants). Most participants had poor oral hygiene: 83.4% reported seldom using dental floss, 78% did not undergo regular 6-monthly dental check-ups and 77.4% seldom brushed their teeth after meal. After adjusting for potentially confounding variables, the intellectual disability group had a significantly higher risk of an NRT <20 than the physical disability group (OR 2.30, 95% CI 1.30 to 4.08). Additionally, the rare use of dental floss and hypertension significantly increased the possibility of an NRT <20 (OR 1.73-2.12, 95% CI 1.15 to 3.71).

CONCLUSIONS

An NRT <20 and edentulism were highly prevalent among adults with disabilities, who displayed poor oral hygiene behaviours. Adults with intellectual disabilities had a greater likelihood of having an NRT <20 than did those with physical disability. In addition to unmodifiable factors, the poor use of dental floss was significantly associated with an NRT <20.