Oxidative Stress Parameters in Saliva and Its Association with Periodontal Disease and Types of Bacteria

The assessment of glutathione, glutathione peroxidase, glutathione reductase, and oxidized glutathione in patients with periodontitis-A systematic review and meta-analysis

OBJECTIVE

The present systematic review explored the involvement of enzymatic and nonenzymatic antioxidants in periodontitis, drawing from established literature.

MATERIALS AND METHODS

The research approach encompassed an extensive electronic search from 2000 to 2023 across databases such as PubMed, Science Direct, and Wiley Online Library and cross-referencing using specific keywords.

RESULTS

The initial literature exploration generated a total of 766 articles. After thoroughly examining the abstracts, 693 articles were excluded from consideration due to duplication and lack of relevance to the central research inquiry. Following that, 73 articles were left for in-depth evaluation. Following a qualitative assessment, 35 studies that satisfied the inclusion criteria were chosen, while 38 were removed for not meeting the necessary standards. Within this selection, a meta-analysis was conducted on 11 articles that provided consistent data for quantitative synthesis. Specifically, the analysis of glutathione (GSH) levels in serum samples revealed a standardized mean difference (SMD) of -5.552 µg/mL (CI 95%: -9.078 to -2.026; P-0.002). In contrast, the analysis of glutathione peroxidase (GPx) enzymes in gingival crevicular fluid (GCF) samples displayed an overall SMD of 2.918 ng/µL (CI 95%: 0.372-5.465; P-0.025), while salivary samples exhibited an overall SMD value of 0.709 U/l (95% CI: -1.907-3.325; P-0.596) which is of insignificant.

CONCLUSION

The systematic review findings suggest a notable decrease in antioxidant enzymes across various systemic biological samples among patients with periodontitis, contrasting with the results from gingival tissue samples meta-analysis of GPx enzyme.

Association between blood ethylene oxide levels and the prevalence of periodontitis: evidence from NHANES 2013-2014

BACKGROUND

The study aimed to establish a link between blood ethylene oxide (EO) levels and periodontitis, given the growing concern about EO's detrimental health effects.

MATERIALS AND METHODS

The study included 1006 adults from the 2013-2014 National Health and Nutrition Examination Survey (NHANES) dataset. We assessed periodontitis prevalence across groups, used weighted binary logistic regression and restricted cubic spline fitting for HbEO-periodontitis association, and employed Receiver Operating Characteristic (ROC) curves for prediction.

RESULTS

In the periodontitis group, HbEO levels were significantly higher (40.57 vs. 28.87 pmol/g Hb, P < 0.001). The highest HbEO quartile showed increased periodontitis risk (OR = 2.88, 95% CI: 1.31, 6.31, P = 0.01). A "J"-shaped nonlinear HbEO-periodontitis relationship existed (NL-P value = 0.0116), with an inflection point at ln-HbEO = 2.96 (EO = 19.30 pmol/g Hb). Beyond this, ln-HbEO correlated with higher periodontitis risk. A predictive model incorporating sex, age, education, poverty income ratio, alcohol consumption, and HbEO had 69.9% sensitivity and 69.2% specificity. The model achieved an area under the ROC curve of 0.761.

CONCLUSIONS

These findings suggest a correlation between HbEO levels and an increased susceptibility to periodontitis.

TNF-α promotes expression of inflammatory factors by upregulating nicotinamide adenine dinucleotide phosphate oxidase-2 expression in human gingival fibroblasts

Background/purpose

Periodontitis is a chronic infectious disease. The oxidative stress environment can cause or exacerbate the inflammation in periodontitis. Nicotinamide adenine dinucleotide phosphate oxidase (NOX) may be the most important source of reactive oxygen species (ROS) in periodontal tissues. The pathological mechanism of periodontitis may be related to the increased ROS caused by enhanced NOX activity. The purpose was to investigate the effect of tumor necrosis factor (TNF-α) on inflammatory cytokines and ROS, and the role of NOX-2 in human gingival fibroblasts (HGFs).

Materials and methods

HGFs were cultured and divided into the normal control group (NC group) and the inflammatory model group (TNF-α group) induced by 10 ng/ml TNF-α. Thereafter, NOX-2 siRNA was used to knock down NOX-2 gene expression. Quantitative real-time PCR was applied to detect IL-6, MCP-1, and NOX-2 mRNA levels. The levels of IL-6 and MCP-1 protein were examined by ELISA. The level of NOX-2 was evaluated by Western blot. ROS expression was measured by the fluorescence microplate.

Results

The mRNA and protein expression levels of IL-6, MCP-1, and NOX-2 were significantly increased, and the expression of ROS was significantly elevated in response to 10 ng/ml TNF-α. Compared with the si-NC group, the mRNA and protein expression levels of IL-6 and MCP-1 were significantly down-regulated and ROS expression was significantly decreased in the si-NOX2 group stimulated by 10 ng/ml TNF-α.

Conclusion

TNF-α promotes the expression of NOX-2 in human gingival fibroblasts and enhances the expression of inflammatory factors and ROS in human gingival fibroblasts through the upregulation of NOX-2 partly.

Comparison of Oral Health and Salivary Biomarkers in Children with Juvenile Idiopathic Arthritis and Healthy Individuals

AIM

This study examines the effects of juvenile idiopathic arthritis (JIA) on the oral health and detectability of inflammatory biomarkers IL-17, tumour necrosis factor-alpha (TNF-α) and total antioxidant status (TAS) in the saliva of children with JIA.

PATIENTS AND METHODS

This study included 117 participants (39 patients with JIA and 78 systemically healthy subjects aged 8-12 years). Demographic data, responses to an oral health-related questionnaire, saliva samples, periodontal parameters [plaque index (PI), gingival index (GI) and bleeding on probing (BOP)] and dental recordings [facial profile (FP) and dental occlusion relationship (DOR)] were obtained. Enzyme-linked immunosorbent assays were used to determine the levels of salivary IL-17, TNF-α and TAS.

RESULTS

The Caries Assessment Spectrum and Treatment (CAST) index, FP and DOR distributions did not change between groups (P > 0.05). JIA patients had more temporomandibular joint (TMJ) discomfort than gingivitis patients and healthy subjects (P < 0.05). JIA patients had greater salivary IL-17 levels than healthy subjects (P < 0.05). The healthy group's TAS was higher than that of the JIA and gingivitis groups (P < 0.05). Saliva TNF-α levels were similar between groups (P > 0.05). PI, GI, BOP and TNF-α were positively associated with salivary IL-17 (P < 0.001).

CONCLUSION

Elevated salivary IL-17 and TAS levels could be used as biological markers for discriminating the clinical health status of children with JIA and gingivitis.

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.

Infrared laser therapy decreases systemic oxidative stress and inflammation in hypercholesterolemic mice with periodontitis

BACKGROUND

Near-infrared irradiation photobiomodulation (NIR-PBM) has been successfully used in periodontal treatment as an adjuvant tool to locally improve cell function and regeneration. Although the relationship between periodontitis and systemic disease constitutes an important aspect of periodontal clinical research, the systemic effects of NIR-PBM in periodontitis are not well known. In this study, we aimed to investigate the effects of NIR-PBM on systemic oxidative stress and inflammation in an apolipoprotein E (ApoE) knockout mouse model of periodontal disease (PD).

METHODS

We evaluated alveolar bone loss by measuring the distance from the cementoenamel junction (CEJ) to the alveolar bone crest (ABC), reactive oxygen species (ROS) production in blood cells, inflammatory activity, plasma cholesterol levels, and lipid peroxidation levels in three experimental groups: (1) ApoEC, control group without intervention; (2) ApoEP, first molar ligation-induced periodontitis for 4 weeks; and (3) ApoEP + PBM, exposed to 808 nm continuous wave, ø ~ 3 mm2, 100 mW, 60 s of NIR-PBM for 7 consecutive days after 4 weeks of periodontitis. At the end of the experimental protocols, ApoEP mice presented significantly increased alveolar bone loss, ROS production, inflammatory activity, plasma cholesterol, and lipid peroxidation levels compared to the ApoEC group (P < 0.05). NIR-PBM for 7 days in the ApoEP + PBM mice significantly decreased systemic ROS production, inflammatory response, plasma cholesterol, and lipid peroxidation levels, similar to those found in the ApoEC group (P > 0.05). However, it was not capable of preventing alveolar bone loss (P > 0.05 compared to ApoEP mice).

CONCLUSION

A 7-day treatment with NIR-PBM effectively reduces systemic oxidative stress and inflammatory parameters in hypercholesterolemic mice with PD. However, more studies with longer evaluation times are needed to confirm the systemic effects of locally applied NIR-PBM on PD associated with hypercholesterolemia.

Anti-inflammatory and pro-regenerative effects of a monoterpene glycoside on experimental periodontitis in a rat model of diabetes

OBJECTIVE

Paeoniflorin (Pae) is a monoterpene glycoside with immune-regulatory effects. Several studies have already demonstrated the impact of Pae on periodontitis, but its effect on diabetic periodontitis is unclear. In this study, our aim was to test the hypothesis that Pae had a strong anti-inflammatory effect that prevented bone loss in diabetic periodontitis.

METHODS

Thirty male Wistar albino rats were randomly divided into control (healthy, n = 10), periodontitis (PD) + diabetes (DM; n = 10), and PD + DM + Pae (n = 10) groups. Ligature-induced periodontitis was created by placing 4-0 silk ligatures around the lower first molars on both sides of the mandibulae. Experimental DM was created via an injection of 50 mg/kg and streptozotocin (STZ). Hyperglycemia was confirmed by the blood glucose levels of rats (>300 mg/dL). The bone mineral density (BMD), trabecular number, trabecular thickness, and bone loss were measured by micro-CT. The expression levels of IL-1β, IL-6, and TNF-α were measured in tissue homogenates by ELISA.

RESULTS

The PD + DM + Pae group had significantly less alveolar crest resorption when compared to the PD + DM group. There was also a significant difference between the PD + DM + Pae group compared to PD + DM group in trabecular thickness, BMD, and the number of trabeculae. Pae application led to a statistically significant decrease in IL-1β, IL-6, and TNF-α levels in diabetic periodontitis.

CONCLUSION

Systemic application of Pae suppressed inflammation caused by PD and DM, leading to reduced bone loss and enhanced bone quality.

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

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

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.

Role of oxidative stress in the relationship between periodontitis and systemic diseases

Periodontitis is a common inflammatory disease. It is characterized by destruction of the supporting structures of the teeth and could lead to tooth loss and systemic inflammation. Bacteria in inflamed gingival tissue and virulence factors are capable of entering the bloodstream to induce systemic inflammatory response, thus influencing the pathological process of many diseases, such as cardiovascular diseases, diabetes, chronic kidney disease, as well as liver injury. An increasing body of evidence show the complex interplay between oxidative stress and inflammation in disease pathogenesis. When periodontitis occurs, increased reactive oxygen species accumulation leads to oxidative stress. Oxidative stress contributes to major cellular components damage, including DNA, proteins, and lipids. In this article, the focus will be on oxidative stress in periodontal disease, the relationship between periodontitis and systemic inflammation, and the impact of periodontal therapy on oxidative stress parameters.

Assessment of Oxidative Stress by the Estimation of Lipid Peroxidation Marker Malondialdehyde (MDA) in Patients with Chronic Periodontitis: A Systematic Review and Meta-Analysis

Objective

The present systematic review and meta-analysis aimed to assess the oxidative stress-mediated lipid peroxidation end product malondialdehyde (MDA) in periodontitis using the available literature.

Materials and Methods

An electronic literature search was performed for the published articles from 2000 to 2022 in PubMed (MeSH), Science Direct, Wiley Online library, and cross-reference using specific keywords.

Results

The literature search identified 1,166 articles. After analyzing the abstracts of the obtained articles, the articles were excluded for the following reasons: duplicate studies (n = 395) and not relevant to the research question (n = 726). The remaining 45 articles were chosen for full-text evaluation. Finally, the present qualitative synthesis selected 34 articles that met the inclusion criteria for evaluation and removed the articles which did not meet the required criteria (n = 11). Out of these, 16 articles had coherent data for quantitative synthesis. The meta-analysis used the standardized mean differences method at a 95% confidence interval by random-effects model. The periodontitis group displayed significantly higher MDA levels (P < 0.001) in gingival crevicular fluid, saliva, and serum samples of the studies analyzed than the healthy control.

Conclusion

The analyzed studies showed significantly higher MDA levels in various biological samples of patients with periodontitis, supporting the role of elevated oxidative stress and consequent lipid peroxidation in periodontitis.

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.

Determination of salivary cortisol and salivary pH level in gaming teenagers - A cross-sectional study

Introduction

Internet gaming disorder and cybervictimization has a disproportionate increase during the COVID 19 pandemic. Teenagers and adolescents have high risk for addiction to online gaming. Online gaming increases the stress level of the users affecting the general and the oral health. The study aims to determine the salivary cortisol and salivary pH among the gaming teenagers.

Materials and methods

The cross-sectional study recruited 45 gaming teenagers with the mean age of 15.5 years. The participants were stratified according to the type of online gaming played as mind, aggressive and betting gaming. Their salivary pH and salivary cortisol were assessed. The collected data was analyzed using SPSS version 23.

Results

The mean salivary pH was found to be less among females playing aggressive games (7.11 ± 0.30) and males playing mind games (7.24 ± 0.16). Salivary cortisol level was found to be statistically high in males (6.66 ± 1.33) and females (7.82 ± 0.66) playing aggressive games. The sub-group analysis of salivary pH and cortisol for gender showed a significant difference in the mean salivary cortisol level (p < 0.05) with no difference in the salivary pH (p > 0.05). Based on the number of hours spent in online gaming, there was a significant increase in the mean salivary cortisol level among the participants playing >3 h (p < 0.05).

Conclusion

Salivary cortisol is high among individuals playing aggressive games compared to mind and betting games. Also, salivary cortisol is high in females compared to males with no change in salivary pH.

Periostin regulates LPS-induced apoptosis via Nrf2/HO-1 pathway in periodontal ligament fibroblasts

OBJECTIVE

Periostin is important for the maintenance of periodontal tissue, but its role in periodontitis is controversial. This research investigated the effect of periostin in periodontitis and the underlying mechanism.

DESIGN

Mouse periodontitis models in vivo and inflammation model in vitro which were induced by Porphyromonas gingivalis lipopolysaccharide were established to evaluate periostin expression. Human periodontal ligament fibroblasts (PDLFs) were treated with lipopolysaccharide and N-acetylcysteine, fluorescence staining, flow cytometry, western blot, and qRT-PCR were used to detect reactive oxygen species (ROS), periostin expression, and apoptosis-related makers. The periostin gene was successfully transfected into PDLFs to verify the effect of periostin on apoptosis. Then, the Nrf2 inhibitor was added to clarify the mechanism.

RESULTS

Periostin expression decreased in the periodontal ligaments of mouse periodontitis models and lipopolysaccharide-induced PDLFs. Lipopolysaccharide promoted the activation of ROS and apoptosis in PDLFs, whereas N-acetylcysteine reversed this condition. Overexpression of periostin suppressed apoptosis of PDLFs and reversed the inhibitory effect of lipopolysaccharide on nuclear Nrf2 expression. Moreover, the Nrf2 inhibitor attenuated the protective effect of periostin on lipopolysaccharide-induced apoptosis.

CONCLUSIONS

Lipopolysaccharide induced apoptosis in PDLFs by inhibiting periostin expression and thus Nrf2/HO-1 pathway, indicating that periostin could be a potential therapeutic target for periodontitis.

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.

Quercetin Prevents Oxidative Stress-Induced Injury of Periodontal Ligament Cells and Alveolar Bone Loss in Periodontitis

Purpose

Emerging evidence has indicated that oxidative stress (OS) contributes to periodontitis. Periodontal ligament cells (PDLCs) are important for the regeneration of periodontal tissue. Quercetin, which is extracted from fruits and vegetables, has strong antioxidant capabilities. However, whether and how quercetin affects oxidative damage in PDLCs during periodontitis remains unknown. The aim of this study was to assess the effects of quercetin on oxidative damage in PDLCs and alveolar bone loss in periodontitis and underlying mechanisms.

Materials and Methods

The tissue block culture method was used to extract human PDLCs (hPDLCs). First, a cell counting kit 8 (CCK-8) assay was used to identify the optimal concentrations of hydrogen peroxide (H₂O₂) and quercetin. Subsequently, a 2,7-dichlorodihydrofluorescein diacetate (DCFH-DA) probe, RT-qPCR, Western blotting and other methods were used to explore the effects of quercetin on OS in hPDLCs and the underlying mechanism. Finally, quercetin was administered to mice with periodontitis through gavage, and the effect of quercetin on the level of OS and alveolar bone resorption in these mice was observed by immunofluorescence, microcomputed tomography (micro-CT), hematoxylin and eosin staining (H&E) staining and so on.

Results

Quercetin at 5 μM strongly activated NF-E2-related factor 2 (NRF2) signaling, alleviated oxidative damage and enhanced the antioxidant capacity of hPDLCs. In addition, quercetin reduced cellular senescence and protected the osteogenic ability of hPDLCs. Finally, quercetin activated NRF2 signaling in the periodontal ligaments, reduced the OS level of mice with periodontitis, and slowed the absorption of alveolar bone in vivo.

Conclusion

Quercetin can increase the antioxidant capacity of PDLCs and reduce OS damage by activating the NRF2 signaling pathway, which alleviates alveolar bone loss in periodontitis.

The relationship between periodontal status and hyperglycemia after kidney transplantation

OBJECTIVES

Several factors have been associated with hyperglycemia after kidney transplantation (KTx), including systemic inflammation. This study aimed to investigate the relationship between periodontal status and hyperglycemia in KTx patients.

MATERIALS AND METHODS

Forty-four KTx patients were included in this cross-sectional study. Periodontitis severity was categorized into stage I to IV. Fasting blood glucose (FBG) was measured, and hyperglycemia was analyzed at different FBG cutoff points (100 mg/dL, 110 mg/dL, 120 mg/dL, 126 mg/dL, 140 mg/dL). Age, history of smoking, prior type 2 diabetes (T2D), and prior cardiovascular disease (CVD) were considered cofounders. Multivariable logistic regression modelling was performed with periodontitis as the exposure and hyperglycemia as the outcome. Pathway analysis was performed with FBG as a continuous outcome.

RESULTS

Periodontitis had increased odds of hyperglycemia from 120 mg/dL FBG cutoff, even after adjustment. In addition, periodontitis severity was positively associated with FBG level (β = 0.323, SE = 0.127, P = 0.011).

CONCLUSION

The findings suggest that periodontitis may be related to increase of hyperglycemia and FBG levels in KTx patients.

CLINICAL RELEVANCE

Periodontitis severity and cardiovascular disease were positively associated with FBG levels in KTx patients. Clinicians and patients should be aware of the potential benefit of periodontal care for better glycemic control management.

A Comparative Study of Antioxidative Activity of Saliva in Children and Young Teenagers with and without Gingivitis

Objectives: The aim of this study was to compare the values of total antioxidant capacity (TAC), catalase (CAT) and glutathione peroxidase (GPX) in the saliva of children and young teenagers with and without gingivitis. Materials and Methods: A total of 120 children and young teenagers of the mean age of 12.2 participated in the research. Gingival condition was assessed using the Löe and Silness Gingival Index. The subjects were divided into groups of those without gingivitis and those with gingivitis. Samples of unstimulated saliva were collected, and TAC, CAT and GPX were determined spectrophotometrically. Results: By comparing the values of TAC, CAT and GPX in subjects with and without gingivitis, significantly lower values of TAC (p < 0.001) and CAT (p < 0.001) were observed in the group of subjects with gingivitis. The correlation analysis of these values showed a positive correlation in groups of subjects not suffering from gingival inflammation and those with gingival inflammation. Conclusions: The study showed significantly lower values of TAC and CAT in the saliva of subjects with gingivitis. This indicates their possible role as a potential biomarker in the early diagnosis and expression of periodontal disease in children and young teenagers.

The Evaluation of Saliva Oxidative and Antioxidative Markers’ Levels in Adolescents with Gingival Inflammation

Periodontal disease is highly prevalent and affects 10%–15% of the world population. Salivary markers of oxidative stress and antioxidant status represent promising tool for research of oral diseases. Given the importance of reactive oxygen species (ROS) in the pathogenesis of periodontal disease, the aim of this study was to determine the association between oxidative stress parameters and periodontal disease gingivitis in adolescents. The study included a consecutive sample of 80 male and female participants referred to the Institute of Dentistry, Kragujevac, Serbia, as a result of periodontal problems or for routine control, aged 18 to 21, with definitive dentition as an inclusion criterion. Patients were divided into three groups depending on their gingival inflammation status. The first group was control group (n=20) with no gingival inflammation, the second group was with mild gingival inflammation (n=19), the third group was with moderate gingival inflammation (n=21) and the fourth group was with severe gingival inflammation (n=20). Oxidative stress parameters were measured in unstimulated whole saliva samples (superoxide anion radical, hydrogen peroxide, nitric oxide, index of lipid peroxidation, reduced gluthatione, catalase and superoxide dismutase). We have found increased levels of hydrogen peroxide and reduced glutathione in the saliva of patients with moderate levels of gingival inflammation, while the other markers were not significantly affected. In conclusion, oxidative stress plays a central role in the pathogenesis and the determination of oxidative and antioxidative levels could be a potent tool in controlling the development of gingivitis.

Exacerbation of AMD Phenotype in Lasered CNV Murine Model by Dysbiotic Oral Pathogens

Emerging evidence underscores an association between age-related macular degeneration (AMD) and periodontal disease (PD), yet the biological basis of this linkage and the specific role of oral dysbiosis caused by PD in AMD pathophysiology remains unclear. Furthermore, a simple reproducible model that emulates characteristics of both AMD and PD has been lacking. Hence, we established a novel AMD+PD murine model to decipher the potential role of oral infection (ligature-enhanced) with the keystone periodontal pathogen Porphyromonas gingivalis, in the progression of neovasculogenesis in a laser-induced choroidal-neovascularization (Li-CNV) mouse retina. By a combination of fundus photography, optical coherence tomography, and fluorescein angiography, we documented inflammatory drusen-like lesions, reduced retinal thickness, and increased vascular leakage in AMD+PD mice retinae. H&E further confirmed a significant reduction of retinal thickness and subretinal drusen-like deposits. Immunofluorescence microscopy revealed significant induction of choroidal/retinal vasculogenesis in AMD+PD mice. qPCR identified increased expression of oxidative-stress, angiogenesis, pro-inflammatory mediators, whereas antioxidants and anti-inflammatory genes in AMD+PD mice retinae were notably decreased. Through qPCR, we detected Pg and its fimbrial 16s-RrNA gene expression in the AMD+PD mice retinae. To sum-up, this is the first in vivo study signifying a role of periodontal infection in augmentation of AMD phenotype, with the aid of a pioneering AMD+PD murine model established in our laboratory.

Evaluation of Oxidative Stress before and after Using Laser and Photoactivation Therapy as Adjuvant of Non-Surgical Periodontal Treatment in Patients with Rheumatoid Arthritis

(1) Background: The aim of this split-mouth design study was to analyze the clinical periodontal indexes and oxidative stress markers in gingival crevicular fluid modifications after three periodontal disease treatment possibilities (scaling and root planning-SRP; SRP and diode laser-L; SRP and photodynamic therapy-PDT). (2) Methods: The study was conducted on 52 patients: systemically healthy subjects with periodontal disease-non-RA (n = 26); and test group (n = 26) subjects with rheumatoid arthritis and periodontal disease-RA. Clinical periodontal measurements (probing depth-PD; Löe and Silness gingival index-GI; papillary bleeding index-PBI; and periodontal community index of treatment needs-CPITN) and oxidative stress markers (8-hydroxy-2'-deoxyguanosine (8-OHdG) and 4 hydroxynonenal (4-HNE)) were analyzed at baseline (T0), after three sessions of periodontal treatment (T1), and 6 months after treatment (T2). (3) Results: Periodontal therapy improved clinical periodontal measurements and oxidative stress markers in both analyzed groups, with supplementary benefits for laser- and PDT-treated periodontal pockets. (4) Conclusions: The analyzed oxidative stress markers decreased significantly following non-surgical periodontal therapy in both rheumatoid arthritis and systemically healthy patients. All the periodontal disease treatment possibilities analyzed in this study offered clinical and paraclinical improvements; however, the association of laser with SRP and photodisinfection with SRP yielded the best clinical and paraclinical outcomes when compared to SRP alone.

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.

Salivary Redox Biomarkers in the Course of Caries and Periodontal Disease

Caries are a pathological process of extracorporeal nature, characterized by demineralization of inorganic substances as well as proteolysis triggered by acids produced by bacteria present in dental plaque, as a result of metabolism of sugars of both external and internal origin. Periodontal disease, on the other hand, is a multifactorial degenerative disease associated with inflammation, involving a group of tissues that surround the dental cervix and root of the tooth. It is believed that one of the mechanisms in the etiopathogenesis of caries and periodontitis are disorders of local and/or general oxidative stress (OS) parameters. Numerous clinical studies have confirmed the relationship between oxidative stress markers and oral diseases. In most analyzed studies, technical and biological variability was so high that none of the markers so far has proven suitable for routine clinical use. The aim of systematic reviews of the literature is to present the existing studies on OS parameters, mainly concerning the activity of antioxidant enzymes in saliva of patients with caries and periodontitis.

Isolation and Identification of Non- Commensal Pathogenic Bacteria in the Saliva of Patients Candidate for Liver Transplant: A Cross Sectional Study in Shiraz, South of Iran

Statement of the Problem

Liver cirrhosis is the end stage of liver failure. It is mentioned as one of the main etiologies of morbidity and mortality in the world. The human salivary bacteria may induce oral disorders and interact with other body microbiota.

Purpose

The aim of the present study is to identify the pathogenic bacteria of non-oral origin from the saliva samples of patients with end stage liver failure.

Materials and Method

In this cross-sectional study, the saliva samples of 88 end stage liver disease cases and 84 age- and sex-matched healthy subjects were collected. The samples were cultured using gram staining and API20E Kit.

Results

According to the statistical analysis, the total amount of the non-commensal bacteria was significantly higher in chronic liver failure (CLF) group than controls (p= 0.001). There was no significant difference between both groups for the presence of other bacteria (p= 0.001) except for Escherichia coli (E. coli). E. coli was isolated from the saliva of 15 cases and only 2 controls.

Conclusion

Oral cavity may act as a reservoir for enteric bacteria such as E. coli in liver failure patients. Adequate oral and general hygiene might reduce the risk of systemic infection especially in immunocompromised cases.

Isolation and Identification of Non- Commensal Pathogenic Bacteria in the Saliva of Patients Candidate for Liver Transplant: A Cross Sectional Study in Shiraz, South of Iran

STATEMENT OF THE PROBLEM

Liver cirrhosis is the end stage of liver failure. It is mentioned as one of the main etiologies of morbidity and mortality in the world. The human salivary bacteria may induce oral disorders and interact with other body microbiota.

PURPOSE

The aim of the present study is to identify the pathogenic bacteria of non-oral origin from the saliva samples of patients with end stage liver failure.

MATERIALS AND METHOD

In this cross-sectional study, the saliva samples of 88 end stage liver disease cases and 84 age- and sex-matched healthy subjects were collected. The samples were cultured using gram staining and API20E Kit.

RESULTS

According to the statistical analysis, the total amount of the non-commensal bacteria was significantly higher in chronic liver failure (CLF) group than controls (p= 0.001). There was no significant difference between both groups for the presence of other bacteria (p= 0.001) except for Escherichia coli (E. coli). E. coli was isolated from the saliva of 15 cases and only 2 controls.

CONCLUSION

Oral cavity may act as a reservoir for enteric bacteria such as E. coli in liver failure patients. Adequate oral and general hygiene might reduce the risk of systemic infection especially in immunocompromised cases.

Oxidative stress, neutrophil elastase and IGFBP7 levels in patients with oropharyngeal cancer and chronic periodontitis

OBJECTIVE

The present study focused on investigating levels of oxidative stress, neutrophil elastase (NE), and insulin-like growth factor-binding protein 7 (IGFBP7) in oropharyngeal cancers (OC) with the presence and absence of periodontitis.

MATERIALS AND METHODS

A healthy non-periodontitis group (H-NP; n = 20), a systemically healthy chronic periodontitis group (H-P; n = 20), a non-periodontitis group with OC (OC-NP; n = 12), and a chronic periodontitis group with OC (OC-P; n = 16) formed the study groups. The levels of NE and IGFBP7 were measured in gingival crevicular fluid (GCF) and saliva. In addition, oxidative status was determined by evaluating total oxidant status (TOS), total antioxidant status (TAS), and OSI (TOS/TAS).

RESULTS

Gingival crevicular fluid NE was higher in all the groups compared with the H-NP group (p < .01). Salivary NE was higher in the OC-P and H-P groups compared with the H-NP and OC-NP groups (p < .05). Salivary IGFBP7 was significantly higher in the OC-NP and OC-P groups compared with the H-NP and H-P groups (p < .001). GCF TOS and OSI levels were significantly higher in all groups compared with the H-NP group (p < .05).

CONCLUSIONS

Gingival crevicular fluid NE levels were lower in healthy conditions compared with periodontal disease and OC. Salivary NE levels were higher in periodontal disease compared to states with no periodontal disease. Salivary IGFBP7 levels were higher in OC. Further analyses may help determine whether high salivary IGFBP7 levels distinguish OC from healthy conditions.

Salivary markers of oxidative stress and periodontal pathogens in patients with periodontitis from Santander, Colombia

Introduction:

Periodontitis affects more than 20% of the Latin American population. Oxidative markers are associated with greater progression of periodontitis; therefore, its role in pathogenesis should be studied.

Objective:

To determine the prevalence of the main oral bacteria and viruses associated with periodontitis and estimate the total antioxidant capacity and lipid peroxidation in saliva from patients with periodontitis.

Materials and methods:

We conducted systemically a cross-sectional study in 101 healthy subjects, 87 of whom had been diagnosed with periodontitis (P), according to the criteria of the Centers of Disease Control and Prevention and the American Academy of Periodontology, and 14 without periodontal pockets as controls (C). In subgingival samples, major viruses and dental pathogenic bacteria were identified using PCR techniques. The levels of total antioxidant capacity and malon-di-aldehyde (MDA) were determined by spectrophotometry in samples of unstimulated saliva.

Results:

The mean of periodontal depth pocket and clinical attachment loss in patients with periodontitis was 5.6 ± 1.7 and 6.1 ± 3.1 mm, respectively. The most prevalent microorganisms were Aggregatibacter actinomycetemcomitans (32.5%) and Porphyromonas gingivalis (18.6%). The patients from rural areas showed a higher percentage of A. actinomycetemcomitans (urban: 17.9% vs. rural: 48.9%, p=0.0018). In patients with periodontitis, the frequency of EBV, HSV1 & 2, and HCMV genes was 2.3%. Periodontitis patients had higher levels of MDA (P: 2.1 ± 1.5; C: 0.46 ± 0.3 µmol/g protein; p=0.0001) and total antioxidant capacity (P: 0.32 ± 0.2; C: 0.15 ± 0.1 mM; p< 0.0036). Oxidative markers showed no modifications due to the presence of periodontopathic bacteria.

Conclusions:

Aggregatibacter actinomycetemcomitans was the most prevalent bacteria; its presence did not modify the levels of oxidative markers in the saliva of patients with periodontitis.

Oxidative stress-related biomarkers in saliva and gingival crevicular fluid associated with chronic periodontitis: A systematic review and meta-analysis

AIM

Oxidative stress (OS) biomarkers have been detected in saliva and gingival crevicular fluid (GCF) during chronic periodontitis (CP) progression; however, the relationship between OS biomarkers and CP progression remains elusive. The purpose of this meta-analysis is to investigate the relationship between local OS biomarkers and CP.

METHODS

This review was conducted through a systematic search from three databases. Studies on CP participants were included as an experimental group, and studies on periodontally healthy (PH) participants were included as a control. Mean effects were expressed as standardized mean difference with their associated 95% confidence intervals.

RESULTS

From a total of 2,972 articles, 32 articles fulfilled the inclusion criteria. We found a significant decrease of total antioxidant capacity and a significant increase of malondialdehyde (MDA), nitric oxide, total oxidant status (TOS), and 8-hydroxy-deoxyguanosine levels in the saliva of CP patients. Moreover, we also found an elevation of MDA level in GCF of CP group when compared with the PH group. There were no significant differences of salivary and GCF superoxide dismutase levels, salivary glutathione peroxidase level, and GCF TOS level between two groups. However, a high heterogeneity was observed among evaluated studies.

CONCLUSIONS

Despite the limitations of this study, the result of our meta-analysis supported the rationale that there was a direct link between CP and OS-related biomarkers' levels in the local site, indicating the important role of OS in the onset and development of CP.

Effects of colchicine on gingival inflammation, apoptosis, and alveolar bone loss in experimental periodontitis

BACKGROUND

The aim of the study was to investigate the effects of colchicine on cytokine production, apoptosis, alveolar bone loss, and oxidative stress in an experimental model of periodontitis in rats.

METHODS

Forty-eight rats were divided equally into four groups: healthy (H); periodontitis (P); periodontitis+colchicine low dose (CL, 30 μg/kg/day), and periodontitis+colchicine high dose (CH, 100 μg/kg/day). After 11 days, interleukin (IL) -1β, IL-8, and IL-10 were analyzed in gingival samples using Enzyme-Linked ImmunoSorbent Assay. Receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), total oxidative stress (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) were measured in gingiva and serum. Alveolar bone volume was evaluated via micro-CT. Apoptotic cells were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay in histological sections.

RESULTS

Colchicine treatment significantly reduced IL-1β, IL-8, RANKL, RANKL/OPG, TOS, OSI, and bone volume ratio levels, and increased TAS levels compared to group P (p < 0.05). High dose colchicine treatment (CH) significantly decreased TUNEL+ cell counts compared to group P (p < 0.05).

CONCLUSIONS

These finding suggest that colchicine has a prophylactic potential for the prevention of periodontal tissue destruction through anti-inflammatory, anti-oxidative, anti-apoptotic, and bone-protective effects.

Histopathological and biochemical evaluation of paeoniflorin administration in an experimental periodontitis model

The purpose of this study was to evaluate the effects of administered Paeoniflorin (Pae) on periodontal tissues within an experimental periodontitis model. Forty male Wistar rats were used in this study and experimental periodontitis was created in all rats except in the control group (n = 10, first group). In the periodontitis group, experimental periodontitis was created but no other application was performed (n = 10, second group). In the other groups created experimental periodontitis, systemic Pae (n = 10, third group) or saline (n = 10, fourth group) was applied. A biochemical analysis of the gingival vascular endothelial growth factor (VEGF) levels and a histomorphometric analysis (measurements of the area of alveolar bone, alveolar bone resorption, and attachment loss) were performed. In the Pae group, the area of the alveolar bone was increased, while alveolar bone resorption and attachment loss decreased. Gingival VEGF levels increased in all groups that created experimental periodontitis and the greatest increase seen in the Pae group. Histomorphometric and biochemical analyses in this study suggest that Pae has a curative effect on periodontal tissues. However, additional studies are needed to confirm these results.

Comparative evaluation of salivary malondialdehyde levels as a marker of lipid peroxidation in early childhood caries

Objective

The aim of this study was to evaluate the association between lipid peroxidation and dental caries in children with ECC by estimating the levels of MDA in saliva of children.

Materials and Methods

A total of 150 children were selected; 75 children with ECC and 75 children without caries (non-ECC). Saliva samples were collected and centrifuged at 12,000 rpm for 24 min at 4°C to obtain a supernatant. MDA levels were estimated by Buege and Aust method by using thiobarbituric acid. The data obtained were analyzed by Student's t-test to compare MDA levels between the groups.

Results

MDA levels were higher in children with ECC. There was no statistically significant difference between children with ECC and without ECC (non-ECC).

Conclusion

MDA levels were slightly higher in children with ECC, indicating the role of lipid peroxidation in the carious process.

Anorexia, Oral Health and Antioxidant Salivary System: A Clinical Study on Adult Female Subjects

The aim of this study was to compare the oral health status and salivary antioxidant system between patients diagnosed with anorexia nervosa (AN) and healthy controls. A total of 25 female AN patients and 25 matched healthy controls were enrolled. Clinical parameters and saliva samples were collected for each patient. Two questionnaires to investigate oral health and hygiene were administered. Superoxide Dismutase (SOD) activity and High Reactive Oxygen Species (hROS) were evaluated. Salivary concentration of SOD was significantly higher in subjects with AN compared with control group (1.010 ± 0.462 vs. 0.579 ± 0.296 U/mL; p = 0.0003). No significant differences between groups were identified for hROS (233.72 ± 88.27 vs. 199.49 ± 74.72; p = 0.15). Data from questionnaires indicated that, although most of the patients recognized the oral hygiene importance in maintaining a good oral health, more than half of them had poor oral hygiene. Altered biochemical composition of saliva in patients with AN could be interpreted as an effective defence mechanism against oxidative stress. Moreover, despite the discrepancy between clinical findings and perception of the oral health in AN population arose, the quality of life of these patients appears not to be significantly affected by their dental condition.

Salivary Oxidant/Antioxidant Status in Chronic Temporomandibular Disorders Is Dependent on Source and Intensity of Pain - A Pilot Study

Temporomandibular disorders (TMD) have been associated with altered salivary oxidative status, but the relation with pain source and pain severity isn't clarified. With the aim to assess their interaction with TMD, we compared levels of selected salivary oxidative stress (OS) markers (glutathione peroxidase, superoxide dismutase, total antioxidant capacity (TAC), uric acid, 8-hydroxydeoxyguanosine, malondialdehyde) and salivary cortisol (SC) as a stress indicator, between 20 TMD patients and 15 healthy control subjects. In order to record differences relating to pain source and severity, patients were respectively classified according to specific diagnoses (myofascial pain or disc displacement (DD)), and pain intensity (high or low). TAC was significantly higher in TMD patients than in controls (morning p = 0.015; afternoon p = 0.005). Significant differences were also observed when TAC levels between high-intensity pain patients and controls were compared, as well as between DD patients and controls. In logistic regression analysis, higher levels of TAC were related to DD (morning OR: 1.66, 95%CI: 1.05-2.64, p = 0.029; afternoon OR: 2.10, 95%CI: 1.11-3.98, p = 0.021) and to high-intensity pain (morning OR: 1.81, 95%CI: 1.04-3.15, p = 0.037; afternoon OR: 1.79, 95%CI: 1.02-3.14, p = 0.043). We also found that morning SC was positively correlated with antioxidant parameters in TMD patients. Our data suggest compensatory mechanism as response to higher level of stress. This stress could be extrinsic and lead toward TMD, or intrinsic, emerging from established TMD, or could be both. The intensity and the source of pain should be considered important factors in future investigations evaluating salivary OS markers in TMD patients.

Meta-Analysis of the Use of 8-OHdG in Saliva as a Marker of Periodontal Disease

The objective was to collect the available evidence on oxidative stress marker measurements in periodontal patients, focusing specifically on 8-hydroxy-2′-deoxyguanosine (8-OHdG) as a salivary marker of periodontal disease, and to perform meta-analyses to calculate differences in concentration compared to healthy persons. A systematic search in PubMed, Cochrane Library, Embase, and Scopus identified 81 articles. Of these, 38 were duplicates. After reading the abstracts of the remaining 43, 42 were selected for full-text assessment. Finally, 17 articles were included in the qualitative synthesis. Those excluded were of low quality, did not answer the research question, or did not meet the inclusion and exclusion criteria. Of the 17 in the qualitative synthesis, 9 were included in the meta-analysis. The 9 studies in the meta-analysis were combined in a random effects model. Their heterogeneity was high (Q = 3982.02, p < 0.001, I² = 99.8%). The difference in mean 8-OHdG concentration in saliva between periodontal and healthy subjects was estimated at 2.11 ng/ml (95% CI 1.23–2.98). The different saliva collection methods (stimulated/unstimulated) did not explain the heterogeneity. The 8-OHdG levels in saliva of periodontal patients were almost double to those of healthy patients: 8-OHdG is clearly a powerful periodontal disease marker.

Sources of free radicals and oxidative stress in the oral cavity

OBJECTIVE

An oral cavity is a place especially susceptible to oxidative damage. It is subjected to many environmental pro-oxidative factors or factors that have the ability to generate reactive oxygen species (ROS). The aim of this article is to present the main sources of ROS and oxidative stress in the oral environment.

DESIGN

A literature search was performed using the PubMed and Google Scholar databases.

RESULTS

One of the most important ROS sources in the oral cavity is periodontal inflammation. Other sources of ROS include: xenobiotics (ethanol, cigarette smoke, drugs), food (high-fat diet, high-protein diet, acrolein), dental treatment (ozone, ultrasound, non-thermal plasma, laser light, ultraviolet light), and dental materials (fluorides, dental composites, fixed orthodontic appliances, and titanium fixations). It has been shown that excessive production of ROS in the oral cavity may cause oxidative stress and oxidative damage to cellular DNA, lipids, and proteins, thus predisposing to many oral and systemic diseases.

CONCLUSIONS

Recognition of the exogenous sources of ROS and limitation of exposure to the ROS generating factors can be one of the prophylactic measures preventing oral and systemic diseases. It is suggested that antioxidant supplementation may be helpful in people exposed to excessive production of ROS in the oral cavity system.

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.

Inflammatory and Oxidative Responses in Pregnancies With Obesity and Periodontal Disease

BACKGROUND

Maternal obesity is related to immunologic and inflammatory systemic modifications that may worsen the pregnancy inflammatory status. Hormonal changes during pregnancy can adversely affect oral biofilms and oral health initiating or worsening periodontal diseases, with enhanced local and systemic oxidative stress and inflammation.

OBJECTIVE

The aim of this study was to examine the relationship between local salivary and systemic parameters of oxidative stress and inflammation in relation to obesity and periodontal diseases.

STUDY DESIGN

Sixty-two women with singleton pregnancies were enrolled. Twenty-seven women were normal weight (NW; 18.5< body mass index [BMI] <25 kg/m²) and 35 obese (BMI ≥30 kg/m²). Seventeen of the obese had gestational diabetes mellitus (GDM). During third trimester, periodontal status was evaluated, saliva (s) was collected to assess total antioxidant capacity (s-TAC) and C-reactive protein (s-CRP) levels, and venous plasma (p) was used to measure CRP levels (p-CRP). Maternal, fetal, and placental data were registered at delivery.

RESULTS

Levels of s-TAC, s-CRP, and p-CRP were significantly higher in obese, particularly in the presence of GDM, compared to NW and related to each other ( P = .000; r > 0.59), to maternal BMI ( P = .000; r > 0.52), and fasting glycemia ( P < .002; r > 0.47). Periodontal disease was more frequent in obese groups (80%) versus NW (52%; P = .04), particularly when GDM was diagnosed ( P = .009). A significant interaction effect between maternal BMI and oral condition was found for s-TAC levels. Obese with periodontitis showed significant increase in local and systemic parameters versus NW.

CONCLUSION

Obesity and periodontal disease could synergistically amplify the inflammatory and oxidative status, resulting in increased local and systemic biomarkers particularly when GDM is diagnosed.

Oxidative stress in the oral cavity is driven by individual-specific bacterial communities

The term "bacterial dysbiosis" is being used quite extensively in metagenomic studies, however, the identification of harmful bacteria often fails due to large overlap between the bacterial species found in healthy volunteers and patients. We hypothesized that the pathogenic oral bacteria are individual-specific and they correlate with oxidative stress markers in saliva which reflect the inflammatory processes in the oral cavity. Temporally direct and lagged correlations between the markers and bacterial taxa were computed individually for 26 volunteers who provided saliva samples during one month (21.2 ± 2.7 samples/volunteer, 551 samples in total). The volunteers' microbiomes differed significantly by their composition and also by their degree of microbiome temporal variability and oxidative stress markers fluctuation. The results showed that each of the marker-taxa pairs can have negative correlations in some volunteers while positive in others. Streptococcus mutans, which used to be associated with caries before the metagenomics era, had the most prominent correlations with the oxidative stress markers, however, these correlations were not confirmed in all volunteers. The importance of longitudinal samples collections in correlation studies was underlined by simulation of single sample collections in 1000 different combinations which produced contradictory results. In conclusion, the distinct intra-individual correlation patterns suggest that different bacterial consortia might be involved in the oxidative stress induction in each human subject. In the future, decreasing cost of DNA sequencing will allow to analyze multiple samples from each patient, which might help to explore potential diagnostic applications and understand pathogenesis of microbiome-associated oral diseases.

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.

Within-Subject Reliability and between-Subject Variability of Oxidative Stress Markers in Saliva of Healthy Subjects: A Longitudinal Pilot Study

The present study evaluated diurnal variations and day-to-day fluctuations of salivary oxidative stress (OS) markers in healthy adult individuals. Whole unstimulated saliva was collected at 2 time intervals over 3 consecutive days. Glutathione peroxidase (GPX), superoxide dismutase (SOD), total antioxidant capacity (TAC), and uric acid (UA) were analyzed using spectrophotometric methods, while 8-hydroxydeoxyguanosine (8-OHdG) and malondialdehyde (MDA) were determined using immunoassays. No significant differences for salivary OS markers between men and women were observed. For all examined OS markers, no significant day-to-day variations were demonstrated. Significant diurnal variations were found in salivary GPX, TAC and MDA levels. For SOD, TAC, GPX, and UA, good-to-moderate intraindividual coefficients of variations (CVs) were observed in more than 75% of the subjects. For MDA and 8-OHdG, intraindividual CVs > 35% were observed in 60% and 40% of the subjects, respectively. Between-subject variance was wide for all examined OS markers (CV% 30.08%–85.70%). Due to high intraindividual variability in the salivary concentrations of MDA and 8-OHdG, those markers cannot be reliably verified based on single measurements and multiple measurements over several days would provide more reliable information. Salivary SOD, TAC, GPX, and UA proved stable across three days of measurement. Trial Registration. ClinicalTrials.gov NCT03029494. Registered on 2017-01-19.

Oxidative Stress and Antioxidant System in Periodontitis

Periodontitis is a common inflammatory disease, which is initiated by bacterial infection and subsequently progressed by aberrant host response. It can result in the destruction of teeth supporting tissues and have an influence on systemic health. When periodontitis occurs, reactive oxygen species, which are overproduced mostly by hyperactive neutrophils, could not be balanced by antioxidant defense system and cause tissues damage. This is characterized by increased metabolites of lipid peroxidation, DNA damage and protein damage. Local and systemic activities of antioxidants can also be influenced by periodontitis. Total antioxidant capacity, total oxidant status and oxidative stress index have been used to evaluate the oxidative stress associated with periodontitis. Studies have confirmed that inflammatory response in periodontitis is associated with an increased local and systemic oxidative stress and compromised antioxidant capacity. Our review focuses on increased oxidative stress in periodontal disease, specifically, on the relationship between the local and systemic biomarkers of oxidative stress and periodontitis and their association with the pathogenesis of periodontitis. Also, the relationship between periodontitis and systemic inflammation, and the effects of periodontal therapy on oxidative stress parameters will be discussed.

5-Fluorouracil induces inflammation and oxidative stress in the major salivary glands affecting salivary flow and saliva composition

This study aimed to elucidate the effect of 5-fluorouracil (5-FU) on the histological aspects of the major salivary glands, salivary flow and saliva composition using an established oral mucositis model in hamsters. Oral mucositis was induced by two intraperitoneal administrations of 5-FU in two consecutive days (60 and 40mg/kg), followed by cheek pouch mucosa scratch, on day 4. The Pilocarpine-stimulated salivary flow was measured 4 and 10days after the first 5-FU injection. Salivary glands were harvested for histopathological analysis, measurement of inflammatory cells, quantification of pro-inflammatory cytokines (TNF-α and IL-1β), investigation of cell death and cell proliferation. Oxidative stress and oxidative defense system were also investigated in the salivary gland tissues using MDA (malondialdehyde), nitrite, non-protein sulfhydryl groups (NP-SH), SOD (superoxide dismutase) and CAT (catalase). In addition, the CAT and lysozyme activities and the IgA and SOD levels were evaluated in the saliva samples. 5-FU significantly reduced the pilocarpine-stimulated salivary flow rate on the 4th experimental day, associated with an increase in the SOD levels in saliva. Recovery of the salivary flow and SOD were observed on day 10, when an increase in the saliva lysozyme levels was detected. In addition, 5-FU promoted vacuolization in parotid (P) and periductal edema in submandibular (SM) gland, combined with an increase in the inflammatory cells influx, mostly observed on the 4th day in SM gland and on 4th and 10th days in P. Oxidative stress was found mostly on day 10 in SM, SL and P glands, associated with release of proinflammatory cytokines, observed in SM and SL glands, but not in P. 5-FU induces an inflammatory response in the major salivary glands, most observed ten days after its first injection, which may contribute to the major salivary glands hypofunction, leading to alterations in the salivary flow rate and composition.

Identification of a discriminative metabolomic fingerprint of potential clinical relevance in saliva of patients with periodontitis using 1H nuclear magnetic resonance (NMR) spectroscopy

Periodontitis is characterized by the loss of the supporting tissues of the teeth in an inflammatory-infectious context. The diagnosis relies on clinical and X-ray examination. Unfortunately, clinical signs of tissue destruction occur late in the disease progression. Therefore, it is mandatory to identify reliable biomarkers to facilitate a better and earlier management of this disease. To this end, saliva represents a promising fluid for identification of biomarkers as metabolomic fingerprints. The present study used high-resolution ¹H-nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate statistical analysis to identify the metabolic signature of active periodontitis. The metabolome of stimulated saliva of 26 patients with generalized periodontitis (18 chronic and 8 aggressive) was compared to that of 25 healthy controls. Principal Components Analysis (PCA), performed with clinical variables, indicated that the patient population was homogeneous, demonstrating a strong correlation between the clinical and the radiological variables used to assess the loss of periodontal tissues and criteria of active disease. Orthogonal Projection to Latent Structure (OPLS) analysis showed that patients with periodontitis can be discriminated from controls on the basis of metabolite concentrations in saliva with satisfactory explained variance (R2X = 0.81 and R2Y = 0.61) and predictability (Q2Y = 0.49, CV-AUROC = 0.94). Interestingly, this discrimination was irrespective of the type of generalized periodontitis, i.e. chronic or aggressive. Among the main discriminating metabolites were short chain fatty acids as butyrate, observed in higher concentrations, and lactate, γ-amino-butyrate, methanol, and threonine observed in lower concentrations in periodontitis. The association of lactate, GABA, and butyrate to generate an aggregated variable reached the best positive predictive value for diagnosis of periodontitis. In conclusion, this pilot study showed that 1H-NMR spectroscopy analysis of saliva could differentiate patients with periodontitis from controls. Therefore, this simple, robust, non-invasive method, may offer a significant help for early diagnosis and follow-up of periodontitis.

Inhibiting PHD2 in bone marrow mesenchymal stem cells via lentiviral vector-mediated RNA interference facilitates the repair of periodontal tissue defects in SD rats

Hypoxia-inducible factors (HIFs) play an important role in angiogenesis, and they can activate the expression of several downstream angiogenic factors. HIF-1 is a major transcriptor of HIFs, composed of α and β subunits. Prolyl hydroxylase domain-containing protein 2 (PHD2) is the main catabolic enzyme for HIF-1α, and it can accelerate its degradation under normoxic conditions. PHD2 expression in bone marrow mesenchymal stem cells (BMMSCs) of SD rats was down-regulated under normoxic conditions in this study by utilizing lentiviral vector-mediated RNA interference to promote HIF-1α accumulation, thus enhancing the expression of angiogenic factors. A tissue-engineered compound was constructed using the composite collagen membrane of BMMSCs after PHD2 gene silencing to repair periodontal fenestration defects in SD rats. The results of this study indicated that, after PHD2 gene silencing, the osteogenic differentiation of BMMSCs was enhanced in vitro, the resistance of cells to oxidative stress was also validated in vitro, thereby illustrating the promotion of the repair of artificially constructed periodontal tissue defects in rats. The results of this study provide a reference and guidance for future applications of RNA interference in periodontal tissue engineering and serve as a basis for improving the survival of seed cells in recipient tissues.

Gingival crevicular fluid and plasma oxidative stress markers and TGM-2 levels in chronic periodontitis

OBJECTIVE

This study was aimed to evaluate the gingival crevicular fluid (GCF) and plasma transglutaminase-2 (TGM-2), total antioxidant capacity (TAC), total oxidant status (TOS), ferric reducing antioxidant power (FRAP) and thiobarbituric acid reactive substances (TBARS) in patients with chronic periodontal disease.

MATERIALS AND METHODS

Twenty patients with chronic periodontitis (CP), 20 patients with gingivitis and 20 healthy subjects were enrolled in the study. Clinical periodontal parameters including probing depth, clinical attachment level, plaque index and papillary bleeding index were recorded. GCF and plasma levels of TGM-2, TAC, TOS, TBARS and FRAP were analyzed.

RESULTS

GCF TGM-2 was significantly lower in CP group than in gingivitis patients (P=0.006). GCF FRAP in CP and gingivitis groups was significantly lower than in healthy subjects (P<0.001). Plasma FRAP level was lower in gingivitis group when compared to healthy subjects (P=0.003). There was no significant difference in GCF and plasma TAC, TOS, TBARS and plasma TGM-2 levels among the study groups (P>0.05). GCF TGM-2 level was positively correlated with GCF TAC and negatively correlated with CAL.

CONCLUSIONS

Decreased FRAP in GCF and plasma indicating lower antioxidant status of CP patients might suggest the role of oxidative stress in periodontitis. GCF TGM-2 data might suggest that TGM2 is associated with stabilization of the extracellular matrix and wound healing in periodontium rather than gingival inflammation.

The Role of Reactive Oxygen Species and Autophagy in Periodontitis and Their Potential Linkage

Periodontitis is a chronic inflammatory disease that causes damage to periodontal tissues, which include the gingiva, periodontal ligament, and alveolar bone. The major cause of periodontal tissue destruction is an inappropriate host response to microorganisms and their products. Specifically, a homeostatic imbalance between reactive oxygen species (ROS) and antioxidant defense systems has been implicated in the pathogenesis of periodontitis. Elevated levels of ROS acting as intracellular signal transducers result in autophagy, which plays a dual role in periodontitis by promoting cell death or blocking apoptosis in infected cells. Autophagy can also regulate ROS generation and scavenging. Investigations are ongoing to elucidate the crosstalk mechanisms between ROS and autophagy. Here, we review the physiological and pathological roles of ROS and autophagy in periodontal tissues. The redox-sensitive pathways related to autophagy, such as mTORC1, Beclin 1, and the Atg12-Atg5 complex, are explored in depth to provide a comprehensive overview of the crosstalk between ROS and autophagy. Based on the current evidence, we suggest that a potential linkage between ROS and autophagy is involved in the pathogenesis of periodontitis.

Pathways that Regulate ROS Scavenging Enzymes, and Their Role in Defense Against Tissue Destruction in Periodontitis

Periodontitis, an inflammatory disease that affects the tissues surrounding the teeth, is a common disease worldwide. It is caused by a dysregulation of the host inflammatory response to bacterial infection, which leads to soft and hard tissue destruction. In particular, it is the excessive inflammation in response to bacterial plaque that leads to the release of reactive oxygen species (ROS) from neutrophils, which, then play a critical role in the destruction of periodontal tissue. Generally, ROS produced from immune cells exhibit an anti-bacterial effect and play a role in host defense and immune regulation. Excessive ROS, however, can exert cytotoxic effects, cause oxidative damage to proteins, and DNA, can interfere with cell growth and cell cycle progression, and induce apoptosis of gingival fibroblasts. Collectively, these effects enable ROS to directly induce periodontal tissue damage. Some ROS also act as intracellular signaling molecules during osteoclastogenesis, and can thus also play an indirect role in bone destruction. Cells have several protective mechanisms to manage such oxidative stress, most of which involve production of cytoprotective enzymes that scavenge ROS. These enzymes are transcriptionally regulated via NRF2, Sirtuin, and FOXO. Some reports indicate an association between periodontitis and these cytoprotective enzymes' regulatory axes, with superoxide dismutase (SOD) the most extensively investigated. In this review article, we discuss the role of oxidative stress in the tissue destruction manifest in periodontitis, and the mechanisms that protect against this oxidative stress.

Evaluation of Salivary and Serum Antioxidant and Oxidative Stress Statuses in Patients with Chronic Periodontitis: A Case-Control Study

Aim: Local bacteria stimulate polymorphonuclear neutrophils to release reactive oxygen species in periodontitis. Increased levels of oxidative stress play a significant role in the pathogenesis of periodontitis. Therefore, this study aimed to evaluate total salivary and serum antioxidant capacity and malondialdehyde in patients with chronic periodontitis.

Materials and methods: Fifty-five healthy subjects and 55 patients with chronic periodontitis, with an age range of 30–50 years, were evaluated. After clinical examination and case selection, unstimulated whole saliva was collected in the morning. Blood samples were taken from the antecubital vein. Total antioxidant capacity and malondialdehyde levels were evaluated by spectrophotometric assay. Data were analyzed with t-test, using Stata.11 software program.

Results: The periodontitis group exhibited lower salivary (0.16) and serum (0.36) total antioxidant capacity (P = 0.11) compared to the control group. Mean salivary malondialdehyde levels in the case and control groups were 0.80 ± 0.09 and 0.42 ± 0.08, respectively. The results showed significantly higher levels of salivary and serum malondialdehyde in the periodontitis group. Gender did not have any effect on antioxidant and oxidative stress levels.

Conclusion: This study indicated increased levels of salivary and serum oxidative stresses in patients with chronic periodontitis. Total antioxidant capacity was mildly lower in the saliva and serum of these patients. Higher malondialdehyde levels with no changes in antioxidant status can result in systemic and local complications in these patients.