Diabetic periodontitis: a model for activated innate immunity and impaired resolution of inflammation

Integrated analyses revealed the potential role and immune link of mitochondrial dysfunction between periodontitis and type 2 diabetes mellitus

There is a reciprocal comorbid relationship between periodontitis and type 2 diabetes mellitus (T2DM). Recent studies have suggested that mitochondrial dysfunction (MD) could be the key driver underlying this comorbidity. The aim of this study is to provide novel understandings into the potential molecular mechanisms between MD and the comorbidity, and identify potential therapeutic targets for personalized clinical management. MD-related differentially expressed genes (MDDEGs) were identified. Enrichment analyses and PPI network analysis were then conducted. Six algorithms were used to explore the hub MDDEGs, and these were validated by ROC analysis and qRT-PCR. Co-expression and potential drug targeting analyses were then performed. Potential biomarkers were identified using LASSO regression. The immunocyte infiltration levels in periodontitis and T2DM were evaluated via CIBERSORTx and validated in mouse models. Subsequently, MD-related immune-related genes (MDIRGs) were screened by WGCNA. The in vitro experiment verified that MD was closely associated with this comorbidity. GO and KEGG analyses demonstrated that the connection between periodontitis and T2DM was mainly enriched in immuno-inflammatory pathways. In total, 116 MDDEGs, eight hub MDDEGs, and two biomarkers were identified. qRT-PCR revealed a distinct hub MDDEG expression pattern in the comorbidity group. Altered immunocytes in disease samples were identified, and their correlations were explored. The in vivo examination revealed higher infiltration levels of inflammatory immunocytes. The findings of this study provide insight into the mechanism underlying the gene-mitochondria-immunocyte network and provide a novel reference for future research into the function of mitochondria in periodontitis and T2DM.

Association of salivary levels of DNA sensing inflammasomes AIM2, IFI16, and cytokine IL18 with periodontitis and diabetes

BACKGROUND

Aberrant deoxyribonucleic acid (DNA) contributes to inflammasome orchestrated progression of chronic inflammatory diseases like diabetes and periodontitis. The purpose of the present study was to estimate salivary levels of DNA sensing inflammasomes, absent in melanoma 2 (AIM2), interferon γ inducible protein (IFI16), and cytokine interleukin 18 (IL18) in individuals with periodontitis, diabetes, and healthy controls and interpret its association with periodontal and diabetic parameters.

METHODS

Salivary levels of AIM2, IFI16, and IL18 were estimated by enzyme linked immunosorbent assay (ELISA) in a total of 120 individuals (n = 30 in each group), namely, healthy (Group 1), periodontitis (Group 2), diabetes (Group 3), and diabetes with periodontitis (Group 4). Correlations of inflammasome levels and periodontal clinical parameters-plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing pocket depth (PPD), clinical attachment level (CAL), and periodontal inflamed surface area (PISA) were performed. Multiple regression was carried out to predict AIM2 and IFI16 with various independent variables.

RESULTS

The mean salivary levels of AIM2, IFI16, and IL18 were highest in diabetes with periodontitis (Group 4) and least in healthy (Group 1) and statistically significant between the groups (p = 0.000). Significant positive correlation between clinical periodontal parameters and AIM2, IFI16, and IL18 was present (p ≤ 0.05). Multiple regression showed glycated hemoglobin (HbA1C) (p = 0.002), GI (p = 0.016), PISA (p = 0.002), and CAL (p = 0.004) were significant predictors of AIM2, while HbA1C (p = 0.012), PISA (p = 0.003), and CAL (p = 0.007) predicted IFI16.

CONCLUSION

The results of the present study showed higher levels of AIM2, IFI16, and IL18 in saliva of individuals with diabetes and periodontitis. HbA1C, PISA, and CAL were significant independent predictors of salivary AIM2 and IFI16 levels.

Ziyin Bushen Fang improves Diabetic Osteoporosis by Inhibiting Autophagy and Oxidative Stress In vitro and In vivo

OBJECTIVE

Diabetic osteoporosis (DOP) belongs to the group of diabetes-induced secondary osteoporosis and is the main cause of bone fragility and fractures in many patients with diabetes. The aim of this study was to determine whether Ziyin Bushen Fang (ZYBSF) can improve DOP by inhibiting autophagy and oxidative stress.

METHODS

Type 1 diabetes mellitus (T1DM) was induced in rats using a high-fat high-sugar diet combined with streptozotocin. Micro-CT scanning was used to quantitatively observe changes in the bone microstructure in each group. Changes in the serum metabolites of DOP rats were analyzed using UHPLC-QTOF-MS. The DOP mouse embryonic osteoblast precursor cell model (MC3T3-E1) was induced using high glucose levels.

RESULTS

After ZYBSF treatment, bone microstructure significantly improved. The bone mineral density, trabecular number, and trabecular thickness in the ZYBSF-M and ZYBSF-H groups significantly increased. After ZYBSF treatment, the femur structure of the rats was relatively intact, collagen fibers were significantly increased, and osteoporosis was significantly improved. A total of 1239 metabolites were upregulated and 1527 were downregulated in the serum of T1DM and ZYBSF-treated rats. A total of 20 metabolic pathways were identified. In cellular experiments, ZYBSF reduced ROS levels and inhibited the protein expression of LC3II / I, Beclin-1, and p-ERK.

CONCLUSION

ZYBSF may improve DOP by inhibiting the ROS/ERK-induced autophagy signaling pathway.

Influence of Reactive Oxygen Species on Wound Healing and Tissue Regeneration in Periodontal and Peri-Implant Tissues in Diabetic Patients

Diabetes mellitus (DM) is associated with periodontal disease. Clinically, periodontal treatment is less effective for patients with DM. Oxidative stress is one of the mechanisms that link DM to periodontitis. The production of reactive oxygen species (ROS) is increased in the periodontal tissues of patients with DM and is involved in the development of insulin resistance in periodontal tissues. Insulin resistance decreases Akt activation and inhibits cell proliferation and angiogenesis. This results in the deterioration of wound healing and tissue repair in periodontal tissues. Antioxidants and insulin resistance ameliorants may inhibit ROS production and improve wound healing, which is worsened by DM. This manuscript provides a comprehensive review of the most recent basic and clinical evidence regarding the generation of ROS in periodontal tissues resulting from microbial challenge and DM. This study also delves into the impact of oxidative stress on wound healing in the context of periodontal and dental implant therapies. Furthermore, it discusses the potential benefits of administering antioxidants and anti-insulin resistance medications, which have been shown to counteract ROS production and inflammation. This approach may potentially enhance wound healing, especially in cases exacerbated by hyperglycemic conditions.

A comparative study of the therapeutic effect of bone marrow mesenchymal stem cells versus insulin on mandibular dento-alveolar complex collagen formation and beta-catenin expression in experimentally induced type I diabetes

Objective

To assess and compare the therapeutic effect of bone marrow mesenchymal stem cells (BM-MSCs) versus insulin on mandibular dento-alveolar complex collagen formation and beta-catenin (β-catenin) expression in experimentally induced type I diabetes in albino rat.

Design

Twenty-eight male albino rats were equally divided as follows; Group I: was composed of rats which received no drug. The remaining rats were administrated a single streptozotocin (STZ) (40 mg/kg) intra-peritoneal injection. After affirmation of diabetes induction, the rats were divided into: Group II: Diabetic rats were given no treatment. Group III: Diabetic rats received a single BM-MSCs intravenous injection (1x106 cells). Group IV: Diabetic rats were given a daily insulin subcutaneous injection (5 IU/kg). After 28 days, mandibles were processed and stained by Hematoxylin & Eosin (H&E), Masson's trichrome and anti-β-catenin antibody. A statistical analysis was performed to measure positive area% of Masson's trichrome and β-catenin.

Results

Dento-alveolar complex tissues and cells of Group II showed destructive changes histologically, while Groups III and IV demonstrated improved histological features. Group II presented almost old collagen in all dento-alveolar complex tissues, and nearly negative β-catenin expression. Groups III and IV revealed a newly formed collagen intermingled with very few areas of old collagen, and both groups showed positive β-catenin immunoreactivity. Statistically, Groups III and IV represented the highest mean values of Masson's trichrome area% and β-catenin area%, while Group II reported the lowest mean.

Conclusions

Streptozotocin has a destructive effect on the dento-alveolar complex structure and function. BM-MSCs and insulin show regenerative capacity in STZ-affected periodontal tissues, and statistically, they increase collagen formation and β-catenin expression.

Effectiveness of subgingival irrigation and powered toothbrush as home care maintenance protocol in type 2 diabetic patients with active periodontal disease: A 4-month randomized controlled trial

Background

There is a bidirectional link between diabetes and periodontal disease. Control of active periodontal infection is an essential requisite to maintain optimal oral and systemic health in diabetic patients. The purpose of this study was to evaluate the efficacy of subgingival irrigation and powered toothbrush as home care maintenance protocol in type 2 diabetic patients with active periodontal disease compared to routine oral hygiene.

Materials and Methods

Forty (n = 40) diabetic (HbA1c >7%) patients were enrolled in this parallel, examiner-blind, interventional clinical trial. Patients were randomized into two groups: Group A (sonic toothbrush and irrigation with water twice daily) or Group B (manual toothbrush and mouth rinsing with 0.12% Chlorhexidine gluconate (CHX) twice daily)). All patients received Phase I therapybefore the start of the study. Clinical parameters (plaque index [PI], gingival index [GI], oral hygiene index [OHI], pocket depth [PD], clinical attachment level [CAL], and bleeding index [BI]) were assessed at baseline, 1, 2, and 4 months. Levels of C-reactive protein (CRP), HbA1c, and interleukin (IL)-1 β were assessed at baseline and 4 months only. Verbal and written instructions were provided to each subject specific to their intervention allocation. Descriptive, parametric, and nonparametric analyses were used where appropriate.

Results

Sixteen (n = 16) patients in Group A and fifteen (n = 15) patients in Group B completed the 4-month study. Both groups showed a significant difference in BI, PD, CAL, and HbA1c from baseline to 4 months. There were no differences within groups for OHI, GI, or PI and CRP, IL-1 β. The results are based on an underpowered study due to the drop out of 9 patients reducing the number below the needed 19 patients per group based on the power analysis.

Conclusion

Results from this study provide information for future studies on self-care regimens for individuals living with Type 2 diabetes.

Periodontal Diseases and Diabetes Mellitus: A Systematic Review

Introduction

Although the fact that the association of the periodontitis and the diabetes mellitus is well accepted, the literature has inconsistent findings regarding this connection. The motive in conducting this systematic review was to define whether poorly controlled diabetes was linked to the development or progression of periodontitis.

Materials and Methods

Databases from PubMed, Scopus, and Embase were searched electronically. All included articles' reference lists were manually searched. Google Scholar was used to research gray literature. For this review, longitudinal studies (prospective) on the association between periodontitis and diabetes were taken into consideration. Studies have to have included at least two parameters of the evolution of health of the periodontium throughout time. The study's design, as well as unadjusted and adjusted estimates, was recorded. This study calculated the combined impact of diabetes-related hyperglycemia on the start or progression of periodontitis using meta-analysis. To look into possible sources of study heterogeneity, subgroup analyses and meta-regression were used.

Results

With 49,262 participants from 13 studies that met the inclusion criteria, 3197 of whom had been diagnosed with diabetes. Diabetes augmented the likelihood of developing or progressing into periodontitis by 86%, according to meta-analyses of adjusted estimates (RR 1.86; 95% CI 1.3-2.8). On the association between periodontitis and diabetes, there is little data, nonetheless.

Conclusions

This study provides proof that persons with diabetes have an increased risk of developing periodontitis. Methodological limitations mentioned in this study should be overcome in upcoming prospective longitudinal investigations.

Effects of Nonsurgical Periodontal Therapy on Glycemic Control in Diabetic Patients under Systemic Administration of Antidiabetic Ayurvedic Drug

AIM

This study aimed to monitor the metabolic response of nonsurgical periodontal therapy in type-2 diabetic patients with chronic periodontitis under systemic administration of antidiabetic ayurvedic drug.

MATERIALS AND METHODS

About 90 newly diagnosed mild-to-moderate forms of type-2 diabetes mellitus (DM) subjects with generalized chronic periodontitis were selected according to the inclusion and exclusion criteria and were randomly divided into group A and group B with 45 patients in each group. Clinical parameters, including plaque index, probing pocket depth, clinical attachment level, and glycemic status, were assessed at baseline. Following initial periodontal clinical examination, the drug Nishamalaki (NA) 2 gm twice daily for 3 months was prescribed after food by an Ayurvedic physician to all the patients enrolled in group A and group B, and scaling and root planing were completed only for group B patients. Patients were recalled for review, and all the parameters were reassessed at the end of the 1st, 2nd, and 3rd months following interventions.

RESULTS

Regarding clinical and metabolic parameters at baseline, no statistically significant differences were displayed between the two groups. However, at the 3-months follow-up period, the patients in group B demonstrated significantly better clinical and metabolic outcomes than patients in group A.

CONCLUSION

Periodontal therapy improved glycemic control in patients with type-2 DM in both groups; however, the reduction in FBS values reached statistical significance only in the group receiving scaling and root planing alone.

CLINICAL SIGNIFICANCE

Nonsurgical periodontal therapy may have a beneficial effect on the periodontal clinical and glycemic levels in type-2 diabetic patients with chronic periodontitis.

Implications of lysyl oxidase-like protein 3 expression in the periodontium of diabetic rats

Objectives

Diabetes has been strongly associated with periodontal diseases. The periodontal ligament (PDL) has an abundant extracellular matrix (ECM). Lysyl oxidases (LOXs) are closely associated with various diseases caused by abnormal ECM functions, however, the role of LOXs in periodontal diseases induced by diabetes remains unclear.

Methodology

In this study, 8-week-old Zucker diabetic fatty rats were used to establish a type 2 diabetes mellitus (T2DM) model. After 9 and 16 weeks, hematoxylin and eosin (H&E), Masson’s trichrome, and immunohistochemical staining were performed.

Results

After 9 weeks, loose collagen fibers were found in the interradicular area of the diabetic group, in opposition to the control group. There were no significant differences in LOX expression between the diabetic and control groups (p>0.05). However, after 16 weeks, the diabetic group presented a disordered arrangement of the PDL, showing decreased collagen content and significantly increased lysyl oxidase-like protein 3 (LOXL3) expression when compared with the control group (p<0.05). This suggests that LOXL3 plays a significant role in periodontal histopathological changes in diabetic rats.

Conclusion

Our study showed elevated LOXL3 expression in the PDL of diabetic rats after 16 weeks, suggesting that LOXL3 may be involved in the occurrence and development of periodontal histopathological changes in diabetic rats. LOXL3 could be further used as an indicator for the early diagnosis of diabetic periodontitis in T2DM patients in clinical settings.

Inflammatory response of gut, spleen, and liver in mice induced by orally administered Porphyromonas gingivalis

Background

Periodontitis is a chronic multifactorial inflammatory disease. Porphyromonas gingivalis is a primary periopathogen in the initiation and development of periodontal disease. Evidence has shown that P. gingivalis is associated with systemic diseases, including IBD and fatty liver disease. Inflammatory response is a key feature of diseases related to this species.

Methods

C57BL/6 mice were administered either PBS, or P. gingivalis. After 9 weeks, the inflammatory response in gut, spleen, and liver was analyzed.

Results

The findings revealed significant disturbance of the intestinal microbiota and increased inflammatory factors in the gut of P. gingivalis-administered mice. Administrated P. gingivalis remarkably promoted the secretion of IRF-1 and activated the inflammatory pathway IFN-γ/STAT1 in the spleen. Histologically, mice treated with P. gingivalis exhibited hepatocyte damage and lipid deposition. The inflammatory factors IL-17a, IL-6, and ROR-γt were also upregulated in the liver of mice fed with P. gingivalis. Lee’s index, spleen index, and liver index were also increased.

Conclusion

These results suggest that administrated P. gingivalis evokes inflammation in gut, spleen, and liver, which might promote the progression of various systemic diseases.

Gingival crevicular fluid CSF-1 and IL-34 levels in patients with stage III grade C periodontitis and uncontrolled type 2 diabetes mellitus

PURPOSE

Periodontal diseases are inflammatory conditions that alter the host's response to microbial pathogens. Type 2 diabetes mellitus (T2DM) is a complex disease that affects the incidence and severity of periodontal diseases. This study investigated the gingival crevicular fluid (GCF) levels of colony-stimulating factor-1 (CSF-1) and interleukin-34 (IL-34) in patients with stage III grade C periodontitis (SIII-GC-P) and stage III grade C periodontitis with uncontrolled type 2 diabetes (SIII-GC-PD).

METHODS

In total, 72 individuals, including 24 periodontally healthy (PH), 24 SIII-GC-P, and 24 SIII-GC-PD patients, were recruited for this study. Periodontitis patients (stage III) had interdental attachment loss (AL) of 5 mm or more, probing depth (PD) of 6 mm or more, radiographic bone loss advancing to the middle or apical part of the root, and tooth loss (<5) due to periodontal disease. Radiographic bone loss in the teeth was also evaluated; grade C periodontitis was defined as a ratio of the percentage of root bone loss to age greater than 1.0. The plaque index (PI), gingival index (GI), presence of bleeding on probing (BOP), PD, and clinical AL were used for clinical periodontal assessments. GCF samples were obtained and analyzed using an enzyme-linked immunosorbent assay.

RESULTS

All clinical parameters-PD, AL, GI, BOP, and PI-were significantly higher in the SIII-GC-PD group than in the PH and SIII-GC-P groups for both the full mouth and each sampling site (P<0.05). The total IL-34 and CSF-1 levels were significantly higher in the SIII-GC-PD group than in the PH and SIII-GC-P groups (P<0.05), and there were significant differences between the periodontitis groups (P<0.05).

CONCLUSIONS

These findings suggest that IL-34 and CSF-1 expression increases in patients with SIII-GC-PD. CSF-1 was associated with the inflammatory status of periodontal tissues and T2DM, while IL-34 was associated only with T2DM.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04891627.

Salivary MMP-9 Levels in Chronic Periodontitis Patients with Type-II Diabetes Mellitus

Chronic periodontitis and diabetes mellitus share a two-way relationship, the common factor being the inflammatory-mediated pathway, and various cytokines are released during this inflammatory cascade, one of which being matrix metalloproteinase-9. The aim of this study was to identify whether the levels of matrix metalloproteinase-9 are increased due to type-II diabetes mellitus in chronic periodontitis patients. It was an observational, analytical, case-control study. Thirty subjects were recruited in the test group, who were suffering from type-II diabetes mellitus and chronic periodontitis, and 30 subjects in the control group, who were subjects with chronic periodontitis but systemically healthy. Periodontal parameters, including the plaque score, gingival bleeding index, probing pocket depth and clinical attachment level of the subjects, were measured, saliva samples of all of the subjects were collected and salivary matrix metalloproteinase-9 levels were analyzed by an enzyme-linked immunosorbent assay (ELISA) technique. The statistical analysis was performed using SPSS 24. Overall, the matrix metalloproteinase-9 levels of the diabetic patients with chronic periodontitis were increased almost twofold (156.95 ± 29.80 ng/mL) compared to the levels in the controls (74.96 ± 6.32 ng/mL) (p < 0.001). Similarly, the periodontal parameters were far worse in diabetics with chronic periodontitis compared to the controls. The average gingivitis score for the test subjects was 78.45 ± 8.93%), compared to 29.32 ± 12.96% in the controls (p < 0.001). The mean probing pocket depth for the test group was 5.39 ± 0.60 mm, and, for the control group, it was 4.35 ± 0.31 mm (p < 0.001). For the test subjects, the average clinical attachment level was 5.86 ± 0.58 mm, and it was 4.66 ± 0.32 mm for the controls (p < 0.001). It was ascertained that there is a two-fold increase in the levels of salivary matrix metalloproteinase-9 in the test group compared to the control group. In addition, the level of periodontal apparatus destruction was greater in the test group. This proved that type-II diabetes mellitus influences the levels of matrix metalloproteinase-9 in humans and elevates them, causing further periodontal destruction.

Effect of ultrasonic scaling with adjunctive photodynamic therapy on the treatment of gingival inflammation among diabetic patients undergoing fixed orthodontic treatment

BACKGROUND

The aim of the present clinical trial was to evaluate the effect of methylene blue-mediated antimicrobial photodynamic therapy (aPDT) on the gingival and immunological parameters in diabetic adolescent patients undergoing fixed orthodontic treatment.

METHODS

The selected 40 participants were randomized equally into two groups; Group I (ultrasonic scaling + oral hygiene instructions) and Group II (ultrasonic scaling/oral hygiene instructions + aPDT). Serum HbA1c levels was assessed for all the participants at chairside. Plaque index (Pi), and bleeding on probing (BOP) were analyzed. Moreover, the assessment of crevicular fluid matrix metalloproteinase 8 (MMP-8) and macrophage inflammatory protein 1 alpha (MIP-1α) was performed using enzyme-linked immunosorbent assay technique. All measurements were recorded at baseline, 6 weeks, and 12 weeks follow-up periods, respectively. Intergroup comparisons for p-value were computed using Mann-Whitney test and Wilcoxon singed ranks test to compute p-value for intra-group comparisons. Stepwise logistic regression analysis was used to identify explanatory variables for reduction in plaque scores and bleeding on probing, after controlling for the effects of other covariates. Odds ratios and 95% confidence intervals were used to assess the direction and strength for associations. Significance level was set at 5% for all analyses.

RESULTS

All 40 individuals completed the clinical trial. There was a statistically significant reduction in Pi and BOP in both Group I and Group II from baseline to 12 weeks of follow up (P<0.05). However, there was slight reduction in the plaque scores in Group-II as compared to Group-I at 12 weeks visit (P<0.05). There was also a statistically significant difference for BOP when Group-I was compared with Group-II on 12 weeks follow up assessment (P<0.05). HbA1c assessment indicated no statistically significant difference either within or between groups at any time point (P>0.05). Both MMP-8 and MIP-1α reported a significant decrease for both Groups I and II at 6 weeks and 12 weeks follow-up periods in comparison to baseline (P<0.05). Inter-group comparison indicated a statistically significant difference noted at both 6 weeks follow up that was maintained at 12 weeks follow up (P<0.05). The logistic regression analysis revealed that even after controlling the mean BMI as a predictor, the change of biomarker levels along with the improvement in plaque scores and bleeding on probing was not significant (p> 0.05).

CONCLUSION

aPDT significantly improved bleeding on probing and proinflammatory biomarkers among diabetic adolescent patients undergoing fixed orthodontic therapy.

Endotoxemia by Porphyromonas gingivalis Alters Endocrine Functions in Brown Adipose Tissue

Improvement of obesity is important for increasing longevity. The characteristics, size, and function of adipocytes are altered in patients with obesity. Adipose tissue is not only an energy storage but also an endocrine organ. Alteration of endocrine activities in adipose tissue, among them the functional decline of brown adipose tissue (BAT), is associated with obesity. Periodontal disease is a risk factor for systemic diseases since endotoxemia is caused by periodontal bacteria. However, the effect of periodontal disease on obesity remains unclear. Thus, this study aimed to investigate the effect of endotoxemia due to Porphyromonas gingivalis, a prominent cause of periodontal disease, on the BAT. Herein, endotoxemia was induced in 12-week-old C57BL/6J mice through intravenous injection of sonicated 10⁸ CFU of P. gingivalis (Pg) or saline (control [Co]) once. Eighteen hours later, despite no inflammatory M1 macrophage infiltration, inflammation-related genes were upregulated exclusively in the BAT of Pg mice compared with Co mice. Although no marked histological changes were observed in adipose tissues, expressions of genes related to lipolysis, Lipe and Pnpla2 were downregulated after P. gingivalis injection in BAT. Furthermore, expression of Pparg and Adipoq was downregulated only in the BAT but not in the white adipose tissues, along with downregulation of Ucp1 and Cidea expression, which are BAT-specific markers, in Pg mice. Microarray analysis of the BAT showed 106 differentially expressed genes between Co and Pg mice. Gene set enrichment analysis revealed that the cholesterol homeostasis gene set and PI3/Akt/mTOR signaling gene set in BAT were downregulated, whereas the TGF-β signaling gene set was enriched in Pg mice. Overall, intravenous injection of sonicated P. gingivalis altered the endocrine functions of the BAT in mice. This study indicates that endotoxemia by P. gingivalis potentially affects obesity by disrupting BAT function.

Accuracy of a 7-Item Patient-Reported Stand-Alone Tool for Periodontitis Screening

Periodontitis is interrelated with various other chronic diseases. Recent evidence suggests that treatment of periodontitis improves glycemic control in diabetes patients and reduces the costs of diabetes treatment. So far, however, screening for periodontitis in non-dental settings has been complicated by a lack of easily applicable and reliable screening tools which can be applied by non-dental professionals. The purpose of this study was to assess the diagnostic accuracy of a short seven-item tool developed by the German Society for Periodontology (DG PARO) to screen for periodontitis by means of patient-reported information. A total of 88 adult patients filled in the patient-reported Periodontitis Risk Score (pPRS; range: 0 points = lowest periodontitis risk; 20 points = very high periodontitis risk) questionnaire before dental check-up at Heidelberg University Hospital. Subsequent clinical assessments according to Periodontal Screening and Recording (PSR®) were compared with pPRS scores. The diagnostic accuracy of pPRS at different cutoff values was assessed according to sensitivity, specificity, positive, and negative predictive values, as well as Receiver-Operator-Characteristic curves, Area Under the Curve (AUC), and logistic regression analysis. According to combined specificity and sensitivity (AUC = 0.86; 95%-CI: 0.76-0.95), the diagnostic accuracy of the pPRS for detecting periodontal inflammation (PSR® ≥ 3) was highest for a pPRS cutoff distinguishing between pPRS scores < 7 vs. ≥ 7. Patients with pPRS scores ≥ 7 had a 36.09 (95%-CI: 9.82-132.61) times higher chance of having a PSR® ≥ 3 than patients with scores < 7. In conclusion, the pPRS may be considered an appropriately accurate stand-alone tool for the screening for periodontitis.

Autophagy facilitates type I collagen synthesis in periodontal ligament cells

Autophagy is a lysosomal protein degradation system in which the cell self-digests its intracellular protein components and organelles. Defects in autophagy contribute to the pathogenesis of age-related chronic diseases, such as myocardial infarction and rheumatoid arthritis, through defects in the extracellular matrix (ECM). However, little is known about autophagy in periodontal diseases characterised by the breakdown of periodontal tissue. Tooth-supportive periodontal ligament (PDL) tissue contains PDL cells that produce various ECM proteins such as collagen to maintain homeostasis in periodontal tissue. In this study, we aimed to clarify the physiological role of autophagy in periodontal tissue. We found that autophagy regulated type I collagen synthesis by elimination of misfolded proteins in human PDL (HPDL) cells. Inhibition of autophagy by E-64d and pepstatin A (PSA) or siATG5 treatment suppressed collagen production in HPDL cells at mRNA and protein levels. Immunoelectron microscopy revealed collagen fragments in autolysosomes. Accumulation of misfolded collagen in HPDL cells was confirmed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis. E-64d and PSA treatment suppressed and rapamycin treatment accelerated the hard tissue-forming ability of HPDL cells. Our findings suggest that autophagy is a crucial regulatory process that facilitates type I collagen synthesis and partly regulates osteoblastic differentiation of PDL cells.

A biochemical and immunohistochemical study of the effects of caffeic acid phenethyl ester on alveolar bone loss and oxidative stress in diabetic rats with experimental periodontitis

Caffeic acid phenethyl ester (CAPE) is used as a therapeutic agent to prevent bone loss. We determined the effects of systemically administered CAPE on alveolar bone loss and oxidative stress in diabetic rats with experimental periodontitis. Forty male rats were divided into four equal groups: control, experimental periodontitis (EP), EP-diabetes mellitus (EP-DM) and EP-DM-CAPE. DM was induced by streptozotocin, then lipopolysaccharide was injected to induce periodontitis. CAPE was administered to the EP-DM-CAPE group daily for 15 days. Then, serum samples were taken and the rats were sacrificed for histological analyses. Serum interleukin (IL-1β) and oxidative stress also were evaluated. Alveolar bone loss was assessed histomorphometrically. Alveolar bone loss and IL-1β levels were significantly less in the EP-DM-CAPE and EP groups compared to the EP-DM group. Oxidative stress was significantly less in the EP-DM-CAPE group compared to the EP and EP-DM groups. Receptor activator of nuclear factor kappa-B ligand (RANKL) levels were significantly higher in the EP-DM group compared to the disease groups. CAPE significantly reduced RANKL levels in the EP-DM-CAPE group compared to the EP-DM group. We found that CAPE treatment significantly inhibited DM induced oxidative stress and RANKL induced osteoclastogenesis and alveolar bone loss in diabetic rats with periodontitis.

[Influence of periodontal non-surgical therapy on serum interleukin 6 expression and carotid artery wall in rats with periodontitis and type 2 diabetes mellitus]

OBJECTIVE

To study the effect of periodontal non-surgical treatment on serum interleukin-6 (IL-6) expression and carotid vascular wall in a rat model of chronic periodontitis (CP) with type 2 diabetes mellitus (T2DM).

METHODS

Twenty-eight 6-week-old SD rats were randomly divided into group A (control group, 7 rats) and group B (T2DM+CP group, 21 rats). According to different intervention measures, group B was randomly subdivided into B1 (natural process), B2 (periodontal mechanical treatment), and B3 (periodontal mechanical treatment + 2% minocycline hydrochloride + systemic metronidazole plus amoxicillin). Serum IL-6 was measured by enzyme-linked immunosorbent assay, and carotid tissue was observed under light microscopy after hematoxylin-eosin (HE) staining.

RESULTS

The carotid artery wall of group A was normal. In group B1, the endothelial cells disappeared, the elastic fibers of the middle membrane were disordered, the local necrosis of smooth muscle tissue was amorphous particles, a small amount of calcium salt was deposited, and the wall thickening was obvious. The endothelial cells in groups B2 and B3 disappeared, and the smooth muscle cells in the middle membrane underwent denaturation. No significant thickening of the vessel wall was noted. The serum IL-6 level in group B1 continually increased with time, and it was higher than that in group A (P<0.001). The IL-6 levels of groups B2 and B3 peaked a week after the first intervention. Subsequently, IL-6 levels gradually decreased. At the last point (five weeks after the second intervention ), the IL-6 levels of groups B2 and B3 were significantly lower than that of group B1 (P<0.001).

CONCLUSIONS

For rats with periodontitis and diabetes, periodontal mechanical treatment may elevate serum IL-6 levels in the short term but might reduce the whole inflammatory state in the long term. Thus, this treatment might be valuable to the improvement of vascular disease. The adjunctive benefits of systemic metronidazole and amoxicillin in non-surgical periodontal therapy are decreased serum IL-6 expression and normal carotid artery.

Role of Protein Kinase C in Diabetic Complications

Diabetes is the most common and systemic disorder associated with hyperglycemia which is the significant factor in the development of micro- and macrovascular changes. Many mechanistic approaches i.e. activation of Protein kinase C, glycation end products production, hexosamine pathway and polyol pathway induce cellular damage and lead to the development of diabetic complications like nephropathy, neuropathy, retinopathy, and myopathy. One of the adverse effects of long-lasting hyperglycemia is activation of PKC (intracellular signaling enzyme) and has become a field of great research interest. Hence, in this review special emphasis is placed on microvascular complications which are due to activation of PKC. Clinical trials have also been conducted using selective PKC inhibitors and have shown positive results against hyperglycemia.

RNA sequencing for ligature induced periodontitis in mice revealed important role of S100A8 and S100A9 for periodontal destruction

Periodontitis is an inflammatory disease caused by pathogenic oral microorganisms that induce the destruction of periodontal tissue. We sought to identify the relevant differentially expressed genes (DEGs) and clarify the mechanism underlying the rapid alveolar bone loss by using ligature-induced periodontitis in mice. A silk ligature was tied around the maxillary left second molar in 9-week-old C57BL/6 J male mice. In-vivo micro-CT analysis revealed that ligation induced severe bone loss. RNA-sequencing analysis, to examine host responses at 3 days post-ligation, detected 12,853 genes with fragments per kilobase of exon per million mapped reads ≥ 1, and 78 DEGs. Gene ontology term enrichment analysis revealed the expression profiles related to neutrophil chemotaxis and inflammatory responses were significantly enriched in the ligated gingiva. The expression levels of innate immune response-related genes, including S100a8 and S100a9, were significantly higher in the ligated side. S100A8 was strongly detected by immunohistochemistry at the attached epithelium in ligated sites. Inhibition of S100A8 and S100A9 expression revealed that they regulated IL1B and CTSK expression in Ca9-22 cells. Thus, innate immune response-related molecules might be associated with the burst-destruction of periodontal tissue in ligature-induced periodontitis. Especially, S100A8 and S100A9 may play an important role in alveolar bone resorption.

Activation of ROS/MAPKs/NF-κB/NLRP3 and inhibition of efferocytosis in osteoclast-mediated diabetic osteoporosis

Diabetes mellitus (DM) affects bone metabolism and leads to osteoporosis; however, its pathogenetic mechanisms remain unknown. We found that high glucose (HG) conditions induced the production of reactive oxygen species (ROS) and the expression of proteins related to MAPKs [phosphorylated (p)-ERK, p-JNK, and p-p38], NF-κB (NF-κB, p-IκB, and IKK), and NACHT-LRR-PYD domains-containing protein 3 (NALP3) (NLRP3) [apoptosis-associated speck-like protein containing a caspase activation and recruitment domain (ASC), caspase-1, IL-18, IL-1β, and NLRP3] in osteoclasts (OCs) in vitro. Further analysis showed that in HG-induced OCs, ROS is an upstream signal for MAPKs, NF-κB, and the NLRP3 inflammasome. Moreover, MAPKs mediated the activation of NF-κB and NLRP3, whereas NF-κB up-regulated the NLRP3 inflammasome response. Interestingly, HG inducement enhanced the bone resorption of OCs but inhibited their efferocytosis, whereas insulin and lipoxin A4 (4) treatment reversed this phenomenon. In streptozotocin-induced diabetic rats in vivo, the numbers and the bone-resorption capacity of OCs as well as the serum levels of TRACP-5b were significantly increased, and the expression of MAPK-, NF-κB-, and NLRP3 inflammasome-related proteins in the proximal tibia were also significantly elevated; however, treatment with insulin and LXA4 reversed this elevation. Together, these results demonstrated that the activation of ROS/MAPKs/NF-κB/NLRP3 and the inhibition of efferocytosis in OCs are the main causes of osteoporosis in DM.-An, Y., Zhang, H., Wang, C., Jiao, F., Xu, H., Wang, X., Luan, W., Ma, F., Ni, L., Tang, X., Liu, M., Guo, W., Yu, L. Activation of ROS/MAPKs/NF-κB/NLRP3 and inhibition of efferocytosis in osteoclast-mediated diabetic osteoporosis.

Homeopathy and Periodontal Treatment in Type II Diabetic Patients: a 1-Year Randomized Clinical Trial

Abstract Chronic periodontitis (CP) and Diabetes mellitus type 2 (DMII) are chronic diseases usually treated by conventional practices. On the other hand, homeopathy can help to treat many different diseases. The aim of this study was to evaluate the effects of homeopathy (H) as an adjunct for non-surgical periodontal therapy (NSPT) in individuals with DMII and CP. Eighty individuals with CP and DM II, of both sexes and aged between 32 and 70 years, participated in this randomized, double-blind, placebo-controlled study. They were divided into two groups: control group (CG) and the test group (TG), and both groups received the NSPT. TG also received homeopathic therapy, including Berberis, Mercurius solubilis/Belladonna/Hepar sulphur and Pyrogenium, while CG received placebo. Clinical and laboratorial examinations were evaluated at baseline and after 1, 6 and 12 months of treatment. Both groups showed significant improvement throughout the study, for most of the parameters studied, but TG presented significative gain of CAL at 1 and 12 months compared to CG. Mean glucose and glycated hemoglobin significantly decreased in both groups after 6 and 12 months. However, there was a significantly further reduction of these parameters in TG, as compared to CG. In conclusion, homeopathy as supplement of NSPT may further improve health condition, including glycemic control, in DMII patients with CP.

A comparative evaluation of the micronutrient profile in the serum of diabetes mellitus Type II patients and healthy individuals with periodontitis

Background

Micronutrients play an important part in metabolism and maintenance of tissue function the maintenance of the integrity and vitality of the periodontal tissues depends on the availability of adequate nutrients, and it is possible that deficiencies can produce pathological alterations in the periodontal tissues. However, the association between nutritional factors and periodontal health is not fully understood. The essential micronutrients for maintaining health include zinc, copper, selenium, and iron. These micronutrients are required for a variety of biomolecules to maintain the normal structure, function, and proliferation of cells and also immune functions. Periodontal disease and diabetes mellitus (DM) are considered to have a bidirectional relationship, and periodontitis is recognized as the 6^th major complication of DM. The number of studies on the role of micronutrients with regard to periodontal disease is limited.

Aims

This study aims to evaluate the role of micronutrients-zinc, copper, selenium, and iron, in the serum of chronic periodontitis patients and chronic periodontitis with DM Type II patients, to see whether they can serve as potential markers for chronic periodontitis and also to assess whether periodontitis can have systemic effects.

Materials and Methods

A volume of 5 ml of venous blood was collected from each of the study participants, from the antecubital vein. The blood was then centrifuged and stored at -20°C before being analyzed. Zinc, copper, and selenium were estimated by the atomic absorption spectrophotometry, bathophenanthroline method was used to estimate iron.

Statistical Analysis

It was carried out using Student's t-test and analysis of variance. The honestly significant difference Tukey test and Pearson's correlation was also used.

Results

The mean serum zinc levels were significantly higher in healthy controls as compared to Periodontitis and Periodontitis with DM type II. The mean serum copper levels were significantly higher in Periodontitis with diabetes as compared to controls and periodontitis. Serum selenium levels were significantly higher in controls as compared to periodontitis with diabetes. The mean serum iron levels were significantly higher in periodontitis with diabetes. The Zinc: Copper (Zn: Cu) ratio was found to be significant for the periodontitis with diabetes group.

Conclusion

The results obtained from this study suggests that the serum levels of micronutrients Zn and Se were decreased and levels of Cu and Fe are increased in chronic periodontitis as compared to healthy control. There was a potentiated difference in the values in patients with DM Type II. The results show that the levels of these micronutrients can be used as effective biomarkers for chronic periodontitis and that periodontitis has systemic manifestations.

Bilateral Interrelationship of Diabetes and Periodontium

Periodontitis is a chronic inflammatory disease characterised by destruction of the supporting structures of the teeth which is a common cause of tooth mortality in all individuals throughout the world. Diabetes is a group of metabolic dysregulation, primarily of carbohydrate metabolism, characterized by hyperglycemia that results from defects in insulin secretion, impaired insulin action, or both. Systematic reviews and meta-analysis have shown that the prevalence of periodontitis is increased in diabetic patients. Based on the evidence, degree of hyperglycemia and severity of periodontitis are inter- related. Diabetic patients with severe periodontitis have six times more poor glycemic control than patients with healthy periodontium. However, improved glycemic control has been postulated to reduce the severity of periodontal disease. In this mini-review, we have presented the previously reviewed studies from the literature and focused on a two-way relationship of diabetes and periodontitis, various pathways involved in it such as RANK/RANKL/OPG axis, AGE-RAGE pathway, Oxidative stress mechanism, and obesity that influence the possibility of periodontitis-Diabetes Mellitus (DM).

Periodontal regenerative effect of enamel matrix derivative in diabetes

The present study aimed to investigate the periodontal regenerative effect of enamel matrix derivative (EMD) in diabetes. Thirty-six rats were assigned to streptozotocin-induced diabetes or control (non-diabetic) groups. Three-wall intrabony defects were surgically generated in the bilateral maxilla molar, followed by application of EMD or saline. Primary wound closure and defect fill were evaluated via histomorphological analysis and micro-computed tomography. mRNA expression levels of inflammatory and angiogenic factors in the defects were quantified via real-time polymerase chain reaction. Gingival fibroblasts were isolated from control animals and cultured in high-glucose (HG) or control medium. The effects of EMD on insulin resistance and PI3K/Akt/VEGF signaling were evaluated. The achievement rate of primary closure and the parameters of defect fill were significantly higher at EMD-treated site than at EMD-untreated sites in both diabetic and non-diabetic rats, although defect fill in the diabetic groups was significantly lower in the control groups on two-way repeated-measures analysis of variance (for both, p<0.05). Newly formed bone and cementum were significantly increased at EMD-treated sites in diabetic rats than at EMD-untreated sites in control rats (for both, p<0.05). Vegf was significantly upregulated at EMD-treated sites in both diabetic and non-diabetic rats (for both, p<0.05). In vitro, insulin or EMD-induced Akt phosphorylation was significantly lower in cells cultured in HG medium (p<0.05). EMD-mediated Vegf upregulation was suppressed by the Akt inhibitor wortmannin, although the effect was significantly lower in HG medium (p<0.01). In conclusion, EMD might promote periodontal tissue regeneration via Akt/VEGF signaling, even in a diabetic condition.

Endotoxemia by Porphyromonas gingivalis Injection Aggravates Non-alcoholic Fatty Liver Disease, Disrupts Glucose/Lipid Metabolism, and Alters Gut Microbiota in Mice

Many risk factors related to the development of non-alcoholic fatty liver disease (NAFLD) have been proposed, including the most well-known of diabetes and obesity as well as periodontitis. As periodontal pathogenic bacteria produce endotoxins, periodontal treatment can result in endotoxemia. The aim of this study was to investigate the effects of intravenous, sonicated Porphyromonas gingivalis (Pg) injection on glucose/lipid metabolism, liver steatosis, and gut microbiota in mice. Endotoxemia was induced in C57BL/6J mice (8 weeks old) by intravenous injection of sonicated Pg; Pg was deactivated but its endotoxin remained. The mice were fed a high-fat diet and administered sonicated Pg (HFPg) or saline (HFco) injections for 12 weeks. Liver steatosis, glucose metabolism, and gene expression in the liver were evaluated. 16S rRNA gene sequencing with metagenome prediction was performed on the gut microbiota. Compared to HFco mice, HFPg mice exhibited impaired glucose tolerance and insulin resistance along with increased liver steatosis. Liver microarray analysis demonstrated that 1278 genes were differentially expressed between HFco and HFPg mice. Gene set enrichment analysis showed that fatty acid metabolism, hypoxia, and TNFα signaling via NFκB gene sets were enriched in HFPg mice. Although sonicated Pg did not directly reach the gut, it changed the gut microbiota and decreased bacterial diversity in HFPg mice. Metagenome prediction in the gut microbiota showed enriched citrate cycle and carbon fixation pathways in prokaryotes. Overall, intravenous injection of sonicated Pg caused impaired glucose tolerance, insulin resistance, and liver steatosis in mice fed high-fat diets. Thus, blood infusion of Pg contributes to NAFLD and alters the gut microbiota.

Effect of diabetes on collagen metabolism and hypoxia in human gingival tissue: a stereological, histopathological, and immunohistochemical study

Diabetes mellitus and periodontitis are chronic inflammatory diseases that disrupt soft tissue metabolism. The diseases separately or together increase apoptosis in gingival fibroblast cells and reduce cell renewal. We investigated the effects of diabetes and periodontitis on the composition and structure of gingival connective tissue. We used gingival biopsies from 16 healthy individuals (control group, C), 16 type 2 diabetic patients with chronic periodontitis (diabetes + periodontitis group, D + P) and 16 healthy chronic periodontitis patients (periodontitis group, P). Biopsies were obtained under local anesthesia. Clinical attachment level (CAL), gingival index (GI) and plaque index (PI) were measured prior to gingival biopsies. Fibroblast cells were counted stereologically. Inflammatory cells were counted histomorphometrically. Hypoxia-inducible factor (HIF)-1α, lysyl hydroxylase (PLOD-2), neutrophil collagenase (MMP-8), and vascular endothelial growth factor (VEGF) levels were evaluated immunohistochemically. CAL, GI and PI for the C group were lower than for the other groups (p < 0.05). Fibroblast cell counts were lower for the D + P group than for the other groups (p < 0.05). Diabetes increased inflammatory cell numbers in the D and D + P groups compared to the C and P groups. MMP-8 levels were higher for the D + P group than for the other groups. VEGF was elevated in both the P and D + P groups compared to the C group, while HIF-1α and PLOD-2 levels were comparable. Diabetes increased tissue destruction and inflammation, and decreased fibroblast cell numbers without affecting collagen crosslinking and HIF-1α levels.

Impact of Glycemic Levels in Type 2 Diabetes on Periodontitis

AIM

The aim is to study the effect of glycemic level in Type 2 diabetes and cardiovascular risk factors on periodontal health.

MATERIALS AND METHOD

Type 2 diabetic and nondiabetic patients in the age group of 35-80 years (n = 1700) were recruited for the study. Periodontal examination included as follows: Probing depth, clinical attachment level (CAL), gingival recession, and bleeding on probing. Periodontitis was diagnosed based on the CAL levels and diabetes was diagnosed based on glycated hemoglobin (HbA1c) levels. Body mass index, total cholesterol, triglyceride, and low-density lipoprotein (LDL) were assessed for cardiovascular risk. Patients were characterized into two groups as follows: diabetic (n = 1235) and nondiabetic (n = 465). Sociodemographic variables included were: age, sex, obesity, smoking, duration of diabetes, and periodontitis were assessed. SPSS version 20.0.1.0 was used for all the statistical assessments.

CONCLUSION

HbA1c and lipid levels were statistically significant with the severity of periodontitis (odds ratio [OR] [95% confidence interval [CI]: HbA1c 1.34 [1.019-1.21]; Total cholesterol 1.01 [1.03-1.42]; triglycerides 1.01 [1.01-1.14]; LDL 1.028 [1.08-1.71]). Smoking and obesity were also found to be significantly associated with the presence of periodontitis [OR (95% CI): smoking 1.35 (1.10-1.67); obesity 1.23 (1.73-2.05)]. The study concluded that uncontrolled HbA1c levels and elevated cardiovascular risk factors significantly increase the severity of periodontitis in Type 2 diabetes mellitus.

Does diabetes increase the risk of periodontitis? A systematic review and meta-regression analysis of longitudinal prospective studies

AIM

Even though the association between diabetes and periodontitis is taken for granted, results on this association are conflicting within the literature. This systematic review assessed whether poorly controlled diabetes was associated with periodontitis onset or progression.

METHODS

Electronic searches were performed in PubMed, Scopus and Embase databases. Hand search was carried out in the reference list of all articles included. Gray literature was investigated with a Google Scholar search. Prospective longitudinal studies on the association between diabetes and periodontitis were considered for this review. Studies should have presented at least two measurements of periodontal conditions over time. Data on study design, crude and adjusted estimates were collected. We used meta-analysis to estimate the pooled effect of hyperglycemia in people with diabetes on periodontitis onset or progression. Meta-regression and subgroup analyses were employed to investigate potential sources of heterogeneity between studies.

RESULTS

Thirteen studies matched the inclusion criteria, comprising 49,262 individuals, including 3197 diagnosed with diabetes. Meta-analyses of adjusted estimates showed that diabetes increased the risk of incidence or progression of periodontitis by 86% (RR 1.86 [95% CI 1.3-2.8]). However, there is scarce information on the association between diabetes and periodontal destruction.

CONCLUSIONS

This study provides evidence that diabetes is associated with increased risk of periodontitis onset and progression in adults. Upcoming prospective longitudinal studies ought to overcome methodological caveats identified in this review.

Are cardiovascular risk parameters and glycemic levels associated with periodontitis in type 2 diabetes patients? A clinical study

This study investigated the associations between cardiovascular risk parameters, glycemic level and periodontitis in the diabetic adult population. BMI (body mass index), total cholesterol and triglyceride was used as cardiovascular risk measure and glycosylated hemoglobin (HbA1c) was recorded for glycemic levels. Study results provide evidence of significant association between periodontal disease, cardiovascular risk and glycemic levels.

EB 2017 Article: Changes in advanced glycation end products, beta-defensin-3, and interleukin-17 during diabetic periodontitis development in rhesus monkeys

The bidirectional relationship between diabetes mellitus (DM) and periodontal disease has drawn great attention; however, the mechanisms underlying their association remain unclear. In this study, we aimed to develop a rhesus monkey model of diabetic periodontitis and explore the potential mechanisms by which DM affects the progression of periodontal disease. Three healthy rhesus monkeys were selected as the control group. Five streptozotocin-induced diabetic rhesus monkeys were chosen as the experimental group. Ligature placement was used to induce periodontitis. The changes in the levels of advanced glycation end products (AGEs), beta-defensin-3 (BD-3), and interleukin-17 (IL-17) were measured using enzyme-linked immunosorbent assays (ELISA) and real-time reverse transcription polymerase chain reaction (RT-PCR) at different stages during disease progression. Periodontitis was confirmed by clinical assessment, radiographic images, and histological examination. Significant changes in the levels of AGEs and BD-3 in serum were observed at the periodontitis stage in diabetic rhesus monkeys ( P < 0.05). The expression of BD-3 mRNA in the gingiva of diabetic group at baseline was significantly high ( P < 0.05). Diabetic monkeys exhibited significantly enhanced IL-17 mRNA expression at the periodontitis stage ( P < 0.05). Our findings indicated that the rhesus monkey can serve as an ideal model for exploring the pathogenesis of diabetic periodontitis, and the hyperglycemic environment may accelerate inflammatory response and weaken the defense system in periodontal tissues. Impact statement The mechanism underlying the association between diabetes mellitus (DM) and periodontal disease is not yet fully understood. Hence, there is a need to establish animal models to reveal the effect of DM on the pathogenesis of periodontitis. In this study, we explored the appropriate methods for inducing periodontitis and shortening the modeling time in rhesus monkeys, to investigate the pathogenesis of diabetic periodontitis and develop innovative therapies. Our results suggest that a hyperglycemic environment might lead to the destruction of periodontal tissues by accelerating inflammatory response and weakening the defense system in periodontal tissues. Therefore, this study has significant treatment implications regarding the regulation of the immune response against periodontal diseases in patients with DM.

Morphometric and histopathological evaluation of the effect of grape seed proanthocyanidin on alveolar bone loss in experimental diabetes and periodontitis

OBJECTIVE

Grape seed proanthocyanidine extract (GSPE) is a strong antioxidant derived from the grape seeds (Vitis vinifera, Terral J.F.) and has a polyphenolic structure with a wide range of biological activity. The aim of the present study was to evaluate the effects of GSPE on alveolar bone loss and histopathological changes in rats with diabetes mellitus and ligature-induced periodontitis.

MATERIAL AND METHODS

Forty rats were divided into 6 study groups. Control (C, 6 rats) group, periodontitis (P, 6 rats) group, diabetes (D, 6 rats) group, diabetes and periodontitis (D+P, 6 rats) group, diabetes, periodontitis and 100 mg/kg/day GSPE (GSPE-100, 8 rats), and diabetes, periodontitis and 200 mg/kg/day GSPE (GSPE-200, 8 rats) group. Diabetes mellitus was induced by intraperitoneal injection of a single dose of streptozotocin (60 mg/kg). Periodontitis was induced via ligation method. Silk ligatures were placed at the mandibular right first molars. GSPE was administered by oral gavage. After 30 days, all rats were killed. Alveolar bone loss was measured morphometrically via a stereomicroscope. For histopathological analyses, Alizarin red staining, and matrix metalloproteinase (MMP)-8, vascular endothelial growth factor and hypoxia inducible factor (HIF)-1α immunohistochemistry were performed. Tartrate-resistant acid phosphatase-positive osteoclast cells and relative total inflammatory cells were also determined.

RESULTS

The highest alveolar bone loss was observed in the D+P group (P < .05). GSP-200 group decreased alveolar bone loss (P < .05). The D+P group had the highest osteoclast counts, but the difference was not significant compared to the P, GSPE-100 and GSPE-200 groups (P > .05). The inflammation in the D+P group was also higher than the other groups (P < .05). The osteoblast numbers increased in the GSPE-100 and GSPE-200 groups compared to the P and D+P groups (P < .05). MMP-8 and HIF-1α levels were highest in the D+P group and GSPE significantly decreased these levels (P < .05).

CONCLUSION

Within the limits of this animal study, it can be suggested that GSPE administration may decrease periodontal inflammation and alveolar bone loss via decreasing MMP-8 and HIF-1α levels and increase osteoblastic activity in diabetic rats with experimental periodontitis.

Does periodontal inflammation affect glycosylated haemoglobin level in otherwise systemically healthy individuals? - A hospital based study

BACKGROUND AND OBJECTIVES

Microbial biofilm and host susceptibility play an important role in the initiation and progression of periodontitis. Periodontitis is considered the sixth complication of diabetes mellitus and a bidirectional relationship exists between diabetes and periodontitis. This cross-sectional observational study was undertaken to evaluate the glycosylated haemoglobin (HbA1c) level in chronic periodontitis.

METHODS

The study involved 100 subjects. The case group consisted of 50 subjects with chronic periodontitis and the control group consisted of 50 periodontally healthy subjects. Periodontal parameters including plaque index, oral hygiene index, modified gingival index, probing pocket depth, and clinical attachment level were measured and recorded. Systemic parameters like Body Mass Index (BMI), Waist Hip Ratio (WHR), C- Reactive Protein (CRP), Glycosylated haemoglobin (HbA1c), lipid profile, fasting blood sugar, post prandial blood sugar and serum albumin were assessed in all subjects.

RESULTS

The mean HbA1C for the case group was 6.27±1.5 and for the control was 5.36±0.4 and the difference was statistically significant (p = 0.001). The mean FBS, PPBS, LDL, WHR, CRP was statistically significant between groups (p ≤0.05). Periodontal parameters like PI, OHI, MGI, PD and CAL were significantly higher in the case group than the control group (p value ≤ 0.05). The multivariate linear regression model with the dependent variable HbA1c showed chronic periodontitis was significantly associated with HbA1c level.

CONCLUSION

In chronic periodontitis patients (otherwise systemically healthy) the presence of periodontal inflammation affected the glycosylated haemoglobin level and they were in prediabetes stage. Therefore, it is plausible that the prediabetes stage might be reduced via appropriate periodontal therapy.

Periodontal pathogenic bacteria, Aggregatibacter actinomycetemcomitans affect non-alcoholic fatty liver disease by altering gut microbiota and glucose metabolism

Increasing evidence indicates that periodontitis affects non-alcoholic fatty liver disease (NAFLD). We examined the relationship between periodontal bacterial infection and clinical/biochemical parameters in 52 NAFLD patients. Anti-Aggregatibacter actinomycetemcomitans (Aa) antibody titers correlated positively with visceral fat, fasting plasma insulin, and HOMA-IR; and negatively with the liver/spleen ratio. C57BL/6J mice (8-weeks-old) were given Aa or saline (control) for 6 weeks, and were fed either normal chow (NCAa, NCco) or high-fat diet (HFAa and HFco). NCAa and HFAa mice presented impaired glucose tolerance and insulin resistance compared to control mice. HFAa mice showed higher hepatic steatosis than HFco animals. Liver microarray analysis revealed that 266 genes were differentially expressed between NCAa and NCco mice. Upregulated genes in Aa-administrated mice were enriched for glucagon signaling pathway, adipocytokine signaling pathway and insulin resistance. Consistently, plasma glucagon concentration was higher in NCAa mice. In addition, Akt phosphorylation was lower in the liver of NCAa/HFAa than in NCco/HFco mice. Based on 16S rRNA sequencing, Aa administration changed composition of the gut microbiota. Metagenome prediction in gut microbiota showed upregulation of fatty acid biosynthesis and downregulation of fatty acid degradation in Aa-administered mice. Thus, infection with Aa affects NAFLD by altering the gut microbiota and glucose metabolism.

The relationship between periapical lesions and the serum levels of glycosylated hemoglobin and C-reactive protein in type 2 diabetic patients

Objectives:

To investigate the relationship between the presence of periapical lesions (PL) and levels of glycosylated hemoglobin (HbA1c), and C-reactive protein (CRP) in patients with type 2 diabetes.

Methods:

This cross-sectional study was conducted at Ibn Sina National College for Medical Studies, Jeddah, Kingdom of Saudi Arabia, between September 2013 and February 2015. Medical and dental history and Sociodemographic data were obtained from participants. Dental and periodontal examinations were conducted and blood samples were obtained to determine levels of HbA1c and CRP. The presence of PL was recorded from panoramic and periapical radiographs. Descriptive statistics and multivariable linear and logistic regression models were used for data analyses.

Results:

One hundred patients were included; mean age was 48.9 ± 8.5 years. Of these patients, 14% had no PL, whereas 25% had one or 2 lesions, 32% had 3 or 4 lesions, and 29% had ≥5 PL. The mean HbA1c was 9.8% (± 2.5) mg/L and CRP was 6.9 mg/L (± 6.3). The presence of PL was significantly associated with a higher level of HbA1c independent of age, gender, probing depth, and plaque index (p=0.023). Individuals with PL were also more likely to have a high CRP level (>3 mg/L) independent of the previous covariates (odds ratio: 1.19; 95% confidence interval: 1.01-1.41).

Conclusion:

Periapical lesions are associated with a poorer glycemic control and a higher CRP level in type 2 diabetic patients.

Preventive dental care in older adults with diabetes

BACKGROUND

The association between poor oral health and diabetes is well documented. Preventive oral health care is, therefore, strongly indicated for people with diabetes. The authors conducted a study to determine if there was a difference in preventive dental care use among older adults with diabetes in 2002 and in 2011 and to compare preventive dental care use by older adults with and without diabetes in 2002 and in 2011.

METHODS

The authors used a data sample of participants from the Medicare Current Beneficiary Survey that included older (65 years and older) fee-for-service Medicare beneficiaries. The key outcome was self-reported preventive dental care. In 2002, there were 8,725 participants; in 2011, there were 7,425 participants. The authors conducted χ(2) and logistic regression analyses.

RESULTS

In 2002, 28.8% of participants with diabetes had preventive dental care. In 2011, this percentage increased to 36.0%. Similar results were seen among participants without diabetes (42.9% in 2002 and 45.5% in 2011). The increase in preventive dental care was statistically significant for participants with and without diabetes. The participants with diabetes, as compared with participants without diabetes, remained statistically less likely to have had preventive dental care in adjusted logistic regression analysis with and without considering the interaction between observation year and diabetes (adjusted odds ratios, 0.73 and 0.86, respectively).

CONCLUSIONS

Although the percentage increase in participants with diabetes receiving preventive dental care is welcomed, older adults with diabetes continue to have substantial preventive dental care needs.

PRACTICAL IMPLICATIONS

Additional efforts are needed to encourage people with diabetes to obtain preventive dental care.

Bone metabolic microarray analysis of ligature-induced periodontitis in streptozotocin-induced diabetic mice

BACKGROUND AND OBJECTIVE

Periodontal disease is a chronic infectious disease that results in bone loss. Many epidemiological studies have reported the progression of periodontal tissue destruction in patients with diabetes; however, the associated mechanism remains unclear. In this study, we comprehensively investigated how diabetes affects the periodontal tissue and alveolar bone loss using a ligature-induced periodontitis model in streptozotocin-induced diabetic (STZ) mice.

MATERIAL AND METHODS

Diabetes was induced by intraperitoneal injection with streptozotocin in 6-wk-old C57/BL6J male mice. A silk ligature was tied around the maxillary left second molar in 9-wk-old wild-type (WT) and STZ mice. Bone loss was evaluated at 3 and 7 d after ligation. mRNA expression levels in the gingiva between the two groups were examined by DNA microarray and quantitative polymerase chain reaction at 1, 3 and 7 d post-ligation. Tartrate-resistant acid phosphatase and alkaline phosphatase staining of the periodontal tissue was performed for evaluation of osteoclasts and osteoblasts in histological analysis.

RESULTS

In the gingiva, hyperglycemia upregulated the osteoprotegerin (Opg) mRNA expression and downregulated Osteocalcin mRNA expression. In the ligated gingiva, tumor necrosis factor-α (Tnf-α) mRNA expression was upregulated at 1 d post-ligation in STZ mice but not in WT mice. At 3 d post-ligation, alveolar bone loss was observed in STZ mice, but not in WT mice. Significantly severe alveolar bone loss was observed in STZ mice compared to WT mice at 7 d post-ligation. Bone metabolic analysis using DNA microarray showed significant downregulation in the mRNA expression of glioma-associated oncogene homologue 1 (Gli1) and collagen type VI alpha 1 (Col6a1) at the gingiva of the ligated site in STZ mice compared to that in WT mice. Quantitative polymerase chain reaction showed that Gli1 and Col6a1 mRNA expression levels were significantly downregulated in the gingiva of the ligated site in STZ mice compared to WT mice. Histological analysis showed lower alkaline phosphatase activity in STZ mice. In addition, an increased number of tartrate-resistant acid phosphatase-positive multinucleated cells were observed at the ligated sites in STZ mice.

CONCLUSIONS

These results suggest that an imbalance of bone metabolism causes osteoclastosis in insulin-deficient diabetes, and that alveolar bone loss could occur at an early phase under this condition.

A review of the evidence for pathogenic mechanisms that may link periodontitis and diabetes

AIMS

To review the evidence for the molecular and cellular processes that may potentially link periodontal disease and diabetes. The pathogenic roles of cytokines and metabolic molecules (e.g. glucose, lipids) are explored and the role of periodontal bacteria is also addressed. Paradigms for bidirectional relationships between periodontitis and diabetes are discussed and opportunities for elaborating these models are considered.

METHODS

Database searches were performed using MeSH terms, keywords, and title words. Studies were evaluated and summarized in a narrative review.

RESULTS

Periodontal microbiota appears unaltered by diabetes and there is little evidence that it may influence glycaemic control. Small-scale clinical studies and experiments in animal models suggest that IL-1β, TNF-α, IL-6, OPG and RANKL may mediate periodontitis in diabetes. The AGE-RAGE axis is likely an important pathway of tissue destruction and impaired repair in diabetes-associated periodontitis. A role for locally activated pro-inflammatory factors in the periodontium, which subsequently impact on diabetes, remains speculative.

CONCLUSION

There is substantial information on potential mechanistic pathways which support a close association between diabetes and periodontitis, but there is a real need for longitudinal clinical studies using larger patient groups, integrated with studies of animal models and cells/tissues in vitro.

The Effect of Melatonin on Bone Loss, Diabetic Control, and Apoptosis in Rats With Diabetes With Ligature-Induced Periodontitis

BACKGROUND

The aim of this study examines the effect of systemic melatonin administration on proinflammatory cytokine levels, apoptosis, alveolar bone loss (ABL), lipid metabolism, and diabetic control in in rats with diabetes mellitus (DM) and ligature-induced periodontitis.

METHODS

Fifty-two male Wistar rats were used in this study. Study groups were as follows: 1) non-ligated control (NL, n = 6); 2) streptozotocin (STZ, n = 8); 3) STZ and melatonin (STZ+Mel, n = 8); 4) ligature (L, n = 6); 5) ligature and melatonin (L+Mel, n = 8); 6) STZ and ligature (STZ+L, n = 8); and 7) STZ, ligature, and melatonin (STZ+L+Mel, n = 8). DM was induced by intraperitoneal injection of a single dose of STZ (60 mg/kg). Melatonin was administered by intraperitoneal injection of a dose of 10 mg/kg/day for 4 weeks. Silk ligatures were placed subgingivally around the mandibular right first molars. The study period was 4 weeks, and animals were sacrificed at the end of 4 weeks. Morphometric analysis of bone loss was performed. Tissues were histopathologically examined. Inducible nitric oxide synthase (iNOS) and B-cell lymphoma-2-associated X (bax) protein expressions, serum interleukin (IL)-1β levels, and tartrate-resistant acid phosphatase-positive (TRAP+) osteoclast numbers were also evaluated.

RESULTS

After 4 weeks, the highest ABL was observed in the STZ+L group, and the difference was significant (P <0.05). Systemically administered melatonin significantly decreased ABL in the STZ+L+Mel group compared with that in the STZ+L group (P <0.05). TRAP+ osteoclast numbers were the highest in the STZ+L group, and melatonin significantly decreased osteoclast numbers (P <0.05) but had no effect on iNOS, IL-1β, or bax levels.

CONCLUSIONS

Within the limits of this study, it can be concluded that systemic melatonin treatment may decrease osteoclastic activity and reduce ABL in the model using rats with DM.

Systemic lycopene as an adjunct to scaling and root planing in chronic periodontitis patients with type 2 diabetes mellitus

Background:

Patients with type 2 diabetes have an increased prevalence of periodontitis and, in turn, periodontitis adversely affects the diabetic status. Oxidative stress plays a key role in affecting the pathophysiology of both the diseases and adjunctive systemic antioxidant therapy may have beneficial effect on the treatment outcome. This study was planned to compare the efficacy of systemic antioxidant therapy with lycopene as an adjunct to scaling and root planing versus scaling and root planing alone in chronic periodontitis patients with type 2 diabetes mellitus.

Materials and Methods:

40 diabetic subjects with periodontitis, attending the OP wing of the Department of Periodontics of a tertiary referral care hospital were randomized and equally divided into group A and group B. Diabetes status was recorded as per ADA guidelines and the periodontitis status as per American Academy of Periodontology (AAP) guidelines. Group A patients underwent scaling and root planing with administration of lycopene 8 mg and group B patients were treated with scaling and root planing alone. Clinical parameters like gingival index (GI), probing depth (PD), and clinical attachment level (CAL) were recorded. Serum markers, i.e. malondialdehyde (MDA) (TBARS assay) and C reactive protein (CRP) (ELISA), and glycated hemoglobin (HbA1c) levels were assessed at baseline and at 2 months and 6 months post-therapy.

Results:

Inter-group comparison showed group A giving statistically significant results in reducing mean serum MDA levels at 2 months and 6 months, and in reducing mean PD (mm) and mean HbA1c (%) levels at 2 months (P < 0.005).

Conclusion:

Lycopene as an adjunctive treatment was effective in reducing oxidative stress and restoring altered glycemic levels. Further longitudinal studies with a larger sample size are required to establish the role of lycopene in the management of chronic periodontitis.

Effect of β-anhydroicaritin on the expression levels of tumor necrosis factor-α and matrix metalloproteinase-3 in periodontal tissue of diabetic rats

The present study aimed to investigate the effect of β-anhydroicaritin on the expression levels of tumor necrosis factor (TNF)-α and matrix metalloproteinase (MMP)-3, and the pathological changes in the periodontal tissue of diabetic rats. Male Wistar rats (n=40; three months old) were randomly divided into four groups: Normal control group, diabetes group, diabetes + β-anhydroicaritin group and diabetes + urate group, (n=10 in each group). Following an overnight fast, diabetes was induced by intraperitoneal injection of streptozocin. The rats were maintained for 12 weeks and the blood sugar, urine sugar and body weight were assessed in week 12. Histological changes of the periodontal tissues were observed by hematoxylin and eosin staining, and the expression levels of TNF-α and MMP-3 were observed by immunohistochemistry. Following 12 weeks, the TNF-α grey value in the diabetes group was significantly lower compared with that in the control group (P<0.05), while no significant difference was observed between TNF-α levels in the diabetes + β-anhydroicaritin group, diabetes + urate group and the control group (P>0.05). However, TNF-α levels in the diabetes + β-anhdroicaritin group and diabetes + urate group were significantly higher compared with those in the diabetes group (P<0.05), and those in the diabetes + β-anhydroicaritin group were lower compared with those in the diabetes + urate group (P<0.05). The MMP-3 grey value in the diabetes group was significantly lower compared with that in the control group (P<0.05), while no significant difference was observed between MMP-3 levels in the diabetes + β-anhydroicaritin group, diabetes + urate group and the control group (P>0.05). However, MMP-3 levels the diabetes + β-anhydroicaritin group and diabetes + urate group were significantly higher compared with those in the diabetes group (P<0.05), and those in the diabetes + β-anhydroicaritin group were lower compared with those in the diabetes + urate group (P<0.01). β-anhydroicaritin normalized the expression levels of TNF-α and MMP-3 in the periodontal tissue of diabetic rats and led to the recovery of the changes in the morphological structure of the periodontal tissue.