Total antioxidant status and 8-hydroxy-2'-deoxyguanosine levels in gingival and peripheral blood of periodontitis patients

Global trends in research on aging associated with periodontitis from 2002 to 2023: a bibliometric analysis

Background

Aging has been implicated in many chronic inflammatory diseases, including periodontitis. Periodontitis is an inflammatory disease caused by long-term irritation of the periodontal tissues by the plaque biofilm on the surface of the teeth. However, only a few bibliometric analyses have systematically studied this field to date. This work sought to visualize research hot spots and trends in aging associated with periodontitis from 2002 to 2023 through bibliometric approaches.

Methods

Graphpad prism v8.0.2 was used to analyse and plot annual papers, national publication trends and national publication heat maps. In addition, CtieSpace (6.1.6R (64-bit) Advanced Edition) and VOSviewer (version 1.6.18) were used to analyse these data and visualize the scientific knowledge graph.

Results

The number of documents related to aging associated with periodontitis has steadily increased over 21 years. With six of the top ten institutions in terms of publications coming from the US, the US is a major driver of research in this area. journal of periodontology is the most published journal in the field. Tonetti MS is the most prolific authors and co-cited authors in the field. Journal of Periodontology and Journal of Clinical Periodontology are the most popular journals in the field with the largest literature. Periodontitis, Alzheimer's disease, and peri-implantitis are current hot topics and trends in the field. Inflammation, biomarkers, oxidative stress cytokines are current research hotspots in this field.

Conclusion

Our research found that global publications regarding research on aging associated with periodontitis increased dramatically and were expected to continue increasing. Inflammation and aging, and the relationship between periodontitis and systemic diseases, are topics worthy of attention.

Oxidative Stress and FOXO-1 Relationship in Stage III Periodontitis

OBJECTIVES

8-Hydroxideoxyguanosine (8-OHdG) is a marker of oxidative stress, and Forkhead Box-O1 (FOXO1) is a transcription factor and signaling integrator in cell and tissue homeostasis. This study aims to determine FOXO1 and 8-OHdG levels in serum and saliva samples of periodontitis patients and to evaluate their relationship with clinical periodontal parameters.

MATERIALS AND METHODS

Twenty healthy individuals, twenty generalized Stage III Grade B periodontitis patients, and nineteen generalized Stage III Grade C periodontitis patients were included in the study. Clinical periodontal parameters (plaque index (PI), probing depth (PD), bleeding on probing (BOP), and clinical attachment level (CAL)) were recorded. Salivary and serum 8-OHdG and FOX-O1 levels were analyzed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Clinical periodontal parameters showed a statistically significant increase in periodontitis groups compared to the control group (p < 0.05). 8-OHdG salivary levels were significantly higher in both periodontitis groups compared to the control group. The salivary FOXO1 levels were significantly lower in both periodontitis groups compared to the control group. Salivary FOXO1 level had a low-grade negative correlation with BOP and salivary 8-OHdG level.

CONCLUSIONS

While reactive oxygen species increase in periodontal inflammation, low expression of FOXO1, an important transcription factor for antioxidant enzymes, supports that this molecule plays a vital role in tissue destruction, and FOXO1 can be seen as a potential immune modulator.

CLINICAL RELEVANCE

The role of FOXO1 in supporting antioxidant defense may suggest that FOXO1 is a candidate target for periodontitis treatment.

Sports Diet and Oral Health in Athletes: A Comprehensive Review

Food and fluid supply is fundamental for optimal athletic performance but can also be a risk factor for caries, dental erosion, and periodontal diseases, which in turn can impair athletic performance. Many studies have reported a high prevalence of oral diseases in elite athletes, notably dental caries 20-84%, dental erosion 42-59%, gingivitis 58-77%, and periodontal disease 15-41%, caused by frequent consumption of sugars/carbohydrates, polyunsaturated fats, or deficient protein intake. There are three possible major reasons for poor oral health in athletes which are addressed in this review: oxidative stress, sports diet, and oral hygiene. This update particularly summarizes potential sports nutritional effects on athletes' dental health. Overall, sports diet appropriately applied to deliver benefits for performance associated with oral hygiene requirements is necessary to ensure athletes' health. The overall aim is to help athletes, dentists, and nutritionists understand the tangled connections between sports diet, oral health, and oral healthcare to develop mitigation strategies to reduce the risk of dental diseases due to nutrition.

Using 8-Hydroxy-2'-Deoxiguanosine (8-OHdG) as a Reliable Biomarker for Assessing Periodontal Disease Associated with Diabetes

In recent years, research has shown that oxidative stress plays a significant role in chronic inflammatory conditions. The alteration of the oxidant/antioxidant balance leads to the appearance of free radicals, important molecules involved in both diabetes mellitus and periodontal disease. Diabetes is considered to be one of the major risk factors of periodontal disease and the inflammation characterizing this condition is associated with oxidative stress, implicitly resulting in oxidative damage to DNA. 8-Hydroxydeoxyguanosine (8-OHdG) is the most common stable product of oxidative DNA damage caused by reactive oxygen species, and its levels have been reported to increase in body fluids and tissues during inflammatory conditions. 8-OHdG emerges as a pivotal biomarker for assessing oxidative DNA damage, demonstrating its relevance across diverse health conditions, including neurodegenerative disorders, cancers, inflammatory conditions, and periodontal disease. Continued research in this field is crucial for developing more precise treatments and understanding the detailed link between oxidative stress and the progression of periodontitis. The use of the 8-OHdG biomarker in assessing and managing chronic periodontitis is an area of increased interest in dental research, with the potential to provide crucial information for diagnosis and treatment.

The association of aldehyde exposure with the risk of periodontitis: NHANES 2013-2014

OBJECTIVES

Three distinct models were utilized to investigate the combined impacts of serum aldehyde exposure and periodontitis.

MATERIALS AND METHODS

We performed a cross-sectional analysis using data from 525 participants in the 2013-2014 National Health and Nutrition Examination Survey (NHANES). The directed acyclic graphs (DAG) were used to select a minimal sufficient adjustment set of variables (MSAs). To investigate the relationship between aldehydes and periodontitis, we established three models including multiple logistic regression model, restricted cubic spline (RCS) model, and Bayesian kernel machine regression (BKMR) model.

RESULTS

After taking all covariates into account, the multiple logistic regression model revealed that elevated concentrations of isopentanaldehyde and propanaldehyde were strongly associated with periodontitis (isopentanaldehyde: OR: 2.38, 95% CI: 1.34-4.23; propanaldehyde: OR: 1.51, 95% CI: 1.08-2.13). Furthermore, the third tertile concentration of isopentanaldehyde was associated with a 2.04-fold increase in the incidence of periodontitis (95% CI: 1.05-3.95) compared to the first tertile concentration, with a P for trend = 0.04. RCS models showed an "L"-shaped relationship between isopentanaldehyde and periodontitis (P for nonlinear association < 0.01), with inflection point of 0.43 ng/mL. BKMR identified a strong connection between mixed aldehydes and periodontitis, with isopentanaldehyde exhibiting the greatest posterior inclusion probability (PIP) with 0.901 and propanaldehyde exhibiting a PIP with 0.775.

CONCLUSIONS

Isopentanaldehyde and propanaldehyde are positively associated with the risk of periodontitis.

CLINICAL RELEVANCE

Periodontitis may be associated with exposure to mixed aldehyde. This study emphasizes the important role of aldehydes in primary prevention of periodontitis.

Meta-Analysis of Assessment of Total Oxidative Stress and Total Antioxidant Capacity in Patients with Periodontitis

Background

Periodontitis is intricately linked to oxidative stress-antioxidant (redox) imbalance. The antioxidant system scavenges the oxygen free radicals in biological fluids in patients with periodontitis. However, little is still known about the free radicals mediated oxidative stress and reductive ability of the antioxidant system. Thus, the present meta-analysis aims to quantitatively review the literature that assessed the oxidative stress marker total oxidative stress (TOS) and total antioxidant capacity (TAC) in various biological fluids of patients with periodontitis. Methodology. Electronic databases were searched for studies that assessed TOS and TAC levels in various biological samples of patients with periodontitis.

Results

From the 1,812 articles identified, 1,754 were excluded based on title and abstract screening due to irrelevance to the topic of interest. A full-text assessment of the remaining 58 articles led to the selection of 42 articles that satisfied the inclusion criteria. Of these, only 24 studies had consistent data for quantitative analysis. The periodontitis group displayed significantly elevated TOS levels (p < 0.05) in serum, gingival crevicular fluid (GCF), and saliva samples in the studies evaluated. In contrast, the periodontitis group exhibited significantly attenuated TAC levels (p < 0.01) compared to healthy controls in plasma, serum, and GCF samples of the studies evaluated, which was insignificant in salivary samples (p=0.433). At the same time, the periodontitis group displayed insignificantly elevated TAC levels after periodontal therapy (p=0.130).

Conclusions

The present meta-analysis showed significantly higher TOS and lower TAC in periodontitis, reflecting the elevated oxidative stress level than the control group. Clinical Relevance. Scientific rationale for the study: The imbalance between oxidants and antioxidants (oxidative stress (OS)) plays a critical role in the onset and progression of periodontitis; the assessment of the relationship between OS-related biomarkers in regional samples and systemic samples of patients with periodontitis helps us to evaluate the periodontal disease progression. The OS biomarker levels can be used to assess periodontal disease and therapeutic efficacy.

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.

Biomarkers for diagnosis of stage III, grade C with molar incisor pattern periodontitis in children and young adults: a systematic review and meta-analysis

AIM

To explore the existing salivary, gingival crevicular fluid (GCF), blood, and serum biomarkers associated with grade C molar-incisor pattern (C/MIP) periodontitis in systemically healthy children and young adults.

MATERIALS AND METHODS

Cross-sectional, case-control, and cohort studies on stage III grade C periodontitis or former equivalent diagnosis with analysis of molecular biomarkers in saliva, GCF, blood, or serum were retrieved from six databases and screened based on the eligibility criteria. The risk of bias in included studies was evaluated. Meta-analysis was planned for biomarkers assessed using the same detection methods and sample type in at least two papers.

RESULTS

Out of 5621 studies identified at initial screening, 28 papers were included in the qualitative analysis of which 2 were eligible for meta-analysis for IgG in serum samples. Eighty-seven biomarkers were assessed with the majority being higher in cases than in controls. Only the meta-analysis of total serum IgG with low heterogeneity value revealed a significant increase in its levels in C/MIPs compared to controls (standardised mean difference: 1.08; 95% CI: 0.76, 1.40).

CONCLUSION

There is a paucity of data on biomarkers associated with molar-incisor pattern periodontitis. Although serum IgG levels are raised, other more specific biomarkers in saliva, GCF, and blood/serum may be promising but require further investigation.

Association between plasma trans fatty acids and chronic periodontitis: Results from a nationally representative cross-sectional survey

BACKGROUND

Trans fatty acid (TFA) consumption has been reported to harbor proinflammatory characteristics and increasing oxidative stress properties, but there has been little research into its association with periodontitis. This study aimed to explore the potential association between TFAs and periodontitis.

METHODS

This large population-based study included participants from the National Health and Nutrition Examination Survey (2009-2010). Weighted binary and ordinal logistic regressions were used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) to evaluate the relationship between plasma TFAs and periodontitis.

RESULTS

A total of 1433 eligible participants, 793 (55.3%) participants with periodontitis and 640 (44.7%) without periodontitis were included. Univariate logistic regression revealed significant associations between plasma trans-11-octadecenoic acid, trans-9-octadecenoic acid, the sum of trans-octadecenoic acids, and the sum of TFAs and periodontitis (all P < 0.01). After controlling for the potential confounders, these four types of TFAs remained significantly associated with periodontitis (the ORs and 95% CIs per interquartile range increase were 1.16 (1.01-1.33), 1.20 (1.03-1.39), 1.18 (1.02-1.35), and 1.17 (1.01-1.35), respectively). Notably, these positive associations were more pronounced among overweight/obese populations. Additionally, plasma trans-9-octadecenoic acid levels were found to be associated with periodontitis severity.

CONCLUSIONS

This study suggests a significant positive association between certain plasma TFAs and chronic periodontitis, especially among overweight/obese populations. These findings provide new insights into periodontitis prevention from a dietary perspective.

Research efficacy of gaseous ozone therapy as an adjuvant to periodontal treatment on oxidative stress mediators in patients with type 2 diabetes: a randomized clinical trial

BACKGROUND

Chronic inflammation and cumulative oxidative stress have been theorized as two common pathways of the interconnection between periodontitis and diabetes. Improvement in oxidizing status has been demonstrated in periodontal patients with diabetes treated with proper non-surgical periodontal treatment. In addition to periodontal treatment, Gaseous ozone therapy has been reported to possess anti-inflammatory properties and the ability to stimulate the endogenous antioxidant defence mechanism. To date, the antioxidant effect of gaseous ozone, in addition with periodontal treatment in diabetic patients, has been examined in only one study. The aim of this study was to determine the efficacy of gaseous ozone therapy as an alternative approach to supporting non-surgical periodontal therapy (NSPT), aimed at improving antioxidant machinery and interfering with ROS production on plasma levels in diabetic individuals diagnosed with moderate or severe periodontitis.

METHODS

One hundred and eighty patients with periodontitis and type 2 diabetes mellitus were randomly assigned to receive non-surgical periodontal treatment (NSPT) plus gaseous ozone therapy (A) NSPT alone (B). Clinical and periodontal parameters -Bleeding on probing (BOP), Periodontal pocket depth (PPD), and Clinical attachment Level (CAL)- and plasma levels of oxidant-antioxidant (TOS- TAOS) levels, glutathione (GSH), and malondialdehyde (MDA) were recorded at baseline and at 3- (T1) and at 6-months (T2) after treatment.

RESULTS

Both treatments were efficacious in reducing clinical parameters. However, there were no significant differences regarding oxidative stress parameters in group A compared to group B.

CONCLUSIONS

In the present study, gaseous ozone therapy did not enhance the effect of periodontal treatment in reducing oxidative stress in plasma levels of periodontitis patients with type II diabetes.

TRIAL REGISTRATION

The study was registered with ISRCTN1728169 (23/07/2022).

Beneficial Effects of Melatonin on Periodontitis Management: Far More Than Oral Cavity

Periodontitis as a highly prevalent chronic infection/inflammatory disease can eventually lead to tooth loss and masticatory dysfunction. It also has a negative impact on general health and largely impairs quality of life. The tissue destruction during periodontitis is mainly caused by the excessive immune-inflammatory response; hence, how to modulate the host's reaction is of profound importance for effective periodontal treatment and tissue protection. Melatonin, as an endogenous hormone exhibiting multiple biological functions such as circadian rhythm regulation, antioxidant, and anti-inflammation, has been widely used in general healthcare. Notably, the past few years have witnessed increasing evidence for the application of melatonin as an adjunctive approach in the treatment of periodontitis and periodontitis-related systemic comorbidities. The detailed underlying mechanisms and more verification from clinical practice are still lacking, however, and further investigations are highly required. Importantly, it is essential to establish standard guidelines in the near future for the clinical administration of melatonin for periodontal health and general wellbeing.

The role of Nrf2 in periodontal disease by regulating lipid peroxidation, inflammation and apoptosis

Nuclear factor E2-related factor 2(Nrf2) is a transcription factor that mainly regulates oxidative stress in the body. It initiates the expression of several downstream antioxidants, anti-inflammatory proteins and detoxification enzymes through the Kelch-like ECH-associating protein 1 (Keap1) -nuclear factor E2-related factor 2(Nrf2) -antioxidant response element (ARE) signaling pathway. Its anti-apoptosis, anti-oxidative stress and anti-inflammatory effects have gradually become the focus of periodontal disease research in recent years. In this paper, the structure and function of Nrf2 pathway and its mechanism of action in the treatment of periodontitis in recent years were analyzed and summarized, so as to further clarify the relationship between Nrf2 pathway and oxidative stress in the occurrence and development of periodontitis, and to provide ideas for the development of new treatment drugs targeting Nrf2 pathway.

Association of SRXN1 Receptor Gene Polymorphism with Susceptibility to Periodontitis

Background

Emerging evidence suggests that oxidative stress forms a key component in the etiopathogenesis of periodontitis. Literature evidence have shown potential antioxidants responsible for combating the pro-oxidants which stress the periodontium, but the peroxiredoxin-sulfiredoxin system is explored very minimally in periodontal disease. Thus, the present study was aimed to evaluate the genetic association of SRXN1 receptor gene polymorphism (rs6053666).

Materials and Methods

A total of 100 subjects were recruited for this study, which included 50 Periodontitis patients (Stage II and above based on the criteria of American Association of Periodontology-2018) and 50 periodontally healthy or mild gingivitis. Genomic DNA was extracted from the whole blood collected from the subjects. DNA was amplified using specific primers flanking the BtgI region of the SRXN1 receptor gene. The amplicon was further subjected to genotyping using restriction fragment length using BtgI enzyme. The genotype obtained based on the restriction fragment length polymorphism pattern was recorded and used for statistical analysis. The distribution of genotypes and allele frequencies in the periodontitis and control groups were compared using the Chi-square test. The risk associated with individual alleles or genotypes was calculated as the odds ratio with 95% confidence intervals. Statistical significance in all tests was determined at P < 0.05.

Results

The genotype frequency and distributions of SRXN1 receptor BtgI polymorphism did not differ significantly at ꭕ2df (P = 0.557). Our study results showed that homozygous and heterozygous mutant genotypes had no significant difference (CC vs. CT + TT) between the periodontitis patients and control group with a P = 0.4266. The detected frequency of CT (38% vs. 34%) and TT (42% vs. 52%) genotype showed no significant difference between control and test group. There was no significant difference in C allele (39% vs. 31%) and T allele (61% vs. 69%) between the test and control group.

Conclusion

The present study denotes that SRXN1 receptor gene polymorphism is not associated with periodontitis in the study group analyzed.

Effects of Nonsurgical Periodontal Therapy on Salivary 8-Hydroxy-Deoxyguanosine Levels and Glycemic Control in Diabetes Mellitus Type 2 Patients

Diabetes and periodontitis are complex chronic diseases that are potentially interrelated, as well as associated with oxidative stress. Thus, the aim of the present study was to evaluate the influence of nonsurgical periodontal treatment on salivary 8-hydroxy-deoxyguanosine (8-OHdG) levels and glycemic control in patients suffering from both diabetes mellitus type 2 (DM2) and periodontitis. The study sample included 53 DM2 patients, while 31 systemically healthy patients served as controls. Participants in both groups suffered from periodontitis of comparable severity. Periodontal clinical parameters, namely plaque index (PI), gingival index (GI), papilla bleeding index (PBI), probing pocket depth (PPD), and clinical attachment level (CAL) were recorded, along with salivary 8-OHdG levels and glycated hemoglobin (HbA1c). Levels of 8-OHdG were analyzed by ELISA. All aforementioned parameters were evaluated prior to commencing the study and at 90-day follow-up upon nonsurgical periodontal therapy completion. At baseline, salivary levels of 8-OHdG in DM2 patients were significantly higher (1.17 ng/mL) than those measured for the control group (0.75 ng/mL) and showed significant positive correlation with GI and PPD (p < 0.05). Three months after nonsurgical periodontal therapy, the salivary 8-OHdG levels were significantly reduced in DM2 patients (p < 0.05). Analysis results also revealed statistically significant changes in all measured clinical parameters between baseline and three-month follow-up in both groups (p < 0.05). Upon treatment completion, a decline in the HbA1c level was noted in DM group, but it did not reach statistical significance (p > 0.05). It can be concluded that DM2 patients benefit from non-surgical periodontal therapy, as indicated by a marked reduction in their salivary 8-OHdG level and a modest improvement in glycemic control. Short-term clinical benefits noted in the DM group were similar to those observed in the non-diabetic periodontal patients.

Osteoporosis and periodontal diseases - An update on their association and mechanistic links

Periodontitis and osteoporosis are prevalent inflammation-associated skeletal disorders that pose significant public health challenges to our aging population. Both periodontitis and osteoporosis are bone disorders closely associated with inflammation and aging. There has been consistent intrigue on whether a systemic skeletal disease such as osteoporosis will amplify the alveolar bone loss in periodontitis. A survey of the literature published in the past 25 years indicates that systemic low bone mineral density (BMD) is associated with alveolar bone loss, while recent evidence also suggests a correlation between clinical attachment loss and other parameters of periodontitis. Inflammation and its influence on bone remodeling play critical roles in the pathogenesis of both osteoporosis and periodontitis and could serve as the central mechanistic link between these disorders. Enhanced cytokine production and elevated inflammatory response exacerbate osteoclastic bone resorption while inhibiting osteoblastic bone formation, resulting in a net bone loss. With aging, accumulation of oxidative stress and cellular senescence drive the progression of osteoporosis and exacerbation of periodontitis. Vitamin D deficiency and smoking are shared risk factors and may mediate the connection between osteoporosis and periodontitis, through increasing oxidative stress and impairing host response to inflammation. With the connection between systemic and localized bone loss in mind, routine dental exams and intraoral radiographs may serve as a low-cost screening tool for low systemic BMD and increased fracture risk. Conversely, patients with fracture risk beyond the intervention threshold are at greater risk for developing severe periodontitis and undergo tooth loss. Various Food and Drug Administration-approved therapies for osteoporosis have shown promising results for treating periodontitis. Understanding the molecular mechanisms underlying their connection sheds light on potential therapeutic strategies that may facilitate co-management of systemic and localized bone loss.

Biomarkers of non-communicable chronic disease: an update on contemporary methods

Chronic diseases constitute a major global burden with significant impact on health systems, economies, and quality of life. Chronic diseases include a broad range of diseases that can be communicable or non-communicable. Chronic diseases are often associated with modifications of normal physiological levels of various analytes that are routinely measured in serum and other body fluids, as well as pathological findings, such as chronic inflammation, oxidative stress, and mitochondrial dysfunction. Identification of at-risk populations, early diagnosis, and prediction of prognosis play a major role in preventing or reducing the burden of chronic diseases. Biomarkers are tools that are used by health professionals to aid in the identification and management of chronic diseases. Biomarkers can be diagnostic, predictive, or prognostic. Several individual or grouped biomarkers have been used successfully in the diagnosis and prediction of certain chronic diseases, however, it is generally accepted that a more sophisticated approach to link and interpret various biomarkers involved in chronic disease is necessary to improve our current procedures. In order to ensure a comprehensive and unbiased coverage of the literature, first a primary frame of the manuscript (title, headings and subheadings) was drafted by the authors working on this paper. Second, based on the components drafted in the preliminary skeleton a comprehensive search of the literature was performed using the PubMed and Google Scholar search engines. Multiple keywords related to the topic were used. Out of screened papers, only 190 papers, which are the most relevant, and recent articles were selected to cover the topic in relation to etiological mechanisms of different chronic diseases, the most recently used biomarkers of chronic diseases and finally the advances in the applications of multivariate biomarkers of chronic diseases as statistical and clinically applied tool for the early diagnosis of chronic diseases was discussed. Recently, multivariate biomarkers analysis approach has been employed with promising prospect. A brief discussion of the multivariate approach for the early diagnosis of the most common chronic diseases was highlighted in this review. The use of diagnostic algorithms might show the way for novel criteria and enhanced diagnostic effectiveness inpatients with one or numerous non-communicable chronic diseases. The search for new relevant biomarkers for the better diagnosis of patients with non-communicable chronic diseases according to the risk of progression, sickness, and fatality is ongoing. It is important to determine whether the newly identified biomarkers are purely associations or real biomarkers of underlying pathophysiological processes. Use of multivariate analysis could be of great importance in this regard.

Presence of periodontal pathogenic bacteria in blood of patients with coronary artery disease

It has been hypothesised that oral bacteria can migrate, through the blood, from the mouth to the arterial plaques, thus exacerbating atherosclerosis. This study compared bacteria present in the peripheral blood of individuals with and without coronary artery disease (CAD). RNA sequences obtained from blood were downloaded from GEO (GSE58150). Eight patients with coronary artery calcification (CAC) scoring > 500 and eight healthy individuals were analysed. After conducting quality control, the sequences were aligned to the hg38 reference genome using Hisat2. Bacterial taxa were analysed by inputting the unmapped sequences into Kraken. Ecological indices were calculated using Vegan. The package DESeq2 was used to compare the counts of bacteria per standard rank between groups. A total of 51 species were found only in patients with CAD and 41 were exclusively present in healthy individuals. The counts of one phylum, one class, three orders, two families and one genus were significantly different between the analysed groups (p < 0.00032, FDR < 10%), including the orders Cardiobacteriales, Corynebacteriales and Fusobacteriales. Twenty-three bacterial species belonging to the subgingival plaque bacterial complexes were also identified in the blood of individuals from both the groups; Fusobacterium nucleatum was significantly less frequent in patients with CAD (p = 0.0012, FDR = 4.8%). Furthermore, the frequency of another 11 bacteria differed significantly among patients with CAD than that among healthy individuals (p < 0.0030, FDR < 10%). These bacteria have not been previously reported in patients with atherosclerosis and periodontitis. The presence of members of the subgingival plaque bacterial complexes in the blood of patients with CAC supports the hypothesis that the periodontopathogens can be disseminated through the blood flow to other body parts where they may enhance inflammatory processes that can lead to the development or exacerbation of atherosclerosis.

Inhibiting PHD2 in human periodontal ligament cells via lentiviral vector-mediated RNA interference facilitates cell osteogenic differentiation and periodontal repair

Periodontal defect regeneration in severe periodontitis remains a challenging task in clinic owing to poor survival of seed cells caused by the remaining oxidative stress microenvironment. Recently, the reduction of prolyl hydroxylase domain-containing protein 2 (PHD2), a primary cellular oxygen sensor, has shown an incredible extensive effect on skeletal muscle tissue regeneration by improving cell resistance to reactive oxygen species, whereas its role in periodontal defect repair is unclear. Here, through lentivirus vector-mediated RNA interference, the PHD2 gene in human periodontal ligament cells (hPDLCs) is silenced, leading to hypoxia-inducible factor-1α stabilization in normoxia. In vitro, PHD2 silencing not only exhibited a satisfactory effect on cell proliferation, but also induced distinguished osteogenic differentiation of hPDLCs. Real-time polymerase chain reaction and Western blotting revealed significant up-regulation of osteocalcin, alkaline phosphatase (ALP), runt-related transcription factor 2, and collagen type I (COL I). Under oxidative stress conditions, COL I and ALP expression levels, suppressed by 100 μM H₂ O₂ , were elevated by PHD2-gene-silencing in hPDLCs. In vivo, periodontal fenestration defects were established in 18 female Sprague-Dawley rats aged 6 wk old, followed by implantation of PHD2 silencing hPDLCs in situ for 21 d. Persistent and stable silencing of PHD2 in hPDLCs promoted better new bone formation according to microcomputed tomography 3D reconstruction and related bone parameter analysis. This work demonstrates the therapeutic efficiency of PHD2 gene interference in osteogenic differentiation and periodontal defect repair for highly efficient periodontal regeneration.

Febuxostat Attenuates the Progression of Periodontitis in Rats

INTRODUCTION

Periodontitis is a lifestyle-related disease that is characterized by chronic inflammation in gingival tissue. Febuxostat, a xanthine oxidase inhibitor, exerts anti-inflammatory and antioxidant effects.

OBJECTIVE

The present study investigated the effects of febuxostat on periodontitis in a rat model.

METHODS

Male Wistar rats were divided into 3 groups: control, periodontitis, and febuxostat-treated periodontitis groups. Periodontitis was induced by placing a ligature wire around the 2nd maxillary molar and the administration of febuxostat (5 mg/kg/day) was then initiated. After 4 weeks, alveolar bone loss was assessed by micro-computed tomography and methylene blue staining. The expression of osteoprotegerin (OPG), a bone resorption inhibitor, was detected by quantitative RT-PCR and immunological staining, and the number of osteoclasts in gingival tissue was assessed by tartrate-resistant acid phosphatase staining. The mRNA and protein expression levels of the proinflammatory cytokines, tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β), in gingival tissue were measured using quantitative RT-PCR and immunological staining. Oxidative stress in gingival tissue was evaluated by the expression of 4-hydroxy-2-nonenal (4-HNE), and 8-hydroxy-2-deoxyguanosine (8-OHdG). To clarify the systemic effects of periodontitis, blood pressure and glucose tolerance were examined.

RESULTS

In rats with periodontitis, alveolar bone resorption was associated with reductions in OPG and increases in osteoclast numbers. The gingival expression of TNF-α, IL-1β, 4-HNE, and 8-OHdG was up-regulated in rats with periodontitis. Febuxostat significantly reduced alveolar bone loss, proinflammatory cytokine levels, and oxidative stress. It also attenuated periodontitis-induced glucose intolerance and blood pressure elevations.

CONCLUSION

Febuxostat prevented the progression of periodontitis and associated systemic effects by inhibiting proinflammatory mediators and oxidative stress.

Inflammation in Periodontal Disease: Possible Link to Vascular Disease

Inflammation is a well-organized protective response to pathogens and consists of immune cell recruitment into areas of infection. Inflammation either clears pathogens and gets resolved leading to tissue healing or remains predominantly unresolved triggering pathological processes in organs. Periodontal disease (PD) that is initiated by specific bacteria also triggers production of inflammatory mediators. These processes lead to loss of tissue structure and function. Reactive oxygen species and oxidative stress play a role in susceptibility to periodontal pathogenic bacterial infections. Periodontal inflammation is a risk factor for systemic inflammation and eventually cardiovascular disease (CVD). This review discusses the role of inflammation in PD and its two way association with other health conditions such as diabetes and CVD. Some of the mechanisms underpinning the links between inflammation, diabetes, CVD and PD are also discussed. Finally, we review available epidemiological data and other reports to assess possible links between oral health and CVD.

THE INFLUENCE OF PERIODONTAL DISEASE TREATMENT ON 8-HYDROXY-DEOXYGUANOSINE CONCENTRATIONS IN SALIVA AND PLASMA OF CHRONIC PERIODONTITIS PATIENTS

The 8-hydroxy-deoxyguanosine (8-OHdG) is one of the customary products of oxidized DNA. The purpose of this study was to compare salivary and plasma 8-OHdG concentrations in a group of chronic periodontitis patients to those measured in a group of patients with healthy periodontium, as well as to determine the impact of periodontal therapy on 8-OHdG concentrations in saliva and plasma in chronic periodontitis patients. The study sample comprised of 24 patients with chronic periodontitis and 16 periodontally healthy individuals. Plaque index, gingival index, papilla bleeding index, probing depth and clinical attachment level were indices used to determine patient periodontal status. Salivary and plasma 8-OHdG concentrations were determined by ELISA method. The salivary 8-OHdG concentration was statistically significantly higher in the group of periodontitis patients compared to periodontally healthy subjects. After initial periodontal therapy, the 8-OHdG concentration in saliva was significantly reduced in the periodontitis group (p=0.021). Differences in plasma 8-OHdG concentrations between the two groups did not reach statistical significance and no significant changes were noted in the periodontitis group following initial periodontal therapy. A higher salivary 8-OHdG concentration reflects increased oxidative stress caused by periodontal disease. Initial periodontal therapy may be helpful in reducing salivary 8-OHdG concentrations in chronic periodontitis patients.

Periodontitis is an inflammatory disease of oxidative stress: We should treat it that way

Periodontitis is a highly prevalent disease. As it progresses, it causes serious morbidity in the form of periodontal abscesses and tooth loss and, in the latter stages, pain. It is also now known that periodontitis is strongly associated with several nonoral diseases. Thus, patients with periodontitis are at greater risk for the development and/or exacerbation of diabetes, chronic obstructive pulmonary disease, and cardiovascular diseases, among other conditions. Although it is without question that specific groups of oral bacteria which populate dental plaque play a causative role in the development of periodontitis, it is now thought that once this disease has been triggered, other factors play an equal, and possibly more important, role in its progression, particularly in severe cases or in cases that prove difficult to treat. In this regard, we allude to the host response, specifically the notion that the host, once infected with oral periodontal pathogenic bacteria, will mount a defense response mediated largely through the innate immune system. The most abundant cell type of the innate immune system - polymorphonuclear neutrophils - can, when protecting the host from microbial invasion, mount a response that includes upregulation of proinflammatory cytokines, matrix metalloproteinases, and reactive oxygen species, all of which then contribute to the tissue damage and loss of teeth commonly associated with periodontitis. Of the mechanisms referred to here, we suggest that upregulation of reactive oxygen species might play one of the most important roles in the establishment and progression of periodontitis (as well as in other diseases of inflammation) through the development of oxidative stress. In this overview, we discuss both innate and epigenetic factors (eg, diabetes, smoking) that lead to the development of oxidative stress. This oxidative stress then provides an environment conducive to the destructive processes observed in periodontitis. Therefore, we shall describe some of the fundamental characteristics of oxidative stress and its effects on the periodontium, discuss the diseases and other factors that cause oxidative stress, and, finally, review potentially novel therapeutic approaches for the management (and possibly even the reversal) of periodontitis, which rely on the use of therapies, such as resveratrol and other antioxidants, that provide increased antioxidant activity in the host.

Gender Differences in the Levels of Periodontal Destruction, Behavioral Risk Factors and Systemic Oxidative Stress in Ischemic Stroke Patients: A Cohort Pilot Study

Background: Due to the higher frequency of ischemic stroke in men compared to women, we aimed to determine if gender differences exist regarding periodontal status and several plasma biomarkers in patients with a recent large artery atherosclerosis ischemic stroke (IS). Material and methods: Patients with their first IS within less than six weeks who were able to undergo periodontal examinations were evaluated. Demographic data, periodontal status, oxidative stress parameters/plasma antioxidant capacity, and C-reactive protein in patients who suffered a recent large artery atherosclerosis ischemic stroke were reccorded. Results: 93 patients were included in the study. More men were smokers (12/57 vs. 3/36) and consumed alcohol (17/57 vs. 3/36), and more women had higher glycemic values (p = 0.023), total cholesterol (p < 0.001), LDL (low-density lipoprotein)-cholesterol (p = 0.010), and HDL (high-density lipoprotein)-cholesterol (p = 0.005) levels. Significantly more men than women had moderate plus severe periodontal disease (p = 0.018), significantly higher levels of nitric oxide (p = 0.034), and significantly lower levels of total antioxidant capacity (p = 0.028). Conclusions: In this pilot study, men seem to be more prone to oxidative stress and to develop more severe forms of periodontitis among patients with stroke, but the results need validation on a larger sample.

Total Oxidant and Antioxidant Capacity of Gingival Crevicular Fluid and Saliva in Patients with Periodontitis: Review and Clinical Study

Periodontitis is inextricably linked to oxidative-reductive (redox) imbalance. However, little is still known about the resultant ability to scavenge oxygen free radicals in saliva and gingival crevicular fluid in patients with periodontitis. The multitude of enzymatic and non-enzymatic antioxidants and their synergistic effects cause an interest in the evaluation of the total antioxidative capacity. Thus, our study aimed to evaluate the total oxidative and antioxidative activity of gingival crevicular fluid and saliva in the periodontitis, as well as to relate these biomarkers to clinical indices of periodontopathy. Additionally, by calculating the oxidative stress index (OSI), the intensity of redox disturbances was also evaluated. Fifty-eight periodontitis patients were included in the study and divided into two subgroups depending on the severity of the disease. In the non-stimulated/stimulated saliva as well as a gingival crevicular fluid of the study group, we found significantly higher OSI and total oxidant status (TOS) as well as lower total antioxidant capacity (TAC). However, the ability to reduce iron ions (FRAP) was significantly lower only in stimulated and non-stimulated saliva of patients with periodontitis. The examined parameters correlated with the periodontium’s clinical condition, which indicates the exacerbation of the inflammatory process. However, TAC, TOS, OSI, and FRAP did not differentiate individual stages of periodontitis.

Molecular inflammation and oxidative stress are shared mechanisms involved in both myocardial infarction and periodontitis

BACKGROUND AND OBJECTIVE

Our aims were to improve the understanding of the pathogenic relationship between cardiovascular diseases and periodontitis and to generate new perspectives in the prevention and treatment of acute myocardial infarction (AMI) and periodontitis. The present study evaluates possible differences in inflammation, oxidative stress, and autophagy markers among subject suffering AMI, periodontitis, or both, to explore possible common pathogenic mechanisms.

MATERIAL AND METHODS

A total of 260 subjects were enrolled in the study: 106 subjects that survived to a first AMI (AMI group) and 154 subjects had no cardiac events in their clinical record (control group). A questionnaire was used to assess age, height, weight, blood pressure, and heart rate. The clinical probing depth, clinical attachment loss, number of remaining teeth, and average number of sites with bleeding on probing were assessed. Lipid peroxidation and protein levels of phosphorylated AMP-activated protein kinase (p-AMPK) and microtubule-associated proteins 1A/1B-light chain 3-II (LC3-II) were determined in isolated peripheral blood mononuclear cells by thiobarbituric acid reactive substances (TBARS) assay and Western blot, respectively. Plasma levels of interleukin-1β were determined using a commercial ELISA kit. All the obtained variables were compared between subjects suffering an AMI with or without periodontitis and control subject periodontal healthy or with periodontitis.

RESULTS

A higher proportion of subjects suffering AMI + periodontitis than only AMI (without periodontitis) was found. Higher levels of TBARS were found in subjects with periodontitis than in subjects without periodontitis in both AMI and control subjects. Positive correlations between IL-1β levels and TBARS and between IL-1β levels and LC3-II were found only in control subjects.

CONCLUSION

Results from the present study are consistent with the suggestion of periodontitis as a potential risk factor for AMI. Periodontitis association with circulating lipid peroxides in both AMI and control subjects were found. The absence of differences in IL-1β levels between AMI subjects (only AMI vs AMI + periodontitis) suggests that oxidative stress could be the main pathogenic link between AMI and periodontitis.

Clinical, microbiological and oxidative stress evaluation of periodontitis patients treated with two regimens of systemic antibiotics, adjunctive to non-surgical therapy: A placebo-controlled randomized clinical trial

Aim of research was to evaluate and compare the clinical and microbiological effects of two different regimens of amoxicillin (AMX) and metronidazole (MTZ) combined with non-surgical periodontal therapy in patients with chronic periodontitis (CP), and identify antibiotic-resistant bacteria and changes in oxidative stress (OS). Forty-six patients with generalized CP were randomly assigned to group A [scaling and root planing within 24 h (SRP) + placebo for 7 days), group B [SRP + AMX + MTZ, both 500 mg three times daily (TID), 3 days), and group C [SRP + AMX + MTZ, both 500 mg TID, 7 days). Periodontal pocket depth (PPD-primary outcome), clinical attachment level (CAL), full-mouth bleeding scores (FMBS), plaque scores (FMPS), blood and subgingival plaque were assessed at baseline and after three months. OS was evaluated via derivatives of reactive oxygen metabolites (d-ROMs) and assessments of biological antioxidant potential (BAP). Bacterial profiling was performed by PCR. Antibiotic resistance was evaluated in cultures. PPD, CAL, number of sites with PPD ≥6 mm, their PPD, CAL and FMBS decreased (P<0.05) in all groups, as well as FMPS in groups A and B, and d-ROMs in group C. There were significant differences among groups regarding decreases in the frequency of detection for Aa and Tf. For Aa, there were differences between groups A and C (P=0.048) and between groups B and C (P=0.048), but not between groups A and B; whereas for Tf, groups A and B were different from group C (P<0.001), but not from each other (P=0.920). No resistance to AMX was identified prior to treatment; two strains were resistant after treatment. Before treatment, 13 strains were resistant to MTZ, and 2 were resistant after. One strain in the same patient was sensitive prior to treatment, and later became resistant to both antibiotics. SRP with a 7-day course of antibiotic therapy was more effective for improving clinical parameters, in decrease of detection of several periopathogens, and in improvement of OS when compared to a 3-day regimen. Resistance was found in fewer strains after treatment than before.

Periodontal disease and hemolysis in glucose-6-phosphate dehydrogenase deficiency: Is there a nexus?

BACKGROUND

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an erythrocyte enzyme defect that amplifies the susceptibility of erythrocytes to oxidative stress due to excessive levels of reactive oxygen species. Consequently, erythrocyte destruction and hemolysis occur.

HIGHLIGHT

The possible mechanism of oxidative stress-mediated destruction of erythrocytes in G6PD deficient individuals induced by periodontal infection is highlighted.

CONCLUSION

Periodontal diseases feature systemic loading of reactive oxygen species, and they may increase the risk of hemolysis in individuals with G6PD deficiency.

Protein carbonyl levels in serum, saliva and gingival crevicular fluid in patients with chronic and aggressive periodontitis

Objective

This study aims at evaluating the degree of protein carbonyl (PC) levels in serum, gingival crevicular fluid (GCF) and saliva in patients who suffer from chronic periodontitis (CP) and generalized aggressive periodontitis (GAP).

Materials and methods

A total of 110 individuals took part in the study. Of this number, 35 were CP patients, 43 GAP patients, and the remaining 32 were healthy controls. Measurements regarding the serum, saliva and GCF PC levels were obtained by high-performance liquid chromatography.

Results

No statistically significant difference was found in serum PC levels between the groups (P > 0.05). In terms of salivary levels, the CP group demonstrated a significantly higher level (P < 0.05) of PC level compared to the GAP group. However, the difference was not found statistically significant when the comparison was drawn with the control group (p > 0.05).

The GCF PC level in the CP group had a significantly higher level of concentration compared to the other groups (P < 0.05), whereas the relevant values in the control group were higher than the values in the GAP group (P < 0.05). GCF PC total values (/30 s) were higher in the CP group than the remaining groups (P < 0.05), whereas the relevant values in the GAP group were higher than the values in the control group (P < 0.05). It could be stated that GCF PC levels were significantly correlated, either positively or negatively, with all clinical periodontal parameters (p < 0.05).

Conclusions

The results obtained suggest that PC levels of serum and salivary in periodontitis, when compared to periodontal health, do not seem to change considerably. However, in the CP group, a statistically significant increase in PC levels of GCF was observed. This finding suggests the salient role of local protein carbonylation in the periodontal area in CP. That the CP group had a higher level of PC level than the GAP group underscores the higher protein oxidation levels in CP patients.

The effect of periodontal therapy on oxidative stress biomarkers: A systematic review

AIM

To systematically review the literature about the effect of periodontal treatment on oxidative stress (OxS) biomarkers.

MATERIAL AND METHODS

Three databases (PubMed, EMBASE, and Scopus) were searched up to February 2018. Clinical trials with a follow-up of at least 6 weeks after mechanical periodontal treatment were included. Due to the high heterogeneity among the units and indices of measurements used in the studies, a meta-analysis was not performed.

RESULTS

Overall, 3,199 studies were retrieved, of which 20 were included. Four studies were randomized clinical trials (RCT), and 16 studies were non-RCTs. The most common OxS biomarkers used were 8-hydroxydeoxiguanosine (8-OHdG), total oxidant status (TOS), and total antioxidant status (TAS). After treatment, most of the studies reported a decrease in 8-OHdG concentration in the gingival crevicular fluid (GCF) and saliva. In addition, the salivary concentration of this biomarker was similar to periodontally healthy patients. Periodontal therapy was effective in reducing TOS in GCF, saliva, and serum in most studies. TAS, however, responded inconsistently to the periodontal intervention.

CONCLUSION

Periodontal therapy reduces the levels of OxS biomarkers, even to values similar to those found in periodontally healthy individuals. Additional RCTs are warranted, as the information is mainly based on nonrandomized studies.

Effects of Chicory Leaf Extract on Serum Oxidative Stress Markers, Lipid Profile and Periodontal Status in Patients With Chronic Periodontitis

AIM

The aim of present study was to evaluate the effects of chicory leaf extract on serum oxidative stress markers, lipid profile, and periodontal status in patients with chronic periodontitis.

METHODS

In this double-blind, randomized controlled clinical trial 40 patients with chronic periodontitis were allocated to intervention and control groups. The intervention group received a 1-gram chicory leaf methanolic extract capsule twice daily for 8 weeks. In the control group, participants received a placebo capsule (containing 1 gram wheat flour) twice daily for 8 weeks. All participants had nonsurgical periodontal therapy during the study. Anthropometric measurements, dietary intake, total antioxidant capacity (TAC), malondialdehyde (MDA), uric acid, lipid profile (total cholesterol [TC], triglycerides [TG], low-density lipoprotein cholesterol [LDL-C], and high-density lipoprotein cholesterol [HDL-C]), and pocket depth (PD) were assessed before and after intervention.

RESULTS

The results showed that mean serum TAC, uric acid, and HDL-C increased and mean serum MDA, TG, LDL-C, and TC decreased significantly in the intervention group compared to their baseline and the control group post-intervention. A significant difference was observed in mean PD between the two groups.

CONCLUSION

Chicory leaf extract as an adjunct nutritional approach with nonsurgical periodontal therapy may be helpful in controlling periodontal status.

A randomised study in young subjects of the effects of eating extra fruit or nuts on periodontal inflammation

Objectives/Aims:

Fruit is often advocated as a healthy source of nutrients and vitamins. However, the high contents of sugars in many fruits could potentially counteract positive effects on the teeth.

Materials and methods:

We recruited 30 healthy non-obese participants who were randomised to either supplement their diet with extra fruits or nuts, each at +7 kcal/kg body weight/day, for 2 months.

Results:

Fructose intake increased from 9.1±6.0 to 25.6±9.6 g/day, P<0.0001, in the fruit group and was reduced from 12.4±5.7 to 6.5±5.3 g/day, P=0.007, in the nut group. Serum-vitamin C increased in both groups (fruit: P=0.017; nuts: P=0.009). α-Tocopherol/cholesterol ratio increased in the fruit group (P=0.0033) while β-carotene/cholesterol decreased in the nut group (P<0.0001). The amount of subjects with probing pocket depths ⩾4 mm in the fruit group was reduced (P=0.045) according to blinded examinations, and the difference in the changes in probing pockets ⩾4 mm was also statistically significant between the food groups (P=0.010).

Conclusion:

A large increase of fruit intake, compared with nuts, had a favourable effect on periodontal status in some respects, despite the high sugar contents. To search for potential protective micronutrients in fruit that protect the teeth could be an aim for further research.

Impact of nonsurgical periodontal therapy on total antioxidant capacity in chronic periodontitis patients

Aim:

The aim of this study was to determine the utility of plasma total antioxidant capacity (TAC) as marker of periodontal disease by estimating TAC of periodontally healthy and chronic periodontitis patients and the impact of scaling and root planning on total antioxidant status of periodontitis patients.

Materials and Methods:

Blood plasma samples were collected from randomly selected eighty individuals (40 periodontally healthy controls and 40 chronic periodontitis patients), with an age range of 20–45 years and were analyzed for TAC by ferric reducing antioxidant power assay. Scaling and root planing was performed in periodontitis patients, and TAC level was measured again after 3 weeks. Data were analyzed with t-test, using SPSS software (PSAW, Windows version 18.0).

Results:

The mean plasma TAC was significantly lower (792.33 ± 124.33 μmol/L, P < 0.001) in chronic periodontitis patients compared to healthy control (1076.08 ± 193.82 μmol/L). Plasma TAC level increased significantly (989.75 ± 96.80, P < 0.001) after scaling and root planing.

Conclusions:

An inverse relationship exists between plasma TAC and severity of chronic periodontitis suggesting disturbed oxidant-antioxidant balance in chronic periodontitis. Scaling and root planing resulted in the restoration of TAC to normal levels. These results are important from the perspective of including antioxidants in periodontal therapy regime to boost up body's antioxidant defense system and to reduce oxidative stress-mediated periodontal tissue damage. We concluded that TAC can be used as a biomarker to evaluate the health of periodontium.

Oxidative Stress and Antioxidants in the Diagnosis and Therapy of Periodontitis

Oxidative stress has been implicated in the pathogenesis of numerous diseases. However, large interventional studies with antioxidants failed to show benefits in the prevention or treatment of cardiovascular diseases, cancer, or diabetes mellitus. Numerous clinical studies have confirmed the association of oxidative stress markers and periodontitis. Technical and biological variability is high for most of the analyzed markers and none of them seems to be optimal for routine clinical use. In a research setting, analysis of a palette of oxidative stress markers is needed to cover lipid peroxidation, protein oxidation, and the antioxidant status. The source of reactive oxygen species and their role in the pathogenesis of periodontitis remains unclear. Interventional experiments indicate that oxidative stress might be more than just a simple consequence of the inflammation. Small studies have confirmed that some antioxidants could have therapeutic value at least as an addition to the standard non-surgical treatment of periodontitis. A clear evidence for the efficiency of antioxidant treatment in large patient cohorts is lacking. Potentially, because lowering of oxidative stress markers might be a secondary effect of anti-inflammatory or antibacterial agents. As the field of research of oxidative stress in periodontitis gains attraction and the number of relevant published papers is increasing a systematic overview of the conducted observational and interventional studies is needed. This review summarizes the currently available literature linking oxidative stress and periodontitis and points toward the potential of adjuvant antioxidant treatment, especially in cases where standard treatment fails to improve the periodontal status.

Oxidative Stress in Oral Diseases: Understanding Its Relation with Other Systemic Diseases

Oxidative stress occurs in diabetes, various cancers, liver diseases, stroke, rheumatoid arthritis, chronic inflammation, and other degenerative diseases related to the nervous system. The free radicals have deleterious effect on various organs of the body. This is due to lipid peroxidation and irreversible protein modification that leads to cellular apoptosis or programmed cell death. During recent years, there is a rise in the oral diseases related to oxidative stress. Oxidative stress in oral disease is related to other systemic diseases in the body such as periodontitis, cardiovascular, pancreatic, gastric, and liver diseases. In the present review, we discuss the various pathways that mediate oxidative cellular damage. Numerous pathways mediate oxidative cellular damage and these include caspase pathway, PERK/NRF2 pathway, NADPH oxidase 4 pathways and JNK/mitogen-activated protein (MAP) kinase pathway. We also discuss the role of inflammatory markers, lipid peroxidation, and role of oxygen species linked to oxidative stress. Knowledge of different pathways, role of inflammatory markers, and importance of low-density lipoprotein, fibrinogen, creatinine, nitric oxide, nitrates, and highly sensitive C-reactive proteins may be helpful in understanding the pathogenesis and plan better treatment for oral diseases which involve oxidative stress.

Evaluation of oxidative stress in chronic periodontitis patients following systemic antioxidant supplementation: A clinical and biochemical study

CONTEXT

Oxidative stress is associated with the pathogenesis of many systemic diseases including chronic periodontitis. Periodontal pathogen activated neutrophils liberate the reactive oxygen species (ROS), which causes the destruction of periodontal tissues. Antioxidants modulate the ROS production and inhibit the tissue destruction.

AIM

We aimed to evaluate the oxidative stress marker malondialdehyde (MDA) in chronic periodontitis patients following scaling and root planing (SRP) after systemic lycopene supplementation.

MATERIALS AND METHODS

This was an interventional single arm study. Twenty systemically healthy patients with chronic periodontitis were recruited. Clinical parameters modified gingival index, probing depth, clinical attachment loss were recorded, and serum MDA levels were assessed by thiobarbituric acid reactive substances assay. Patients were supplemented with 8 mg lycopene daily for 2 months following SRP treatment. All the parameters were assessed at pretreatment and 2 months and 6 months posttreatment.

RESULTS

From pretreatment to posttreatment at 2 months, the mean values of all parameters were reduced. While from 2 to 6 months when lycopene was not administered, an increase in the mean values of all the parameters was observed; however, these values were still below baseline values.

CONCLUSION

There was a reduction in oxidative stress and improvement in clinical parameters following systemic antioxidant therapy along with SRP, which was maintained up to 4 months after discontinuation of lycopene treatment.

Impact of non-surgical periodontal therapy on saliva and serum levels of markers of oxidative stress

OBJECTIVE

The purpose of this study was to determine the effect of non-surgical periodontal treatment on markers of oxidative stress in saliva and serum in patients with chronic periodontitis.

MATERIALS AND METHODS

In total, 25 patients, who were diagnosed with generalized chronic periodontitis (11 females and 14 males), and 26 systemically and periodontally healthy individuals (15 females and 11 males) were included. The plaque index (PI), gingival index (GI), probing pocket depth (PPD), attachment loss (AL), gingival recession (GR), and bleeding on probing (BOP) were recorded at baseline and 6 weeks later. Malondialdehyde (MDA), 8-hydroxydeoxyguanosine (8-OHdG), and 4-hydroxy-2-nonenal (4-HNE) were assessed in saliva and serum samples before and after the non-surgical treatment by enzyme-linked immune sorbent assay (ELISA).

RESULTS

In the group with chronic periodontitis, all clinical parameters were significantly higher compared to the control group at baseline (p < 0.001). Periodontal treatment reduced plaque, gingival inflammation, and pocket depth significantly (p < 0.001). At baseline, salivary 8-OHdG was significantly higher in chronic periodontitis (p < 0.001) and reduced significantly subsequent to the periodontal treatment (p < 0.001). Salivary MDA and serum 4-HNE were significantly higher in the patients with periodontitis compared to the control group (p < 0.001). Periodontal treatment did not significantly change the levels of 4-HNE and salivary MDA (p = 0.503, p = 0.093).

CONCLUSIONS

Salivary 8-OHdG and MDA may be associated with local impact of periodontal disease, while 4-HNE may be associated with systemic impact of chronic periodontitis.

CLINICAL RELEVANCE

Clinical intervention in periodontitis may be beneficial for periodontitis patients' systemic oxidative stress control, and using lipidic agents for the use of anti-inflammatory/pro-resolving processes for blocking the actions of arachidonic acid cascade can enable some late therapeutic strategies in order to lead oxidative stress-induced inflammation.

Influence of Periodontal Clinical Status on Salivary Levels of Glutathione Reductase

BACKGROUND

Inadequate antioxidant balance may play a role in the excessive tissue breakdown in periodontitis. Because aggressive periodontitis (AgP) not only differs from chronic periodontitis (CP) in terms of clinical manifestations, this study investigates whether the salivary levels of glutathione reductase (GR) may be linked with periodontal status.

METHODS

Saliva samples from patients with CP (n = 121), patients with AgP (n = 18), and healthy controls (n = 69) were collected. Periodontal status was assessed by criteria based on probing depth, clinical attachment level, and extent and severity of periodontal breakdown. GR salivary levels were analyzed by spectrophotometry. The association among GR concentration and CP or AgP was analyzed individually and adjusted for confounding using multivariate binary logistic regression models.

RESULTS

GR levels not only differed significantly between the two periodontitis groups, being significantly greater in patients with AgP, but also were significantly greater than those observed in healthy controls. Synchronously, positive significant correlations between salivary GR concentration and clinical parameters were observed. After binary logistic regression analysis, both GR salivary levels ≥15.38 and ≥24.20 mU/mL were associated independently with CP and AgP, respectively. A significant interaction effect was also detected between increased GR salivary concentration and aging in the CP group.

CONCLUSIONS

Increased GR salivary concentration may be a strong/independent prognostic indicator of the amount and extent of oxidative stress-induced periodontal damage in both CP and AgP. Likewise, saliva samples might reflect an interactive effect of GR levels associated with the aging-related cumulative characteristics of periodontal damage in CP.

Nuclear Factor Erythroid 2-Related Factor 2 Down-Regulation in Oral Neutrophils Is Associated with Periodontal Oxidative Damage and Severe Chronic Periodontitis

The balance between reactive oxygen species and antioxidants plays an important role in periodontal health. We previously demonstrated that high reactive oxygen species production by oral polymorphonuclear neutrophils (oPMNs) in chronic periodontitis (CP) refractory to conventional therapy is associated with severe destruction of periodontium. Herein, we show that inhibition of antioxidant production through down-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in oPMN, despite enhanced recruitment in the oral cavity, is associated with severe CP. Twenty-four genes in the Nrf2-mediated oxidative stress response pathway were down-regulated in PMNs of diseased patients. Downstream of Nrf2, levels of oPMN superoxide dismutase 1 and catalase were decreased in severe CP, despite increased recruitment. Nrf2(-/-) mice had more severe loss of periodontium in response to periodontitis-inducing subgingival ligatures compared with wild-types. Levels of 8-hydroxy-deoxyguanosine were increased in periodontal lesions of Nrf2(-/-) mice, indicating high oxidative damage. We report, for the first time, Nrf2 pathway down-regulation in oPMNs of patients with severe CP. PMNs of CP patients may be primed for low antioxidant response in the context of high recruitment in the oral cavity, resulting in increased oxidative tissue damage.

Malondialdehyde, superoxide dismutase and melatonin levels in gingival crevicular fluid of aggressive and chronic periodontitis patients

BACKGROUND

The aim of this study was to investigate malondialdehyde (MDA), superoxide dismutase (SOD) and melatonin levels in the gingival crevicular fluid (GCF) of patients with chronic periodontitis (CP) and generalized aggressive periodontitis (GAgP) as biomarkers for oxidative stress.

METHODS

The study comprised 65 subjects: 15 healthy individuals, 25 CP patients and 25 GAgP patients. Plaque index, gingival index, pocket depth, clinical attachment level measurements and GCF samples were obtained from all subjects. MDA, SOD and melatonin levels were determined utilizing enzyme-linked immunosorbent assay.

RESULTS

GCF-MDA levels were significantly higher in the GAgP group compared to the CP and control groups (p < 0.001) and significantly higher in the CP group than the C group (p < 0.001). SOD and melatonin GCF levels were significantly higher in the control than the GAgP and CP groups (p < 0.05), and significantly lower in the GAgP than the CP group (p < 0.05). The CP group demonstrated a significant negative correlation between GCF-MDA and melatonin concentrations. A positive correlation was observed between SOD and CAL in the CP group and PD in the GAgP group.

CONCLUSIONS

MDA, melatonin and SOD could be considered as biomarkers for oxidative stress in periodontal diseases and might be useful diagnostic aids in distinguishing CP and GAgP patients.

Nutrients, Microglia Aging, and Brain Aging

As the life expectancy continues to increase, the cognitive decline associated with Alzheimer's disease (AD) becomes a big major issue in the world. After cellular activation upon systemic inflammation, microglia, the resident immune cells in the brain, start to release proinflammatory mediators to trigger neuroinflammation. We have found that chronic systemic inflammatory challenges induce differential age-dependent microglial responses, which are in line with the impairment of learning and memory, even in middle-aged animals. We thus raise the concept of “microglia aging.” This concept is based on the fact that microglia are the key contributor to the acceleration of cognitive decline, which is the major sign of brain aging. On the other hand, inflammation induces oxidative stress and DNA damage, which leads to the overproduction of reactive oxygen species by the numerous types of cells, including macrophages and microglia. Oxidative stress-damaged cells successively produce larger amounts of inflammatory mediators to promote microglia aging. Nutrients are necessary for maintaining general health, including the health of brain. The intake of antioxidant nutrients reduces both systemic inflammation and neuroinflammation and thus reduces cognitive decline during aging. We herein review our microglia aging concept and discuss systemic inflammation and microglia aging. We propose that a nutritional approach to controlling microglia aging will open a new window for healthy brain aging.

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.

Periodontitis and Sleep Disordered Breathing in the Hispanic Community Health Study/Study of Latinos

STUDY OBJECTIVES

To investigate the association between sleep disordered breathing (SDB) and severe chronic periodontitis.

DESIGN

Cross-sectional data analysis from the Hispanic Community Health Study/Study of Latinos.

SETTING

Community-based setting with probability sampling from four urban US communities.

PARTICIPANTS

12,469 adults aged 18-74 y.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Severe chronic periodontitis was defined using the Centers for Disease Control and Prevention/American Academy of Periodontology case classification based on full-mouth periodontal assessments performed by calibrated dentists. SDB was evaluated in standardized home sleep tests, and defined as the number of apnea plus hypopnea events associated with ≥ 3% desaturation, per hour of estimated sleep. SDB was quantified using categories of the apnea-hypopnea index (AHI): 0.0 events (nonapneic); 0.1-4.9 (subclinical); 5.0-14.9 (mild); and ≥ 15 (moderate/severe). Covariates were demographic characteristics and established periodontitis risk factors. C-reactive protein was a potential explanatory variable. Using survey estimation, multivariable binary logistic regression estimated odds ratios (OR) and 95% confidence limits (CL). Following adjustment for confounding, the SDB and periodontitis relationship remained statistically significant, but was attenuated in strength and no longer dose-response. Compared with the nonapneic referent, adjusted odds of severe periodontitis were 40% higher with subclinical SDB (OR = 1.4, 95% CL: 1.0, 1.9), 60% higher with mild SDB (OR = 1.6, 95% CL: 1.1, 2.2) and 50% higher with moderate/severe SDB (OR = 1.5, 95% CL: 1.0, 2.3) demonstrating an independent association between SDB and severe periodontitis.

CONCLUSIONS

This study identifies a novel association between mild sleep disordered breathing and periodontitis that was most pronounced in young adults.

Prognostic Value of 8-Hydroxy-2'-Deoxyguanosine and Human Neutrophil Elastase/α1-Proteinase Inhibitor Complex as Salivary Biomarkers of Oxidative Stress in Chronic Periodontitis

BACKGROUND

8-Hydroxy-2'-deoxyguanosine (8-OHdG) and human neutrophil elastase/α1-proteinase inhibitor (HNE/α1-PI) complex have been regarded as reliable biomarkers of oxidative stress in inflammatory conditions. This study investigates whether the salivary levels of these two analytes may be linked with periodontal health status.

METHODS

One hundred ten patients with chronic periodontitis (CP) and 50 healthy controls were selected. Periodontal status was assessed by criteria based on probing depth, clinical attachment level, and extent and severity of periodontal breakdown. 8-OHdG and HNE/α1-PI salivary levels were analyzed by enzyme-linked immunosorbent assay. The association of these analytes with CP was analyzed individually and adjusted for confounding factors using a multivariate binary logistic regression model.

RESULTS

Significantly higher levels of both markers were detected in the CP group in comparison to controls. Weak-to-moderate positive significant correlations between salivary biomarkers and clinical parameters were observed. After binary logistic regression analysis, salivary levels of 8-OHdG >17.35 ng/mL and HNE/α1-PI complex >158.28 ng/mL were independently associated with disease status. Interaction effects among candidate prognostic variables were also noted.

CONCLUSIONS

Increased salivary levels of 8-OHdG and HNE/α1-PI complex may be strong, independent prognostic indicators of the amount and extent of oxidative stress-induced periodontal breakdown. In addition, unstimulated whole saliva samples might reflect a synergistic biologic interactive effect of HNE/α1-PI associated with the aging and smoking cumulative characteristics of periodontal damage.

Oxidative Stress and Dietary Fat Type in Relation to Periodontal Disease

Oxidative stress is one of the main factors studied to explain the pathophysiological mechanisms of inflammatory conditions, such as periodontitis. In this respect, nutrition may be of great importance. Actually, research on nutrients' effects on periodontal diseases has expanded to include those influencing the redox status, which correlates to the inflammatory process. Dietary fat or lipids are often blamed as the major source of excess energy. Consequently, when caloric intake exceeds energy expenditure, the resultant substrate-induced increase in citric acid cycle activity generates an excess of reactive oxygen species (ROS). In addition, dietary fatty acid intake influences in relative fatty acid composition of biological membranes determining its susceptibility to oxidative alterations. From this standpoint, here, we reviewed studies analyzing the dietary fat role in periodontal disease. Research data suggest that periodontal health could be achieved by main dietary strategies which include substitution of saturated fats with monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA), particularly n-3 PUFA. Maybe in the future, we should analyze the diet and provide some advice to periodontitis patients to improve treatment outcomes.

Evaluation of lipid peroxidation and oxidative DNA damage in patients with periodontitis and hyperlipidemia

BACKGROUND

The purpose of this study is to determine the serum levels of malondialdehyde (MDA), as a lipid peroxidation marker, and 8-hydroxydeoxyguanosine (8-OHdG), as an oxidative DNA damage marker, in patients with chronic periodontitis (CP) and hyperlipidemia.

METHODS

A total of 74 individuals were divided into four age- and sex-matched groups: 18 patients with hyperlipidemia and CP (HLp), 18 periodontally healthy patients with hyperlipidemia (HLh), 19 systemically healthy individuals with CP (Cp), and 19 systemically and periodontally healthy controls (Ch). Clinical periodontal parameters were measured, and serum lipids, MDA, and 8-OHdG levels were assessed in blood samples.

RESULTS

8-OHdG, MDA, probing depth, clinical attachment level, and percentage of sites bleeding on probing (BOP) were significantly higher in the HLp group than the Cp group. In the hyperlipidemic group, BOP was significantly correlated with total cholesterol, the ratio of total cholesterol to high-density lipoprotein cholesterol, and 8-OHdG levels. A significant correlation between 8-OHdG and MDA was also observed in the hyperlipidemia group.

CONCLUSIONS

In this study, serum MDA and 8-OHdG were found to be highest in the HLp group. The increased levels of MDA and 8-OHdG in HLp patients may be a result of a harmful oxidative status in association with hyperlipidemia and periodontitis.

Systemic oxidative stress biomarkers in chronic periodontitis: a meta-analysis

Oxidative stress biomarkers have been observed in peripheral blood of chronic periodontitis patients; however, their associations with periodontitis were not consistent. This meta-analysis was performed to clarify the associations between chronic periodontitis and oxidative biomarkers in systemic circulation. Electronic searches of PubMed and Embase databases were performed until October 2014 and articles were selected to meet inclusion criteria. Data of oxidative biomarkers levels in peripheral blood of periodontitis patients and periodontal healthy controls were extracted to calculate standardized mean differences (SMDs) and 95% confidence intervals (CIs) by using random-effects model. Of 31 eligible articles, 16 articles with available data were included in meta-analysis. Our results showed that periodontitis patients had significantly lower levels of total antioxidant capacity (SMD = -2.02; 95% CI: -3.08, -0.96; P = 0.000) and higher levels of malondialdehyde (SMD = 0.99; 95% CI: 0.12, 1.86; P = 0.026) and nitric oxide (SMD = 4.98; 95% CI: 2.33, 7.63; P = 0.000) than periodontal healthy control. Superoxide dismutase levels between two groups were not significantly different (SMD = -1.72; 95% CI: -3.50, 0.07; P = 0.059). In conclusion, our meta-analysis showed that chronic periodontitis is significantly associated with circulating levels of three oxidative stress biomarkers, indicating a role of chronic periodontitis in systemic diseases.

The histopathological and morphometric investigation of the effects of systemically administered boric acid on alveolar bone loss in ligature-induced periodontitis in diabetic rats

OBJECTIVE

The purpose of this study was to evaluate the effects of systemically administered boric acid on alveolar bone loss, histopathological changes and oxidant/antioxidant status in ligature-induced periodontitis in diabetic rats.

MATERIALS AND METHODS

Forty-four Wistar rats were divided into six experimental groups: (1) non-ligated (NL, n = 6) group, (2) ligature only (LO, n = 6) group, (3) Streptozotocin only (STZ, n = 8) group, (4) STZ and ligature (STZ+LO, n = 8) group, (5) STZ, ligature and systemic administration of 15 mg/kg/day boric acid for 15 days (BA15, n = 8) group and (6) STZ, ligature and systemic administration of 30 mg/kg/day boric acid for 15 days (BA30, n = 8) group. Diabetes mellitus was induced by 60 mg/kg streptozotocin. Silk ligatures were placed at the gingival margin of lower first molars of the mandibular quadrant. The study duration was 15 days after diabetes induction and the animals were sacrificed at the end of this period. Changes in alveolar bone levels were clinically measured and tissues were histopathologically examined. Serum total antioxidant status (TAS), total oxidant status (TOS), calcium (Ca) and magnesium (Mg) levels and oxidative stress index (OSI) were evaluated. Primary outcome was alveolar bone loss. Seconder outcome (osteoblast number) was also measured.

RESULTS

At the end of 15 days, the alveolar bone loss was significantly higher in the STZ+LO group compared to the other groups (p < 0.05). There was no significant difference in alveolar bone loss between the STZ+LO 15 mg/kg boric acid and STZ+LO 30 mg/kg boric acid groups (p > 0.05). Systemically administered boric acid significantly decreased alveolar bone loss compared to the STZ+LO group (p < 0.05). The osteoblast number in the BA30 group was significantly higher than those of the NL, STZ and STZ+LO groups (p < 0.05). Inflammatory cell infiltration was significantly higher in the STZ+LO group the other groups (p < 0.05). Serum TAS levels were significantly higher in the NL and LO groups than the other groups (p < 0.05). The differences in TOS levels were not found to be significant among all the groups (p > 0.05). The OSI values of the BA30 group were significantly lower than the STZ+LO group (p < 0.05). Also, the differences in serum calcium and magnesium levels were insignificant among the all groups (p > 0.05).

CONCLUSION

Within the limits of this study, it can be suggested that BA, when administered systemically, may reduce alveolar bone loss in the diabetic rat model.