The association between periodontitis and cerebrovascular disease, and dementia. Scientific report of the working group of the Spanish Society of Periodontology and the Spanish Society of Neurology

OBJECTIVE

This article reviews the scientific evidence on the relationship between periodontitis and neurological disease, and particularly cerebrovascular disease and dementia. We also issue a series of recommendations regarding the prevention and management of periodontitis and these neurological diseases at dental clinics and neurology units.

DEVELOPMENT

In response to a series of questions proposed by the SEPA-SEN working group, a literature search was performed, with no restrictions on study design, to identify the most relevant articles on the association between periodontitis and cerebrovascular disease and dementia from the perspectives of epidemiology, treatment, and the biological mechanisms involved in these associations.

CONCLUSIONS

Periodontitis increases the risk of ischaemic stroke and Alzheimer dementia. Recurrent bacterial infections and increased low-grade systemic inflammation seem to be possible biological mechanisms underlying this association. Limited evidence suggests that various oral health interventions can reduce the future risk of cerebrovascular disease and dementia.

Association between toothbrushing and cardiovascular risk factors: a cross-sectional study using Korean National Health and Nutrition Examination Survey 2015-2017

BACKGROUND

Previous studies have suggested that frequent toothbrushing is associated with a lower risk of future cardiovascular events. We sought to investigate further the relationship between toothbrushing, cardiovascular risk factors, and lifestyle behaviours.

METHODS

We analysed a cross-sectional survey including 13,761 adults aged 30 years or older without a history of cardiovascular diseases from the Korean National Health and Nutritional Examination Survey. Conventional cardiovascular risk factors (blood pressure, lipid profiles, and fasting glucose), and inflammatory markers (high-sensitivity C-reactive protein [hsCRP], and white blood cell counts [WBC]) were investigated in relation to the frequency of toothbrushing.

RESULTS

The estimated 10-year atherosclerotic cardiovascular disease (ASCVD) risk, calculated using the pooled cohort equations was 13.7%, 9.1%, and 7.3% for participants who reported toothbrushing 0-1, 2, and ≥ 3 times a day, respectively. Both conventional risk factors and inflammatory markers were significantly associated with frequent toothbrushing. However, after adjusting potential confounding factors such as age, sex, comorbidities, and lifestyle behaviours, only inflammatory markers were remained as significant factors.

CONCLUSIONS

Oral hygiene behaviours are closely linked to cardiovascular risk factors. This study suggests that reduced systemic inflammatory burden may explain the benefit of improved oral hygiene in terms of cardiovascular risk.

Association of periodontitis with cognitive decline and its progression: Contribution of blood-based biomarkers of Alzheimer's disease to this relationship

AIM

To assess whether periodontitis is associated with cognitive decline and its progression as well as with certain blood-based markers of Alzheimer's disease.

MATERIALS AND METHODS

Data from a 2-year follow-up prospective cohort study (n = 101) was analysed. Participants with a previous history of hypertension and aged ≥60 years were included in the analysis. All of them received a full-mouth periodontal examination and cognitive function assessments (Addenbrooke's Cognitive Examination (ACE) and Mini-Mental State Examination [MMSE]). Plasma levels of amyloid beta (Aβ)1-40 , Aβ1-42 , phosphorylated and total Tau (p-Tau and t-Tau) were determined at baseline, 12 and 24 months.

RESULTS

Periodontitis was associated with poor cognitive performance (MMSE: β = -1.5 [0.6]) and progression of cognitive impairment (hazard ratio [HR] = 1.8; 95% confidence interval: 1.0-3.1). Subjects with periodontitis showed greater baseline levels of p-Tau (1.6 [0.7] vs. 1.2 [0.2] pg/mL, p < .001) and Aβ1-40 (242.1 [77.3] vs. 208.2 [73.8] pg/mL, p = .036) compared with those without periodontitis. Concentrations of the latter protein also increased over time only in the periodontitis group (p = .005).

CONCLUSIONS

Periodontitis is associated with cognitive decline and its progression in elderly patients with a previous history of hypertension. Overexpression of p-Tau and Aβ1-40 may play a role in this association.

Periodontal inflammation is associated with increased circulating levels of endothelial progenitor cells: a retrospective cohort study in a high vascular risk population

Background

One of the main biological mechanisms behind the link between periodontitis and atherosclerotic vascular diseases is vascular endothelial dysfunction. Particularly, circulating endothelial progenitor cells (EPCs) have been considered a biomarker of altered vascular endothelial function.

Objectives

The aim of this study was to investigate relationship between periodontal inflammation and increased number of circulating EPCs.

Design

This is retrospective cohort study.

Methods

In this study, 85 elderly patients with a previous history of hypertension were followed up to 12 months. A baseline full-mouth periodontal assessment was carried out, and the amount of periodontal tissue inflamed per subject was calculated as a proxy of periodontal inflammation [periodontal inflamed surface area (PISA)]. The number of circulating EPCs (CD34+/CD133+/KDR+) was determined by flow cytometry from peripheral blood samples collected at baseline and 12 months.

Results

Mean concentrations of CD34+/CD133+/KDR+ progenitor cells were higher in periodontitis patients than in those without periodontitis at baseline [55.4, 95% confidence interval (CI) = 20.8 to 90.0 versus 27.2, 95% CI = 13.6 to 40.8, p = 0.008] and 12 months (114.6, 95% CI = 53.5 to 175.7 versus 19.1, 95% CI = 10.8 to 27.4, p = 0.003). A significant increase over the follow-up was noticed in the group of subjects with periodontitis (p = 0.049) but not in the nonperiodontitis group (p = 0.819). PISA was independently associated with CD34+/CD133+/KDR+ EPCs at baseline (B coefficient = 0.031, 95% CI = 0.005 to 0.058; p = 0.021). The relationship between PISA and CD34+/CD133+/KDR+ EPCs at 12 months was confounded by increased baseline body mass index (B coefficient = 0.064, 95% CI = -0.005 to 0.132; p = 0.066).

Conclusion

Periodontal inflammation is associated with high number of CD34+/CD133+/KDR+ EPCs, thus supporting a potential link between periodontitis and endothelial dysfunction.

Complications and treatment errors in periodontal therapy in medically compromised patients

Patients who are medically compromised may be at an increased risk of complications and treatment errors following periodontal therapy. A review of the evidence on the topic is presented, in relation to the type of complication reported, of periodontal treatment, and of patients' medical status. Further, a framework for risk assessment and appropriate treatment modifications is introduced, with the aim of facilitating the management of patients with existing comorbidities and reducing the incidence of treatment complications.

Periodontitis is associated with subclinical cerebral and carotid atherosclerosis in hypertensive patients: A cross-sectional study

OBJECTIVE

To examine the relationship between periodontitis and subclinical intracranial atherosclerosis. The association of periodontitis with preclinical markers of atherosclerosis in other vascular territories was also explored.

MATERIAL AND METHODS

This was a cross-sectional study where 97 elderly subjects with a previous history of hypertension received an ultrasonographic evaluation to assess subclinical atherosclerosis in different vascular territories: (1) cerebral [pulsatility (PI) and resistance index (RI) of the middle cerebral artery], (2) carotid [intima-media thickness (IMT)], and (3) peripheral [ankle-brachial index (ABI)]. Additionally, participants underwent a full-mouth periodontal assessment together with blood sample collection to determine levels of inflammatory biomarkers (leukocytes, fibrinogen, and erythrocyte sedimentation rate), lipid fractions (total cholesterol and high- and low-density lipoprotein), and glucose.

RESULTS

Sixty-one individuals had periodontitis. Compared to subjects without periodontitis, those with periodontitis showed higher values of PI (1.24 ± 0.29 vs 1.01 ± 0.16), RI (0.70 ± 0.14 vs 0.60 ± 0.06), and IMT (0.94 ± 0.15 vs 0.79 ± 0.15) (all p < 0.001). No statistically significant differences were found neither for ABI or for other clinical and biochemical parameters. An independent association was found between periodontitis and increased intracranial atherosclerosis (OR_adjusted = 10.16; 95% CI: 3.14-32.90, p < 0.001) and to a lesser extent with thicker carotid IMT (OR_adjusted = 4.10; 95% CI: 1.61-10.48, p = 0.003).

CONCLUSIONS

Periodontitis is associated with subclinical atherosclerosis in both intracranial and carotid arteries in elderly subjects with hypertension.

CLINICAL RELEVANCE

The association of periodontitis with intracranial atherosclerosis implies that periodontitis patients might have greater chances to develop ischemic stroke in the future.

Influence of low insertion torque values on survival rate of immediately loaded dental implants: A systematic review and meta-analysis

AIM

The aim was to systematically evaluate the effect of low insertion torque values on the survival rate of immediately loaded dental implants.

MATERIALS AND METHODS

The protocol was registered with PROSPERO (ID CRD42020189499). An electronic search was performed in PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials until June 2022 in English and Spanish. Studies analysing the failure or survival rate of immediately loaded dental implants according to different insertion torque values were included.

RESULTS

Five-hundred seventy-three articles were assessed for eligibility, of which seven articles, four randomized clinical trials (RCTs), one controlled clinical trial, and two prospective case series studies were included in the qualitative analysis. The RCTs were classified as having low risk of bias and the non-RCTs as having moderate and serious risk of bias. The mean survival rate for implants with low insertion toque (≤35 Ncm) was 96% (p > .001, 95% confidence interval [CI]: 0.91-0.98) and that for implants with medium or high insertion torque (>35 Ncm) was 92% (p > .001, 95% CI: 0.86-0.96) (incidence rate ratio [IRR] = 1.05, 95% CI: 0.79-1.39, p = .175, I²  = 0.0%). Splinted implants with insertion torque >20 Ncm and single implants with insertion torque >35 Ncm had a higher survival rate than implants with lower insertion torque values (IRR = 1.05, 95% CI: 0.78-1.43, p = .956, I²  = 0.0%, and RR = 0.92, 95% CI: 0.48-1.75, p = .799, I²  = 0.0%, respectively). Different insertion torque values achieved equivalent outcomes. The mean follow-up was 24 months.

CONCLUSIONS

Low insertion torque values have no significant effect on survival rates of immediate loading implants at a mean follow-up of 24 months.

Association between periodontitis and peripheral markers of innate immunity activation and inflammation

BACKGROUND

Immune response leading to increased systemic inflammation is one of the mechanisms linking periodontitis to chronic inflammatory diseases. The aim of this study was to compare the expression of toll-like receptors 2 and 4 in monocytes and neutrophils (TLR2M, TLR2N, TLR4M, and TLR4N) and its endogenous ligands (cellular fibronectin [cFN] and heat shock protein 60 [HSP60]) in patients with and without periodontitis. Additionally, the relationship between cFN and HSP60 expression with innate immunity activation and systemic inflammatory response (interleukin 6 [IL-6]) was also evaluated.

METHODS

A case-controlled study was designed in which 30 patients with periodontitis (cases) and 30 age- and sex-matched participants without periodontitis (controls) were included. Fasting blood samples were collected to determine: (1) expression of TLR2N, TLR2M, TLR4N, and TLR4M by flow cytometry; and (2) serum concentrations of cFN, HSP60, and IL-6 by ELISA technique.

RESULTS

Expression of TLR2M (411.5 [314.2, 460.0] vs. 236.5 [204.0, 333.0] AFU), TLR2N (387.0 [332.0, 545.5] vs 230.0 [166.2, 277.7] AFU), TLR4M (2478.5 [1762.2, 2828.0] vs 1705.0 [1274.5, 1951.2] AFU), and TLR4N (2791.0 [2306.7, 3226.2] vs. 1866.0 [1547.5, 2687.2] AFU) as well as serum levels of cFN (301.1 [222.2, 410.9] vs. 156.4 [115.3, 194.0] ng/ml) and IL-6 (10.4 [6.5, 11.5] vs. 3.5 [2.6, 4.9] pg/ml) were significantly higher in periodontitis patients than those without periodontitis. A positive association was found between periodontitis and cFN (odds ratio [OR] = 1.028, p < 0.001), TLR2N (OR = 1.026, p < 0.001), TLR4M (OR = 1.001, p = 0.002), and IL-6 (OR = 1.774, p < 0.001).

CONCLUSIONS

Periodontitis patients exhibited high expression of TLRs, cFN, and IL-6.

Treatment of periodontitis and C-reactive protein: A systematic review and meta-analysis of randomized clinical trials

BACKGROUND

Systemic inflammation is implicated in the onset and progression of several chronic diseases. Periodontitis is a potential trigger of systemic inflammation.

PURPOSE

To comprehensively appraise all the evidence on the effects of the treatment of periodontitis on systemic inflammation assessed by serum C-reactive protein (CRP) levels.

DATA SOURCES

Six electronic databases were searched up to 10 February 2022 to identify and select articles in English language only.

STUDY SELECTION

Twenty-six randomized controlled clinical trials reporting changes amongst 2579 participants about CRP levels at 6 months or more after treatment.

DATA EXTRACTION

Two reviewers independently extracted data and rated the quality of studies. Meta-analyses were performed using random and fixed effect models.

RISK OF BIAS

Risk of bias (RoB 2.0 tool) and quality of evidence (GRADEpro GDT tool) analyses were completed.

DATA SYNTHESIS

Treatment of periodontitis reduced CRP levels by 0.69 mg/L (95% confidence interval: -0.97 to -0.40) after 6 months, but limited evidence was retrieved from studies with longer follow-ups. Similar findings were observed in participants with other co-morbidities in addition to periodontitis. Greatest reductions were observed in participants with concentrations of CRP >3 mg/L at baseline.

LIMITATIONS

High level of heterogeneity.

CONCLUSIONS

Treatment of periodontitis reduces serum CRP levels (up to 6 months follow-up) to a degree equivalent to that observed after traditional lifestyle or drug interventions. This evidence supports a causal association between periodontitis and systemic inflammation.

Ceramide/Sphingosine 1-Phosphate Axis as a Key Target for Diagnosis and Treatment in Alzheimer’s Disease and Other Neurodegenerative Diseases

Alzheimer’s disease (AD) is considered the most prevalent neurodegenerative disease and the leading cause of dementia worldwide. Sphingolipids, such as ceramide or sphingosine 1-phosphate, are bioactive molecules implicated in structural and signaling functions. Metabolic dysfunction in the highly conserved pathways to produce sphingolipids may lead to or be a consequence of an underlying disease. Recent studies on transcriptomics and sphingolipidomics have observed alterations in sphingolipid metabolism of both enzymes and metabolites involved in their synthesis in several neurodegenerative diseases, including AD. In this review, we highlight the most relevant findings related to ceramide and neurodegeneration, with a special focus on AD.

Invasive dental treatment and acute vascular events: A systematic review and meta-analysis

BACKGROUND

Acute infection/inflammation increases the risk of acute vascular events (AVEs). Invasive dental treatments (IDTs) trigger short-term acute inflammation.

PURPOSE

The aim of this work is to critically appraise the evidence linking IDTs and AVEs.

DATA SOURCES

Six bibliographical databases were searched up to 31 August 2021. A systematic review following PRISMA guidelines was performed.

STUDY SELECTION

Intervention and observational studies reporting any AVEs following IDT were included.

DATA EXTRACTION

Two reviewers independently extracted data and rated the quality of studies. Data were pooled using fixed-effect, inverse variance weights analysis.

RISK OF BIAS

Risk of bias was assessed by the Newcastle-Ottawa Quality Assessment Scale for observational studies and the Cochrane Handbook-Rob 2.0 for randomized controlled trials.

DATA SYNTHESIS

In 3 out of 16 clinical studies, a total of 533,175 participants, 124,344 myocardial infarctions, and 327,804 ischaemic strokes were reported. Meta-analysis confirmed that IDT did not increase incidence ratios (IR) for combined vascular events either at 1-4 weeks (IR of 1.02, 95% CIs: 0.92 to 1.13) and at 5-8 weeks (IR of 1.04, 95% CIs: 0.97 to1.10) after treatment.

LIMITATIONS

A high level of heterogeneity (study designs and time point assessments) was found.

CONCLUSION

Patients who received IDT exhibited no substantial increase in vascular risk over 8 weeks post treatment.

Peri-implantitis, systemic inflammation, and dyslipidemia: a cross-sectional biochemical study

Purpose

The aim of this study was to compare the inflammatory and lipid profile of patients with and without peri-implantitis.

Methods

A cross-sectional biochemical study was carried out in which blood samples were collected from 16 patients with peri-implantitis and from 31 subjects with healthy implants. Clinical peri-implant parameters were obtained from all subjects. Levels of tumor necrosis factor-alpha and interleukin-10 (IL-10) were measured in serum. Lipid fractions, glucose and creatinine levels, and complete blood count were also assessed.

Results

After controlling for a history of periodontitis, statistically significant differences between peri-implantitis patients and controls were found for total cholesterol (estimated adjusted mean difference, 76.4 mg/dL; 95% confidence interval [CI], 39.6, 113.2 mg/dL; P<0.001), low-density lipoprotein (LDL) cholesterol (estimated adjusted mean difference, 57.7 mg/dL; 95% CI, 23.8, 91.6 mg/dL; P<0.001), white blood cells (WBC) (estimated adjusted mean difference, 2.8×10³/μL; 95% CI, 1.6, 4.0×10³/μL; P<0.001) and IL-10 (estimated adjusted mean difference, −10.4 pg/mL; 95% CI, −15.8, −5.0 pg/mL; P<0.001). The peri-implant probing pocket depth (PPD) was modestly positively correlated with total cholesterol (r=0.512; P<0.001), LDL cholesterol (r=0.463; P=0.001), and WBC (r=0.519; P<0.001). A moderate negative correlation was observed between IL-10 and PPD (r=0.609; P<0.001).

Conclusions

Otherwise healthy individuals with peri-implantitis showed increased low-grade systemic inflammation and dyslipidemia.

Periodontitis and Systemic Lupus Erythematosus: A systematic review and meta-analysis

This systematic review and meta-analysis evaluated the association between periodontitis (PD) and systemic lupus erythematosus (SLE). A systematic search was conducted through the following electronic databases: Cochrane Library, MEDLINE, EMBASE, Scopus, LILACS, CINAHL and SIGLE (System for Information on Grey Literature in Europe) for relevant publications up to September 2020 with no language restriction. The association between PD and SLE was assessed by the prevalence of PD in SLE patients (both sex and females only) as the primary outcome. Secondary outcomes included differences in common gingival parameters including probing pocket depth (PPD), clinical attachment level (CAL), disease activity index (SLEDAI) scores of SLE patients with or without PD. A total of 1183 citations and 22 full text articles were screened. Eighteen articles were included in the qualitative synthesis, and 13 in the quantitative analysis. SLE diagnosis was associated with greater odds of PD (OR = 1.33, 95% Confidence Interval [CI]: 1.20-1.48), but these were non-significant when examined in females (OR = 3.20, 95%CI: 0.85-12.02). Patients with SLE exhibited no differences in PPD (SMD: -0.09 mm, 95%CI: -0.45-0.27) and CAL (SMD: 0.05 mm, 95%CI: -0.30-0.40) when compared with systemically healthy controls. PD diagnosis was, however, associated with higher SLEDAI scores in patients suffering from SLE (SMD: 0.68, 95% CI: 0.03-1.32). PD and SLE are both inflammatory diseases and their association could be bi-directional. This review suggested that the patients with SLE have greater odds of suffering with PD. Further investigations are required to assess the association between PD and SLE.

Periodontal Inflamed Surface Area Mediates the Link between Homocysteine and Blood Pressure

Here, we assess the association between homocysteine (Hcy) serum levels and periodontal status in a large representative sample of the National Health and Nutrition Examination Survey (NHANES). Using the 2001–2002 and 2003–2004 NHANES databases, participants with a periodontal examination, medical self-reported data, blood pressure (BP) and blood samples to determine complete blood count, C-reactive protein (CRP) and Hcy levels. We then calculated the periodontal inflamed surface area (PISA) and the periodontal epithelial surface area (PESA). Multivariable regression analysis explored the association between Hcy, periodontal measures and BP. Mediation analysis was performed to understand the effect of PISA and PESA in the link between Hcy and BP. 4021 participants fulfilled the inclusion criteria. Hcy levels showed significant correlations with systolic BP, diastolic BP, PISA, PESA and age. PESA showed to be significantly associated with Hcy both for the crude and adjusted models (p < 0.01), but not PISA (p > 0.05). In the association of Hcy with systolic BP, PISA significantly mediated 17.4% and PESA 0.9%. In the association of Hcy with diastolic BP, PISA significantly mediated 16.3% and PESA 47.2%. In conclusion, Hcy and periodontitis are associated. Further, both PISA and PESA significantly mediated the association of Hcy with systolic BP and diastolic BP. Future studies shall deepen the mechanisms by which Hcy levels increase in a clinical situation of periodontitis.

Remote Ischemic Preconditioning Protects Against Endothelial Dysfunction in a Human Model of Systemic Inflammation: A Randomized Clinical Trial

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Economic burden of periodontitis in the United States and Europe - an updated estimation

BACKGROUND

The aim of this study is to estimate the direct and indirect economic burdens of periodontal disease in the US and in Europe.

METHODS

We used the most recent data available for the US and for Europe (32 European countries) to estimate the cost of periodontal disease. Global health, dental and periodontal expenditures were estimated. We tried to estimate the direct and the indirect costs of periodontitis. Indirect costs, those related to productivity losses, are a consequence of periodontal disease proper, plus edentulism and caries because of periodontal disease.

RESULTS

In 2018, the aggregate cost in the US was estimated at $3.49B and €2.52B in Europe. Indirect costs because of periodontal disease amounted to $150.57B (95% confidence interval [CI]: 103.32-189.87) in the US countries and €156.12B (95% CI: 123.72-221.86) in Europe. The majority of the projected indirect costs were because of edentulism related to periodontal disease and periodontal disease. Indirect costs were the majority of the estimated economic impact with an average of 0.73% (95% CI: 0.50%-0.93%) of annual gross domestic product in the US and 0.99% (95% CI: 0.78%-1.40%) in Europe.

CONCLUSIONS

Periodontal disease caused an estimated loss of $154.06B in the US and €158.64B in Europe, in 2018. These results show that the economic burden of periodontal disease is significant and its indirect costs are impactful.

Network Protein Interaction in the Link between Stroke and Periodontitis Interplay: A Pilot Bioinformatic Analysis

The clinical interaction between stroke and periodontitis has been consistently studied and confirmed. Hence, exploring potentially new protein interactions in this association using bioinformatic strategies presents potential interest. In this exploratory study, we conducted a protein-protein network interaction (PPI) search with documented encoded proteins for both stroke and periodontitis. Genes of interest were collected via GWAS database. The STRING database was used to predict the PPI networks, first in a sensitivity purpose (confidence cut-off of 0.7), and then with a highest confidence cut-off (0.9). Genes over-representation was inspected in the final network. As a result, we foresee a prospective protein network of interaction between stroke and periodontitis. Inflammation, pro-coagulant/pro-thrombotic state and, ultimately, atheroma plaque rupture is the main biological mechanism derived from the network. These pilot results may pave the way to future molecular and therapeutic studies to further comprehend the mechanisms between these two conditions.

Is systemic inflammation a missing link between periodontitis and hypertension? Results from two large population-based surveys

OBJECTIVE

The primary objective was to investigate the relationship between periodontitis and hypertension in two independent large surveys. The secondary objective was to ascertain whether systemic inflammation had a mediation effect in the association.

METHODS

This cross-sectional study analysed representative samples of the US (n = 3460; NHANES 2009/10) and Korean (n = 4539; 2015 KNHANES VI-3) populations. The association between periodontitis (exposure), hypertension (outcome) and inflammatory markers [C-reactive protein (CRP) and white blood cell counts (WBC)] (mediators) was assessed using multivariate linear and logistic regression models and mediation analysis.

RESULTS

Participants with periodontitis were more likely to have hypertension (NHANES: OR = 1.3, 95% CI: 1.0-1.6, P = 0.025; KNHANES: OR = 1.2, 95% CI: 1.0-1.4, P = 0.041) and actual systolic blood pressure ≥ 140 mmHg (NHANES: OR = 1.6, 95% CI: 1.1-2.3, P < 0.001; KNHANES: OR = 1.3, 95% CI :1.0-1.6, P < 0.031) than those without the disease. These associations were independent of age, gender, BMI, education level, smoking, alcohol consumption, creatinine, physical activity, presence of other comorbidities and confirmed in participants not taking antihypertensive medications. Diagnosis of periodontitis was directly associated with WBC (in both surveys: NHANES: β ± SE = 0.3 ± 0.1, P < 0.004; KNHANES: β ± SE = 0.3 ± 0.1, P < 0.001) and with CRP levels (in one survey: NHANES: β ± SE = 0.1 ± 0.03, P < 0.007; KNHANES: β ± SE = 0.1 ± 0.04, P > 0.213). Mediation analyses confirmed that CRP acted as a mediator in the association between periodontitis and hypertension in both populations (mediated effect: NHANES: β ± SE = 0.010 ± 0.003, P < 0.001; KNHANES: β ± SE = 0.003 ± 0.001, P = 0.015). WBC acted as a mediator in the KNHANES (mediated effect: β ± SE = 0.004 ± 0.001, P = 0.004) whilst in the NHANES, its effect was dependent of CRP inclusion in the model (mediated effect WBC + CRP: β ± SE = 0.002 ± 0.001, P = 0.001).

CONCLUSIONS

These findings suggest that periodontitis is closely linked to hypertension and systemic inflammation is, in part, a mediator of this association.

Subgingival instrumentation for treatment of periodontitis. A systematic review

OBJECTIVES

To evaluate the efficacy of subgingival instrumentation (PICOS-1), sonic/ultrasonic/hand instruments (PICOS-2) and different subgingival instrumentation delivery protocols (PICOS-3) to treat periodontitis.

METHODS

Systematic electronic search (CENTRAL/MEDLINE/EMBASE/SCOPUS/LILACS) to March 2019 was conducted to identify randomized controlled trials (RCT) reporting on subgingival instrumentation. Duplicate screening and data extraction were performed to formulate evidence tables and meta-analysis as appropriate.

RESULTS

As only one RCT addressed the efficacy of subgingival instrumentation compared with supragingival cleaning alone (PICOS-1), baseline and final measures from 9 studies were considered. The weighted pocket depth (PD) reduction was 1.4 mm (95%CI: 1.0 1.7) at 6/8 months, and the proportion of pocket closure was estimated at 74% (95%CI: 64-85). Six RCTs compared hand and sonic/ultrasonic instruments for subgingival instrumentation (PICOS-2). No significant differences were observed between groups by follow-up time point or category of initial PD. Thirteen RCTs evaluated quadrant-wise versus full-mouth approaches (PICOS-3). No significant differences were observed between groups irrespective of time-points or initial PD. Five studies reported patient-reported outcomes, reporting no differences between groups.

CONCLUSIONS

Nonsurgical periodontal therapy by mechanical subgingival instrumentation is an efficacious means to achieve infection control in periodontitis patients irrespective of the type of instrument or mode of delivery. Prospero ID: CRD42019124887.

The Role of Inflammatory Diet and Vitamin D on the Link between Periodontitis and Cognitive Function: A Mediation Analysis in Older Adults

Patients suffering from periodontitis are at a higher risk of developing cognitive dysfunction. However, the mediation effect of an inflammatory diet and serum vitamin D levels in this link is unclear. In total, 2062 participants aged 60 years or older with complete periodontal diagnosis and cognitive tests from the National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-2014 were enrolled. The Consortium to Establish a Registry for Alzheimer's disease (CERAD) word learning subtest (WLT) and CERAD delayed recall test (DRT), the animal fluency test (AFT) and the digit symbol substitution test (DSST) was used. Dietary inflammatory index (DII) was computed via nutrition datasets. Mediation analysis tested the effects of DII and vitamin D levels in the association of mean probing depth (PD) and attachment loss (AL) in all four cognitive tests. Periodontitis patients obtained worse cognitive test scores than periodontally healthy individuals. DII was negatively associated with CERAD-WLT, CERAD-DRT, AFT and DSST, and was estimated to mediate between 9.2% and 36.4% of the total association between periodontitis with cognitive dysfunction (p < 0.05). Vitamin D showed a weak association between CERAD-DRT, AFT and DSST and was estimated to between 8.1% and 73.2% of the association between periodontitis and cognitive dysfunction (p < 0.05). The association between periodontitis and impaired cognitive function seems to be mediated both by a proinflammatory dietary load and vitamin D deficiency. Future studies should further explore these mediators in the periodontitis-cognitive decline link.

Severe Periodontitis and Biomarkers of Bacterial Burden. Results From a Case-Control and Intervention Clinical Trial

Background and aims: Periodontitis is an inflammatory-infectious disease. Identifying markers of systemic exposure of periodontitis might be of interest to study its interaction with other conditions. Soluble triggering receptor expressed on myeloid cells 1 (sTREM-1) is upregulated during bacterial infections. Our aim was therefore to investigate whether periodontitis and its treatment are associated with bacterial endotoxin and sTREM-1.

Methods: Fifty patients with severe periodontitis and 50 age-matched controls were included in a case-control study (all never smokers). A secondary analysis of a previously published intervention study was performed, in which included 69 patients with severe periodontitis were randomized to receive either intensive (IPT) or control periodontal therapy (CPT) and monitored over 6 months. Serum levels of bacterial endotoxin and sTREM-1 were determined at one time point (case-control study) and at baseline, 1 day, 1 and 6 months after periodontal treatment (intervention study).

Results: Severe periodontitis was associated with elevated circulating endotoxin levels when cases (22.9 ± 2.2 EU/ml) were compared to controls (3.6 ± 0.5 EU/ml, p < 0.001) and with sTREM-1 levels (1302.6 ± 47.8 vs. 870.6 ± 62.0 pg/ml, p < 0.001). A positive correlation was observed between sTREM-1 and endotoxin levels (r = 0.4, p < 0.001). At 6 months after treatment, IPT significantly decreased serum levels of sTREM-1 compared to CPT (adjusted mean difference of 500.2 pg/ml, 95% CI: 18.9–981.4; p = 0.042). No substantial differences were noted in endotoxin levels at any time point after treatment between groups.

Conclusions: Severe periodontitis is linked to increased circulating endotoxin and sTREM-1 levels and following IPT a reduction in sTREM-1 levels is observed.

Mild systemic inflammation enhances response to OnabotulinumtoxinA in chronic migraineurs

The anti-inflammatory effect of OnabotulinumtoxinA (OnabotA) has been a matter of discussion for many years. In chronic migraine, however, increased pro-inflammatory state is associated with good response to OnabotA. We aimed to investigate whether a mild systemic inflammatory state elicited by a common oral infection (periodontitis) could enhance treatment response to OnabotA. In this study, we included 61 chronic migraineurs otherwise healthy treated with OnabotA of which 7 were poor responders and 54 good responders. Before receiving OnabotA therapy, all participants underwent a full-mouth periodontal examination and blood samples were collected to determine serum levels of calcitonin gene-related peptide (CGRP), interleukin 6 (IL-6), IL-10 and high sensitivity C-reactive protein (hs-CRP). Periodontitis was present in 70.4% of responders and 28.6% of non-responders (P = 0.042). Responders showed greater levels of inflammation than non-responders (IL-6: 15.3 ± 8.7 vs. 9.2 ± 4.7 ng/mL, P = 0.016; CGRP: 18.8 ± 7.6 vs. 13.0 ± 3.1 pg/mL, P = 0.002; and hs-CRP: 3.9 ± 6.6 vs. 0.9 ± 0.8 mg/L, P = 0.003). A linear positive correlation was found between the amount of periodontal tissue inflamed in the oral cavity and markers of inflammation (IL-6: r = 0.270, P = 0.035; CGRP: r = 0.325, P = 0.011; and hs-CRP: r = 0.370, P = 0.003). This report shows that in presence of elevated systemic inflammatory markers related to periodontitis, OnabotA seems to reduce migraine attacks. The changes of scheduled inflammatory parameters after treatment and subsequent assessment during an adequate period still need to be done.

Association between Periodontitis and High Blood Pressure: Results from the Study of Periodontal Health in Almada-Seixal (SoPHiAS)

Periodontitis is a common chronic inflammatory disease which could have an important impact on blood pressure (BP). This study aimed to explore (a) the association between periodontal health and BP in a large representative cohort, (b) the predictive value of diagnosis of periodontitis in undiagnosed raised BP and (c) whether age is a mediator of this relationship. In total, 1057 randomly recruited individuals (mean age, 60.9 ± 16.3 years, 57.7% women) underwent periodontal clinical assessment and one-single BP measurement using an automated sphygmomanometer device. Logistic and linear regression models were used to estimate the odds of hypertension based on periodontitis case definitions. Mediation analysis was performed to understand the effect of age on the association of periodontitis with hypertension. Adjusted logistic model for gender, smoking habits and body mass index confirmed the association between high BP and periodontitis (OR = 2.31, 95%CI: 1.75-3.04, p < 0.001). Among 168 participants with undiagnosed high BP (15.9% of the study sample), 62.5% had periodontitis (n = 105). In this study, the association between periodontitis with both systolic blood pressure (SBP) (77.6%, p < 0.001) and diastolic blood pressure (DBP) (66.0%, p < 0.001) was mediated by age. Periodontitis is closely linked to BP in a representative Portuguese population.

Periodontitis and vascular inflammatory biomarkers: an experimental in vivo study in rats

The objective of this preclinical in vivo study was to determine changes in vascular inflammatory biomarkers in systemic circulation after injection of lipopolysaccharide (LPS) from Porphyromonas gingivalis (Pg) in rats. Experimental periodontitis was induced by injections of Pg-LPS. Gingival soft and hard tissues changes were analysed by means of magnetic resonance imaging and micro computed tomography. Serum levels of interleukin (IL)-6, IL-10, pentraxin (PTX) 3, and soluble fragment of tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) were determined at baseline and 24 h, 7, 14, and 21 days after periodontal induction. Significant periodontal inflammation and alveolar bone loss were evident at the end of periodontal induction. Experimental periodontitis posed an acute systemic inflammatory response with increased serum levels of IL-6 and PTX3 at 24 h post-induction, followed by a significant overexpression of sTWEAK at 7 days. This inflammatory state was maintained until the end of the experiment (21 days). As expected, IL-10 serum levels were significantly lower during the follow-up compared to baseline concentrations. In the present animal model, experimental periodontitis is associated with increased systemic inflammation. Further studies are needed to confirm whether PTX3 and sTWEAK could be useful biomarkers to investigate potential mechanisms underlying the relationship between periodontitis and atherosclerotic vascular diseases.

Cell-Based Therapies for Alveolar Bone and Periodontal Regeneration: Concise Review

Current regenerative strategies for alveolar bone and periodontal tissues are effective and well adopted. These are mainly based on the use of a combination of synthetic/natural scaffolds and bioactive agents, obviating the incorporation of cells. However, there are some inherent limitations associated with traditional techniques, and we hypothesized that the use of cell-based therapies as part of comprehensive regenerative protocols may help overcome these hurdles to enhance clinical outcomes. We conducted a systematic review of human controlled clinical trials investigating the clinical and/or histological effect of the use of cell-based therapies for alveolar bone and periodontal regeneration and explored the translational potential of the different cell-based strategies identified in the included trials. A total of 16 studies (11 randomized controlled trials, 5 controlled clinical trials) were included for data synthesis and qualitative analysis with meta-analyses performed when appropriate. The results suggest a clinical benefit from the use of cell therapy. Improved outcomes were shown for alveolar ridge preservation, lateral ridge augmentation, and periodontal regeneration. However, there was insufficient evidence to identify best-performing treatment modalities amongst the different cell-based techniques. In light of the clinical and histological outcomes, we identify extraction socket and challenging lateral and vertical bone defects requiring bone block grafts as strong candidates for the adjuvant application of mesenchymal stem cells. Given the complexity, invasiveness, and costs associated with techniques that include "substantial manipulation" of tissues and cells, their additional clinical benefit when compared with "minimal manipulation" must be elucidated in future trials. Stem Cells Translational Medicine 2019;8:1286&1295.

Severe periodontitis is linked with increased peripheral levels of sTWEAK and PTX3 in chronic migraineurs

OBJECTIVES

Periodontitis (PD) and chronic migraine (CM) have been recently linked, and inflammatory processes and vascular endothelial changes are hypothesized as potential mediators of this relationship. The aim of this cross-sectional analysis was to investigate the potential association of PD with vascular systemic inflammation and complement activation in patients with CM.

MATERIALS AND METHODS

Ninety-four chronic migraineurs underwent a full-mouth periodontal evaluation and a measure of PD activity and severity, namely the periodontal inflamed surface area (PISA) was calculated for each patient. We divided CM patients according to their periodontal status: mild PD (N = 14), moderate PD (N = 22), severe PD (N = 19), and non-PD (N = 39). Serum levels of C-reactive protein (CRP), pentraxin 3 (PTX3), soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK), and complements C3 and C4 were measured outside of migraine attacks.

RESULTS

We found that severe periodontal patients had significantly higher circulating levels of PTX3 and sTWEAK compared with those without PD (2475.3 ± 1646.8 pg/mL vs. 516.6 ± 1193.8 pg/mL, P < 0.0001 and 672.4 ± 118.2 pg/mL vs. 485.7 ± 112.2 pg/mL, P < 0.0001; respectively). For the remaining biomarkers, no significant differences were found between groups. Severe PD was independently associated with higher levels of PTX3 (β = 1997.6, P < 0.0001) and sTWEAK (β = 187.1, P < 0.0001) but not with CRP, C3, and C4. PISA positively correlated to PTX3 (r = 0.475, P < 0.0001) and sTWEAK (r = 0.386, P < 0.0001).

CONCLUSIONS

Based on these preliminary results, severe PD was linked with vascular systemic inflammation in patients with CM. However, further longitudinal studies should be performed to confirm these findings.

CLINICAL RELEVANCE

sTWEAK and PTX3 measured in serum could be used as biomarkers in the PD-CM link.

Porphyromonas gingivalis lipopolysaccharide-induced periodontitis and serum amyloid-beta peptides

OBJECTIVE

The aim of this investigation was to determine the circulating levels of amyloid beta (Aβ) peptides using the Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS) model to induce periodontitis.

METHODS

Experimental periodontitis was induced in 6 male Sprague-Dawley rats. Alveolar bone loss was measure by micro computed tomography. Serum concentrations of Aβ_1-40 and Aβ_1-42 prior to periodontal induction, at 24 h, 7, 14, and 21 days the last injection of Pg-LPS.

RESULTS

The distance between the cemento-enamel junction and the bone crest (i.e., alveolar bone loss) was significantly higher at the end of periodontal induction compared to baseline (2.92 ± 0.29 mm vs. 3.8 ± 0.28 mm, P < 0.001). Periodontitis evoked a slight acute elevation of Aβ_1-40 serum levels that were maintained during the whole experiment. Aβ_1-42 peptide levels peak at the end of the study. A positive strong correlation was observed between alveolar bone loss and Aβ_1-40 serum levels at 7 days (r = 0.695, P = 0.012) and as well as with serum Aβ_1-42 concentrations at 21 days (r = 0.968, P = 0.002).

CONCLUSIONS

Periodontitis induced Pg-LPS produced increased serum levels of Aβ peptides. Further studies are needed to confirm our results and to investigate the mechanisms by which periodontitis could be associated with an overexpression of Aβ.

Periodontitis as a risk indicator and predictor of poor outcome for lacunar infarct

AIM

To investigate the association between periodontitis (PD) and lacunar infarct (LI) as well as to analyse whether PD could be a predictor of poor functional prognosis in patients with LI.

MATERIAL AND METHODS

Full-mouth periodontal examination was done in 120 cases (patients with LI) and 157 healthy controls. Demographic, clinical, medical and neurological information were collected from all of them. In addition, a measure of periodontal inflammation and disease activity, namely the periodontal inflamed surface area (PISA), was also calculated for each patient. Poor functional outcome was considered as a modified Rankin Scale >2 at 3 months.

RESULTS

PD was independently associated with the presence of LI (OR = 3.3, p < 0.001). Poor outcome was observed in 31 patients with LI (25.8%), of which 90.3% had PD. A PISA value ≥727 mm² was an independent predictor of poor prognosis, after adjusting for clinical confounders (OR = 6.5, p = 0.001).

CONCLUSIONS

PD and LI were associated. Active moderate to severe PD predicted poor prognosis in patients with LI. Further evidence is warranted to confirm our results and investigate potential mechanisms behind this association.

Association between periodontitis and chronic migraine: a case-control study

The aim of this investigation was to examine whether chronic periodontitis (CP) is a risk indicator of chronic migraine (CM). We performed a case-control study consisted of 102 cases (patients diagnosed with CM) and 91 controls (non-CM individuals) matched by age and gender. Full-mouth periodontal charts, demographic, medical, clinical, as well as neurological data were obtained. In addition, high sensitive C-reactive protein serum levels were determined from blood samples of both cases (taken during migraine interictal period) and controls. The prevalence of CP was significantly higher in patients with CM compared to those without CM (58.8 vs. 30.8%, p < 0.0001). Logistic regression analysis showed that CP was significantly associated with the presence of CM, independently of well-known chronifying factors of migraine (OR 2.4; 95% CI 1.2-4.7; p = 0.012). Based on our results, CP could be considered as a risk indicator of CM. However, more evidence is necessary to investigate if this relationship is causal or not.

Periodontal inflamed surface area and periodontal case definition classification

OBJECTIVE

To assess whether a higher periodontal inflamed surface area (PISA) may reflect more severe periodontitis, and if so, to calculate which cut-off point should be used to classify a patient as suffering from periodontitis.

MATERIAL AND METHODS

Eighty subjects were selected based on their periodontal status and were divided into 4 groups of 20 each; periodontally healthy, mild periodontitis, moderate periodontitis and severe periodontitis. In addition, demographic data, smoking status and socioeconomic status were also recorded.

RESULTS

The highest mean PISA value was obtained for the severe periodontitis group (2309.42 ± 587.69 mm²) and the least for the periodontally healthy (34.30 ± 16.48 mm²). The PISA values corresponding to the three categories of periodontitis severity were significantly higher than the periodontally healthy group. When receiver operating characteristic (ROC) analysis was performed, a PISA value ≥130.33 mm² predicted the presence of periodontitis with a sensitivity of 98% and a specificity of 100%.

CONCLUSIONS

PISA is a periodontal parameter that may be used in conjunction with the Centers for Disease Control and Prevention - American Academy of Periodontology case definition classification in periodontal medicine research.

OnabotulinumtoxinA in chronic migraine: predictors of response. A prospective multicentre descriptive study

BACKGROUND AND PURPOSE

OnabotulinumtoxinA is a treatment specifically approved for the prophylaxis of chronic migraine in adults. The aim of this study was to assess the effectiveness of OnabotulinumtoxinA in chronic migraine after 1 year of treatment in a real-life setting and to identify clinical predictors of outcome.

METHODS

We designed a prospective multicentre study performed in 13 hospitals in Spain. Patients underwent a complete medical history and examination. They were treated with OnabotulinumtoxinA every 12 weeks for 1 year. Data about outcome, adverse events, abortive medication use, emergency room use and disability were collected at 3 and 12 months.

RESULTS

A total of 725 subjects completed the study. At 12 months, 79.3% showed >50% reduction in number of headaches per month and 94.9% reported no adverse events. Unilaterality of pain, fewer days of disability per month and milder headache at baseline were correlated with good outcome. Duration of disease <12 months increased the chances of response to treatment with OnabotulinumtoxinA (odds ratio, 1.470; 95% confidence interval, 1.123-2.174; P = 0.045).

CONCLUSIONS

This study confirmed the effectiveness of treatment with OnabotulinumtoxinA after 1 year of treatment. The chances of a good outcome may be increased by starting treatment in the first 12 months after chronic migraine diagnosis.

The role of leptin as a biomarker in the relationship between periodontitis and chronic migraine

AIM

To evaluate the prevalence of periodontitis (CP) and its contribution to serum leptin levels in chronic migraine (CM).

MATERIAL AND METHODS

In this case-control study, we included 150 subjects divided into healthy controls (n = 58) and CM patients (n = 92). Demographic, neurological, clinical data as well as full-mouth periodontal records were obtained. Serum leptin levels were measured by ELISA technique.

RESULTS

Both the prevalence of CP and mean serum leptin levels were significantly higher in patients with CM in comparison with controls (57.6% versus 36.2%, p = .01 and 16.4 versus 7.2 ng/ml, p < .0001, respectively). Patients from the CM group who had CP showed significantly higher leptin concentrations than CM patients without CP (19.8 versus 11.8 ng/ml, p < .0001). Multivariable linear regression analysis showed that CP was an independent contributor to raised leptin levels in CM patients (R²  = 0.270, p = 0.013).

CONCLUSIONS

CP is prevalent in CM patients and when present it contributes to elevated serum leptin levels, independently of other confounding factors. Therefore, it seems that CP via leptin could be involved in the process of migraine chronification.

Periodontal disease as a potential factor of migraine chronification

Migraine is a hereditary constitutional base disorder, which is characterized by recurrent episodes of headache pulsatile characteristics associated with photophobia/phonophobia, nausea and/or vomiting. The main complication in migraine is the chronicity of the process, now recognized as a chronic migraine. Although pathogenic mechanisms that may influence the pathophysiology of migraine and its possible chronicity are not fully understood, previous studies have shown in patients with migraine molecular alterations of systemic inflammation, neurogenic inflammation, endothelial dysfunction, innate immunity, dysfunction of matrix proteases and blood-brain barrier. Periodontal disease is an inflammatory lesion caused by bacteria. After the bacterial infection begins, an immune response that will be responsible for individual susceptibility appears. More advanced forms of periodontitis have demonstrated molecular alterations of inflammation, endothelial dysfunction, dysfunction of matrix proteases and innate immunity, similar to those observed in migraine. Furthermore, the main molecular mediators of neurogenic inflammation related to activation of the trigeminovascular system, which are characteristic of migraine, are overexpressed in gingival crevicular fluid and mucosa in patients with periodontal disease. Hypertension, hypercholesterolemia, insulin resistance, stroke or coronary artery disease are comorbidities that periodontal disease and migraine could share. Therefore, several mechanisms and hypotheses could explain the possible association between both diseases. However, epidemiological and molecular studies will be necessary to provide a better understanding of this potential association, which could be implicated in the chronification of migraine.

Is Periodontal Disease Associated with Alzheimer's Disease? A Systematic Review with Meta-Analysis

BACKGROUND

In the last decade, several observational studies have suggested that there exists an association between periodontal disease (PD) and Alzheimer's disease (AD). The aim of this systematic review was to investigate whether or not this link exists.

SUMMARY

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guideline for systematic review was used and registered at PROSPERO (CRD42016035377). The search strategy included using electronic databases and by hand searching articles published up to January 2016. MEDLINE via PubMed, EMBASE and Web of Science were searched by 2 independent reviewers. Observational studies including patients meeting criteria for both AD and PD were eligible to be included in the analysis. Quality assessment of selected studies was performed by the Newcastle-Ottawa Scale. From a total of 550 titles and abstracts, 5 studies were included (2 cross-sectional, 2 case-control and one cohort study) in the review. A fixed effects meta-analysis showed that the presence of PD is associated with the presence of AD (OR 1.69, 95% CI 1.21-2.35). When only severe forms of PD were evaluated, a significant association was also observed (OR 2.98, 95% CI 1.58-5.62). Key Messages: In the present review, a significant association was observed between PD and AD. Further studies should be carried out in order to investigate the direction of the association and factors that may confound it.

Chronic periodontitis is associated with lacunar infarct: a case-control study

BACKGROUND AND PURPOSE

Chronic periodontitis (ChP) and lacunar infarct (LI) are two common diseases amongst the elderly. Although several studies have shown an association between ischaemic stroke and ChP, little is known about the relationship between ChP and LI. The study aims to investigate whether ChP is associated with the presence of lacunar stroke.

METHODS

An age- and gender-matched case-control study of 62 cases (subjects diagnosed with LI) and 60 controls is reported. Clinical periodontal measures (probing pocket depth, recession, clinical attachment level, full mouth plaque score and full mouth gingival bleeding on probing score) were assessed, and associated risk factors for periodontitis and lacunar stroke were ascertained by means of a structured questionnaire.

RESULTS

Chronic periodontitis showed a strong association with LI after adjusting for common vascular risk factors (odds ratio 4.20; 95% confidence interval 1.81-10.20; P = 0.001). Likewise, severe ChP and LI also tended to be significantly associated, independent of other vascular covariates (odds ratio 3.53; 95% confidence interval 1.07-12.77; P = 0.04).

CONCLUSIONS

Chronic periodontitis was independently associated with the presence of LI after adjusting for well-known vascular risk factors for lacunar stroke. Further observational studies are necessary to investigate the pathophysiological mechanisms that can explain this relationship.

Association between periodontitis and ischemic stroke: a systematic review and meta-analysis

Several observational studies have suggested an association between periodontitis and cerebral ischemia. This meta-analysis aimed to investigate whether this link exists, and if so, the degree to which it is significant. The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guideline for systematic review was used. The search strategy included using electronic databases and hand searching works published up to March 2015. MEDLINE via PubMed, EMBASE, Proceedings Web of Science and Current Contents Connect were searched by two independent reviewers. Case-control, cross-sectional or cohort studies including patients with measures of periodontitis and ischemic stroke were eligible to be included in the analysis. Quality assessments of selected studies were performed. From a total of 414 titles and abstracts, 57 potentially relevant full text papers were identified. After inclusion criteria were applied, 8 studies were included in the present systematic review (5 case-control and 3 cohort studies). Although it was not the intention, cross-sectional studies were excluded due to eligibility criteria were not accomplished. Therefore, meta-analyses were conducted with data retrieved from the 8 studies included. These meta-analyses showed statistically significant association between periodontitis and ischemic stroke in both cohort pooled relative risks at 2.52 (1.77-3.58), and case-control studies pooled relative risks at 3.04 (1.10-8.43). In conclusion, the present meta-analysis demonstrated an association between periodontitis and ischemic stroke. However, well-designed prospective studies should be carried out to provide robust evidence of the link between both diseases. In regards to ischemic stroke subtypes, further case-control studies should be carried out to investigate whether there is any association between the different subtypes of cerebral infarcts and periodontitis.

[Association between periodontal disease and cerebrovascular disease. A review of the literature]

Periodontal disease and cerebrovascular disease are two of the most prevalent processes in elderly people. Various studies have shown an association between them, although some methodological differences exist and this difficult the data interpretation. The aim of this paper is to conduct a critical review of the studies published about this association. Eleven prospective studies and 11 retrospective studies are included in this review. We analyse the different methodological outcomes (study population, periodontal diagnosis, cerebrovascular disease definition, adjusted outcomes and odds ratio/relative risk). Furthermore, we review several pathogenic mechanisms implicated in the progression and the relationship between both processes.