Diabetes mellitus and periodontitis: a tale of two common interrelated diseases

Association between life's essential 8 and periodontitis: a population-based study

BACKGROUND

The American Heart Association has developed a novel cardiovascular health indicator called Life's Essential 8 (LE8). However, no one has reported using LE8 to assess periodontitis. This study aimed to investigate the association between LE8 and periodontitis in American adults.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2014 were used for this investigation. LE8 was the independent variable, and it is divided into three grades: high, moderate, and low. Periodontitis was the dependent variable, and the classification of periodontitis was based on the criteria of Eke in 2012. Multivariable logistic regression models were used to explore the relationship between LE8 and periodontitis.

RESULTS

A total of 9,039 participants with an average age of 52.16 ± 14.21 years were enrolled in this study, of whom 48.29% were male and 51.71% were female. The mean and standard deviation of LE8 was 66.29 ± 14.57, and the prevalence of periodontitis was 50.48% overall. The LE8 score and periodontitis in the fully adjusted logistic regression model showed a negative correlation (OR = 0.98; 95% CI, 0.98-0.99, p < 0.001). This result persisted when Life's Essential 8 was categorized into low, moderate, and high groups. Compared with those in the lowest group, those in the highest LE8 group had a 47% decreased risk of periodontitis (OR = 0.53; 95% CI, 0.46-0.66, P < 0.001).

CONCLUSIONS

This cross-sectional investigation revealed a negative relationship between the LE8 score and the likelihood of periodontitis.

Oral Microbial and Molecular Cross Talk between SARS-CoV-2 and Diabetes Mellitus - A Mini Review

The oral microbiome has long been considered a measure of overall systemic health. It is often significantly altered in case of chronic inflammation or any other systemic infection. Therefore, a shift in oral microbiota and oral health is bound to be observed in diabetics infected with the coronavirus. The prognosis of COVID-19 in a diabetic individual is often worse than that in a healthy individual. The increased pathogenicity of coronavirus in diabetics is due to the peculiar ways in which it interacts with specific physiological mechanisms in a diabetic patient and vice versa. Diabetes Mellitus Type-II (DM -II) is one of the most frequently associated co-morbidities in a COVID-19 patient, and therefore it is even more pertinent that their interrelationship is understood. It is essential to recognize the above-mentioned interactions and consider their implications while treating susceptible patients. This article attempts to review and summarize the said vital interactions. Additionally, it attempts to guide and prepare oral health professionals on what to expect and how to treat diabetic patients in a future where coronavirus is, as unfortunate as it is, a regularity and not a rarity.

Prevalence and Severity of Periodontal Disease and its Association with Type-II Diabetes Mellitus and Smoking by Using Periodontal Screening and Recording: A Retrospective Study

Background

Periodontal screening recording (PSR) is considered a quick, reliable, reproducible valuable screening tool for periodontal disease. This study aims to find the prevalence and severity of periodontal disease and its association with self-reported diabetic status and smoking history of the patients by using PSR codes over a period of 2 years.

Material and Methods

This was a cross-sectional retrospective study in a dental hospital in Chandigarh. Data of 10,882 patients comprising self-reported history of smoking (893) and diabetes (725) patients were assessed for the prevalence of periodontal disease by using PSR codes. Pearson Chi-Square test was used for statistical evaluation of PSR codes data.

Results

Out of a total of 65,292 sextants assessed, the maximum and minimum reported PSR codes were 2 and 4, respectively. Gingivitis was found to be the most prevalent, followed by periodontitis and periodontal health in the total assessed population (P < 0.001). Mucogingival problems and complete edentulism were found to be more prevalent in posterior sextants in comparison to anterior sextants. Both self-reported smokers and type-II diabetes mellitus patients presented gingivitis as the most common clinical presentation, with the highest prevalence seen in the 55-74-year age group, which also comprised the group with maximum mucogingival problems and edentulism.

Conclusion

This study gives an overview of patients' general oral health status and reflects the burden of periodontal disease in the Chandigarh region, thus contributing to the national oral health data.

Sex-Related Effect of Aging in Gingival Gamma-Delta T Cells

Aging affects the number and function of gamma-delta (γδ) T cells in a tissue-specific manner, modifying the risk for inflammatory disease. These aging-related γδT-cell variations in gingival tissues that could increase the risk for inflammation and periodontal disease remain unknown. Here we sought to identify quantitative and qualitative variations in gingival γδT cells associated with aging that could have an impact in oral immunoinflammatory responses. For this, gingival tissues from young (4 mo) and aged (24 mo) male and female mice were collected and analyzed by flow cytometry. Cell suspensions were stimulated and stained with eFluor450 (cell viability), anti-CD45 (hematopoietic cells), anti-CD3 (lymphocytes), anti-TCRγδ (γδT cells), anti-IL-15rα (cell proliferation), and anti-Notch-3 (senescence marker). Detection of intracellular cytokines IL-17A and interferon γ (IFNγ) was performed. Gingival expression of specific γ- and δ-chains and cytokines was evaluated by quantitative reverse transcription polymerase chain reaction. A significantly higher number of IL-17A-producing γδT cells and IL-17A expression levels were observed in gingival tissues from aged females but not males. Similarly, the number of gingival Notch-3+ γδT cells increased with aging only in females. IL-15rα was not detected in gingival γδT cells. Chains γ1, 2, 4, 5, 6, and 7 as well as δ1, 2, 4, and 6 were detected. Detection levels of all γ chains except γ1 as well as δ1 and δ2 changed with aging in males, females, or both. Interestingly, number of IL-17A-producing conventional T cells similarly increased with aging only in females. Both sexes showed increased IFNγ+ conventional T-cell numbers with aging; however, it reached significance only in females. In conclusion, the number of gingival IL-17A-producing γδT cells and IL-17A expression increase naturally with aging specifically in females. This sexual dimorphism in gingival γδT and conventional Th17 cell numbers and phenotypes suggests distinct aging-related mechanisms of periodontitis in males and females.

The association between periodontitis and hepatitis virus infection: a cross-sectional study utilizing data from the NHANES database (2003-2018)

OBJECTIVES

Periodontitis and hepatitis virus infection significantly impact individuals' well-being and are prevalent public health concerns globally. Given the current scarcity of large-scale cross-sectional epidemiological studies, this study seeks to enrich the evidence base by examining the link between these two conditions.

STUDY DESIGN AND METHODS

A cross-sectional study was conducted using data from the National Health and Nutrition Examination Survey (NHANES) spanning the years 2003-2018. A multivariate logistic regression analysis was performed to assess the association between periodontitis and hepatitis virus infection, adjusting for the potential confounding factors. Subsequently, a stratified analysis was conducted to explore the relationship between periodontitis and hepatitis virus infection based on age, gender, race, marital status, alcohol consumption, smoking status, and the presence of chronic diseases.

RESULTS

In this study, which included 5755 participants, there was a positive association between hepatitis virus infection and periodontitis (odds ratio [OR]: 2.609 [95% confidence interval (CI): 1.513, 4.499]). Furthermore, a significant association was observed between moderate periodontitis and hepatitis virus infection (OR: 2.136 [95% CI: 1.194, 3.822]), and this association was even stronger for severe periodontitis (OR: 3.583 [95% CI: 1.779, 7.217]). Importantly, this positive association between hepatitis virus infection and periodontitis was consistent across different subgroups.

CONCLUSIONS

This study presents evidence of a significant association between periodontitis and hepatitis virus infection. These findings highlight the crucial importance of integrating periodontal health and liver health considerations into public health interventions. Further research is necessary to elucidate the underlying mechanisms and develop targeted interventions for effectively managing periodontitis and hepatitis virus infection.

Effectiveness of Probiotic Therapy in the Management of PeriodontalDisease in Diabetic Patients: A Scoping Review

BACKGROUND

Probiotics can compete with periodontal pathogens in the formation of dental biofilm, and they are able to modulate local and systemic immune responses. Thus, its use in diabetic patients with periodontal disease (PD) can overcome the limitations of conventional periodontal treatment.

OBJECTIVE

This scoping review aimed to understand the extent and type of evidence in relation to the effects of probiotic therapy on periodontal and glycaemic parameters of diabetic patients with PD.

METHODS

An electronic search was performed in the following databases: Cochrane Library, EMBASE, Virtual Health Library (including LILACS and BBO), PubMed (including Medline), Scopus, Web of Science, and Google Scholar. The review included clinical trials on patients with type 2 diabetes, diagnosed with gingivitis or periodontitis, who received probiotic therapy as a single therapy or adjuvant to scaling and root planning, and on whom the analyses of clinical periodontal, immunological, microbiological, or glycaemic parameters were performed.

RESULTS

The electronic search yielded a total of 1165 articles. After removing duplicate titles and performing systematic screening, 6 studies were included in the qualitative summary. Probiotic administration improved clinical periodontal parameters (bleeding on probing and probing depth), oxidative stress markers, and inflammatory cytokines (IL-8, IL-10, and TNF-α) in relation to control groups. Experimental groups were also more advantageous in reducing the frequency of periodontopathogenic bacteria. However, the evidence of probiotics in decreasing glycated hemoglobin is still uncertain.

CONCLUSION

Probiotics may provide safe additional benefits to periodontal parameters of patients with type 2 diabetes and periodontal disease.

The oral microbial odyssey influencing chronic metabolic disease

INTRODUCTION

Since the oral cavity is the gateway to the gut, oral microbes likely hold the potential to influence metabolic disease by affecting the gut microbiota.

METHOD

A thorough review of literature has been performed to link the alterations in oral microbiota with chronic metabolic disease by influencing the gut microbiota.

RESULT

A strong correlation exists between abnormalities in oral microbiota and several systemic disorders, such as cardiovascular disease, diabetes, and obesity, which likely initially manifest as oral diseases. Ensuring adequate oral hygiene practices and cultivating diverse oral microflora are crucial for the preservation of general well-being. Oral bacteria have the ability to establish and endure in the gastrointestinal tract, leading to the development of prolonged inflammation and activation of the immune system. Oral microbe-associated prophylactic strategies could be beneficial in mitigating metabolic diseases.

CONCLUSION

Oral microbiota can have a profound impact on the gut microbiota and influence the pathogenesis of metabolic diseases.

Endogenous and microbial biomarkers for periodontitis and type 2 diabetes mellitus

It has been well documented that there is a two-way relationship between diabetes mellitus and periodontitis. Diabetes mellitus represents an established risk factor for chronic periodontitis. Conversely, chronic periodontitis adversely modulates serum glucose levels in diabetic patients. Activated immune and inflammatory responses are noted during diabetes and periodontitis, under the modulation of similar biological mediators. These activated responses result in increased activity of certain immune-inflammatory mediators including adipokines and microRNAs in diabetic patients with periodontal disease. Notably, certain microbes in the oral cavity were identified to be involved in the occurrence of diabetes and periodontitis. In other words, these immune-inflammatory mediators and microbes may potentially serve as biomarkers for risk assessment and therapy selection in diabetes and periodontitis. In this review, we briefly provide an updated overview on different potential biomarkers, providing novel diagnostic and therapeutic insights on periodontal complications and diabetes mellitus.

Mendelian Randomisation Study on Association of Gut Microbiota and Periodontitis

OBJECTIVE

Several studies have demonstrated the possible association between gut microbiota and periodontitis. The mechanism by which gut microbiota contribute to periodontitis remains unknown.

METHODS

A 2-sample Mendelian randomisation (MR) study was conducted using publicly available Genome-Wide Association Studies (GWAS) data of European ancestry. The relationships between gut microbiota and tooth loss and periodontitis were assessed using summary-level data. Moreover, inverse variance weighted (IVW), MR-Egger, weighted median, and simple Mendelian were used. The results were further validated using sensitivity analyses.

RESULTS

A total of 211 gut microbiota were studied, including 9 phyla, 16 classes, 20 orders, 35 families, and 131 genera. The IVW method identified 16 bacterial genera related to the risk of periodontitis and tooth loss. Lactobacillaceae was associated with an increased risk of periodontitis (odds ratio [OR], 1.40, 95% confidence interval [CI], 1.03-1.91, P<.001) and tooth loss (OR, 1.12; 95% CIs, 1.02-1.24, P = .002), whereas Lachnospiraceae UCG008 was linked to a lower risk of tooth loss (P = .041). There was no heterogeneity and horizontal pleiotropy in the sensitivity analysis.

CONCLUSIONS

Several microorganisms were identified to be linked to the risk of periodontitis. Furthermore, the findings improved our understanding of gut microbiota and periodontitis pathology.

Diabetes Mellitus Increases the Risk of Apical Periodontitis in Endodontically-Treated Teeth: A Meta-Analysis from 15 Studies

INTRODUCTION

At present, the incidence of diabetes mellitus (DM) is gradually increasing globally. In clinical practice, many patients with diabetes with apical periodontitis (AP) have poor and slow healing of periapical lesions. However, the potential relationship between the 2 is still unclear and controversial. The consensus is that DM can be deemed a risk factor for AP in endodontically-treated teeth. Therefore, we pooled existing studies and carried out a meta-analysis to explore the potential association between the 2.

METHODS

Studies that met the inclusion criteria were selected from the database, and relevant data were extracted. Stata SE 17.0 software was used to analyze the relevant data, and the Newcastle-Ottawa Scale was used to assess the literature's quality. The pooled odds ratio (OR) with a 95% confidence interval (CI) was used to determine the strength of the association between DM and the prevalence of AP after root canal treatment (RCT).

RESULTS

After searching, 262 relevant studies were retrieved, fifteen of which met the inclusion criteria. A total of 1087 patients with 2226 teeth were included in this meta-analysis. According to the findings, diabetics showed a higher prevalence of AP after RCT than controls at the tooth level (OR = 1.51, 95% CI = 1.22-1.87, P < .01). At the patient level, DM increased the probability of developing AP in RCT teeth more than 3 times (OR = 3.38, 95% CI = 1.65-6.93, P < .01). Additionally, subgroup analysis was performed by blood glucose status, preoperative AP, and study design. Except for the status of blood glucose, the results were significant in the other 2 groups (P < .05).

CONCLUSIONS

Available scientific evidence suggests that DM may increase the risk of AP in endodontically-treated teeth. In teeth with preoperative AP, DM might promote the development of AP.

Periodontal-Systemic Disease: A Study on Medical Practitioners' Knowledge and Practice

OBJECTIVE

Oral health is intricately linked with systemic health. However, the knowledge and practice levels of medical practitioners (MPs) about this concern are extremely variable. The current study, therefore, sought to assess the status of knowledge and practice of MPs concerning the link between periodontal disease and different systemic conditions as well as the efficacy of a webinar as an interventional tool in enhancing knowledge of MPs of Jazan Province of Saudi Arabia.

METHODS

This prospective interventional study involved 201 MPs. A 20-item questionnaire on evidence-based periodontal/systemic health associations was used. The participants answered the questionnaire before and 1 month after a webinar training that explained the mechanistic interrelation of periodontal and systemic health. McNemar test was performed for statistical analysis.

RESULTS

Out of the 201 MPs who responded to the pre-webinar survey, 176 attended the webinar and hence were included in the final analyses. Sixty-eight (38.64%) were female, and 104 (58.09%) were older than 35 years. About 90% of MPs reported not being trained on oral health. Pre-webinar, 96 (54.55%), 63 (35.80%), and 17 (9.66%) MPs rated their knowledge about the association of periodontal disease with systemic diseases as limited, moderate, and good, respectively. Post-webinar, these figures improved remarkably: 36 (20.45%), 88 (50.00%), and 52 (29.55%) MPs rated their knowledge as limited, moderate, and good, respectively. Around 64% of MPs had relatively good levels of knowledge about the positive influence of periodontal disease treatment on diabetic patients' blood glucose levels.

CONCLUSIONS

MPs revealed low levels of knowledge on the oral and systemic disease interrelationship. Conducting webinars on the oral-systemic health interrelationship seems to improve the overall knowledge and understanding of MPs.

The rosetta stone of successful ageing: does oral health have a role?

Ageing is an inevitable aspect of life and thus successful ageing is an important focus of recent scientific efforts. The biological process of ageing is mediated through the interaction of genes with environmental factors, increasing the body's susceptibility to insults. Elucidating this process will increase our ability to prevent and treat age-related disease and consequently extend life expectancy. Notably, centenarians offer a unique perspective on the phenomenon of ageing. Current research highlights several age-associated alterations on the genetic, epigenetic and proteomic level. Consequently, nutrient sensing and mitochondrial function are altered, resulting in inflammation and exhaustion of regenerative ability.Oral health, an important contributor to overall health, remains underexplored in the context of extreme longevity. Good masticatory function ensures sufficient nutrient uptake, reducing morbidity and mortality in old age. The relationship between periodontal disease and systemic inflammatory pathologies is well established. Diabetes, rheumatoid arthritis and cardiovascular disease are among the most significant disease burdens influenced by inflammatory oral health conditions. Evidence suggests that the interaction is bi-directional, impacting progression, severity and mortality. Current models of ageing and longevity neglect an important factor in overall health and well-being, a gap that this review intends to illustrate and inspire avenues for future research.

Prevalence of oral lesions and evaluation of the periodontal status among diabetic females attending Princess Nourah Bint Abdulrahman University (PNU)

Objective

To evaluate the prevalence of different oral lesions and periodontal status among diabetic Saudi female patients in the College of Dentistry, PNU University.

Materials and Method

A retrospective study was performed by reviewing the files of all patients who visited the College of Dentistry, PNU University, during the last 5 years. We selected diabetic 20-40-year-old Saudi female patients. Ethical approval was obtained from the Institutional Review Board of PNU University. Data collection sheets were used to gather information on demographics, education, medical and dental history, and extra and intra-oral findings. Data on the duration of diabetes, any major complications, and type of diabetes therapy were retrieved from medical records. The data were entered into an Excel sheet, and descriptive statistics were performed. The analytical phase proceeded to correlate oral lesions with patient age, type of diabetes, and periodontal status.

Result

A total of 226 diabetic patients were found after reviewing the records. The most common oral mucosal lesions were traumatic ulcers (10.2%), cheek biting (8.8%), and fissured tongue (8.4%). Furthermore, 81.86% of them had periodontitis, and 18.14% had a healthy periodontal status.

Conclusion

The prevalence of periodontitis among diabetic female patients is higher than that of oral lesions. Stage III periodontitis showed the strongest association to oral lesion.

Association of periodontitis and tooth loss with extent of coronary atherosclerosis in patients with type 2 diabetes mellitus

Aim

The objective was to investigate the association of periodontitis and tooth loss with extent of diabetic coronary atherosclerosis.

Materials and methods

272 patients who were hospitalized at Shanghai East hospital and underwent a coronary artery calcium (CAC) CT scan were enrolled in this study. Individuals were grouped based on their CAC scores into a normal-to-mild coronary atherosclerosis (AS) group (0 ≤ score ≤ 100, n=184) and a moderate-to-severe group (score≥101, n=88). Periodontitis parameters and number of missing teeth were evaluated for every patient. The severity of periodontitis was categorized as mild, moderate, or severe. The taxonomic composition of the microbiota was determined using full-length 16S ribosomal RNA gene sequencing. Salivary inflammatory factors were tested by ELISA.

Results

Clinical attachment loss (CAL) (P =0.05) and the number of teeth lost (P = 0.016) were significantly higher in the moderate-to-severe coronary AS group, with these differences being more obvious in younger patients and patients with short-duration diabetes. Multivariate logistic regression analysis revealed that CAL (OR = 1.231, 95% CI = 1.066-1.214, P = 0.047) and having 10-19 missing teeth (OR = 1.604, 95% CI = 1.393-6.555, P = 0.05) were strongly associated with the presence of moderate-to-severe coronary AS. Salivary IL-6 and TNF-α levels, as well as levels of Porphyromonas gingivalis and Neisseria mucosa, were significantly elevated in the moderate-to-severe coronary AS group.

Conclusion

It was found that both tooth loss and CAL were related to the extent of diabetic coronary AS. Saliva inflammatory factors and oral bacteremia may be new biomarkers for moderate-to-severe coronary AS.

Knowledge and practice attitudes regarding the relationship between diabetes and periodontitis: a survey among Swiss endocrinologists and general physicians

BACKGROUND

The objective of the present survey is to assess the knowledge about the relationship between oral health and diabetes and to identify the practice behaviors of Swiss endocrinologists and general practitioners regarding oral health in diabetic patients.

METHODS

A thirty- item questionnaire was mailed to 428 internists and 99 endocrinologists working in the French speaking part of Switzerland. Participants were asked about their awareness of the relationship between diabetes and periodontal disease, their practice behaviors as well as their willingness for an interdisciplinary education and collaboration with oral health professionals. The questions were answered according to a three-point or five-point Likert scale.

RESULTS

The response rate was 23%. All participants were aware of the inflammatory and infectious nature of periodontal disease. They all agreed that good periodontal health is important for overall health. However, most of the practitioners responded that only rarely received information during their education curricula on the link between systemic and oral health or concerning periodontal problems in diabetic patients (60.9% for endocrinologists and 54.1% for general physicians); thus, only a minority of health practitioners addresses oral health care to their patients (13% and 15.3%, respectively). Both endocrinologists and general health physicians agreed that an oral health screening could be included in their practice (79% for both groups).

CONCLUSIONS

An interdisciplinary education and collaboration among medical and dental health providers should be established to effectively prevent, manage, and control both diabetes and periodontal disease in diabetic patients.

O-Linked N-Acetylglucosamine Transferase Regulates Bone Homeostasis Through Alkaline Phosphatase Pathway in Diabetic Periodontitis

Periodontitis is one of the most common complications of diabetes, which seriously affects patients' life quality. It is important to find the key factors and mechanisms to improve the treatment of periodontitis. In our study, high glucose (HG) and lipopolysaccharide (LPS) treated human periodontal ligament cells (hPDLCs) and LPS treated diabetic mice was used to establish the diabetic periodontitis model in vitro and in vivo. O-linked beta-N-acetylglucosamine glycosylation (O-GlcNAcylation) and O-linked N-acetylglucosamine transferase (OGT) protein levels were detected by western blot assay. Cell counting kit-8, alkaline phosphatase (ALP), and alizarin red staining (ARS) assays were used to observe the O-GlcNAcylation and OGT effects on cell viability and osteoblast differentiation. Co-immunoprecipitation (Co-IP) assay was used to detect the relationship between OGT and ALP. The results showed that the levels of OGT and O-GlcNAcylation were significantly increased in both cell and mouse models. ALP and ARS staining results showed that silencing of OGT or inhibition of O-glycosylation notably improved osteogenic differentiation, increased the osteoprotegerin (OPG) protein levels and decreased the receptor activator for nuclear factor-κB Ligand (RANKL) protein levels of the HG and LPS treated hPDLCs. In diabetic periodontitis mice, knockdown of OGT relieved the injury of gingival tissue, increased the ALP and OPG levels and decreased the RANKL levels. Besides, ALP interacted with OGT protein, and OGT protein was found to act on ALP serine 513 glycosylation. In conclusion, our study demonstrated that excessive O-GlcNAcylation could restrain osteoblast differentiation by O-glycosylation in ALP.

Advanced glycation end products impair bone marrow mesenchymal stem cells osteogenesis in periodontitis with diabetes via FTO-mediated N6-methyladenosine modification of sclerostin

BACKGROUND

Diabetes mellitus (DM) and periodontitis are two prevalent diseases with mutual influence. Accumulation of advanced glycation end products (AGEs) in hyperglycemia may impair cell function and worsen periodontal conditions. N6-methyladenosine (m6A) is an important post-transcriptional modification in RNAs that regulates cell fate determinant and progression of diseases. However, whether m6A methylation participates in the process of periodontitis with diabetes is unclear. Thus, we aimed to investigate the effects of AGEs on bone marrow mesenchymal stem cells (BMSCs), elucidate the m6A modification mechanism in diabetes-associated periodontitis.

METHODS

Periodontitis with diabetes were established by high-fat diet/streptozotocin injection and silk ligation. M6A modifications in alveolar bone were demonstrated by RNA immunoprecipitation sequence. BMSCs treated with AGEs, fat mass and obesity associated (FTO) protein knockdown and sclerostin (SOST) interference were evaluated by quantitative polymerase chain reaction, western blot, immunofluorescence, alkaline phosphatase and Alizarin red S staining.

RESULTS

Diabetes damaged alveolar bone regeneration was validated in vivo. In vitro experiments showed AGEs inhibited BMSCs osteogenesis and influenced the FTO expression and m6A level in total RNA. FTO knockdown increased the m6A levels and reversed the AGE-induced inhibition of BMSCs differentiation. Mechanically, FTO regulated m6A modification on SOST transcripts, and AGEs affected the binding of FTO to SOST transcripts. FTO knockdown accelerated the degradation of SOST mRNA in presence of AGEs. Interference with SOST expression in AGE-treated BMSCs partially rescued the osteogenesis by activating Wnt Signaling.

CONCLUSIONS

AGEs impaired BMSCs osteogenesis by regulating SOST in an m6A-dependent manner, presenting a promising method for bone regeneration treatment of periodontitis with diabetes.

Microenvironment-Regulating Drug Delivery Nanoparticles for Treating and Preventing Typical Biofilm-Induced Oral Diseases

The oral cavity comprises an environment full of microorganisms. Dysregulation of this microbial-cellular microenvironment will lead to a series of oral diseases, such as implant-associated infection caused by Staphylococcus aureus (S. aureus) biofilms and periodontitis initiated by Streptococcus oralis (S. oralis). In this study, a liposome-encapsulated indocyanine green (ICG) and rapamycin drug-delivery nanoparticle (ICG-rapamycin) is designed to treat and prevent two typical biofilm-induced oral diseases by regulating the microbial-cellular microenvironment. ICG-rapamycin elevates the reactive oxygen species (ROS) and temperature levels to facilitate photodynamic and photothermal mechanisms under near-infrared (NIR) laser irradiation for anti-bacteria. In addition, it prevents biofilm formation by promoting bacterial motility with increasing the ATP levels. The nanoparticles modulate the microbial-cellular interaction to reduce cellular inflammation and enhance bacterial clearance, which includes promoting the M2 polarization of macrophages, upregulating the anti-inflammatory factor TGF-β, and enhancing the bacterial phagocytosis of macrophages. Based on these findings, ICG-rapamycin is applied to implant-infected and periodontitis animal models to confirm the effects in vivo. This study demonstrates that ICG-rapamycin can treat and prevent biofilm-induced oral diseases by regulating the microbial-cellular microenvironment, thus providing a promising strategy for future clinical applications.

Glipizide Alleviates Periodontitis Pathogenicity via Inhibition of Angiogenesis, Osteoclastogenesis and M1/M2 Macrophage Ratio in Periodontal Tissue

New consensus indicates type 2 diabetes mellitus (T2DM) and periodontitis as comorbidity and may share common pathways of disease progression. Sulfonylureas have been reported to improve the periodontal status in periodontitis patients. Glipizide, a sulfonylurea widely used in the treatment of T2DM, has also been reported to inhibit inflammation and angiogenesis. The effect of glipizide on the pathogenicity of periodontitis, however, has not been studied. We developed ligature-induced periodontitis in mice and treated them with different concentrations of glipizide and then analyzed the level of periodontal tissue inflammation, alveolar bone resorption, and osteoclast differentiation. Inflammatory cell infiltration and angiogenesis were analyzed using immunohistochemistry, RT-qPCR, and ELISA. Transwell assay and Western bolt analyzed macrophage migration and polarization. 16S rRNA sequencing analyzed the effect of glipizide on the oral microbial flora. mRNA sequencing of bone marrow-derived macrophages (BMMs) stimulated by P. gingivalis lipopolysaccharide (Pg-LPS) after treatment with glipizide was analyzed. Glipizide decreases alveolar bone resorption, periodontal tissue degradation, and the number of osteoclasts in periodontal tissue affected by periodontitis (PAPT). Glipizide-treated periodontitis mice showed reduced micro-vessel density and leukocyte/macrophage infiltration in PAPT. Glipizide significantly inhibited osteoclast differentiation in vitro experiments. Glipizide treatment did not affect the oral microbiome of periodontitis mice. mRNA sequencing and KEGG analysis showed that glipizide activated PI3K/AKT signaling in LPS-stimulated BMMs. Glipizide inhibited the LPS-induced migration of BMMs but promoted M2/M1 macrophage ratio in LPS-induced BMMs via activation of PI3K/AKT signaling. In conclusion, glipizide inhibits angiogenesis, macrophage inflammatory phenotype, and osteoclastogenesis to alleviate periodontitis pathogenicity suggesting its' possible application in the treatment of periodontitis and diabetes comorbidity.

Revealing a potential necroptosis-related axis (RP11-138A9.1/hsa-miR-98-5p/ZBP1) in periodontitis by construction of the ceRNA network

BACKGROUND AND OBJECTIVES

Periodontitis, a prevalent chronic inflammatory condition, poses a significant risk of tooth loosening and subsequent tooth loss. Within the realm of programmed cell death, a recently recognized process known as necroptosis has garnered attention for its involvement in numerous inflammatory diseases. Nevertheless, its correlation with periodontitis is indistinct. Our study aimed to identify necroptosis-related lncRNAs and crucial lncRNA-miRNA-mRNA regulatory axes in periodontitis to further understand the pathogenesis of periodontitis.

MATERIALS AND METHODS

Gene expression profiles in gingival tissues were acquired from the Gene Expression Omnibus (GEO) database. Selecting hub necroptosis-related lncRNA and extracting the key lncRNA-miRNA-mRNA axes based on the ceRNA network by adding novel machine-learning models based on conventional analysis and combining qRT-PCR validation. Then, an artificial neural network (ANN) model was constructed for lncRNA in regulatory axes, and the accuracy of the model was validated by receiver operating characteristic (ROC) curve analysis. The clinical effect of the model was evaluated by decision curve analysis (DCA). Weighted correlation network analysis (WGCNA) and single-sample gene set enrichment analysis (ssGSEA) was performed to explore how these lncRNAs work in periodontitis.

RESULTS

Seven hub necroptosis-related lncRNAs and three lncRNA-miRNA-mRNA regulatory axes (RP11-138A9.1/hsa-miR-98-5p/ZBP1 axis, RP11-96D1.11/hsa-miR-185-5p/EZH2 axis, and RP4-773 N10.4/hsa-miR-21-5p/TLR3 axis) were predicted. WGCNA revealed that RP11-138A9.1 was significantly correlated with the "purple module". Functional enrichment analysis and ssGSEA demonstrated that the RP11-138A9.1/hsa-miR-98-5p/ZBP1 axis is closely related to the inflammation and immune processes in periodontitis.

CONCLUSION

Our study predicted a crucial necroptosis-related regulatory axis (RP11-138A9.1/hsa-miR-98-5p/ZBP1) based on the ceRNA network, which may aid in elucidating the role and mechanism of necroptosis in periodontitis.

Different doses of vitamin D supplementation to nonsurgical treatment for vitamin-D-insufficient patients with diabetic periodontitis and the effect on gingival BMP-2 levels

Epidemiological data show people with diabetes mellitus (DM) have three-fold increase in risk of periodontitis. A vitamin D insufficiency can affect the progression of DM and periodontitis. This study evaluated the effects of different-dose vitamin D supplementation to nonsurgical periodontal therapy for vitamin-D-insufficient diabetic patients coexisting with periodontitis and changes of gingival bone morphogenetic protein-2 (BMP-2) levels. The study included 30 vitamin-D-insufficient patients receiving nonsurgical treatment followed by administration of 25,000 international units (IU) vitamin D3 per week (the low-VD group) and 30 patients receiving 50,000 UI vitamin D per week (the high-VD group). The decreases of probing pocket depth, clinical attachment loss, bleeding index, and periodontal plaque index values of patients after the six-month supplementation of 50,000 UI vitamin D3 per week to nonsurgical treatment were more significant than those after the six-month supplementation of 25,000 UI vitamin D3 per week to nonsurgical treatment. It was found that 50,000 IU per week vitamin D supplementation for 6 months could lead to a better glycemic control for vitamin-D-insufficient diabetic patients coexisting with periodontitis after nonsurgical periodontal therapy. Increased levels of serum 25(OH) vitamin D3 and gingival BMP-2 were found in both low- and high-dose VD groups, and the high-dose VD group exhibited higher levels than the low-dose VD group. Vitamin D supplementation in large doses for 6 months tended to improve the treatment of periodontitis and increase gingival BMP-2 levels in diabetic patients coexisting with periodontitis who were vitamin D deficient.

Experimental tooth loss affects spatial learning function and blood-brain barrier of mice

OBJECTIVE

This study aims to investigate how experimental tooth loss affected learning, memory function, and brain pathophysiology in mice.

MATERIALS AND METHODS

The mice (C57BL/6 J, 2-month-old, male) were divided into tooth loss and control groups. The behavioral test battery was performed at 6 and 12 months after tooth extraction. The protein levels of the tight junctions in the brains of the mice were analyzed. Hippocampal astrocyte was measured using immunohistochemical staining.

RESULTS

The results of behavioral tests and biochemical analysis performed during the 6 months observation period did not show significant differences between the groups. However, the escape latency in the tooth loss group was significantly longer than that in the control group at the 12 months after tooth extraction. The level of claudin-5 decreased in the tooth loss group. Additionally, hippocampal astrogliosis was found in the tooth loss group.

CONCLUSIONS

Experimental tooth loss reduced the level of claudin-5 and caused astrogliosis in the brains of mice, which was accompanied by deterioration of learning functions. This study may provide a new insight about the association between tooth loss and cognitive dysfunction.

The role of mitochondrial dysfunction in periodontitis: From mechanisms to therapeutic strategy

Periodontitis is an inflammatory and destructive disease of tooth-supporting tissue and has become the leading cause of adult tooth loss. The most central pathological features of periodontitis are tissue damage and inflammatory reaction. As the energy metabolism center of eukaryotic cells, mitochondrion plays a notable role in various processes, such as cell function and inflammatory response. When the intracellular homeostasis of mitochondrion is disrupted, it can lead to mitochondrial dysfunction and inability to generate adequate energy to maintain basic cellular biochemical reactions. Recent studies have revealed that mitochondrial dysfunction is closely related to the initiation and development of periodontitis. The excessive production of mitochondrial reactive oxygen species, imbalance of mitochondrial biogenesis and dynamics, mitophagy and mitochondrial DNA damage can all affect the development and progression of periodontitis. Thus, targeted mitochondrial therapy is potentially promising in periodontitis treatment. In this review, we summarize the above mitochondrial mechanism in the pathogenesis of periodontitis and discuss some potential approaches that can exert therapeutic effects on periodontitis by modulating mitochondrial activity. The understanding and summary of mitochondrial dysfunction in periodontitis might provide new research directions for pathological intervention or treatment of periodontitis.

Artesunate ameliorates ligature-induced periodontitis by attenuating NLRP3 inflammasome-mediated osteoclastogenesis and enhancing osteogenic differentiation

Periodontitis, arguably the greatest common infective chronic inflammatory disease, is characterized by an imbalance of the host immune system and excessive osteoclastogenesis activity with severe alveolar bone loss. Nevertheless, in consideration of the harmful effects of repeated treatment, more sensible intervention drugs for periodontitis need to be developed. Artesunate (ART), derived from Artemisia annua L., has shown remarkable pharmacokinetic and clinical value, as well as anti-inflammatory and immunomodulatory effects in various immune and chronic diseases due to its endoperoxide group. However, the role of ART in mediating periodontitis-induced alveolar bone resorption has not been examined. In this study, ART treatment effectively ameliorated ligature-induced periodontitis via attenuating osteoclast formation in a dose-dependent manner. Mechanistically, RNA-seq revealed that ART dramatically reduced the enrichment of NLRP3 inflammasome-related genes. Concordant with our study, MCC950, a specific inhibitor of NLRP3 inflammasome, also greatly restrained osteoclastogenesis, suggesting that ART suppressed osteoclast formation by blocking NLRP3 inflammasome activation. In addition to regulating osteoclastogenesis, ART significantly enhanced osteogenic differentiation by alleviating the expression of cytokines in inflammatory conditions. Our data shed light on the probably potential mechanism of ART treatment for the intervention of periodontitis.

Single-cell transcriptional profiling reveals immunomodulatory properties of stromal and epithelial cells in periodontal immune milieu with diabetes in rats

Periodontitis is the sixth major complication of diabetes. Gingiva, as an important component of periodontal tissues, serves as the first defense barrier against infectious stimuli. However, relatively little is known about cellular heterogeneity and cell-specific changes in gingiva in response to diabetes-associated periodontitis. To characterize molecular changes linking diabetes with periodontitis, we profiled single-cell transcriptome analyses of a total of 45,259 cells from rat gingiva with periodontitis under normoglycemic and diabetic condition. The single-cell profiling revealed that stromal and epithelial cells of gingiva contained inflammation-related subclusters enriched in functions of immune cell recruitment. Compared to normoglycemic condition, diabetes led to a reduction in epithelial basal cells, fibroblasts and smooth muscle cells in gingiva with periodontitis. Analysis of differentially expressed genes indicated that stromal and epithelial populations were reprogrammed towards pro-inflammatory phenotypes promoting immune cell recruitment in diabetes-related periodontitis. In aspect of immune cells, diabetes prominently enhanced neutrophil and M1 macrophage infiltration in periodontitis lesions. Cell-cell communications revealed enhanced crosstalk between stromal/epithelial cells and immune cells mediating by chemokine/chemokine receptor interplay in diabetes-associated periodontitis. Our findings deconvolved cellular heterogeneity of rat gingiva associated with periodontitis and diabetes, uncovered altered immune milieu caused by the disease, and revealed immunomodulatory functions of stromal and epithelial cells in gingival immune niche. The present study improves the understanding of the link between the diabetes and periodontitis and helps in formulating precise therapeutic strategies for diabetes-enhanced periodontitis.

Periodontitis and progression of gastrointestinal cancer: current knowledge and future perspective

Periodontitis is a polymicrobial disorder caused by dysbiosis. Porphyromonas gingivalis (P.gingivalis) and Fusobacterium nucleatum (F.nucleatum) are pathobiont related to periodontitis pathogenesis and were found to be abundant in the intestinal mucosa of inflammatory bowel disease (IBD) and colorectal cancer (CRC) patients. Besides, periodontal infections have been found in a variety of tissues and organs, indicating that periodontitis is not just an inflammation limited to the oral cavity. Considering the possible translocation of pathobiont from the oral cavity to the gastrointestinal (GI) tract, this study aimed to review the published articles in this field to provide a comprehensive view of the existing knowledge about the relationship between periodontitis and GI malignancies by focusing on the oral/gut axis.

Thioredoxin-1 promotes the restoration of alveolar bone in periodontitis with diabetes

Treatment of periodontitis in people with diabetes remains challenging. The present study aimed to investigate the therapeutic potential of thioredoxin-1 (TRX1) in periodontitis with diabetes, as well as its role in modulating osteogenic differentiation. Our findings indicated that the production of reactive oxygen species (ROS) was elevated, while the expression of TRX1 was significantly reduced in the periodontal tissues of periodontitis mice with diabetes. Furthermore, knockdown of TRX1 in periodontal ligament stem cells (PDLSCs) resulted in the inhibition of osteogenic differentiation through disrupting Wnt/β-catenin signaling. However, this inhibition was restored upon administration of recombinant human TRX1 (rhTRX1). Importantly, rhTRX1 treatment decreased ROS generation, activated Wnt/β-catenin signal pathway and considerably promoted the alveolar bone repair of periodontitis mice with diabetes. These findings highlighted the crucial protective role of TRX1 in periodontitis with diabetes and suggested that it may serve as a potential therapeutic target for refractory periodontitis associated with oxidative stress.

A Protease-Responsive Polymer/Peptide Conjugate and Reversible Assembly of Silver Clusters for the Detection of Porphyromonas gingivalis Enzymatic Activity

We report the reversible aggregation of silver nanoparticle (AgNP) assemblies using the combination of a cationic arginine-based peptide and sulfur-capped polyethylene glycol (PEG). The formation and dissociation of the aggregates were studied by optical methods and electron microscopy. The dissociation of silver clusters depends on the peptide sequence and PEG size. A molecular weight of 1 kDa for PEG was optimal for the dissociation. The most important feature of this dissociation method is that it can operate in complex biofluids such as plasma, saliva, bile, urine, cell media, or even seawater without a significant decrease in performance. Moreover, the peptide-particle assemblies are highly stable and do not degrade (or express of loss of signal upon dissociation) when dried and resolubilized, frozen and thawed, or left in daylight for a month. Importantly, the dissociation capacity of PEG can be reduced via the conjugation of a peptide-cleavable substrate. The dissociation capacity is restored in the presence of an enzyme. Based on these findings, we designed a PEG-peptide hybrid molecule specific to the Porphyromonas gingivalis protease RgpB. Our motivation was that this bacterium is a key pathogen in periodontitis, and RgpB activity has been correlated with chronic diseases including Alzheimer's disease. The RgpB limit of detection was 100 pM RgpB in vitro. This system was used to measure RgpB in gingival crevicular fluid (GCF) samples with a detection rate of 40% with 0% false negatives versus PCR for P. gingivalis (n = 37). The combination of PEG-peptide and nanoparticles dissociation method allows the development of convenient protease sensing that can operate independently of the media composition.

An In Vitro Evaluation of the Antibacterial Efficacy of Solanum xanthocarpum Extracts on Bacteria From Dental Plaque Biofilm

OBJECTIVE

The focus of research has recently shifted toward developing herbal-based medicines due to the emerging bacterial resistance and side effects of antibiotics. Solanum xanthocarpum (Sx) is a medicinal plant with potent pharmacological properties. This study aimed to evaluate the antibacterial activity of its crude extracts on bacteria isolated from dental plaque in patients with gingivitis.

MATERIALS AND METHODS

Aqueous, ethyl acetate, hexane, chloroform, and ethanolic extracts were prepared from Sx. Dental plaque samples were collected from patients with plaque-induced gingivitis. Disk diffusion assay was performed to determine the antibacterial activity of the extracts at concentrations of 25 mg/ml, 50 mg/ml, and 75 mg/ml with ampicillin 200 mg/ml as a positive control. The minimum inhibitory concentration (MIC) of the aqueous extract was also evaluated by broth dilution test against bacteria isolated from dental plaque biofilm.

RESULTS

The antibacterial activity was estimated by measuring the zones of inhibition through the disc diffusion method. The Kruskal Wallis with Dunn post hoc test performed for intergroup comparison between the various extracts showed a statistically significant difference in inhibition of bacterial growth between 25 mg/ml and 75 mg/ml concentrations. There was no significant difference between the 75 mg/ml Sx concentration and the positive control. In addition, the MIC was elucidated to be 0.625 g/ml, at which there was maximum inhibition of bacterial growth.

CONCLUSION

The Sx extract exhibited antibacterial activity against periodontal pathogens. Thus, it can be concluded that optimum concentrations of Sx could be used in therapeutic strategies to prevent and manage periodontal diseases.

Inhibition of gingival fibroblast necroptosis mediated by RIPK3/MLKL attenuates periodontitis

AIM

Necroptosis participates in the pathogenesis of many inflammatory diseases, including periodontitis. Here, we aimed to investigate the role and mechanism of necroptosis inhibitors in attenuating periodontitis.

MATERIALS AND METHODS

The Gene Expression Omnibus (GEO) dataset GSE164241 was re-analysed to identify the role of necroptosis in periodontitis. Gingival specimens from healthy subjects or periodontitis patients were collected to evaluate the expression level of necroptosis-associated proteins. The therapeutic effect of necroptosis inhibitors on periodontitis was assessed in vivo and in vitro. Moreover, Transwell assays and Western blotting and siRNA transfection were used to identify the effects of necroptotic human gingival fibroblasts (hGFs) on THP-1 macrophages.

RESULTS

Re-analysis revealed that gingival fibroblasts (GFs) in periodontitis gingiva showed the highest area under the curve score of necroptosis. Elevated levels of necroptosis-associated proteins were identified in GFs in periodontitis gingiva collected from patients and mice. In ligature-induced periodontitis mice, local administration of receptor interacting protein kinase 3(RIPK3) inhibitor GSK'872 or sh-mixed-lineage kinase domain-like pseudokinase (Mlkl) markedly abrogated necroptosis and rescued periodontitis. Analogously, necroptosis inhibitors alleviated the inflammatory response and release of damage-associated molecular patterns in lipopolysaccharide- or LAZ (LPS + AZD'5582 + z-VAD-fmk, necroptosis inducer)-induced GFs and then reduced THP-1 cell migration and M1 polarization.

CONCLUSIONS

Necroptosis in GFs aggravated gingival inflammation and alveolar bone loss. Necroptosis inhibitors attenuate this process by modulating THP-1 macrophage migration and polarization. This study offers novel insights into the pathogenesis and potential therapeutic targets of periodontitis.

Association of periodontitis with handgrip strength and skeletal muscle mass in middle-aged US adults from NHANES 2013-2014

OBJECTIVES

The relationship between periodontitis and sarcopenia parameters in middle-aged adults is largely unexplored. This study investigated the association between periodontitis and combined handgrip strength and skeletal muscle mass in middle-aged adults.

MATERIALS AND METHODS

A sub-cohort of 1912 individuals with complete periodontal and whole-body dual X-ray absorptiometry examinations from the 2013-2014 wave of the National Health and Nutrition Examination Survey (n = 10,175) were analyzed using fully adjusted multiple linear regression models for associations between periodontitis and skeletal muscle mass index (kg/m2) and combined handgrip strength (kg).

RESULTS

The mean age of the study cohort was 43 (± 8.4) years and 49.4% of the participants were male. In total, 612 participants (32%) were determined to have periodontitis, of which 513 (26.8%) had non-severe (mild or moderate) periodontitis, and 99 (5.2%) had severe periodontitis. In unadjusted regression models, both non-severe and severe periodontitis were associated with SMMI (βnon-severe = 1.01, 95% CI 0.50; 1.52 and βsevere = 1.42, 95% CI 0.59; 2.25) but not with cHGS. After adjusting for age, sex, education, body mass index, bone mineral density, diabetic status, education, total energy intake, total protein intake, and serum vitamin D2 + D3, periodontitis was associated with cHGS (βnon-severe = -2.81, 95% CI - 4.7; - 1.15 and βsevere = - 2.73, 95% CI - 6.31; 0.83). The association between periodontitis and SMMI remained for non-severe periodontitis (βnon-severe = 0.07, 95% CI - 0.26; 0.40 and βsevere = 0.22, 95% CI - 0.34; 0.78).

CONCLUSION

The present study highlights the need of further prospective research to investigate the nature and direction of the relationship between periodontitis and sarcopenia indicators. Future studies can support the screening, prevention and clinical management of sarcopenia and periodontitis, and emphasize the interdisciplinary and complementary approach between the disciplines of geriatric medicine and periodontology.

The adiponectin receptor agonist AdipoAI attenuates periodontitis in diabetic rats by inhibiting gingival fibroblast-induced macrophage migration

BACKGROUND AND PURPOSE

Low-grade inflammation, a common feature of both diabetes and periodontitis, partly accounts for the complexity and refractoriness of diabetes-associated periodontitis. Adiponectin (APN), the most abundant adipokine in human blood, has been widely reported to have anti-inflammatory functions. Herein, we investigated the ability of an APN receptor agonist, AdipoAI, to alleviate diabetes-associated periodontitis. Furthermore, we revealed the possible mechanism underlying its anti-inflammatory effects.

EXPERIMENTAL APPROACH

The maxillary first molar of Zucker diabetic fatty (ZDF) rats was ligated to construct a diabetes-associated periodontitis model, and rats were administered AdipoAI by gavage. We examined diabetes-related indexes, pathological changes in insulin target organs, alveolar bone resorption and systemic and local inflammation. In vitro, transwell assays were used to evaluate monocyte/macrophage migration induced by human gingival fibroblasts (hGFs) with/without AdipoAI treatment. Additionally, we examined chemokine expression levels in hGFs and hGF-induced monocyte/macrophage migration upon siRNA knockdown of Adiponectin receptor expression. Expression of Adipo1/Adipo2 receptors and inflammation-related signalling pathways were examined by IHC and WB, followed by confirmation with an NF-κB P65 inhibitor (BAY 11-7082).

KEY RESULTS

AdipoAI lowered fasting blood glucose and serum insulin in ZDF rats and alleviated inflammation in insulin target tissues. Locally, AdipoAI reduced alveolar bone absorption and gingival inflammation. Mechanistically, AdipoAI inhibited hGF-induced monocyte/macrophage migration by reducing CCL2 secretion. In hGFs, AdipoAI attenuated LPS-induced activation of NF-κB P65 and CCL2 expression, which was dependent on the Adipo receptor 1.

CONCLUSION AND IMPLICATIONS

AdipoAI, with its ability to alleviate inflammatory damage in tissues, is a candidate for diabetes-associated periodontitis treatment.

Exploring the Role of IL-17A in Oral Dysbiosis-Associated Periodontitis and Its Correlation with Systemic Inflammatory Disease

Oral microbiota play a pivotal role in maintaining homeostasis, safeguarding the oral cavity, and preventing the onset of disease. Oral dysbiosis has the potential to trigger pro-inflammatory effects and immune dysregulation, which can have a negative impact on systemic health. It is regarded as a key etiological factor for periodontitis. The emergence and persistence of oral dysbiosis have been demonstrated to mediate inflammatory pathology locally and at distant sites. The heightened inflammation observed in oral dysbiosis is dependent upon the secretion of interleukin-17A (IL-17A) by various innate and adaptive immune cells. IL-17A has been found to play a significant role in host defense mechanisms by inducing antibacterial peptides, recruiting neutrophils, and promoting local inflammation via cytokines and chemokines. This review seeks to present the current knowledge on oral dysbiosis and its prevention, as well as the underlying role of IL-17A in periodontitis induced by oral dysbiosis and its impact on systemic inflammatory disease.

Rational Designs of Biomaterials for Combating Oral Biofilm Infections

Oral biofilms, which are also known as dental plaque, are the culprit of a wide range of oral diseases and systemic diseases, thus contributing to serious health risks. The manner of how to achieve good control of oral biofilms has been an increasing public concern. Novel antimicrobial biomaterials with highly controllable fabrication and functionalization have been proven to be promising candidates. However, previous reviews have generally emphasized the physicochemical properties, action mode, and application effectiveness of those biomaterials, whereas insufficient attention has been given to the design rationales tailored to different infection types and application scenarios. To offer guidance for better diversification and functionalization of anti-oral-biofilm biomaterials, this review details the up-to-date design rationales in three aspects: the core strategies in combating oral biofilm, as well as the biomaterials with advanced antibiofilm capacity and multiple functions based on the improvement or combination of the abovementioned antimicrobial strategies. Thereafter, insights on the existing challenges and future improvement of biomaterial-assisted oral biofilm treatments are proposed, hoping to provide a theoretical basis and reference for the subsequent design and application of antibiofilm biomaterials.

Effect of subgingival periodontal therapy on glycaemic control in type 2 diabetes patients: Meta-analysis and meta-regression of 6-month follow-up randomized clinical trials

BACKGROUND

Periodontitis worsens the hyperglycaemia in patients with type 2 diabetes mellitus (T2DM). Subgingival instrumentation, with or without surgical access, is the gold-standard treatment for periodontitis. The aim was to summarize the evidence on the effect of subgingival instrumentation (with or without open flap) on the reduction of glycosylated haemoglobin (HbA1c).

METHODS

Nine electronic databases were searched up to 15 February 2023. Twelve randomized controlled trials with at least 6 months of follow-up were included. Studies using systemic or local-delivery antimicrobial therapies were excluded. Meta-analyses were performed using the random-effects model. The sources of heterogeneity were assessed by applying linear meta-regression. Risk of bias was assessed by RoB 2, and certainty of evidence by GRADE.

RESULTS

Eleven studies were included in the quantitative analyses (1374 patients). Subgingival instrumentation resulted in 0.29% lower HbA1c (95% confidence interval: 0.10-0.47; p = .03) compared with non-active treatment.

DISCUSSION

None of the 12 studies were assessed as having low risk of bias. The percentage of females and the time of diabetes diagnosis significantly explained the high level of heterogeneity. Subgingival periodontal therapy results in a significant and clinically relevant improvement in glycaemic control over 6 months in patients with T2DM and periodontitis. The grade of evidence was moderate.

Relationship between circulating senescence-associated secretory phenotype levels and severity of type 2 diabetes-associated periodontitis: A cross-sectional study

BACKGROUND

Senescence-associated secretory phenotype (SASP) has recently been found to drive comorbid diabetes and periodontitis by inducing a chronic, low-degree inflammatory state. Here, we sought to explore the relationship between circulating SASP and the severity of type 2 diabetes-associated periodontitis (DP).

METHODS

Eighty patients (middle-aged periodontitis, M-P group; aged periodontitis, A-P group; M-DP group; and A-DP group; n = 20) provided gingival epithelium, serum, and periodontal clinical parameters. Circulating levels of 12 DP-related SASP factors were analyzed by immunoassay. Correlation between periodontal clinical parameters and circulating SASP levels was analyzed by Spearman's rank correlation coefficient and back propagation artificial neural network (BPNN). Senescence markers (p16, p21, and HMGB1) in gingiva were determined by immunofluorescence assay.

RESULTS

M-DP group had increased serum levels of twelve SASP factors compared with the M-P group (p < 0.5). Serum levels of IL-6, IL-4, and RAGE were higher in the A-DP group than the A-P group (p < 0.5). The circulating concentrations of certain SASP proteins, including IL-1β, IL-4, MMP-8, OPG, RANKL, and RAGE were correlated with the clinical parameters of DP. BPNN showed that serum SASP levels had considerable predictive value for CAL of DP. Additionally, the DP group had higher expressions of p16, p21, and cytoplasmic-HMGB1 in the gingiva than the P group (p < 0.5).

CONCLUSIONS

Significantly enhanced circulating SASP levels and aggravated periodontal destruction were observed in patients with DP. Importantly, a non-negligible association between serum SASP levels and the severity of DP was found.

Host insulin resistance caused by Porphyromonas gingivalis-review of recent progresses

Porphyromonas gingivalis (P. gingivalis) is a Gram-negative oral anaerobic bacterium that plays a key role in the pathogenesis of periodontitis. P. gingivalis expresses a variety of virulence factors that disrupt innate and adaptive immunity, allowing P. gingivalis to survive and multiply in the host and destroy periodontal tissue. In addition to periodontal disease, P.gingivalis is also associated with systemic diseases, of which insulin resistance is an important pathological basis. P. gingivalis causes a systemic inflammatory response, disrupts insulin signaling pathways, induces pancreatic β-cell hypofunction and reduced numbers, and causes decreased insulin sensitivity leading to insulin resistance (IR). In this paper, we systematically review the studies on the mechanism of insulin resistance induced by P. gingivalis, discuss the association between P. gingivalis and systemic diseases based on insulin resistance, and finally propose relevant therapeutic approaches. Overall, through a systematic review of the mechanisms related to systemic diseases caused by P. gingivalis through insulin resistance, we hope to provide new insights for future basic research and clinical interventions for related systemic diseases.

Efferocytosis: An Emerging Therapeutic Strategy for Type 2 Diabetes Mellitus and Diabetes Complications

Increasing evidence indicates that chronic, low-grade inflammation is a significant contributor to the fundamental pathogenesis of type 2 diabetes mellitus (T2DM). Efferocytosis, an effective way to eliminate apoptotic cells (ACs), plays a critical role in inflammation resolution. Massive accumulation of ACs and the proliferation of persistent inflammation caused by defective efferocytosis have been proven to be closely associated with pancreatic islet β cell destruction, adipose tissue inflammation, skeletal muscle dysfunction, and liver metabolism abnormalities, which together are considered the most fundamental pathological mechanism underlying T2DM. Therefore, here we outline the association between the molecular mechanisms of efferocytosis in glucose homeostasis, T2DM, and its complications, and we analyzed the present constraints and potential future prospects for therapeutic targets in T2DM and its complications.

Association and comparison of periodontal and oral hygiene status with serum HbA1c levels: a cross-sectional study

BACKGROUND

Diabetes Mellitus and periodontitis are chronic diseases with known reciprocal association. Studies have shown that uncontrolled diabetes increases the risk of development and progression of periodontal disease. This study aimed to explore the association and severity of periodontal clinical parameters and oral hygiene with HbA1c levels in non-diabetics and T2DM patients.

MATERIALS AND METHODS

In this cross-sectional study, the periodontal status of 144 participants, categorized into non-diabetics, controlled T2DM, and uncontrolled T2DM and were assessed via the Community Periodontal Index (CPI), Loss of Attachment Index (LOA index), and the number of missing teeth, while oral hygiene was measured by utilizing the Oral Hygiene Index Simplified (OHI-S). SPSS was used for data analysis. Chi-square test was used to find out the association of different independent variables with HbA1c groups, while ANOVA and post-hoc tests were run for inter-group and intra-group comparison respectively.

RESULTS

Out of 144 participants, the missing dentition was prevalent in uncontrolled T2DM with mean 2.64 ± 1.97 (95% CI 2.07-3.21; p = 0.01) followed by controlled T2DM 1.70 ± 1.79 (95% CI 1.18-2.23; p = 0.01) and non-diabetics 1.35 ± 1.63 (95% CI 0.88-1.82; p = 0.01) respectively. Furthermore, non-diabetics had a higher proportion of CPI score 0 (Healthy) [30 (20.8%); p = 0.001] as compared to uncontrolled T2DM [6 (4.2%); p = 0.001], while CPI score 3 was more prevalent in uncontrolled T2DM in comparison to non-diabetics. Loss of attachment (codes-2,3 and 4) was also frequently observed in uncontrolled T2DM compared to non-diabetics (p = 0.001). Similarly, based on Oral Hygiene Index- Simplified (OHI-S), the result showed that poor oral hygiene was most commonly observed in uncontrolled T2DM 29 (20.1%) followed by controlled T2DM patients 22 (15.3%) and non-diabetic [14 (9.7%); p = 0.03].

CONCLUSION

This study showed that periodontal status and oral hygiene status were deteriorated in uncontrolled T2DM patients compared to non-diabetic participants and controlled T2DM.

Peri-implantitis and systemic inflammation: A critical update

Peri-implantitis is an inflammatory condition induced by bacterial biofilm that affects the soft and hard tissues surrounding dental implants, compromising the success of implant therapy. Recent studies have highlighted the potential links between peri-implant health and systemic inflammation, including uncontrolled diabetes mellitus, psychological stress, cardiovascular disease, obesity, and infectious diseases such as COVID-19. As an inflammatory disease, peri-implantitis may trigger systemic inflammation by elevating circulating levels of pro-inflammatory cytokines, which could have unknown impacts on overall health. While the relationship between periodontal health and systemic conditions is better understood, the association between peri-implant disease and systemic inflammation remains unclear. Therefore, this comprehensive review aims to summarize the most recent evidence on the relationship between peri-implantitis and systemic inflammation, focusing on biological complications, microbiology, and biomarkers. This review aims to enhance our understanding of the links between peri-implantitis and systemic inflammation and promote further research in this field by discussing the latest insights and clinical implications.

Clinical outcomes of single full-coverage lithium disilicate restorations: A systematic review

Introduction

Lithium disilicate glass-ceramic (LDC) restorations exhibit microorganism infiltration, recurrent caries, pulpal lesions, periodontal inflammation, and cement exposure to the oral environment over time. All these factors lead to restoration failure. This systematic review aimed to investigate the clinical outcomes of LDC full-coverage crowns (FCC) in permanent teeth compared with those of other full-coverage restoration materials.

Materials & Methods

Search strategies were developed for four databases: Web of Science, OVID, PubMed, and Scopus. Data extraction and quality appraisals were performed by two independent reviewers. Data on the presence of caries, post-operative sensitivity, and periodontal changes were extracted from the included clinical studies. In addition to the outcome measures, data on the sample size, study groups, method of restoration fabrication, type of impression, and type of abutment were recorded.

Results

We retrieved 3989 records for the title and abstract screening. Of these, 19 clinical studies met the inclusion criteria. The overall quality of the included studies indicates a low risk of bias. Most studies reported no pulpal involvement, recurrent caries, or post-operative sensitivity and presented a favorable periodontal response after the cementation of LDC-FCC during different follow-up periods.

Conclusion

Based on the endodontic and periodontic clinical responses of natural tooth abutments and their supporting periodontium, LDC-FCC can be considered a clinically successful restorative option.

aMMP-8 Point-of-Care Test (POCT) Identifies Reliably Periodontitis in Patients with Type 2 Diabetes as well as Monitors Treatment Response

BACKGROUND

The link between diabetes and periodontitis is bi-directional: high glucose levels increase the risk of periodontitis and elevated oral fluid aMMP-8 as well as diabetic development while untreated periodontitis worsens glycaemic control.

METHODS

Type-2 patients (N = 161) underwent an aMMP-8 Point-of-Care Test (POCT) at diabetes clinics. If the test was positive, the patient was sent to an oral health care clinic and oral health examination, health-promoting as well as necessary treatment procedures were carried out. Only 41 patients underwent full clinical evaluations. At the end of the treatment, an aMMP-8 POCT (B) was performed and if the test was positive, the treatment was continued and a new test (C) was performed, aiming for test negativity. The glycated haemoglobin (GHbA1c) test was performed approximately 6 months from the original appointment.

RESULTS

GHbA1c concentrations did not decrease during the follow-up. The concentrations of aMMP-8 assessed by POCT, and clinical parameters decreased. Changes in GHbA1c and aMMP-8 levels assessed by POCT during the treatment correlated positively with each other (p < 0.01).

CONCLUSION

aMMP-8 POCT proved its reliability, and that its use is beneficial in the diabetes clinic, it enables identifying patients with periodontal findings reliably and guides them directly to an oral health clinic.

The Genetic Cross-Talk between Periodontitis and Chronic Kidney Failure Revealed by Transcriptomic Analysis

Periodontitis and chronic kidney failure (CKF) are potentially related to each other. This bioinformatics analysis aimed at the identification of potential cross-talk genes and related pathways between periodontitis and CKF. Based on NCBI Gene Expression Omnibus (GEO), datasets GSE10334, GSE16134, and GSE23586 were extracted for periodontitis. A differential expression analysis (p < 0.05, |log2(FC)| > 0.5) was performed to assess deregulated genes (DEGs). CKF-related genes were extracted from DisGeNET and examined regarding their overlap with periodontitis-related DEGs. Cytoscape was used to construct and analyze a protein-protein interaction (PPI) network. Based on Cytoscape plugin MCODE and a LASSO regression analysis, the potential hub cross-talk genes were identified. Finally, a complex PPI of the hub genes was constructed. A total of 489 DEGs for periodontitis were revealed. With the 805 CKF-related genes, an overlap of 47 cross-talk genes was found. The PPI network of the potential cross-talk genes was composed of 1081 nodes and 1191 edges. The analysis with MCODE resulted in 10 potential hub genes, while the LASSO regression resulted in 22. Finally, five hub cross-talk genes, CCL5, FCGR3B, MMP-9, SAA1, and SELL, were identified. Those genes were significantly upregulated in diseased samples compared to controls (p ≤ 0.01). Furthermore, ROC analysis showed a high predictive value of those genes (AUC ≥ 73.44%). Potentially relevant processes and pathways were primarily related to inflammation, metabolism, and cardiovascular issues. In conclusion, five hub cross-talk genes, i.e., CCL5, FCGR3B, MMP-9, SAA1, and SELL, could be involved in the interplay between periodontitis and CKF, whereby primarily inflammation, metabolic, and vascular issues appear to be of relevance.

NADPH-dependent ROS accumulation contributes to the impaired osteogenic differentiation of periodontal ligament stem cells under high glucose conditions

Diabetes mellitus is an established risk factor for periodontal disease that can aggravate the severity of periodontal inflammation and accelerate periodontal destruction. The chronic high glucose condition is a hallmark of diabetes-related pathogenesis, and has been demonstrated to impair the osteogenic differentiation of periodontal ligament stem cells (PDLSCs), leading to delayed recovery of periodontal defects in diabetic patients. Reactive oxygen species (ROS) are small molecules that can influence cell fate determination and the direction of cell differentiation. Although excessive accumulation of ROS has been found to be associated with high glucose-induced cell damage, the underlying mechanisms remain unclear. Nicotinamide adenine dinucleotide phosphate (NADPH) is an important electron donor and functions as a critical ROS scavenger in antioxidant systems. It has been identified as a key mediator of various biological processes, including energy metabolism and cell differentiation. However, whether NADPH is involved in the dysregulation of ROS and further compromise of PDLSC osteogenic differentiation under high glucose conditions is still not known. In the present study, we found that PDLSCs incubated under high glucose conditions showed impaired osteogenic differentiation, excessive ROS accumulation and increased NADPH production. Furthermore, after inhibiting the synthesis of NADPH, the osteogenic differentiation of PDLSCs was significantly enhanced, accompanied by reduced cellular ROS accumulation. Our findings demonstrated the crucial role of NADPH in regulating cellular osteogenic differentiation under high glucose conditions and suggested a new target for rescuing high glucose-induced cell dysfunction and promoting tissue regeneration in the future.

Predictive value of TCM clinical index for diabetic peripheral neuropathy among the type 2 diabetes mellitus population: A new observation and insight

Aims

The objectives of this study were to identify clinical predictors of the Traditional Chinese medicine (TCM) clinical index for diabetic peripheral neuropathy (DPN) in type 2 diabetes mellitus (T2DM) patients, develop a clinical prediction model, and construct a nomogram.

Methods

We collected the TCM clinical index from 3590 T2DM recruited at the Second Affiliated Hospital of Tianjin University of Traditional Chinese Medicine from January 2019 to October 2020. The participants were randomly assigned to either the training group (n = 3297) or the validation group (n = 1426). TCM symptoms and tongue characteristics were used to assess the risk of developing DPN in T2DM patients. Through 5-fold cross-validation in the training group, the least absolute shrinkage and selection operator (LASSO) regression analysis method was used to optimize variable selection. In addition, using multifactor logistic regression analysis, a predictive model and nomogram were developed.

Results

A total of eight independent predictors were found to be associated with the DPN in multivariate logistic regression analyses: advanced age of grading (odds ratio/OR 1.575), smoke (OR 2.815), insomnia (OR 0.557), sweating (OR 0.535), loose teeth (OR 1.713), dry skin (OR 1.831), purple tongue (OR 2.278). And dark red tongue (OR 0.139). The model was constructed using these eight predictor's medium discriminative capabilities. The area under the curve (AUC) of the training set is 0.727, and the AUC of the validation set is 0.744 on the ROC curve. The calibration plot revealed that the model's goodness-of-fit is satisfactory.

Conclusions

We established a TCM prediction model for DPN in patients with T2DM based on the TCM clinical index.

GPR40 deficiency worsens metabolic syndrome-associated periodontitis in mice

BACKGROUND AND OBJECTIVE

G protein-coupled receptor 40 (GPR40) is a receptor for medium- and long-chain free fatty acids (FFAs). GPR40 activation improves type 2 diabetes mellitus (T2DM), metabolic syndrome (MetS), and the complications of T2DM and MetS. Periodontitis, a common oral inflammatory disease initiated by periodontal pathogens, is another complication of T2DM and MetS. Since FFAs play a key role in the pathogenesis of MetS which exacerbates periodontal inflammation and GPR40 is a FFA receptor with anti-inflammatory properties, it is important to define the role of GPR40 in MetS-associated periodontitis.

MATERIALS AND METHODS

We induced MetS and periodontitis by high-fat diet and periodontal injection of lipopolysaccharide (LPS), respectively, in wild-type and GPR40-deficient mice and determined alveolar bone loss and periodontal inflammation using micro-computed tomography, histology, and osteoclast staining. We also performed in vitro study to determine the role of GPR40 in the expression of proinflammatory genes.

RESULTS

The primary outcome of the study is that GPR40 deficiency increased alveolar bone loss and enhanced osteoclastogenesis in control mice and the mice with both MetS and periodontitis. GPR40 deficiency also augmented periodontal inflammation in control mice and the mice with both MetS and periodontitis. Furthermore, GPR40 deficiency led to increased plasma lipids and insulin resistance in control mice but had no effect on the metabolic parameters in mice with MetS alone. For mice with both MetS and periodontitis, GPR40 deficiency increased insulin resistance. Finally, in vitro studies with macrophages showed that deficiency or inhibition of GPR40 upregulated proinflammatory genes while activation of GPR40 downregulated proinflammatory gene expression stimulated synergistically by LPS and palmitic acid.

CONCLUSION

GPR40 deficiency worsens alveolar bone loss and periodontal inflammation in mice with both periodontitis and MetS, suggesting that GPR40 plays a favorable role in MetS-associated periodontitis. Furthermore, GPR40 deficiency or inhibition in macrophages further upregulated proinflammatory and pro-osteoclastogenic genes induced by LPS and palmitic acid, suggesting that GPR40 has anti-inflammatory and anti-osteoclastogenic properties.

Green Alternatives as Antimicrobial Agents in Mitigating Periodontal Diseases: A Narrative Review

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Effects of periodontitis on cancer outcomes in the era of immunotherapy

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Oral microbiome correlates with selected clinical biomarkers in individuals with no significant systemic disease

The oral microbiome is an important component of the microbiome in the human body. Although the association of the oral microbiome with various diseases, including periodontitis and cancer, has been reported, information on how the oral microbiome is related to health-related indicators in healthy populations is still insufficient. In this study, we examined the associations of the oral microbiome with 15 metabolic and 19 complete blood count (CBC)-based markers in 692 healthy Korean individuals. The richness of the oral microbiome was associated with four CBC markers and one metabolic marker. Compositional variation in the oral microbiome was significantly explained by four markers: fasting glucose, fasting insulin, white blood cell count, and total leukocyte count. Furthermore, we found that these biomarkers were associated with the relative abundances of numerous microbial genera, such as Treponema, TG5, and Tannerella. By identifying the relationship between the oral microbiome and clinical biomarkers in a healthy population, our study presents a direction for future studies on oral microbiome-based diagnosis and interventions.

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Macrophage pyroptosis drives the secretion of IL-1β, which has been recently reported to be a featured salivary biomarker for discriminating periodontitis in the presence of diabetes. This study aimed to explore whether macrophage pyroptosis plays a role in the development of diabetes mellitus–periodontitis, as well as potential therapeutic strategies. By establishing a model of experimental diabetes mellitus–periodontitis in rats, we found that IL-1β and gasdermin D were highly expressed, leading to aggravated destruction of periodontal tissue. MCC950, a potent and selective molecule inhibitor of the NLRP3 inflammasome, effectively inhibited macrophage pyroptosis and attenuated alveolar bone losses in diabetes mellitus–periodontitis. Consistently, in vitro, high glucose could induce macrophage pyroptosis and thus promoted IL-1β production in macrophages stimulated by lipopolysaccharide. In addition, autophagy blockade by high glucose via the mTOR-ULK1 pathway led to severe oxidative stress response in macrophages stimulated by lipopolysaccharide. Activation of autophagy by rapamycin, clearance of mitochondrial ROS by mitoTEMPO, and inhibition of inflammasome by MCC950 could significantly reduce macrophage pyroptosis and IL-1β secretion. Our study demonstrates that hyperglycemia promotes IL-1β production and pyroptosis in macrophages suffered by periodontal microbial stimuli. Modulation of autophagy activity and specific targeting of the ROS-inflammasome pathway may offer promising therapeutic strategies to alleviate diabetes mellitus–periodontitis.