Effects of periodontal treatment on carotid intima-media thickness in patients with lifestyle-related diseases: Japanese prospective multicentre observational study

Impact of nonsurgical periodontal treatment on arterial stiffness outcomes related to endothelial dysfunction: A systematic review and meta-analysis

BACKGROUND

To assess the available evidence on whether nonsurgical periodontal treatment (NSPT) improves arterial stiffness outcomes in patients with periodontitis (PD).

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and population, intervention, comparison, outcomes, and study design (PICOS) question, electronic databases were screened for clinical interventional studies addressing the impact of NSPT on pulse wave velocity (PWV), carotid intima-media thickness (CIMT), and flow-mediated dilatation (FMD) outcomes in PD patients. Furthermore, the research strategy was implemented using a hand search. Studies were selected, and data were extracted by two independent reviewers. Random effects models were applied to perform a meta-analysis, and methodological index for nonrandomized studies (MINORS) and Cochrane Rob2 tools were used to assess the risk of bias.

RESULTS

Fifteen articles were finally included for qualitative synthesis. Among them, eight single-arm cohort studies met the final inclusion criteria for meta-analysis. The Rob2 analysis evidenced that one randomized clinical trial (RCT) had a low risk, three RCTs raised some concerns, and three RCTs had a high risk of bias, while the MINORS scores ranged from 9 to 14. The meta-analysis showed that NSPT significantly impacted FMD (p < 0.001) and CIMT (p = 0.004), while changes in PWV were not statistically significant. However, there was high heterogeneity among studies (I2 = 78% for FMD and I2 = 62% for CIMT).

CONCLUSION

Despite some beneficial effects on FMD and CIMT, due to study limitations, high heterogeneity, and risk of bias, it cannot be concluded that NSPT is effective in improving arterial stiffness. Therefore, further studies are necessary to achieve high-quality evidence on the effect of NSPT on arterial stiffness outcomes in PD patients.

TRIAL REGISTRATION

PROSPERO ID CRD42024501399.

PLAIN LANGUAGE SUMMARY

Periodontitis (PD) has been associated with alterations in arterial stiffness outcomes related to early endothelial dysfunction. Based on noninterventional studies, this meta-analysis indicates that nonsurgical periodontal treatment (NSPT) may reduce cardiovascular disease risk in patients with PD. The moderate evidence derived from the studies that were finally included showed that NSPT had beneficial effects on flow-mediated dilatation and carotid intima-media thickness, while this trend was not observed for pulse wave velocity. Moreover, the findings of the present meta-analysis were characterized by high heterogeneity and risk of bias and were derived from uncontrolled clinical trials or randomized clinical trials with limitations. Therefore, more studies with standardized protocols and homogeneous arterial stiffness outcomes are needed to elevate the quality of the present evidence.

Bacterial DNA and serum IgG antibody titer assays for assessing infection of human-pathogenic and dog-pathogenic Porphyromonas species in dogs

Periodontal disease is highly prevalent in both humans and dogs. Although there have been reports of cross-infection of periodontopathic bacteria, methods for assessing it have yet to be established. The actual status of cross-infection remains to be seen. The purpose of this study was to evaluate the utility of bacterial DNA and serum immunoglobulin G (IgG) antibody titer assays to assess infection of human-pathogenic and dog-pathogenic Porphyromonas species in dogs. Four experimental beagles were used for establishing methods. Sixty-six companion dogs at veterinary clinics visiting for treatment and prophylaxis of periodontal disease were used and divided into healthy, gingivitis, and periodontitis groups. Periodontal pathogens such as Porphyromonas gingivalis and Porphyromonas gulae were investigated as target bacteria. DNA levels of both bacteria were measured using species-specific primers designed for real-time polymerase chain reaction (PCR). Serum IgG titers of both bacteria were measured by enzyme-linked immunosorbent assay (ELISA). PCR primers were confirmed to have high sensitivity and specificity. However, there was no relationship between the amount of bacterial DNA and the severity of the periodontal disease. In addition, dogs with periodontitis had higher IgG titers against both bacteria compared to dogs in the healthy and gingivitis groups; there was cross-reactivity between the two bacteria. Receiver operating characteristic (ROC) analysis of IgG titers against both bacteria showed high sensitivity (>90 %) and specificity (>75 %). Since both bacteria were distinguished by DNA assays, the combination of these assays may be useful in the evaluation of cross-infection.

Measurement of atherosclerosis markers in individuals with periodontitis

PURPOSE

The inflammatory response due to inflammatory cytokines, bacterial pathogens, and the altered lipoprotein metabolism in patients with periodontitis indicates that infection with periodontal anaerobic bacteria may influence atherogenesis in vitro and in vivo. We aimed to explore the effect of periodontitis concerning clinical and ultrasound markers of early atherosclerosis.

METHODS

In this case-control study, a total of 30 systemically healthy adults (15 with periodontitis and 15 without periodontitis) over 40 years of age were studied. Periodontitis was determined by measuring the clinical attachment level (CAL) and radiographic bone loss (RBL). Conventional cardiovascular risk factors, including body mass index, serum levels of total cholesterol (TCH), triglycerides (TG), and high-density and low-density lipoprotein (HDL and LDL, respectively) cholesterol were evaluated. Carotid artery intima-media thickness (IMT) was measured using ultrasonography.

RESULTS

The mean values of the CAL and carotid IMT were 5.02±0.9 mm and 0.084±0.01 cm vs. 1.6±0.61 mm and 0.072±0.02 cm in the periodontitis and healthy groups, respectively, reflecting statistically significant differences (P=0.001 and P=0.037, respectively). There were statistically significant differences in the serum levels of TCH, TG, and LDL between the 2 groups (P=0.017). The CAL and RBL were positively associated with carotid IMT and serum cholesterol levels, except for HDL, whereas tooth loss was not associated with any markers (P<0.05). Compared to the healthy group, participants with periodontitis exhibited 2.09 times higher odds (95% confidence interval, 1.22-3.59) of having subclinical atherosclerosis.

CONCLUSIONS

The presence of periodontitis increased the risk of atherosclerosis.

The Association between High-density Lipoproteins and Periodontitis

Periodontitis is one of the most typical chronic dental diseases. This inflammatory disease can change various functions of immune cells and impair lipid metabolism through proinflammatory cytokines. High-Density Lipoprotein (HDL) is considered protective of the cardiovascular system. It has anti-thrombotic and anti-inflammatory effects. In this article, we have reviewed the association between periodontitis and HDL. Various studies have demonstrated a reverse relationship between inflammatory cytokines and HDL. HDL contains antioxidative enzymes and proteins, whereas periopathogens impair HDL's antioxidant function. The presence of periodontal bacteria is associated with a low HDL level in patients with periodontitis. Genetic variants in the interleukin- 6 (IL)-6 gene and cytochrome (CYP)1A1 rs1048943 gene polymorphism are associated with HDL levels and periodontal status. Studies showed that HDL levels improve after treatment for periodontitis. On the one hand, periodontal pathogenic bacteria and their metabolites and pro-inflammatory cytokines from periodontal infection can result in various disorders of lipid metabolism and lipid peroxidation. On the other hand, hyperlipidemia and lipid peroxidation stimulate proinflammatory cytokines, resulting in oxidative stress and delayed wound healing, making individuals susceptible to periodontitis.

Association between the interval of worksite dental check-ups and dental and medical expenditures: a single-site, 12-year follow-up study in Japan

OBJECTIVES

The purpose of this study was to identify the effective intervals of worksite dental check-ups to reduce cumulative dental expenditures (CDEs) and cumulative medical expenditures (CMEs), based on 12 years of follow-up dental check-ups.

SETTING, DESIGN AND PARTICIPANTS

A longitudinal study was conducted between 2002 and 2014 fiscal years. A total of 2691 full-time employees (2099 males and 592 females) aged 20-59 years in a manufacturing company in Japan were recruited.

PRIMARY AND SECONDARY OUTCOME MEASURES

Based on the follow-up of 12-year dental check-ups, the interval of dental check-ups visits was classified into the following categories: 'Once per year' as the regular group, 'At least once per 2 years' as the subregular group and others as the irregular group. CDEs and CMEs per capita were examined by the three groups of dental check-ups interval after adjustment for sex, age, occupation and total CMEs at baseline. For sensitivity analysis, decayed teeth, missing teeth and Community Periodontal Index were added as adjustment factors.

RESULTS

Compared with the irregular group, the pooled CDEs (including dental check-ups fee) per capita in the subregular group (OR 0.91, 95% CI 0.85 to 0.98) and regular group (OR 0.87, 95% CI 0.81 to 0.93) were significantly lower overall. The younger adults in the subregular group and younger-aged and middle-aged adults in the regular group had significantly lower CDEs. Sensitivity analysis confirmed these findings.

CONCLUSIONS

Our findings suggest that regular and subregular worksite dental check-ups were related to reduction of CDEs. It is important to promote a yearly interval between dental check-ups.

Risk Assessment of Cnm-Positive Streptococcus mutans in Stroke Survivors (RAMESSES): Protocol for a Multicenter Prospective Cohort Study

Introduction

The role of commensal microbiota in systemic diseases, including brain diseases, has attracted increasing attention. Oral infectious diseases, such as dental caries and periodontitis, are also involved in cerebrovascular diseases and cognitive impairment. Cerebral microbleeds (CMBs) and intracerebral hemorrhage due to small vessel disease (SVD), are presumably associated with a high risk of vascular cognitive impairment and stroke. We previously reported that Streptococcus mutans (S. mutans, the main pathogen of dental caries), harboring the cnm gene that encodes the collagen-binding protein Cnm, is associated with the development of hypertensive intracerebral hemorrhage and aggravation of CMBs. We also proposed a mechanism by which the circulating Cnm-expressing S. mutans causes intracerebral hemorrhage or CMBs; it binds to denuded basement membranes mainly composed of collagen IV through damaged tight junctions or it directly invades endothelial cells, resulting in blood-brain barrier injury. In November 2018, we initiated a multicenter, prospective cohort study (RAMESSES: Risk Assessment of Cnm-positive S. mutans in Stroke Survivors; UMIN Clinical Trials Registry: UMIN000045559) to explore the longitudinal association between Cnm-positive S. mutans and CMBs with comprehensive dental findings, which should determine the effect of Cnm-positive S. mutans in the oral cavity on the risk of CMB development and cognitive decline.

Methods

Fifteen domestic institutes will be enlisted to enroll 230 patients who have at least one CMB in the deep brain area and develop a stroke within the past year. The prevalence of Cnm-positive S. mutans based on oral specimens and dental hygiene will be examined. The primary outcome is the number of newly developed deep CMBs. The secondary outcomes include the new development of lobar, subtentorial, or any type of CMBs; symptomatic intracerebral hemorrhage or ischemic stroke; changes in cognitive function or frailty; major bleeding; all-cause mortality; and antibody titers against periodontal pathogens. The observation period will be 2 years.

Discussion

The 2-year longitudinal prospective cohort study is expected to establish the role of Cnm-positive S. mutans in SVD including CMBs and intracerebral hemorrhage from the perspective of the “brain-oral axis” and provide guidance for novel prophylactic strategies against Cnm-positive S. mutans-induced SVD.

Periodontopathic Microbiota and Atherosclerosis: Roles of TLR-Mediated Inflammation Response

Atherosclerosis is a chronic inflammatory disease with a high prevalence worldwide, contributing to a series of adverse cardiovascular and cerebrovascular diseases. Periodontal disease induced by pathogenic periodontal microbiota has been well established as an independent factor of atherosclerosis. Periodontal microorganisms have been detected in atherosclerotic plaques. The high-risk microbiota dwelling in the subgingival pocket can stimulate local and systematic host immune responses and inflammatory cascade reactions through various signaling pathways, resulting in the development and progression of atherosclerosis. One often-discussed pathway is the Toll-like receptor-nuclear factor-κB (TLR-NF-κB) signaling pathway that plays a central role in the transduction of inflammatory mediators and the release of proinflammatory cytokines. This narrative review is aimed at summarizing and updating the latest literature on the association between periodontopathic microbiota and atherosclerosis and providing possible therapeutic ideas for clinicians regarding atherosclerosis prevention and treatment.

The Effects of Porphyromonas gingivalis on Atherosclerosis-Related Cells

Atherosclerosis (AS), one of the most common types of cardiovascular disease, has initially been attributed to the accumulation of fats and fibrous materials. However, more and more researchers regarded it as a chronic inflammatory disease nowadays. Infective disease, such as periodontitis, is related to the risk of atherosclerosis. Porphyromonas gingivalis (P. gingivalis), one of the most common bacteria in stomatology, is usually discovered in atherosclerotic plaque in patients. Furthermore, it was reported that P. gingivalis can promote the progression of atherosclerosis. Elucidating the underlying mechanisms of P. gingivalis in atherosclerosis attracted attention, which is thought to be crucial to the therapy of atherosclerosis. Nevertheless, the pathogenesis of atherosclerosis is much complicated, and many kinds of cells participate in it. By summarizing existing studies, we find that P. gingivalis can influence the function of many cells in atherosclerosis. It can induce the dysfunction of endothelium, promote the formation of foam cells as well as the proliferation and calcification of vascular smooth muscle cells, and lead to the imbalance of regulatory T cells (Tregs) and T helper (Th) cells, ultimately promoting the occurrence and development of atherosclerosis. This article summarizes the specific mechanism of atherosclerosis caused by P. gingivalis. It sorts out the interaction between P. gingivalis and AS-related cells, which provides a new perspective for us to prevent or slow down the occurrence and development of AS by inhibiting periodontal pathogens.

Number of teeth is associated with all-cause and disease-specific mortality

BACKGROUND

Tooth loss has been shown to correlate with multiple systemic comorbidities. However, the associations between the number of remaining natural teeth (NoT) and all-cause mortality have not been explored extensively. We aimed to investigate whether having fewer NoT imposes a higher risk in mortality. We tested such hypotheses using three groups of NoT (20-28,10-19, and 0-9), edentulism and without functional dentition (NoT < 19).

METHODS

The National Health and Nutrition Examination Survey in the United States (NHANES) (1999-2014) conducted dental examinations and provided linkage of mortality data. NHANES participants aged 20 years and older, without missing information of dental examination, age, gender, race, education, income, body-mass-index, smoking, physical activities, and existing systemic conditions [hypertension, total cardiovascular disease, diabetes, and stroke (N = 33,071; death = 3978), or with femoral neck bone mineral density measurement (N = 13,131; death = 1091)] were analyzed. Cox proportional hazard survival analyses were used to investigate risks of all-cause, heart disease, diabetes and cancer mortality associated with NoT in 3 groups, edentulism, or without functional dentition.

RESULTS

Participants having fewer number of teeth had higher all-cause and disease-specific mortality. In fully-adjusted models, participants with NoT0-9 had the highest hazard ratio (HR) for all-cause mortality [HR(95%CI) = 1.46(1.25-1.71); p < .001], mortality from heart diseases [HR(95%CI) = 1.92(1.33-2.77); p < .001], from diabetes [HR(95%CI) = 1.67(1.05-2.66); p = 0.03], or cancer-related mortality [HR(95%CI) = 1.80(1.34-2.43); p < .001]. Risks for all-cause mortality were also higher among the edentulous [HR(95%CI) = 1.35(1.17-1.57); p < .001] or those without functional dentition [HR(95%CI) = 1.34(1.17-1.55); p < .001].

CONCLUSIONS

Having fewer NoT were associated with higher risks for all-cause mortality. More research is needed to explore possible biological implications and validate our findings.

Association between periodontal disease and vulnerable plaque morphology in patients undergoing carotid endarterectomy

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Periodontal disease is associated with echolucent plaques.

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Periodontal disease is associated with increased macrophages in plaques.

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Periodontal disease is associated with decreased smooth muscle cells in plaques.

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Periodontal disease is associated with plaque instability.

Background

Periodontal disease (PD) is a chronic inflammatory oral condition with potentially important systemic sequelae. We sought to determine whether the presence of PD in patients with severe carotid disease was associated with morphological features consistent with carotid plaque instability.

Methods

A total of 52 dentate patients hospitalized for carotid endarterectomy (CEA) had standardized assessments of their periodontal status, including measurements of probing pocket depth (PPD), clinical attachment level (CAL) and bleeding on probing (BoP). Carotid plaque morphology was assessed by ultrasound using the gray scale median (GSM) score and by immunohistochemistry using anti-CD68 and anti-alpha-actin antibodies, markers for macrophages and smooth muscle cells (SMCs) respectively.

Results

In total 30/52 patients (58%) had PD. Significant associations were noted between low GSM on ultrasound and each mm in PPD (p = 0.001), each mm in CAL (p = 0.002) and with a 10% increase in BoP (p = 0.009). Using the standardized PERIO definition the association remained robust (aOR = 10.4 [95% CI:2.3–46.3], p = .002). Significant associations were also observed with high macrophage accumulation and each individual PD measure (p < 0.01 for PPD, CAL and BoP) and with the PERIO definition (aOR = 15 [95% CI:1.8–127.8], p = .01). Similarly, low SMC density was also significantly associated with individual measures of PD (p < 0.05 for PPD, CAL and BoP), but not with the PERIO definition (aOR 3.4 [95% CI:0.9–12.8], p = .07).

Conclusions

The presence of PD was significantly associated with both ultrasound and immunohistochemistry features of carotid plaque instability in patients undergoing CEA.

Identification and Modification of Porphyromonas gingivalis Cysteine Protease, Gingipain, Ideal for Screening Periodontitis

Chronic periodontitis is an inflammatory disease caused by the formation of oral microbial biofilms. Periodontitis is associated with general health and not only oral diseases. Porphyromonas gingivalis is a well-known keystone pathogen for periodontitis and is associated with several systemic diseases, such as diabetes mellitus and Alzheimer's disease. We previously developed a system for screening periodontitis using P. gingivalis-specific serum immunoglobulin G (IgG) in an enzyme-linked immunosorbent assay with a sensitivity of 0.774 and a specificity of 0.586 and an area under the receiver operating characteristic curve of 0.708. However, the antigens elicited non-specific responses, since they were obtained from whole extracts of sonicated cultured bacteria. The purpose of this study was to identify antigens ideal for a sensitive and specific serum test. We identified the specific antigens using immunoaffinity columns immobilized with IgG antibodies from periodontitis patients. Liquid chromatography-tandem mass spectrometry identified 29 antigens from the elutes. Recombinant proteins for these candidates were synthesized using the wheat germ cell-free translation system and screened by dot blot analysis with serum from the columns. Three of the 16 candidates that reacted showed strongest affinities upon dot blot analysis; they included outer membrane protein 28, cysteine proteases, lysine gingipain Kgp, and arginine gingipain RgpA. Outer membrane protein 28 was not suitable for screening P. gingivalis infection because of its high false-negative rates. Kgp and RgpA were unstable antigens since they underwent self-digestion. They were made stable by substituting the active cysteine residues in Kgp and RgpA with alanine using site-directed mutagenesis. Using the modified antigens, we demonstrated that the patient serum IgG level against RgpA was the highest among all the antigens expressed in P. gingivalis. Moreover, the N-terminus of recombinant RgpA was excellent in differentiating between diseased and non-diseased states (with sensitivity of 0.85, specificity of 0.9, and area under the curve of 0.915). Although dot blot analysis was the only experiment used, the N-terminus of RgpA is an excellent antigen to immunologically test for P. gingivalis infection, especially for estimating the risks for periodontitis-associated systemic diseases. In conclusion, we have developed a P. gingivalis antigen for screening periodontitis.