An update on the evidence for pathogenic mechanisms that may link periodontitis and diabetes

Are Inflamed Periodontal Tissues Endogenous Source of Advanced Glycation End-Products (AGEs) in Individuals with and without Diabetes Mellitus? A Systematic Review

Advanced glycation end-products (AGEs) are heterogeneous compounds formed when excess sugars condense with the amino groups of nucleic acids and proteins. Increased AGEs are associated with insulin resistance and poor glycemic control. Recently, inflamed periodontal tissues and certain oral bacteria were observed to increase the local and systemic AGE levels in both normoglycemic and hyperglycemic individuals. Although hyperglycemia induced AGE and its effect on the periodontal tissues is known, periodontitis as an endogenous source of AGE formation is not well explored. Hence, this systematic review is aimed to explore, for the first time, whether inflamed periodontal tissues and periodontal pathogens have the capacity to modulate AGE levels in individuals with or without T2DM and how this affects the glycemic load. Six electronic databases were searched using the following keywords: (Periodontitis OR Periodontal disease OR Periodontal Inflammation) AND (Diabetes mellitus OR Hyperglycemia OR Insulin resistance) AND Advanced glycation end products. The results yielded 1140 articles, of which 13 articles were included for the review. The results showed that the mean AGE levels in gingival crevicular fluid was higher in individuals with diabetes mellitus and periodontitis (521.9 pg/mL) compared to healthy individuals with periodontitis (234.84 pg/mL). The serum AGE levels in normoglycemic subjects having periodontitis was higher compared to those without periodontitis (15.91 ng/mL vs. 6.60 ng/mL). Tannerella forsythia, a common gram-negative anaerobe periodontal pathogen in the oral biofilm, was observed to produce methylglyoxal (precursor of AGE) in the gingival tissues. Increased AGE deposition and activate of AGE receptors was noted in the presence of periodontitis in both normoglycemic and hyperglycemic individuals. Hence, it can be concluded that periodontitis can modulate the local and systemic levels of AGE levels even in absence of hyperglycemia. This explains the bidirectional relationship between periodontitis and development of prediabetes, incident diabetes, poor glycemic control, and insulin resistance.

Role of Interleukin-17A in the Pathomechanisms of Periodontitis and Related Systemic Chronic Inflammatory Diseases

Periodontitis is a chronic inflammatory and destructive disease caused by periodontal microbial infection and mediated by host immune response. As the main cause of loosening and loss of teeth in adults, it is considered to be one of the most common and serious oral diseases in the world. The co-existence of periodontitis and systemic chronic inflammatory diseases such as rheumatoid arthritis, psoriasis, inflammatory bowel disease, diabetes and so on is very common. It has been found that interleukin-17A (IL-17A) secreted by various innate and adaptive immune cells can activate a series of inflammatory cascade reactions, which mediates the occurrence and development of periodontitis and related systemic chronic inflammatory diseases. In this work, we review the role of IL-17A in the pathomechanisms of periodontitis and related systemic chronic inflammatory diseases, and briefly discuss the therapeutic potential of cytokine targeted agents that modulate the IL-17A signaling. A deep understanding of the possible molecular mechanisms in the relationship between periodontitis and systemic diseases will help dentists and physicians update their clinical diagnosis and treatment ideas.

A Mouse Periodontitis Model With Humanized Oral Bacterial Community

Increasing evidence suggests that periodontitis, characterized by oral dysbiosis, is a critical player in the progression of multiple systemic diseases in humans. However, there is still a lack of a proper mouse model of periodontitis with the colonization of human periodontitis-associated bacteria. We here established a new mouse periodontitis model by combining ligation of the second molars with application of subgingival plaques from periodontitis patients. Using 16S rRNA gene sequencing and Taxonomic classification, we found that human periodontitis-associated bacteria efficiently colonized in the mouse model and were enriched in both ligature silk and mouse saliva. Furthermore, the well-recognized periodontal pathogens including Porphyromonas gingivalis, Fusobacterium nucleatum, Prevotella intermedia, and Tannerella forsythia were enriched in the new model, but not in ligature-induced periodontitis model or Sham mice. The human periodontitis-associated bacteria potently aggravated mouse periodontitis, as demonstrated by more severe bone resorption and higher expression of inflammatory and osteoclastogenesis genes. In summary, the new mouse periodontitis model paves the way for studying human periodontitis-associated bacteria in oral diseases and systemic diseases.

Radiographic Bone Loss and Its Relation to Patient-Specific Risk Factors, LDL Cholesterol, and Vitamin D: A Cross-Sectional Study

The influence of patient-specific factors such as medical conditions, low-density lipoprotein cholesterol (LDL-C) or levels of 25-hydroxyvitamin D (25OHD) on periodontal diseases is frequently discussed in the literature. Therefore, the aim of this retrospective cross-sectional study was to evaluate potential associations between radiographic bone loss (RBL) and patient-specific risk factors, particularly LDL-C and 25OHD levels. Patients from a dental practice, who received full-mouth cone beam CTs (CBCTs) and blood-sampling in the course of implant treatment planning, were included in this study. RBL was determined at six sites per tooth from CBCT data. LDL-C and 25OHD levels were measured from venous blood samples. Other patient-specific risk factors were assessed based on anamnesis and dental charts. Statistical analysis was performed applying non-parametric procedures (Mann-Whitney U tests, error rates method). Data from 163 patients could be included in the analysis. RBL was significantly higher in male patients, older age groups, smokers, patients with high DMFT (decayed/missing/filled teeth) score, lower number of teeth, and high LDL-C levels (≥160 mg/dL). Furthermore, patients with high 25OHD levels (≥40 ng/mL) exhibited significantly less RBL. In summary, RBL was found to be associated with known patient-specific markers, particularly with age and high LDL-C levels.

pH and lipase-responsive nanocarrier-mediated dual drug delivery system to treat periodontitis in diabetic rats

Precise and controlled drug delivery to treat periodontitis in patients with diabetes remains a significant clinical challenge. Nanoparticle-based drug delivery systems offer a potential therapeutic strategy; however, the low loading efficiency, non-responsiveness, and single effect of conventional nanoparticles hinder their clinical application. In this study, we designed a novel self-assembled, dual responsive, and dual drug-loading nanocarrier system, which comprised two parts: the hydrophobic lipid core formed by 1, 2-Distearoyl-sn-glycero-3-phosphoethanolamine-Poly (ethylene glycol) (DSPE-PEG) loaded with alpha-lipoic acid (ALA); and a hydrophilic shell comprising a poly (amidoamine) dendrimer (PAMAM) that electrostatically adsorbed minocycline hydrochloride (Mino). This unique design allows the controlled release of antioxidant/ALA under lipase stimulation from periodontal pathogens and antimicrobial/Mino under the low pH of the inflammatory microenvironment. In vivo and in vitro studies confirmed that this dual nanocarrier could inhibit the formation of subgingival microbial colonies while promoting osteogenic differentiation of cells under diabetic pathological conditions, and ameliorated periodontal bone resorption. This effective and versatile drug-delivery strategy has good potential applications to inhibit diabetes-associated periodontal bone loss.

•

The nanocarriers are pH and lipase sensitive for controlled drug release.

•

The nanocarriers simultaneously exert antibacterial, antioxidant, anti-inflammatory, and osteogenic functions via the controlled release of antibacterial/Mino and antioxidant/ALA.

•

The nanocarriers offer a promising strategy to treat periodontitis under DM conditions.

Pathogenic Molecular Mechanisms in Periodontitis and Peri-Implantitis: Role of Advanced Glycation End Products

Advanced Glycation End Products (AGEs), the products of the non-enzymatic oxidation of proteins, nucleic acids, and lipids, are accumulated in periodontal tissues under hyperglycemic conditions such as Diabetes Mellitus (DM) and are responsible for sustained periodontal destruction. AGEs mediate their intracellular effects either directly or indirectly through receptor binding (via RAGE) in all types of periodontal ligament cells (osteocytes, gingival fibroblasts, stem cells, epithelial cells), indicating an important target for intervention. In combination with lipopolysaccharides (LPS) from Porphyromonas gingivalis (Pg), the negative impact of AGEs on periodontal tissue is further enhanced and accentuated. In addition, AGE accumulation is evident in peri-implantitis, yet through different underlying molecular mechanisms. Novel therapeutic approaches targeting the effects of AGEs in periodontal ligament cells show beneficial effects in pre-clinical studies. Herein, we provide evidence on the detrimental role of AGE accumulation in oral cavity tissues and their associated signaling pathways in periodontitis and peri-implantitis to further highlight the significance of oral or topical use of AGE blockers or inhibitors along with dental biofilms’ removal and DM regulation in patients’ management.

Interplay Among the Oral Microbiome, Oral Cavity Conditions, the Host Immune Response, Diabetes Mellitus, and Its Associated-Risk Factors-An Overview

This comprehensive review of the literature aimed to investigate the interplay between the oral microbiome, oral cavity conditions, and host immune response in Diabetes mellitus (DM). Moreover, this review also aimed to investigate how DM related risk factors, such as advanced age, hyperglycemia, hyperlipidemia, obesity, hypertension and polycystic ovary syndrome (PCOS), act in promoting or modifying specific mechanisms that could potentially perpetuate both altered systemic and oral conditions. We found that poorly controlled glycemic index may exert a negative effect on the immune system of affected individuals, leading to a deficient immune response or to an exacerbation of the inflammatory response exacerbating DM-related complications. Hyperglycemia induces alterations in the oral microbiome since poor glycemic control is associated with increased levels and frequencies of periodontal pathogens in the subgingival biofilm of individuals with DM. A bidirectional relationship between periodontal diseases and DM has been suggested: DM patients may have an exaggerated inflammatory response, poor repair and bone resorption that aggravates periodontal disease whereas the increased levels of systemic pro-inflammatory mediators found in individuals affected with periodontal disease exacerbates insulin resistance. SARS-CoV-2 infection may represent an aggravating factor for individuals with DM. Individuals with DM tend to have low salivary flow and a high prevalence of xerostomia, but the association between prevalence/experience of dental caries and DM is still unclear. DM has also been associated to the development of lesions in the oral mucosa, especially potentially malignant ones and those associated with fungal infections. Obesity plays an important role in the induction and progression of DM. Co-affected obese and DM individuals tend to present worse oral health conditions. A decrease in HDL and, an increase in triglycerides bloodstream levels seem to be associated with an increase on the load of periodontopathogens on oral cavity. Moreover, DM may increase the likelihood of halitosis. Prevalence of impaired taste perception and impaired smell recognition tend to be greater in DM patients. An important interplay among oral cavity microbiome, DM, obesity and hypertension has been proposed as the reduction of nitrate into nitrite, in addition to contribute to lowering of blood pressure, reduces oxidative stress and increases insulin secretion, being these effects desirable for the control of obesity and DM. Women with PCOS tend to present a distinct oral microbial composition and an elevated systemic response to selective members of this microbial community, but the association between oral microbiome, PCOS are DM is still unknown. The results of the studies presented in this review suggest the interplay among the oral microbiome, oral cavity conditions, host immune response and DM and some of the DM associated risk factors exist. DM individuals need to be encouraged and motivated for an adequate oral health care. In addition, these results show the importance of adopting multidisciplinary management of DM and of strengthening physicians-dentists relationship focusing on both systemic and on oral cavity conditions of DM patients.

Novel Insight into the Mechanisms of the Bidirectional Relationship between Diabetes and Periodontitis

Periodontitis and diabetes are two major global health problems despite their prevalence being significantly underreported and underestimated. Both epidemiological and intervention studies show a bidirectional relationship between periodontitis and diabetes. The hypothesis of a potential causal link between the two diseases is corroborated by recent studies in experimental animals that identified mechanisms whereby periodontitis and diabetes can adversely affect each other. Herein, we will review clinical data on the existence of a two-way relationship between periodontitis and diabetes and discuss possible mechanistic interactions in both directions, focusing in particular on new data highlighting the importance of the host response. Moreover, we will address the hypothesis that trained immunity may represent the unifying mechanism explaining the intertwined association between diabetes and periodontitis. Achieving a better mechanistic insight on clustering of infectious, inflammatory, and metabolic diseases may provide new therapeutic options to reduce the risk of diabetes and diabetes-associated comorbidities.

Impact of Impaired Glucose Metabolism on Periodontitis Progression over Three Years

We evaluated the relationship between glucose abnormalities and periodontitis in overweight/obese individuals. Eight hundred and seventy (870) diabetes-free participants aged 40-65 years completed the three-year follow-up in the San Juan Overweight Adults Longitudinal Study. The ADA thresholds for fasting and 2-h post-load glucose and HbA1c were used to define prediabetes. The NHANES methods were used to assess periodontitis. Multivariable linear regression was used to evaluate the relationship between baseline glucose metabolism measures and periodontitis at follow-up, adjusting for potential confounders. There was no association between impaired glucose measures and mean pocket depth (PD), mean clinical attachment loss (CAL), or mean percent of sites ≥5 mm PD. Impaired glucose tolerance (IGT) was associated with a lower mean percent of sites ≥5 mm CAL (β = -1.6, p = 0.037). Prediabetes and impaired fasting glucose (IFG) were associated with improvement in mean percent of sites ≥5 mm PD (β = -1.4, p = 0.022; β = -1.6, p = 0.032; respectively). IFG and IGT were associated with improvement in mean percent of sites with ≥5 mm CAL (β = -1.6, p = 0.038; β = -1.9, p = 0.020; respectively). In conclusion, there were no consistent associations between baseline prediabetes or insulin resistance and periodontitis progression over a three-year period.

Therapeutic potential of PPARα agonist in ligature-induced experimental periodontitis

Inflammation-related immune responses and bone metabolism lead to extensive tooth loss in periodontitis.

Therapeutic Potential of Liraglutide for Diabetes-Periodontitis Comorbidity: Killing Two Birds with One Stone

BACKGROUND

The relationship between diabetes and periodontitis is bidirectional, and there is now consensus that periodontitis and diabetes are comorbid. There is a quest for a drug that can be used to treat both conditions simultaneously. This study evaluated the anti-inflammatory and osteoprotective effects of liraglutide (LIRA) on periodontitis in diabetic rats.

METHODS

Male Wistar rats (n = 46) were randomly divided into four groups: control group (n = 8), LIRA group (n = 8), diabetes-associated periodontitis+0.9% saline group (diabetic periodontitis (DP)+NaCl group, n = 15), and diabetes-associated periodontitis+LIRA group (DP+LIRA group, n = 15). LIRA treatment lasted for 4 weeks (300 μg/kg/d) after establishment of a rat model of DP. The expression of IL-6, TNF-α, and IL-1β was detected by enzyme-linked immunosorbent assay. The morphological changes of periodontal tissues were observed by hematoxylin-eosin staining. The absorption of alveolar bone and its ultrastructural changes were observed by histomorphometry and microcomputed tomography. The expression of receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) in alveolar bone was detected by immunohistochemistry. The levels of Runx2 mRNA and ALP mRNA in the gingival epithelium were examined by quantitative real-time polymerase chain reaction.

RESULTS

LIRA decreased alveolar bone resorption, improved the microstructure of alveolar bone, and reduced periodontal inflammation and damage (P < 0.05). LIRA also reduced blood glucose level and inhibited the secretion of serum IL-6, TNF-α, and IL-1β (P < 0.05). In addition, after treatment with LIRA, the ratio of RANKL/OPG was reduced, and the expression levels of ALP mRNA and Runx2 mRNA were upregulated (P < 0.05).

CONCLUSIONS

LIRA not only controls blood glucose level but also reduces inflammation and bone loss and enhances osteogenic differentiation in diabetes-associated periodontitis. Those indicate that LIRA may be used as a potential medicine for the adjunctive therapy of diabetes-periodontitis comorbidity.

Grafting Resveratrol onto Mesoporous Silica Nanoparticles towards Efficient Sustainable Immunoregulation and Insulin Resistance Alleviation for Diabetic Periodontitis Therapy

The treatment of diabetic periodontitis (DP) has become a tough challenge in dental clinic mainly due to the intrinsic drawbacks of conventional therapy strategy and currently unclear mechanisms to elucidate...

Inhibition of acid sphingomyelinase by imipramine abolishes the synergy between metabolic syndrome and periodontitis on alveolar bone loss

BACKGROUND AND OBJECTIVE

Clinical studies have shown that metabolic syndrome (MetS) exacerbates periodontitis. However, the underlying mechanisms remain largely unknown. Since our animal study has shown that high-fat diet-induced MetS exacerbates lipopolysaccharide (LPS)-stimulated periodontitis in mouse model and our in vitro study showed that acid sphingomyelinase (aSMase) plays a key role in the amplification of LPS-triggered pro-inflammatory response by palmitic acid (PA) in macrophages, we tested our hypothesis that inhibitor of aSMase attenuates MetS-exacerbated periodontitis in animal model. Furthermore, to explore the potential underlying mechanisms, we tested our hypothesis that aSMase inhibitor downregulates pro-inflammatory and pro-osteoclastogenic gene expression in macrophages in vitro.

MATERIAL AND METHODS

We induced MetS and periodontitis in C57BL/6 mice by feeding high-fat diet (HFD) and periodontal injection of A. actinomycetemcomitans LPS, respectively, and treated mice with imipramine, a well-established inhibitor of aSMase. Micro-computed tomography (micro-CT), tartrate-resistant acid phosphatase staining, histological and pathological evaluations as well as cell cultures were performed to evaluate alveolar bone loss, osteoclast formation, periodontal inflammation and pro-inflammatory gene expression.

RESULTS

Analysis of metabolic parameter showed that while HFD induced MetS by increasing bodyweight, insulin resistance, cholesterol and free fatty acids, imipramine reduced free fatty acids but had no significant effects on other metabolic parameters. MicroCT showed that either MetS or periodontitis significantly reduced bone volume fraction (BVF) of maxilla and the combination of MetS and periodontitis further reduced BVF. However, imipramine increased BVF in mice with both MetS and periodontitis to a level similar to that in mice with periodontitis alone, suggesting that imipramine abolished the synergy between MetS and periodontitis on alveolar bone loss. Consistently, results showed that imipramine inhibited osteoclast formation and periodontal inflammation in mice with both MetS and periodontitis. To elucidate the mechanisms by which imipramine attenuates MetS-exacerbated periodontitis, we showed that imipramine inhibited the upregulation of pro-inflammatory cytokines and transcription factor c-FOS as well as ceramide production by LPS plus PA in macrophages.

CONCLUSION

This study has shown that imipramine as an inhibitor of aSMase abolishes the synergy between MetS and periodontitis on alveolar bone loss in animal model and inhibits pro-inflammatory and pro-osteoclastogenic gene expression in macrophages in vitro. This study provides the first evidence that aSMase is a potential therapeutic target for MetS-exacerbated periodontitis.

Subgingival pathogens in chronic periodontitis patients affected by type 2 diabetes mellitus: a retrospective case-control study

Purpose

The aim of this study was to compare the prevalence and bacterial load of 6 main periodontal pathogens between pairs of periodontal patients with and without type 2 diabetes mellitus. Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans genotypes were also investigated.

Methods

Twenty patients affected by chronic periodontitis and type 2 diabetes were retrospectively selected and matched to 20 patients without diabetes on the basis of the degree and severity of periodontal disease. Microbiological data of subgingival biofilms were analysed and compared for the examined pathogens: A. actinomycetemcomitans, P. gingivalis, Prevotella intermedia, Treponema denticola, Fusobacterium nucleatum, and Tannerella forsythia.

Results

The pairs were balanced in terms of demographic and clinical parameters, except for bleeding on probing and suppuration. In the microbiological test sites (4 for each patient), the mean probing pocket depth was 6.34±1.63 mm in patients with diabetes and 6.41±1.78 mm in patients without diabetes. No significant difference between pairs in the prevalence of P. gingivalis or the distribution of its genotypes was recorded. Patients with diabetes had a significantly greater amount of total bacterial load, P. gingivalis, T. denticola, T. forsythia, and F. nucleatum (P<0.05). Moreover, patients with diabetes had a higher number of sites with a greater cell count than patients without diabetes. When compared to the total bacterial load, only T. forsythia maintained its relative load in patients with diabetes (P=0.001).

Conclusions

This retrospective matched study supports the hypothesis that microbiological differences exist among periodontal patients with and without diabetes mellitus.

Trial Registration

ClinicalTrials.gov Identifier: NCT03786133

Pyroptosis-Mediated Periodontal Disease

Pyroptosis is a caspase-dependent process relevant to the understanding of beneficial host responses and medical conditions for which inflammation is central to the pathophysiology of the disease. Pyroptosis has been recently suggested as one of the pathways of exacerbated inflammation of periodontal tissues. Hence, this focused review aims to discuss pyroptosis as a pathological mechanism in the cause of periodontitis. The included articles presented similarities regarding methods, type of cells applied, and cell stimulation, as the outcomes also point to the same direction considering the cellular events. The collected data indicate that virulence factors present in the diseased periodontal tissues initiate the inflammasome route of tissue destruction with caspase activation, cleavage of gasdermin D, and secretion of interleukins IL-1β and IL-18. Consequently, removing periopathogens’ virulence factors that trigger pyroptosis is a potential strategy to combat periodontal disease and regain tissue homeostasis.

Association between periodontitis and glycated hemoglobin levels in individuals living in rural Southern Brazil

OBJECTIVES

To estimate the prevalence of prediabetes in individuals with moderate or severe periodontitis and to verify the association between periodontitis and glycated hemoglobin levels.

MATERIAL AND METHODS

A cross-sectional study was conducted including individuals age 18-93 years from a representative sample residing in rural Southern Brazil. Data collection included full mouth periodontal clinical examinations, laboratory screens, and structured questionnaires. Glycemic levels were based on glycated hemoglobin. Periodontitis case definition was based on criteria established by the Centers for Disease Control and Prevention and the American Academy of Periodontology. A logistic regression model adjusted for body mass index was used to estimate odds ratios (OR) and 95% confidence intervals (CI). The association between periodontal parameters and changes in glycated hemoglobin levels was evaluated using linear regression models.

RESULTS

A higher prevalence of prediabetes was observed among individuals with moderate (39.6%) and severe periodontitis (49.7%) than in individuals with mild (23.8%) or no periodontitis (27.8%). Adjusting for body mass index, individuals with severe periodontitis exhibited a 2.5 greater chance of being prediabetic (OR=2.5; 95% CI: 1.3-4.9) that was significantly associated with an increase of 0.10% in HbA1c.

CONCLUSION

Severe periodontitis was associated with elevated blood glucose levels. Individuals with this condition having a higher percentage HbA1c are more likely to be prediabetic.

CLINICAL RELEVANCE

This study highlights the importance of the clinicians' awareness of the association between severe periodontitis and prediabetes allowing its early detection in the dental office.

The Factors Affecting Orthodontic Pain with Periodontitis

The occurrence of pain is often closely related to the psychological status, and the threshold for pain tolerance varies from patient to patient. In short, the factors affecting orthodontic pain are diverse and have individual differences. Tooth pain after the first force of intraoral malocclusion orthodontic treatment is one of the common complications of fixed orthodontic treatment, which often affects the outcome of treatment of patients with malocclusion and their subjective satisfaction with fixed orthodontic treatment. The purpose of the paper was to investigate the basic patterns and influencing factors of dental pain in fixed orthodontic patients within seven days after the initial wearing of straight arch aligners and the analysis of the effect of psychological intervention on dental pain using the visual simulation scoring method. According to the inclusion criteria of the experimental design, 89 patients who visited the Department of Orthodontics of Hospital for malocclusion were randomly divided into observation group and control group, and the observation group used chewing gum as psychological intervention, while the control group did not use any intervention. The effect of psychological intervention on periodontal pain was analyzed. The results of the paper were that all but 3 of the 89 patients had no pain, and all the patients had different degrees of dental pain at different points in time.

The Outcomes of Enamel Matrix Derivative on Periodontal Regeneration under Diabetic Conditions

Background and Objectives: Enamel matrix derivative (EMD) is a biomaterial used for periodontal regenerative therapy due to its properties of stimulating cementum development and bone synthesis. Diabetes is a chronic condition that affects healing and predisposes to infection. The aim of this review was to evaluate the current studies available on the application and results of EMD for periodontal regenerative therapy under diabetic conditions. Materials and Methods: Five databases (PubMed, ResearchGate, Scopus, Web of Science and Google Scholar) were searched for relevant articles, using specific keywords in different combinations. The inclusion criteria were clinical trials, case reports, case studies, and animal studies published in English, where periodontal treatment for bone defects includes EMD, and it is performed under diabetic conditions. Results: Of the 310 articles resulted in search, five studies published between 2012 and 2020 met the inclusion criteria and were selected for the current review. In human studies, the use of EMD in infrabony defects showed favorable results at follow-up. In animal studies, periodontal regeneration was reduced in diabetic rats. Conclusions: EMD might promote bone healing when used under diabetic conditions for the regenerative periodontal therapy. Due to limited number of studies, more data are required to sustain the effects of EMD therapy in diabetic settings.

Prevalence of periodontitis in people clinically diagnosed with diabetes mellitus: a meta-analysis of epidemiologic studies

AIMS

The relationship between diabetes mellitus and periodontitis has long been discussed, but the conclusion of this relationship was controversial. We conducted this meta-analysis to explore the association between diabetes mellitus and the prevalence of periodontitis.

METHODS

PubMed, Embase, Web of Science, and the Cochrane Library were searched for studies reporting associations of periodontitis with diabetes. Gray literature was integrated from the Open-Gray database. Prevalence estimates and odds ratios were extracted by two independent reviewers and synthesized through meta-analyses.

RESULTS

Twenty-seven papers met the inclusion criteria involving 3092 diabetic patients and 23,494 controls. Overall prevalence of periodontitis was 67.8% in diabetics (combined types) and 35.5% in patients without diabetes (OR, 1.85; 95%CI, 1.61-2.11). Probing depth (MD 0.23; 95% CI, 0.17-0.29; I² = 25%) and plaque index (MD, 0.20; 95% CI, 0.18-0.23; P = 0.59; I² = 0%) severity scores were significantly greater among the diabetic group.

CONCLUSIONS

The prevalence and severity of periodontitis are greater in patients with diabetes than in non-diabetic populations.

The use of probiotics can reduce the severity of experimental periodontitis in rats with metabolic syndrome: an immunoenzymatic and microtomographic study

BACKGROUND

This study evaluated the effects of Bifidobacterium animalis subsp. lactis HN019 (B. lactis HN019) in the development of periodontitis (PE), associated or not with metabolic syndrome, (MS) in rats.

METHODS

96 rats were grouped according to a food protocol: high-fat diet for induction of MS or standard diet for the control groups (C). They were subdivided into groups with (+) and without (-) PE, receiving (*) or not (**) probiotic (PROB): C -**, CP-*, PE+**, PEP+*, MS-**, MSP-*, MSPE+** and MSPEP+*. PROB administration started on the 8^th week of the study and PE was induced on the 14^th week by placing ligature on the animals' lower first molars. Euthanasia occurred in the 16^th week. Biomolecular analyzes, immunoenzymatic assays, and microtomographic analyses were performed. The data obtained were analyzed statistically (p <0.05).

RESULTS

The PEP and MSPEP groups showed lower levels of alveolar bone loss when compared to the PE and MSPE groups, respectively (p <0.05). The immunoenzymatic analysis showed higher levels of interleukin (IL)-1β and a higher receptor activator of NF-kappaB ligand (RANKL)/ osteoprotegerin (OPG) ratio in the MSPE group when compared to the MSPEP group (p <0.05). The PEP group showed lower levels of tumor necrosis factor (TNF)-α and IL-6 when compared to the PE group. The use of PROB attenuated dyslipidemia parameters in animals with MS, with or without PE.

CONCLUSION

B. lactis HN019 reduced more significantly the severity of PE in rats with MS, modulating both systemic metabolic and immunoinflammatory parameters in periodontal tissues. This article is protected by copyright. All rights reserved.

The Effect of Periodontal Disease on Metabolic Control in Patients With Diabetes Mellitus in South Africa: Protocol for a Systematic Review

BACKGROUND

The increase in the prevalence of type 2 diabetes mellitus (T2DM) and its associated complications is burdensome to the South African health system. Understanding the role of comorbid diseases, such as periodontal disease (PD), and their effect on metabolic control in patients with DM in South Africa will raise awareness about the importance of periodontal interventions among patients with DM in South Africa.

OBJECTIVE

The review will aim to determine the effect of PD on the metabolic control of T2DM in a South African population.

METHODS

A systematic review of the relationship between PD and metabolic control in patients with T2DM in a South African population will be conducted. Cohort, cross-sectional, and case-controlled studies will be considered in which the outcome of interest is diabetic control. A search will be done in the following sources: EBSCOhost (academic search complete; dentistry and oral sciences), PubMed, ScienceDirect, and the South African National ETD Portal for articles published in English. There will be no limit placed on the date of the publication. The reference list of articles will be reviewed for further inclusion of critical articles. Two independent reviewers (AJ and FK-D) will do study selection, data extraction, and quality analysis. All disputes will be resolved by discussion, and the entire team will verify final decisions.

RESULTS

The systematic review protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO). A preliminary search was conducted using the keywords ((perio*) AND (diabet*)) AND ("South Africa"). The review process should be completed by December 2021.

CONCLUSIONS

The review will determine the effect of PD on metabolic control in patients with T2DM in South Africa. The outcome would inform health policy to highlight the need to include periodontal care into treatment protocols in patients with T2DM. In this process, the feasibility for future research in this area of interest will also be defined.

TRIAL REGISTRATION

PROSPERO International Prospective Register of Systematic Reviews CRD42020221064; https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=221064.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/27471.

The Emerging Role of microRNA in Periodontitis: Pathophysiology, Clinical Potential and Future Molecular Perspectives

During the last few decades, it has been established that messenger ribonucleic acid (mRNA) transcription does not inevitably lead to protein translation, but there are numerous processes involved in post-transcriptional regulation, which is a continuously developing field of research. MicroRNAs (miRNAs) are a group of small non-coding RNAs, which negatively regulate protein expression and are implicated in several physiological and pathological mechanisms. Aberrant expression of miRNAs triggers dysregulation of multiple cellular processes involved in innate and adaptive immune responses. For many years, it was thought that miRNAs acted only within the cell in which they were synthesised, but, recently, they have been found outside cells bound to lipids and proteins, or enclosed in extracellular vesicles, namely exosomes. They can circulate throughout the body, transferring information between cells and altering gene expression in the recipient cells, as they can fuse with and be internalised by the recipient cells. Numerous studies on miRNAs have been conducted in order to identify possible biomarkers that can be used in the diagnosis of periodontal disease. However, as therapeutic agents, single miRNAs can target several genes and influence multiple regulatory networks. The aim of this review was to examine the molecular role of miRNAs and exosomes in the pathophysiology of periodontal disease and to evaluate possible clinical and future implications for a personalised therapeutical approach.

Development and evaluation of an integrated diabetes-periodontitis nutrition and health education module

BACKGROUND

A good understanding of the bi-directional relationship between diabetes and periodontitis is essential to ensure the successful management of both diseases. This study aimed to develop and evaluate an integrated diabetes-periodontitis nutrition and health education module.

METHODS

The module was developed as an iterative and review process by five experts in nutrition and dietetics, periodontics, and dental public health. It consisted of three phases: (i) needs assessment on module contents and characteristics, (ii) module development and (iii) module evaluation by experts. Twelve healthcare professionals aged between 30 and 53 years (average 13.5 years of working experience) validated the module contents and its comprehensibility using the Patient Education Materials Assessment Tool for printable materials (PEMAT-P) and audio-visual materials (PEMAT-A/V). Scores of 0 (disagree) or 1 (agree) were given for sets of understandability and actionability statements and presented as a total percentage.

RESULTS

Seventeen infographic-flip charts and 13 short-videos were developed in the Malay language and grouped into four topics: (i) Introduction to Diabetes and Periodontitis, (ii) Diabetes and Periodontitis Care, (iii) Lifestyle Modification, and (iv) Myths and Facts. Flip charts were rated between 76-100% for understandability and 80-100% for actionability, while videos rated between 90-100% for understandability and 100% for actionability, respectively.

CONCLUSION

Overall, the newly developed module ranked high median scores for understandability and actionability. This finding reflects positive acceptance of the integrated module among the various healthcare professionals involved in managing patients with diabetes and periodontitis.

Bidirectional Association between Metabolic Control in Type-2 Diabetes Mellitus and Periodontitis Inflammatory Burden: A Cross-Sectional Study in an Italian Population

This study assessed the periodontal conditions of type 2 diabetes (T2DM) patients attending an Outpatient Center in North Italy and explored the associations between metabolic control and periodontitis. Periodontal health of 104 T2DM patients (61 men and 43 women, mean age of 65.3 ± 10.1 years) was assessed according to CDC/AAP periodontitis case definitions and Periodontal Inflamed Surface Area (PISA) Index. Data on sociodemographic factors, lifestyle behaviors, laboratory tests, and glycated hemoglobin (HbA1c) levels were collected by interview and medical records. Poor glycemic control (HbA1c ≥ 7%), family history of T2DM, and C-reactive protein levels were predictors of severe periodontitis. An increase in HbA1c of 1% was associated with a rise in PISA of 89.6 mm². On the other hand, predictors of poor glycemic control were severe periodontitis, waist circumference, unbalanced diet, and sedentary lifestyle. A rise in PISA of 10 mm² increased the odds of having HbA1c ≥ 7% by 2%. There is a strong bidirectional connection between periodontitis and poor glycemic control. The inflammatory burden posed by periodontitis represents the strongest predictor of poor glycemic control.

Salivary Biomarkers and Oral Health in Liver Transplant Recipients, with an Emphasis on Diabetes

Salivary biomarkers have been linked to various systemic diseases. We examined the association between salivary biomarkers, periodontal health, and microbial burden in liver transplant (LT) recipients with and without diabetes, after transplantation. We hypothesized that diabetic recipients would exhibit impaired parameters. This study included 84 adults who received an LT between 2000 and 2006 in Finland. Dental treatment preceded transplantation. The recipients were re-examined, on average, six years later. We evaluated a battery of salivary biomarkers, microbiota, and subjective oral symptoms. Periodontal health was assessed, and immunosuppressive treatments were recorded. Recipients with impaired periodontal health showed higher matrix metalloproteinase-8 (MMP-8) levels (p < 0.05) and MMP-8/tissue inhibitor of matrix metalloproteinase 1 (TIMP1) ratios (p < 0.001) than recipients with good periodontal health. Diabetes post-LT was associated with impaired periodontal health (p < 0.05). No difference between groups was found in the microbial counts. Salivary biomarker levels did not seem to be affected by diabetes. However, the advanced pro-inflammatory state induced by and associated with periodontal inflammation was reflected in the salivary biomarker levels, especially MMP-8 and the MMP-8/TIMP-1 molar ratio. Thus, these salivary biomarkers may be useful for monitoring the oral inflammatory state and the course of LT recipients.

Periodontal Inflammation-Triggered by Periodontal Ligament Stem Cell Pyroptosis Exacerbates Periodontitis

Periodontitis is an immune inflammatory disease that leads to progressive destruction of bone and connective tissue, accompanied by the dysfunction and even loss of periodontal ligament stem cells (PDLSCs). Pyroptosis mediated by gasdermin-D (GSDMD) participates in the pathogenesis of inflammatory diseases. However, whether pyroptosis mediates PDLSC loss, and inflammation triggered by pyroptosis is involved in the pathological progression of periodontitis remain unclear. Here, we found that PDLSCs suffered GSDMD-dependent pyroptosis to release interleukin-1β (IL-1β) during human periodontitis. Importantly, the increased IL-1β level in gingival crevicular fluid was significantly correlated with periodontitis severity. The caspase-4/GSDMD-mediated pyroptosis caused by periodontal bacteria and cytoplasmic lipopolysaccharide (LPS) dominantly contributed to PDLSC loss. By releasing IL-1β into the tissue microenvironment, pyroptotic PDLSCs inhibited osteoblastogenesis and promoted osteoclastogenesis, which exacerbated the pathological damage of periodontitis. Pharmacological inhibition of caspase-4 or IL-1β antibody blockade in a rat periodontitis model lead to the significantly reduced loss of alveolar bone and periodontal ligament damage. Furthermore, Gsdmd deficiency alleviated periodontal inflammation and bone loss in mouse experimental periodontitis. These findings indicate that GSDMD-driven PDLSC pyroptosis and loss plays a pivotal role in the pathogenesis of periodontitis by increasing IL-1β release, enhancing inflammation, and promoting osteoclastogenesis.

Are occupational and environmental noises associated with periodontitis? Evidence from a Korean representative cross-sectional study

BACKGROUND

Evidences have shown that noise could be a risk factor for cardiovascular and metabolic diseases. Since periodontitis and CVD are characterized by inflammation, it is reasonable to doubt that occupational/environmental noise is a risk factor for periodontitis. The aim of this study was to examine the relationship between occupational/environmental noise and periodontitis in a nationally representative sample of Korean adults.

METHODS

This cross-sectional study used data from the 7th Korean National Health and Nutrition Examination Survey. The study sample included 8327 adults aged 40 to 80 years old. Noise exposure and the duration of the exposure were assessed with self-report questionnaires. The dependent variable was periodontitis. Age, gender, place of residence, income, marital status, smoking, frequency of daily tooth brushing, recent dental checkup, and diabetes were included as covariates. Logistic regression analyses estimated the association between noise exposure and periodontitis.

RESULTS

Those who were exposed to environmental noise during their lifetime had an increased prevalence of severe periodontitis (odds ratio [OR] 1.88; 95% confidence interval [CI] 1.05 to 3.40), and this association was strengthened as the duration of the environmental noise exposure was longer (OR of > 120 months 2.35 and OR of ≤120 months 1.49). There was a combined relationship for severe periodontitis between occupational and environmental noise exposure (OR of both exposures 2.62, OR of occupational exposure only 1.12, and OR of environmental exposure only 1.57).

CONCLUSION

Our study shows that noise exposure is associated with periodontitis, and the association was higher in the synergism between occupational and environmental interaction.

Comparative Analysis of Cytokine Expression in Oral Keratinocytes and THP-1 Macrophages in Response to the Most Prevalent Serotypes of Aggregatibacter actinomycetemcomitans

BACKGROUND

Periodontitis is a chronic inflammatory disease associated with a dysbiotic biofilm. Many pathogens have been related with its progression and severity, one of which is Aggregatibacter actinomycetemcomitans, a Gram-negative bacteria with seven serotypes (a-g) according with the structure of its LPS, with serotype b defined as the most virulent compared with the other serotypes. The aim of this study was to evaluate the response of oral keratinocytes and macrophages to A. actinomycetemcomitans.

METHODS

Oral keratinocytes (OKF6/TERT2) and macrophages (THP-1) were infected with A. actinomycetemcomitans serotypes a, b and c. The expression of IL-1β, IL-6, IL-8, IL-18, TNF-α, MMP-9, RANKL, TLR-2, TLR-4, TLR-6, thymic stromal lymphopoietin (TSLP), and ICAM-1 was evaluated by qPCR at 2 and 24 h after infection.

RESULTS

An increase in the expression of these molecules was induced by all serotypes at both times of infection, with macrophages showing higher levels of expression at 24 h compared to epithelial cells in which the highest levels were observed in the first hours after infection.

CONCLUSIONS

Keratinocytes and macrophages contribute to the inflammation in periodontitis from the early stages of infection, producing the first waves of cytokines, acting as the first signal for professional immune cell recruitment and modulation of more specific immune responses.

Are there correlations between radiographic grade levels and modified grade levels of periodontitis?

BACKGROUND

At the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions, periodontitis was reclassified according to a multidimensional staging and grading system. Grading takes variabilities in the rate of disease progression into account, relying on recognized progression risk factors, and is based on the assessment of bone loss at the worst-affected tooth in the dentition as a function of age, which is then modified by factors such as smoking and diabetes mellitus. In this context, the aim of this study was to determine whether there are correlations between radiographically calculated grades and grades modified by the presence of smoking or diabetes.

MATERIALS AND METHODS

In this descriptive study, individuals diagnosed with periodontitis according to the 2017 classifications were examined. The grade of periodontitis was measured using periapical radiography. A modified-grade level was assigned to the patients according to their glycated hemoglobin levels (in diabetics) or their smoking status.

RESULTS

The study included 341 individuals. No statistically significant relationship was revealed by Chi-square testing (P > 0.05) or in the kappa agreement index between the modified grades and the radiographic grades.

CONCLUSIONS

Although there was no correlation between radiographic grade and modified grade in smokers and diabetic individuals, increasing the grade score in these individuals in accordance with the 2017 classification provides clinicians the opportunity to develop a risk-based treatment plan, commensurate with the severity of periodontal disease and the level of risk.

Long-term effect of non-surgical periodontal treatment on glycaemic control in patients with diabetes with periodontitis: a systematic review and meta-analysis protocol

INTRODUCTION

Non-surgical periodontal therapy consisting of scaling and root planning has been shown to be effective in the improvement of glycaemic control in patients with diabetes with periodontitis for up to 3 months. However, questions remain about this beneficial effect over a longer period of time. This systematic review and meta-analysis aims to determine the long-term effect (at least 6 months from the therapy) of non-surgical periodontal therapy with or without adjuvant on glycaemic control of patients with diabetes with periodontitis.

METHODS AND ANALYSIS

This systematic review will include randomised control trials with a follow-up period of at least 6 months after initial therapy, with measurement of glycated haemoglobin as the primary endpoint. A literature search will be conducted in MEDLINE, CENTRAL, EMBASE, CINAHL, The Cochrane Oral Health Group Trials Register, and the US National Institutes of Health Trials Registry: ClinicalTrials.gov, from inception to 30 June 2020. Selection of studies, data extraction and bias assessment will be conducted independently by two reviewers. A DerSimonian-Laird random-effect meta-analysis will be conducted to pool studies deemed to be homogeneous. A subgroup analysis will be conducted in case of substantial heterogeneity. Egger's test and observation of the funnel plot will be used to assess publication bias. The statistical analysis will be done using R V.4.0.0 software.

ETHICS AND DISSEMINATION

Since primary data are not collected, ethical approval is not required. The final report will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42020192635.

Study on the Effects of Melatonin on Glycemic Control and Periodontal Parameters in Patients with Type II Diabetes Mellitus and Periodontal Disease

Background and Objectives: There is evidence that melatonin could improve the periodontal status and also glycemic control of patients with diabetes mellitus. Therefore, the aim of this study was to assess the effects of scaling and root planing plus adjunctive systemic treatment with melatonin on periodontal parameters and glycemic control in patients with type 2 diabetes and chronic periodontitis. Materials and Methods: The study was conducted on 54 subjects with periodontitis and diabetes mellitus randomly assigned to the study group (n = 27, subjects with scaling and root planing + melatonin) or control group (n = 27, subjects with scaling and root planing + placebo). Periodontal parameters (probing depth-PD; clinical attachment loss-CAL; bleeding on probing-BOP; and hygiene level) and glycated hemoglobin (HbA1c) were assessed at baseline and 8 weeks after. Results: At baseline, there were no significant differences between groups, but at the second evaluation 8 weeks later the association of melatonin with the non-surgical periodontal therapy exerted statistically significant improvements, both in periodontal parameters, with a significant decrease in periodontal disease severity, and glycated hemoglobin when compared to the control subjects. Conclusions: In our study, combined non-surgical periodontal treatment and systemic treatment with melatonin provided additional improvements to severe periodontal condition and the glycemic control of patients with diabetes type 2 when compared to non-surgical periodontal treatment alone.

Impact of diabetes and periodontal status on life quality

Objectives

To investigate impact of periodontal status on quality of life (QoL) in type-1 (T1D) and type-2 (T2D) diabetes patients pre- and post-periodontal treatment using the Well-being Questionnaire 12 (W-BQ12) and Audit of Diabetes-Dependent Quality of Life-19 (ADDQoL-19).

Methods

W-BQ12 and ADDQoL-19 were self-completed by 56 T1D and 77 T2D patients at baseline and by those with periodontitis 3 and 6-months after therapy.

Results

At baseline, T1D patients had significantly higher general W-BQ12 [Median (IQR); 24.00 (20.25–27.75)] and positive well-being scores [8.00 (6.00–9.00)] (indicating better QoL) compared to T2D patients [22.00 (15.50–26.00) and 6.00 (3.50–9.00)], respectively (p < 0.05). Within both groups, general W-BQ12 scores did not differ significantly between patients with periodontal health, gingivitis, or periodontitis (p > 0.05). Significantly higher general W-BQ12 scores were observed in T1D patients at month 3 [28.00 (22.00–29.50)] compared to baseline [22.00 (17.00–24.50)] (p < 0.01), suggesting an initial improvement in QoL post-treatment. ADDQoL-19 identified that diabetes had greatest impact on the domain ‘freedom to eat’, with participants placing most importance on ‘family life’. No significant changes in ADDQoL-19 scores were seen post-treatment (p > 0.05).

Conclusions

Diabetes had impacts upon aspects of life quality in both T1D and T2D patients, though any additional impact based on periodontal status was not observed when using W-BQ12 and ADDQoL-19.

Prolonged multimodal fasting modulates periodontal inflammation in female patients with metabolic syndrome: A prospective cohort study

AIM

To determine the potential anti-inflammatory effect of a multimodal periodic fasting programme on surrogate parameters of periodontal inflammation in hospitalized patients diagnosed for metabolic syndrome (MetS).

MATERIAL AND METHODS

A total of 47 patients were recruited and hospitalized in an integrative ward for an intensified two-week multimodal fasting, diet and lifestyle programme. Patients were periodontally examined at baseline (t1), after the 2-week fasting protocol (t2) and, subsequently, 4 months after fasting (t3). The following parameters were determined: periodontal screening index (PSI), bleeding on probing (BOP), gingival crevicular fluid volume (GCF), plaque index (PI), C-reactive protein (CRP), blood pressure (BP), waist circumference (WC), fasting glucose (FGLU), triglycerides (TRG), high-density lipoprotein (HDL) and HbA1c.

RESULTS

A total of 28 female and 8 male patients fulfilled the defined criteria for MetS and were analysed separately by gender. At t2, BOP and GCF were reduced when compared to t1 (median: t2 = 39; t1 = 33.1%; p < .001 and t2 = 73.9; t1 = 59.3 Periotron units p = .02, respectively). BOP reduction correlated to FGLU (R = .37, p = .049) and weight reduction (R = .4, p = .04).

CONCLUSION

This study showed for the first time that clinically supervised periodic fasting in female patients with MetS may facilitate the reduction of periodontal inflammation.

Association of bacterial vaginosis with periodontitis in a cross-sectional American nationwide survey

To explore the association between bacterial vaginosis (BV) and periodontitis (PD) and to determine whether PD and BV might be linked with systemic serum alterations. We used the National Health and Nutrition Examination Survey 2001-2004, with women aged 18-49 years old and diagnosed with or without BV according to Nugent's method. PD was defined according to the 2012 case definition. We compared serum counts according to the presence of PD and the presence of BV. Multivariable regression was used to explore and identify relevant variables towards the presence of BV. 961 women fulfilled the inclusion criteria. In women with BV, PD was associated with higher inflammation, characterized by increased white blood cells (p = 0.006) and lymphocyte (p = 0.009) counts. Predictive models presented a statistically significant association between PD and BV [Odds Ratio (OD) = 1.69, 95% Confidence Interval (CI): 1.09-2.61 for periodontitis; OD = 2.37, 95% CI: 1.30-4.29 for severe PD]. Fully adjusted models for age, smoking, body mass index, diabetes mellitus and number of systemic conditions reinforced this association [OD = 1.71, 95% CI: 1.06-2.76 for PD; OD = 2.21, 95% CI: 1.15-4.25 for severe PD]. An association between BV and PD is conceivable. PD was associated with higher systemic markers of inflammation in women with BV. Our data is novel and could serve as a foundation to guide future studies in the confirmation of this association and the underlying mechanisms.

Nutrition as a Key Modifiable Factor for Periodontitis and Main Chronic Diseases

Nutrition is recognized as an essential component in the prevention of a number of chronic diseases, including periodontal disease. Based on these considerations, a better understanding is required regarding how the diet, and more particularly the intake of macronutrients and micronutrients, could impact the potential relationship between nutrition and periodontal diseases, periodontal diseases and chronic diseases, nutrition and chronic diseases. To overcome this complexity, an up-to-date literature review on the nutriments related to periodontal and chronic diseases was performed. High-sugar, high-saturated fat, low-polyols, low-fiber and low-polyunsaturated-fat intake causes an increased risk of periodontal diseases. This pattern of nutrients is classically found in the Western diet, which is considered as an ‘unhealthy’ diet that causes cardiovascular diseases, diabetes and cancers. Conversely, low-sugar, high-fiber and high-omega-6-to-omega-3 fatty acid ratio intake reduces the risk of periodontal diseases. The Mediterranean, DASH, vegetarian and Okinawa diets that correspond to these nutritional intakes are considered as ‘healthy’ diets, reducing this risk of cardiovascular diseases, diabetes and cancers. The role of micronutrients, such as vitamin D, E, K and magnesium, remains unclear, while others, such as vitamin A, B, C, calcium, zinc and polyphenols have been shown to prevent PDs. Some evidence suggests that probiotics and prebiotics could promote periodontal health. Periodontal and chronic diseases share, with a time delay, nutrition as a risk factor. Thus, any change in periodontal health should be considered as a warning signal to control the dietary quality of patients and thus reduce the risk of developing chronic diseases later on.

Association of type 2 diabetes mellitus and periodontal disease susceptibility with genome-wide association-identified risk variants in a Southeastern Brazilian population

OBJECTIVE

Genome-wide association studies (GWAS) and literature have identified polymorphisms in the KCNJ11, HNF1A, IRS1, TCF7L2, CDKAL1, CDKN2B, RPSAP52, GPR45 HHEX, IL18, and RUNX2 genes associated with type 2 diabetes mellitus (T2DM) and/or periodontitis (P) in diverse populations, and we sought to evaluate them as genetic risk variants for these diseases in the Brazilian population.

MATERIAL AND METHODS

Periodontal, glycemic, and lipid data were obtained from 931 individuals divided into: control (n = 334), periodontitis (P; n = 358), and periodontitis associated with T2DM (P + T2DM; n = 239). After genotyping, associations between polymorphisms and pathologies were tested by multiple logistic and linear regressions, adjusting for age, sex, and smoking habits.

RESULTS

Considering the studied subjects, the increased risk to develop periodontitis in the periodontitis P + T2DM group was found for HNF1A-rs7957197-TA, CDKAL1-rs7754840-CG, RPSAP52-rs1531343-GC, TCF7L2-rs7903146-TT, and CDKN2B-rs7018475-GG. The association of these genetic variants for TCF7L2 and CDKN2B was confirmed for female, never smokers, and poorly controlled P + T2DM. CDKN2B-rs7018475 was associated with worse glycemic condition and periodontal parameters.

CONCLUSION

These five reported genetic variants were associated in the studied Southeastern Brazilian population as genetic risk variants of periodontitis and T2DM associated to periodontitis as comorbidity. Gene-phenotype associations with sex and smoking habits and the CDKN2B-rs7018475 with the poor glycemic control and more severe periodontal conditions should be further investigated.

CLINICAL RELEVANCE

Polymorphisms in the CDKAL1-rs7754840, HNF1A-rs7957197, RPSAP52-rs1531343, TCF7L2-rs7903146, and CDKN2B-rs7018475 might predispose to periodontitis and T2DM associated with periodontitis. These findings may be useful in public health genomics and future advanced clinical practice, since genetic carriage can be measured before disease onset, being of potential great benefit for treatment planning and prognosis in early disease stages.

Influence of Natural Killer Cells and Natural Killer T Cells on Periodontal Disease: A Systematic Review of the Current Literature

Natural killer (NK) cells, as members of the innate immune system, and natural killer T (NKT) cells, bridging innate and adaptive immunity, play a prominent role in chronic inflammatory diseases and cancerogenesis, yet have scarcely been examined in oral diseases. Therefore, systematic research on the latest literature focusing on NK/NKT cell-mediated mechanisms in periodontal disease, including the time period 1988-2020, was carried out in MEDLINE (PubMed) using a predetermined search strategy, with a final selection of 25 studies. The results showed that NK cells tend to have rather proinflammatory influences via cytokine production, cytotoxic effects, dendritic-cell-crosstalk, and autoimmune reactions, while contrarily, NKT cell-mediated mechanisms were proinflammatory and immunoregulatory, ranging from protective effects via B-cell-regulation, specific antibody production, and the suppression of autoimmunity to destructive effects via cytokine production, dendritic-cell-crosstalk, and T-/B-cell interactions. Since NK cells seem to have a proinflammatory role in periodontitis, further research should focus on the proinflammatory and immunoregulatory properties of NKT cells in order to create, in addition to antibacterial strategies in dental inflammatory disease, novel anti-inflammatory therapeutic approaches modulating host immunity towards dental health.

A quantitative bias analysis to assess the impact of unmeasured confounding on associations between diabetes and periodontitis

AIM

To investigate unmeasured confounding in bidirectional associations between periodontitis and diabetes using quantitative bias analysis.

METHODS

Subsamples from the Veterans Affairs Dental Longitudinal Study were selected. Adjusted for known confounders, we used Cox proportional hazards models to estimate associations between pre-existing clinical periodontitis and incident Type II Diabetes (n = 672), and between pre-existing diabetes and incident severe periodontitis (n = 521), respectively. Hypothetical confounders were simulated into the dataset using Bernoulli trials based on pre-specified distributions of confounders within categories of each exposure and outcome. We calculated corrected hazard ratios (HR) over 10,000 bootstrapped samples.

RESULTS

In models using periodontitis as the exposure and incident diabetes as the outcome, adjusted HR = 1.21 (95% CI: 0.64-2.30). Further adjustment for simulated confounders positively associated with periodontitis and diabetes greatly attenuated the association or explained it away entirely (HR = 1). In models using diabetes as the exposure and incident periodontitis as the outcome, adjusted HR = 1.35 (95% CI: 0.79-2.32). After further adjustment for simulated confounders, the lower bound of the simulation interval never reached the null value (HR ≥ 1.03).

CONCLUSIONS

Presence of unmeasured confounding does not explain observed associations between pre-existing diabetes and incident periodontitis. However, presence of weak unmeasured confounding eliminated observed associations between pre-existing periodontitis and incident diabetes. These results clarify the bidirectional periodontitis-diabetes association.

Management of periodontal disease in patients with diabetes- good clinical practice guidelines: A joint statement by Indian Society of Periodontology and Research Society for the Study of Diabetes in India

There is a huge body of literature suggesting an association and a bidirectional relationship between periodontal disease and diabetes. Diabetes and periodontal diseases are both chronic diseases with a high prevalence. Dentists/periodontists, in their daily clinical practice, very often attend to diabetes patients with diverse oral health conditions and cater to their dental treatment needs. Safe and effective periodontal therapy in this population requires a broad understanding of diabetes, medical management of diabetes, and essential modifications to dental/periodontal therapy that may be required. This paper describes a joint statement put forth by the Indian Society of Periodontology and the Research Society for the Study of Diabetes in India aiming to provide expert consensus and evidence-based guidelines for optimal clinical management of periodontal conditions in diabetes patients or patients at risk for diabetes. Although this paper is not envisioned to be a comprehensive review of this topic, it intends to provide the guidelines for dental professionals and periodontists.

Evaluation of a questionnaire-based diabetes screening concept in German patients with Stage III or IV periodontitis: A practice-based study

BACKGROUND

This practice-based retrospective study evaluated a screening method for diabetes mellitus (DM) in patients with Stage III or IV periodontitis using the FINDRISC questionnaire.

METHODS

Patients with Stage III or IV periodontitis who received FINDRISC screening in a German private dental practice were recruited. Individuals with positive FINDRISC scores (≥12, FINDRISC+) were referred for diabetological examination. Several general and periodontal findings from the patients' documentation were recorded and analyzed.

RESULTS

A total of 179 patients (52.65 ± 11.49 years) were included. In DM screening, 24.6% (n = 44) patients were FINDRISC+, including all patients with currently known DM (21 of 21). Of the remaining FINDRISC+ patients, 82.6% (19 of 23) visited their general practitioner, and 63.2% (12 of 19, 7.6% of total cohort) had an HbA1c ≥5.7%. Accordingly, 75% of the FINDRISC+ patients were diabetologically conspicuous (HbA1c ≥ 5.7%), including those with already known DM. Patients with previously unknown DM showed higher mean age, more missing teeth, a higher periodontitis stage (more Stage IV) and more frequently teeth with suppuration compared with the diabetologically inconspicuous individuals (P <0.01).

CONCLUSION

The FINDRISC questionnaire is appropriate for patients with Stage III or IV periodontitis and can be recommended in dental practice setting.

Influence of root debridement with adjunct photodynamic therapy on periodontal parameters and gingival crevicular fluid cortisol levels among patients with and without type-2 diabetes mellitus

OBJECTIVE

The aim of the present study was to assess the influence of scaling and root planing (SRP) with adjunct antimicrobial photodynamic therapy (aPDT) on periodontal parameters and gingival crevicular fluid (GCF) cortisol levels in type-2 diabetic and non-diabetic patients with periodontitis.

METHODS

One hundred and twenty-eight patients with periodontitis (64 with and 64 without type-2 diabetes mellitus, respectively) were included. In the test- and control-groups, patients underwent SRP with and without aPDT, respectivey. In both groups, plaque and gingival indices (PI and GI), probing depth (PD), clinical attachment loss (CAL), marginal bone loss (MBL) and GCF volume and cortisol levels were assessed at baseline and three and six-months after SRP with or without aPDT. The aPDT was performed at baseline using methylene blue and photobiomodulation. The Kruskall-Wallis test was used to assess data normality; and group-comparisons were done. P-values, which were below 0.01 indicated statistical significance.

RESULTS

Sixty-four type-2 diabetic patients with and 64 non-diabetic patients with periodontitis were included. All individuals had Stage-III/Grade-C periodontitis. Among patients with type-2 diabetes mellitus (DM), there was no statistically significant difference in hemoblobin A1c, PI, GI, PD, CAL and MBL at baseline and at 3- and 6-months intervals. Amongst diabetic patietns, there was no difference in the GCF volume and cortisol levels in the test- and control-groups at all time intervals. In non-diabetic patients, there was a significqnt reductionin GCF volume and cortisol levels when SRP was done with aPDT than when SRP was carried out as the sole treatment strategy CONCLUSION: Among non-diabetic patients, SRP with aPDT helps reduce periodontal inflammation and GCF cortisol levels for up to 6-months; however poorly-controlled DM compromises the beneficial effects of this treatment strategy.

Oral infectious bacteria in dental plaque and saliva as risk factors in patients with esophageal cancer

BACKGROUND

High levels of periodontopathic bacteria as well as Streptococcus anginosus were detected in cancer tissue from patients with esophageal cancer. An association between oral infectious bacteria and esophageal cancer has been reported.

METHODS

Characteristics of the oral microbiota and periodontal conditions were studied as clinicopathologic factors in patients with esophageal cancer. The study included 61 patients with esophageal cancer and 62 matched individuals without any cancers. Samples of subgingival dental plaque and unstimulated saliva were collected to evaluate the prevalence and abundance of the following oral bacteria using a real-time polymerase chain reaction assay: Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, Treponema denticola, and S. anginosus.

RESULTS

In the cancer group, the prevalence of all bacteria, with the exception of F. nucleatum, in dental plaque; the prevalence of A. actinomycetemcomitans in saliva; the abundance of all bacteria, with the exception of F. nucleatum and P. intermedia, in dental plaque; and the abundance of A. actinomycetemcomitans and S. anginosus in saliva were significantly higher. Furthermore, a logistic regression analysis suggested that the prevalence of T. forsythia and S. anginosus in dental plaque and of A. actinomycetemcomitans in saliva, as well as a drinking habit, were associated with a high risk of esophageal cancer, with a high odds ratio.

CONCLUSIONS

The current findings have potential implications for the early diagnosis of esophageal cancer.

Association of hyperglycaemia with periodontal status: Results of the Northern Finland Birth Cohort 1966 study

AIM

To investigate the association of hyperglycaemia and changes in glycaemic control with periodontal status in non-diabetic individuals.

MATERIALS AND METHODS

A sub-population (n = 647) of the Northern Finland Birth Cohort 1966 was studied. We categorized long-term glucose balance based on fasting plasma glucose (FPG) at ages 31 and 46: FPG <5.0 mmol/l (strict normoglycaemia), FPG 5.0-5.59 mmol/l (slightly elevated FPG) and FPG 5.6-6.9 mmol/l (prediabetes). Probing pocket depth (PPD) and alveolar bone level (BL) data were collected at age 46. Relative risks (RR, 95% CI) were estimated using Poisson regression models.

RESULTS

Periodontal status was poorer in individuals whose glucose balance worsened from age 31 to 46 years than in those with a stable glucose balance. In the case of strict normoglycaemia at age 31 and slightly elevated FPG or prediabetes at age 46, the RRs for PPD ≥4 mm were 1.8 (95% CI 1.4-2.2) and 2.8 (95% CI 2.0-3.8) and for BL ≥5 mm 1.1 (95% CI 0.8-1.4) and 1.8 (95% CI 1.2-2.8), respectively.

CONCLUSION

The results of this population-based cohort study suggest that impairment in glucose control in non-diabetic individuals is associated with periodontal pocketing and alveolar bone loss.

Functional haplotype in the Interleukin8 (CXCL8) gene is associated with type 2 Diabetes Mellitus and Periodontitis in Brazilian population

BACKGROUND AND AIM

Type 2 Diabetes Mellitus (T2DM) and Periodontitis (P) are prevalent multifactorial disorders worldwide, sharing a bidirectional relationship influenced by the genetic susceptibility of the host immune system. We investigated whether SNPs in the Interleukin 8 (IL8, alias CXCL8) gene could be associated with T2DM and Periodontitis.

METHODS

Genomic DNA was obtained from 874 Brazilian individuals divided into: Healthy group (n = 307), Periodontitis group (n = 334), and individuals affected by both T2DM and Periodontitis (T2DM_P) group (n = 233). The SNPs -251(T>A) rs4073, +396(T>G) rs2227307 and +781(C>T) rs2227306 were genotyped by TaqMan®. Multiple logistic regressions were used to determine the degree of association between polymorphisms (and haplotypes) with periodontitis and T2DM adjusted for known confounders.

RESULTS

The additive model revealed that the heterozygous AT(-251), GT(+396) and CT(+781) genotypes showed a lower risk for the diseased phenotypes, and carriers of the TTC/TTC haplotype were significantly susceptible to T2DM and Periodontitis concomitantly, as well to isolated Periodontitis (mainly the severe form).

CONCLUSIONS

We concluded, for the first time, that these functional CXCL8 SNPs, and the homozygous TTC haplotype are relevant genetic factors for T2DM and Periodontitis as comorbidities, as well as for severe Periodontitis susceptibility in Brazilian population.