Periodontitis in individuals with liver cirrhosis: A case-control study

Microbial Approaches to Treat and Prevent Hepatic Encephalopathy

This review articulates the significance of the gut-liver-brain axis in understanding hepatic encephalopathy (HE), emphasizing the role of gut microbiota in influencing liver and brain health. Key treatments like lactulose, rifaximin, probiotics, and fecal microbiota transplantation are examined for their ability to modulate the gut microbiome, thereby mitigating HE symptoms through reduced neurotoxin production and enhanced gut barrier integrity. The synopsis highlights both established and emerging microbial therapies, presenting them as crucial to the management and future strategies of HE. This comprehensive overview explores current therapeutic approaches alongside promising future interventions, suggesting that personalized microbiome-focused treatments may revolutionize HE management.

Population-specific differences in the human microbiome: Factors defining the diversity

Differences in microbial communities at different body habitats define the microbiome composition of the human body. The gut, oral, skin vaginal fluid and tissue microbiome, are pivotal for human development and immune response and cross talk between these microbiomes is evident. Population studies reveal that various factors, such as host genetics, diet, lifestyle, aging, and geographical location are strongly associated with population-specific microbiome differences. The present review discusses the factors that shape microbiome diversity in humans, and microbiome differences in African, Asian and Caucasian populations. Gut microbiome studies show that microbial species Bacteroides is commonly found in individuals living in Western countries (Caucasian populations), while Prevotella is prevalent in non-Western countries (African and Asian populations). This association is mainly due to the high carbohydrate, high fat diet in western countries in contrast to high fibre, low fat diets in African/ Asian regions. Majority of the microbiome studies focus on the bacteriome component; however, interesting findings reveal that increased bacteriophage richness, which makes up the virome component, correlates with decreased bacterial diversity, and causes microbiome dysbiosis. An increase of Caudovirales (bacteriophages) is associated with a decrease in enteric bacteria in inflammatory bowel diseases. Future microbiome studies should evaluate the interrelation between bacteriome and virome to fully understand their significance in the pathogenesis and progression of human diseases. With ethnic health disparities becoming increasingly apparent, studies need to emphasize on the association of population-specific microbiome differences and human diseases, to develop microbiome-based therapeutics. Additionally, targeted phage therapy is emerging as an attractive alternative to antibiotics for bacterial infections. With rapid rise in microbiome research, focus should be on standardizing protocols, advanced bioinformatics tools, and reducing sequencing platform related biases. Ultimately, integration of multi-omics data (genomics, transcriptomics, proteomics and metabolomics) will lead to precision models for personalized microbiome therapeutics advancement.

Periodontal disease and cirrhosis: current concepts and future prospects

Periodontal diseases are prevalent among the general population and are associated with several systemic conditions, such as chronic kidney disease and type 2 diabetes mellitus. Chronic liver disease and cirrhosis have also been linked with periodontal disease, an association with complex underlying mechanisms, and with potential prognostic implications. Multiple factors can explain this relevant association, including nutritional factors, alcohol consumption, disruption of the oral-gut-liver axis and associated dysbiosis. Additionally, patients with liver disease have been observed to exhibit poorer oral hygiene practices compared with the general population, potentially predisposing them to the development of periodontal disease. Therefore, it is recommended that all patients with liver disease undergo screening and subsequent treatment for periodontal disease. Treatment of periodontal disease in patients with cirrhosis may help reduce liver-derived inflammatory damage, with recent research indicating a potential benefit in terms of reduced mortality. However, further studies on periodontal disease treatment in patients with liver disease are still warranted to determine optimal management strategies. This narrative review describes current concepts on the association between periodontal disease and chronic liver disease.

Oral Pathogens' Substantial Burden on Cancer, Cardiovascular Diseases, Alzheimer's, Diabetes, and Other Systemic Diseases: A Public Health Crisis-A Comprehensive Review

This review synthesizes the findings from 252 studies to explore the relationship between the oral pathogens associated with periodontitis, dental caries, and systemic diseases. Individuals with oral diseases, such as periodontitis, are between 1.7 and 7.5 times (average 3.3 times) more likely to develop systemic diseases or suffer adverse pregnancy outcomes, underscoring the critical connection between dental and overall health. Oral conditions such as periodontitis and dental caries represent a significant health burden, affecting 26-47% of Americans. The most important oral pathogens, ranked by publication frequency, include the herpes virus, C. albicans, S. mutans, P. gingivalis, F. nucleatum, A. actinomycetemcomitans, P. intermedia, T. denticola, and T. forsythia. The systemic diseases and disorders linked to oral infections, ranked similarly, include cancer, respiratory, liver, bowel, fever, kidney, complications in pregnancy, cardiovascular bacteremia, diabetes, arthritis, autoimmune, bladder, dementia, lupus, and Alzheimer's diseases. Evidence supports the efficacy of dental and periodontal treatments in eliminating oral infections and reducing the severity of systemic diseases. The substantial burden that oral pathogens have on cancer, cardiovascular diseases, Alzheimer's, diabetes, and other systemic diseases poses a significant public health crisis.

Exosomes derived from periodontitis induce hepatic steatosis through the SCD-1/AMPK signaling pathway

AIM

To investigate the impact of exosomes released by Porphyromonas gingivalis-Lipopolysaccharide activated THP-1 macrophages and human periodontal ligament fibroblasts on hepatocyte fat metabolism.

RESULTS

The liver of rats with experimental periodontitis showed obvious steatosis and inflammation compared with control rats. The culture supernatant of macrophages and human periodontal ligament fibroblasts (hPDLFs), when stimulated with Pg-LPS, induced lipogenesis in HepG2 cells. Furthermore, the lipid-promoting effect was effectively inhibited by the addition of the exosome inhibitor GW4869. Subsequently, we isolated exosomes from cells associated with periodontitis. Exosomes released by Pg-LPS-stimulated macrophages and hPDLFs are taken up by hepatocytes, causing mRNA expression related to fat synthesis, promoting triglyceride synthesis, and aggravating NAFLD progression. Finally, two sets of exosomes were injected into mice through the tail vein. In vivo experiments have also demonstrated that periodontitis-associated exosomes promote the development of hepatic injury and steatosis, upregulate SCD-1 expression and inhibit the AMPK signaling pathway.

CONCLUSIONS

In conclusion, we found that exosomes associated with periodontitis promote hepatocyte adipogenesis by increasing the expression of SCD-1 and suppressing the AMPK pathway, which indicates that close monitoring of the progression of stomatopathy associated extra-oral disorders is important and establishes a theoretical foundation for the prevention and management of fatty liver disease linked to periodontitis.

Histological and Biochemical Evaluation of Silibinin in Treatment of Periodontitis Induced in Rats with Liver Cirrhosis

AIM

This study aimed to evaluate the impact of silibinin as a therapeutic agent on ligature-induced periodontitis in rats with liver cirrhosis.

MATERIALS AND METHODS

Twenty-five Wistar rats were enrolled in this study. Group A (Control) included eight rats. The other 17 rats received CCl4 to develop cirrhosis, which was confirmed by sacrificing one of the rats and performing a histological examination of its liver tissue. Periodontitis was induced in the remaining 16 rats then they were allocated into (n = 8) group B-periodontitis with cirrhosis and group C-silibinin-treated group, 5 times/week starting from week 11 till week 14. Animals of the three groups were euthanized, and biochemical analysis comprising of liver functions assessment (serum levels of glutamate-pyruvate transaminase, serum levels of glutamate-oxalate transaminase, TIMP1) and oxidative stress index [MDA, nitric oxide (NO), superoxide dismutase (SOD), and catalase (CAT)] and histological examination were conducted by the end of week 14.

RESULTS

Group C revealed a more organized orientation of the periodontal ligament (PDL) collagen fibers with a marked regain of the alveolar bone height compared to group B. Biochemical analysis confirmed the potent therapeutic effect of silibinin manifested by a significant improvement in the biochemical parameters: tissue inhibitor of metalloproteinase-1, MDA, NO levels, and antioxidant enzymes.

CONCLUSION

Group B was associated with the most unfavorable biochemical findings and the maximum periodontal destruction. Group C demonstrated a positive osteogenic capacity and a noteworthy improvement in biochemical findings, which were comparable to those of group A, which displayed normal and healthy findings.

CLINICAL SIGNIFICANCE

The study highlights the potential use of silibinin as a natural remedy with minimal side effects for treating periodontitis in rats with liver cirrhosis. The findings could be translated to human clinical trials, which may lead to new treatment strategies using silibinin as a targeted therapy or as adjunctive therapy to conventional periodontal treatment for patients with liver cirrhosis who are more susceptible to periodontitis. How to cite this article: Shawky HA, Ahmed NM, Essawy MM, et al. Histological and Biochemical Evaluation of Silibinin in Treatment of Periodontitis Induced in Rats with Liver Cirrhosis. J Contemp Dent Pract 2024;25(7):631-638.

Periodontitis and NAFLD-related diseases: A bidirectional two-sample Mendelian randomization study

BACKGROUND

Epidemiological studies have shown an association between periodontitis and nonalcoholic fatty liver disease (NAFLD)-related diseases. However, a causal relationship between these two diseases remains unclear. To examine the causal relationship between these two diseases, we conducted a bidirectional two-sample Mendelian randomization (MR) analysis using genetic markers as proxies.

METHODS

Statistical summary was obtained from a large genome-wide association study (GWAS) on NAFLD (N = 342,499), nonalcoholic steatohepatitis (NASH, N = 342,499), fibrosis (N = 339,081), cirrhosis (N = 342,499), fibrosis/cirrhosis (N = 334,553), and periodontitis (N = 34,615) in the European ancestry. The inverse variance weighted (IVW) method was used as the main method to estimate the bidirectional association. Sensitivity analysis was performed to evaluate the rigidity of the results.

RESULTS

Limited evidence indicated positive causal associations between genetically predicted NAFLD and periodontitis (IVW odds ratio [OR], 1.094; 95% confidence interval [CI], 1.006-1.189; p = 0.036) and between cirrhosis and periodontitis (IVW OR, 1.138; 95% CI, 1.001-1.294; p = 0.048). However, the opposite trend did not indicate a causative effect of periodontitis on NAFLD-related diseases. The sensitivity analysis revealed no obvious pleiotropy or heterogeneity.

CONCLUSIONS

Our MR analysis provides new evidence in favor of the moderate causal impact of NAFLD on periodontitis. The causal effects of periodontitis on NAFLD-related diseases warrant further investigation.

A literature review of bioactive substances for the treatment of periodontitis: In vitro, in vivo and clinical studies

Periodontitis is a common chronic inflammatory disease of the supporting tissues of the tooth that involves a complex interaction of microorganisms and various cell lines around the infected site. To prevent and treat this disease, several options are available, such as scaling, root planning, antibiotic treatment, and dental surgeries, depending on the stage of the disease. However, these treatments can have various side effects, including additional inflammatory responses, chronic wounds, and the need for secondary surgery. Consequently, numerous studies have focused on developing new therapeutic agents for more effective periodontitis treatment. This review explores the latest trends in bioactive substances with therapeutic effects for periodontitis using various search engines. Therefore, this study aimed to suggest effective directions for therapeutic approaches. Additionally, we provide a summary of the current applications and underlying mechanisms of bioactive substances, which can serve as a reference for the development of periodontitis treatments.

Oral Pathogenic Bacteria and the Oral-Gut-Liver Axis: A New Understanding of Chronic Liver Diseases

Liver diseases have long been a prevalent cause of morbidity and mortality, and their development and progression involve multiple vital organs throughout the body. Recent studies on the oral-gut-liver axis have revealed that the oral microbiota is associated with the pathophysiology of chronic liver diseases. Since interventions aimed at regulating oral biological disorders may delay the progress of liver disease, it is crucial to better comprehend this process. Oral bacteria with potential pathogenicity have been extensively studied and are closely related to several types of chronic liver diseases. Therefore, this review will systemically describe the emerging role of oral pathogenic bacteria in common liver diseases, including alcoholic liver disease (ALD), non-alcoholic steatohepatitis (NASH), non-alcoholic fatty liver disease (NAFLD), cirrhosis, autoimmune liver diseases (AILD), and liver cancer, and bring in new perspectives for future research.

Periodontal health status in cirrhotic patients: a systematic review and meta-analysis

OBJECTIVES

Liver cirrhosis is a disease with widespread prevalence and high mortality. Oral manifestations, particularly periodontal-related manifestations such as bleeding gums, red and swollen gums, are common in cirrhotic patients but may often be overshadowed by other systemic complications, making them easy to ignore. So this article conducts a systematic review and meta-analysis of periodontal health status in patients with cirrhosis.

MATERIAL AND METHODS

We performed electronic searches on the following databases: PubMed, EMBASE, Scopus, Web of Science, and Cochrane Library. Risk of bias evaluation was carried out according to the Fowkes and Fulton guidelines. Meta-analyses were performed with tests for sensitivity and statistical heterogeneity.

RESULTS

Of the 368 potentially eligible articles, 12 studies were included for qualitative analysis, and 9 contributed to the meta-analysis. In terms of periodontal-related parameters, cirrhotic patients presented a greater mean of clinical attachment loss (CAL) (weighted mean differences [WMD] = 1.078, 95% confidence interval [95% CI]: 0.546-1.609, p < 0.001), probing depth (PD) (WMD = 0.796, 95% CI: 0.158 to 1.434, p = 0.015) and alveolar bone loss (ABL) (WMD = 3.465, 95% CI: 2.946-3.984, p < 0.001) than those without, while no statistical difference was found in the papillary bleeding index (PBI) (WMD = 0.166, 95% CI: -0546 to 0.878, p = 0.647) and bleeding on probing (BOP) (WMD = 4.913, 95% CI: -3.099 to 12.926, p = 0.229). The prevalence of periodontitis was higher in cirrhotic patients than in the control group (odds ratio [OR] = 2.630, 95% CI: 1.531-4.520, p < 0.001).

CONCLUSIONS

The results indicate that cirrhotic patients have poor periodontal conditions and a higher prevalence of periodontitis. We advocate that they should receive regular oral hygiene and basic periodontal treatment.

Long‐term impact of patients' compliance to peri‐implant maintenance therapy on the incidence of peri‐implant diseases: An 11‐year prospective follow‐up clinical study

OBJECTIVE

To prospectively evaluate the incidence of peri-implant diseases and the associated risk factors during 11 years of peri-implant maintenance therapy (PIMT).

MATERIAL AND METHODS

A sample of 80 partially edentulous individuals rehabilitated with dental implants was invited to participate in a PIMT program (T1-prior to entering the PIMT program). After 11 years, 51 individuals remained regularly or irregularly adherent to PIMT (T2-last recall after 11 years) and were classified as regular (RC; n = 27) or irregular (IC; n = 24) compliers. Data of interest were analyzed using univariate and multivariate logistic regression analyses.

RESULTS

The incidence of peri-implant mucositis and peri-implantitis observed at T2 in the IC group (70.8% and 37.5%, respectively) were significantly higher than those observed in the RC group (37.0% and 11.1%, respectively). The incidence of peri-implant diseases was mostly attributable to potentially modifiable risk factors, as such: RC group-PM (p = 0.013); IC group-high plaque index (p < 0.001), irregular compliance (p < 0.001), the presence of PM (p = 0.015) and periodontitis (p < 0.039).

CONCLUSION

Regular compliance during PIMT had a strong effect in minimizing the incidence of peri-implant diseases. Increasing regular dental visits and improving oral hygiene would provide benefits for preventing peri-implant diseases.

The burden of liver cirrhosis in mortality: Results from the global burden of disease study

BACKGROUND

Liver cirrhosis-related death is a serious threat worldwide. The number of studies exploring the mortality trend of cirrhosis caused by specific etiologies was limited. This study aimed to demonstrate the pattern and trend based on the data of global burden of disease (GBD).

METHODS

The data of cirrhosis mortality were collected from the GBD 2017. The Age standardized mortality rate (ASR) and estimated annual percentage changes (EAPC) were used to estimate the temporal trend of liver cirrhosis mortality by etiologies, regions, sociodemographic index (SDI), and sexes.

RESULTS

Globally, mortality cases of cirrhosis increased by 47.15%. Although the global ASR of cirrhosis mortality remained stable during this period, the temporal trend varied in etiologies. The ASR of mortality caused by hepatitis C virus (HCV), alcohol consumption, and non-alcoholic steatohepatitis (NASH) increased with an EAPC of 0.17 (95% CI, 0.14-0.20), 0.20 (95% CI, 0.16-0.24), 1.00 (95% CI, 0.97-1.04), respectively. A decreasing trend of ASR was found among the causes of hepatitis B virus (BV) and other causes. The increased pattern was heterogeneous worldwide. The most pronounced increase trend was found in middle-high SDI regions and Eastern Europe. Contrarily, the most pronounced decrease trend was found in low SDI regions and Western Sub-Saharan Africa.

CONCLUSION

Cirrhosis is still a public health problem. The growth trend of cirrhosis mortality caused by HCV was slowed by promoting direct-acting antiviral therapy. Unfortunately, we observed an unfavorable trend in etiologies for alcohol consumption and NASH, which indicated that more targeted and specific strategies should be established to limit alcohol consumption and promote healthy lifestyles in high-risk countries, especially in middle-high SDI regions and Eastern Europe.

Bleeding disorders in implant dentistry: a narrative review and a treatment guide

Purpose

Considering a high prevalence of congenital and especially acquired bleeding disorders, their heterogeneity and the multitude of possible treatments strategies, a review of the scientific data on this topic is needed to implement a treatment guide for healthcare professionals.

Methods

A selective literature review was performed via PubMed for articles describing oral surgery / dental implant procedures in patients with congenital and acquired bleeding disorders. Out of the existing literature, potential treatment algorithms were extrapolated.

Results

In order to assess the susceptibility to bleeding, risk stratification can be used for both congenital and acquired coagulation disorders. This risk stratification, together with an appropriate therapeutic pathway, allows for an adequate and individualized therapy for each patient. A central point is the close interdisciplinary cooperation with specialists. In addition to the discontinuation or replacement of existing treatment modalities, local hemostyptic measures are of primary importance. If local measures are not sufficient, systemically administered substances such as desmopressin and blood products have to be used.

Conclusions

Despite the limited evidence, a treatment guide could be developed by means of this narrative review to improve safety for patients and practitioners. Prospective randomized controlled trials are needed to allow the implementation of official evidence-based guidelines.

Association between liver cirrhosis and peri-implant diseases: a case-control study on implant- and patient-related risk factors

OBJECTIVE

The objective of this study was to evaluate the potential association between liver cirrhosis and peri-implant diseases, as well as the influence of different risk indicators on this association.

METHODS

This case-control study included 64 cases with liver cirrhosis and 128 controls without liver diseases that presented the same socio-demographic and economic profile. The specific inclusion criteria were the following: aged group of 35-55 years and presenting at least one osseointegrated implant functioning for >5 years. A full-mouth peri-implant and periodontal examination was performed and risk variables were recorded. The association between risk variables and the occurrence of peri-implant diseases was tested through univariate analysis and multivariate logistic regression, stratified by alcohol status. Additionally, a mediation analysis was performed to examine the mediating effect of age with peri-implantitis.

RESULTS

A high prevalence of peri-implantitis (29.7%) was observed among cases when compared to controls (18.0%). Individuals with cirrhosis presented ~2.5 higher chance of having peri-implantitis than controls (p<0.001). Significant variables associated with the occurrence of peri-implantitis in the final logistic model were the following: cirrhosis, alcohol use, age (>55 years), male sex, smoking, periodontitis, and number of ≤14.

CONCLUSIONS

An important risk association between liver cirrhosis and peri-implantitis was reported. Future studies with a larger sample size controlling for the patient- and implant-related confounders are needed to better understand the link between peri-implantitis and liver cirrhosis.

CLINICAL RELEVANCE

Cirrhosis individuals, age, and periodontitis, as well as alcohol use and smoking interaction, should be considered as potential risk indicators for peri-implantitis.

Association between cumulative smoking exposure, span since smoking cessation, and peri-implantitis: a cross-sectional study

OBJECTIVES

To investigate the association of cumulative smoking exposure and span since smoking cessation with the occurrence of peri-implantitis.

METHODS

A sample of 350 individuals aged ≥ 35 years, with the presence of at least one osseointegrated implant functioning for > 5 years, were enrolled in the study. According to smoking habits, participants were categorized into 3 groups: non-smokers (NS; n = 212), former smokers (FC; n = 66), and current smokers (CS; n = 72). Complete peri-implant and periodontal examinations were evaluated. Associations between the occurrence of peri-implantitis and smoking habits, as well as potential confounders, were evaluated through univariate and multivariate analyses.

RESULTS

The occurrence of peri-implantitis in the NS, FS, and CS groups was 18.2%, 19.7%, and 30.5%, respectively. A high prevalence of the overall number of cases with periodontitis (54.2%) was observed in the CS group when compared to the FS and NS groups. After adjusting for confounders, the odds ratio (OR) for the occurrence of peri-implantitis was 2.63 (1.39-6.77; p < 0.001) for CS compared to NS. There was a significant dose-response relationship between pack/year of smoking and the occurrence of peri-implantitis, as well as a significant decrease in the risk as the years of smoking cessation increased.

CONCLUSIONS

The occurrence of peri-implantitis among CS was high. The cumulative smoking exposure in an incremental manner and the shorter smoking cessation span was directly associated with a higher risk for peri-implantitis.

CLINICAL RELEVANCE

Educational and preventive strategies in general health services must attempt to reduce the adverse effects of cumulative smoking exposure and to explore the beneficial effects of smoking cessation on peri-implant status.

Periodontitis, chronic liver diseases, and the emerging oral-gut-liver axis

The liver carries out a wide range of functions ranging from the control of metabolites, nutrient storage, and detoxification to immunosurveillance. While inflammation is essential for the tissue remodeling and maintenance of homeostasis and normal liver physiology, constant exposure to dietary and microbial products creates a niche for potentially prolonged immune activation and unresolved inflammation in susceptible host. Failure to restrain inflammation can lead to development of chronic liver diseases characterized by fibrosis, cirrhosis and eventually liver failure. The liver maintains close interactions with numerous organs which can influence its metabolism and physiology. It is also known that oral cavity microenvironment can influence the physiological conditions of other organs and emerging evidence implicates that this could be true for the liver as well. Presence of chronic inflammation and dysbiotic microbiota is a common feature leading to clinical pathology both in periodontitis and chronic liver diseases (CLDs). In fact, known CLDs appear to have some relationship with periodontitis, which impacts the onset or progression of these conditions in a bidirectional crosstalk. In this review, we explore the emerging association between oral‐gut‐liver axis focusing on periodontitis and common CLDs including nonalcoholic fatty liver disease, chronic viral hepatitis, liver cirrhosis, and hepatocellular cancer. We highlight the immune pathways and oral microbiome interactions which can link oral cavity and liver health and offer perspectives for future research.

ASSOCIATION BETWEEN PERIODONTITIS AND LIVER DISEASE

Recent clinical and scientific evidence confirms the negative impact of long-term periodontitis on the clinical course and progression of various liver diseases. Periodontitis is a chronic, slow-progressing infectious disease of the tooth supporting tissues caused mainly by the gram-negative bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola and Tannerella forsythia. These specific pathogens can be easily translocated from oral cavity to the intestine. Disruption of the intestine microbiota composition by orally derived periodontal pathogenic bacteria has recently been suggested to be a causal mechanism between periodontitis and liver disease. Furthermore, both diseases have the ability to induce an inflammatory response and lead to the creation of inflammatory mediators through which they may influence each other. Recent epidemiologic studies have demonstrated that individuals with liver cirrhosis have considerably poorer periodontal clinical parameters than those without cirrhosis. Periodontal therapy in cirrhosis patients favorably modulates oral and gut microbiome, the course of systemic inflammation, cirrhosis prognostic factors, and cognitive function. Therefore, future clinical researches should be focused on detailed examination of the biological mechanisms, strength and direction of the association between advanced liver disease and periodontitis.

Do cytokines associate periodontitis with metabolic disorders? An overview of current documents

Periodontitis is an oral chronic inflammatory condition affecting the adult population worldwide. Many microorganisms act as an initiator for induction of inflammatory immune responses, which participate in the destruction of connective tissue surrounding the teeth and thereby result in tooth loss. Cytokines may have indispensable roles in its pathogenesis through enhancing inflammatory and immune responses. Cytokines can affect functions of some cells of different tissues, such as the cells of the pancreas, liver, and adipose tissues. There is evidence that periodontitis is associated with metabolic disorders, like liver cirrhosis, obesity, and diabetes mellitus. Hence, this review was focused on determining how cytokines can participate in the correlation of periodontitis with metabolic disorders.

Deciphering the toxicological role of Porphyromonas gingivalis derived endotoxins in liver diseases

Periodontitis is a most prevalent and infectious multifactorial inflammatory disease and is characterized by the progressive destruction of the tooth-supporting tissues. Porphyromonas gingivalis, a Gram‑negative oral anaerobe, mainly causes periodontitis and it is one of the most important risk factors responsible for aggravation of existing systemic diseases. Several experimental and clinical studies have shown the positive association between periodontitis and different forms of liver disease. Periodontal diseases increase the prevalence of non-alcoholic fatty liver diseases and cirrhosis. Infected periodontium and pathogens in the periodontal microenvironments release pathogen-associated molecular patterns such as peptidoglycan, lipopolysaccharides, gingipain, fimbria, bacterial DNA, etc, and damage-associated molecular patterns such as interleukins-1α, β, - 8, and galectin-3, etc. These virulence factors and cytokines enter the bloodstream, disseminate into the whole body, and induce a variety of systemic pathological effects, including liver diseases (steatosis and fibrosis). Maintaining oral hygiene by scaling and root planning significantly improves liver damage in patients with periodontitis. Dentists and physicians should have more awareness in understanding the bidirectional nature of the relationship between oral and systemic diseases. Importantly, periodontitis condition aggravates simple fatty liver into fibrotic disease and therefore, the aim of this review is to understand the possible link between periodontitis and liver diseases.

Effect of peroxisome proliferator-activated receptor-γ coactivator-1α on liver injury induced by periodontitis in rats

OBJECTIVES

To investigate the effect of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) on liver injury induced by periodontitis in rats.

METHODS

Twenty-four male Wistar rats were randomly divided into two groups: control group and periodontitis group, twelve per group. In periodontitis group, the periodontitis models were established for the maxillary first molars in rats by means of "wire ligation+vaccinationwith Porphyromonas gingivalis", the control group was inoculated with the equal volume of 2% sodium carboxymethyl cellulose in the same position, for 6 weeks. The probing depth, tooth mobility and sulcus bleeding index were detected. Hematoxylin-eosin (HE) staining was used to observe the pathological changes of liver tissues in rats. The quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) were used to detect the gene and protein expression levels of PGC-1α, nuclear factor erythroid 2-related factor 2 (Nrf2) and mitochondrial transcription factor A (TFAM) in liver tissues of rats.

RESULTS

The probing depth, tooth mobility and sulcus bleeding index in periodontitis group were significantly higher than that in control group. HE staining showed in periodontitis group, hepatic cords ranged disorderly and there were vacuoles in cells and inflammatory cells infiltrated in liver tissues of rats, and there was no obvious abnormality in control group. The qRT-PCR results showed that the mRNA expression levels of Pgc-1α, Nrf2 and Tfam in liver tissues of rats in periodontitis group were lower obviously than that in control group. IHC results showed that the protein expression level of PGC-1α in liver tissues of rats in periodontitis group was decreased significantly than that in control group.

CONCLUSIONS

PGC-1α may be involved in the process of periodontitis-induced liver injury in rats.

Association of periodontitis and tooth loss with liver cancer: A systematic review

A number of epidemiological studies have suggested a positive association between periodontal diseases and oro-digestive cancers, including liver cancer. The purpose of the present systematic review was to analyze the current evidence regarding the potential association between periodontitis and/or tooth loss and the risk of liver cancer. A comprehensive search of PubMed, Scopus and Web of Science databases was conducted in August 2019. The inclusion criteria comprised all observational studies that assessed the relationship between periodontitis or tooth loss and liver cancer. Case reports, animal studies, experimental studies, and reviews were excluded. Due to great heterogeneity among the included studies, no meta-analysis was conducted. Six studies (five prospective cohorts and one case-control) comprising 619,834 subjects (including 916 liver cancer cases) were included. The studies were conducted in the United States, Europe, and Asia. Three large-scale cohort studies reported a positive association between periodontitis or tooth loss and the risk of liver cancer. One case-control study found some association between liver cancer and loss of 12-23 teeth, but such association was not replicated in patients with greater number of tooth loss. Contrarily, two studies failed to report any association between periodontitis and/or tooth loss and the risk of liver cancer. The available evidence suggests a possible link between tooth loss/periodontitis and the risk of liver cancer. However, the evidence is not conclusive enough, a fact that drives to conduct more, well-designed, prospective cohort studies to further explore the potential association between periodontitis and the risk of liver cancer.

The burden of liver cirrhosis and underlying etiologies: results from the global burden of disease study 2017

BACKGROUND

To evaluate the pattern and prevalence trends of liver cirrhosis caused by specific etiologies.

RESULTS

Globally, the number of prevalent cases increased 74.53% from 1990 to 2017. The ASR increased 0.75 per year. The most pronounced increases were found in middle-high and high socio-demographic index (SDI) regions, especially in the Caribbean and Latin America. Among the etiologies, non-alcoholic steatohepatitis (NASH) related liver cirrhosis accounted for 59.46% of the cases. The ASR increased 1.74 per year, and the increase was observed in all 5 SDI regions. In addition, the ASR of liver cirrhosis caused by alcohol also increased in both sexes and all SDI regions. In contrast, the ASR of liver cirrhosis caused by hepatitis B virus (HBV) and hepatitis C virus (HCV) decreased, especially in middle and low-middle SDI regions.

CONCLUSIONS

Though the number of people suffering from HBV and HCV decreases, liver cirrhosis is still a major threat to health. Additionally, the number of people with cirrhosis caused by alcohol and NASH continues to grow. Thus, more targeted and specific strategies should be established based on etiology and prevalence trends of liver cirrhosis.

METHODS

We collected data based on Global Burden of Disease (GBD) 2017 study. The age standardized prevalence rate (ASR) and estimated annual percentage changes (EAPC) were used to estimate the trends in prevalence by population, etiologies and regions.

Association between periodontal disease, tooth loss and liver diseases risk

AIM

The purpose of this study is to assess the associations between periodontal disease, tooth loss and liver diseases.

MATERIALS AND METHODS

PubMed and Embase databases were utilized to search eligible studies. Odds ratio (OR) with 95% confidence interval (CI) was used as effect size to assess the associations between periodontal disease, tooth loss and liver diseases risk.

RESULTS

Our results indicated positive associations between periodontal disease and non-alcoholic fatty liver disease (NAFLD) (OR = 1.19, 95% CI = 1.06-1.33), liver cirrhosis (OR = 2.28, 95% CI = 1.50-3.48) and elevated transaminase level risk (OR = 1.08, 95% CI = 1.02-1.15). Moreover, tooth loss could increase NAFLD (OR = 1.33, 95% CI = 1.12- 1.56) and liver cancer risk (OR = 1.34, 95% CI = 1.04-1.74), and every five increment in tooth loss was associated with 5% increased liver cancer risk (OR = 1.05, 95% CI = 1.01 - 1.10) with a linear relationship. In addition, tooth loss had a positive tendency towards liver cirrhosis risk (OR = 2.03, 95% CI = 0.85-4.85) although there was no statistical significance.

CONCLUSION

Periodontal disease and tooth loss are positively associated with liver diseases including NAFLD, elevated transaminase level, liver cirrhosis and liver cancer.