Resveratrol attenuates oxidative stress during experimental periodontitis in rats exposed to cigarette smoke inhalation

Resveratrol facilitates bone formation in high-glucose conditions

Periodontitis is known to be affected by high-glucose conditions, which poses a challenge to periodontal tissue regeneration, particularly in bone formation. In this study, the potential effects of resveratrol (3,5,4'-trihydroxystilbene, RSV) in facilitating bone formation under high-glucose conditions after periodontitis has been investigated. We focused on the analysis of osteoblasts and periodontal ligament cells, which are essential for bone formation including cell proliferation and differentiation. And we aimed to investigate the impact of RSV on bone healing, employed diabetic mouse model induced by streptozotocin and confirmed through histological observation. High-glucose conditions adversely affected cell proliferation and ALP activity in both MC3T3-E1 and hPDLF in vitro, with more significant impact on MC3T3-E1 cells. RSV under high-glucose conditions had positive effects on both, showing early-stage effects for MC3T3-E1 cells and later-stage effects for hPDLF cells. RSV seemed to have a more pronounced rescuing role in MC3T3-E1 cells. Increased ALP activity was observed and the expression levels of significant genes, such as Col 1, TGF-β1, ALP, and OC, in osteogenic differentiation were exhibited stage-specific expression patterns. Upregulated Col 1 and TGF-β1 were detected in the early stage, and then ALP and OC expressions became more pronounced in the later stages. Similarly, stronger positive reactions against RUNX2 were detected in the RSV-treated group compared to the control. Furthermore, in in vivo experiment, RSV stimulates the growth and differentiation of osteoblasts, thereby promoting bone formation. High-glucose levels have the potential to impair cellular functions and the regenerative capacity to facilitate bone formation with MC3T3-E1 rather than hPDLF cells. Resveratrol appears to facilitate the inherent abilities of MC3T3-E1 cells compared with hPDLF cells, indicating its potential capacity to restore functionality during periodontal regeneration.

Cellular Senescence in Craniofacial Tissue Regeneration: Inducers, Biomarkers, and Interventions

Craniofacial defects and dental tissue loss have significant negative impacts on the structure and function of jaws and face, often resulting in psychological issues in patients, emphasizing the urgent need for effective craniofacial tissue reconstruction. Unfortunately, natural regeneration of these tissues is limited. Dental-derived mesenchymal stem cells (MSCs) have emerged as a promising resource for tissue engineering-based therapeutic approaches. However, the clinical outcomes of MSC-based transplantation have not met expectations due to various complex reasons, and cellular senescence is recognized as one of the potential mechanisms contributing to the suboptimal results. The quality of MSC decreases during large-scale in vitro expansion, and it is also influenced by the age and the health status of donors. To address these challenges, extensive efforts have been made to developing strategies to combat senescence in tissue engineering, leveraging on current knowledge of underlying mechanisms. This review aims to elucidate the impact of cell senescence in craniofacial and dental regeneration and provides an overview of state-of-the-art antisenescence strategies. We first discuss the potential factors that trigger cell senescence in craniofacial tissue engineering. Then we describe senescence biomarkers, monitoring methods for senescent MSCs, and their underlying molecular mechanisms. The primary focus of this review is on current strategies to inhibit and alleviate cell senescence in tissue engineering. We summarize the strategies concerning the prevention of cell senescence, senolysis, modulation of the senescent associated secretory phenotype, and reversal of senescent MSCs, offering promising opportunities to overcome the challenges associated with cell senescence in craniofacial tissue engineering.

Resveratrol can improve spinal cord injury by activating Nrf2/HO-1 signaling pathway

Spinal cord injury (SCI) often induces severe sensory and motor dysfunction. Oxidative stress is an important pathophysiological process of secondary SCI, and its inhibition could facilitate the alleviation of the injury. Resveratrol is a natural plant polyphenol compound that has significant antioxidant and anti-inflammatory effects. It can inhibit oxidative stress by activating the Nrf2/HO-1 signal pathway. In this report, we analyze the antioxidant effect of resveratrol in SCI, clarify the specific mechanism of action and provide a theoretical basis for the clinical employment of resveratrol for SCI.

Association between smoking and peri-implant diseases: A retrospective study

OBJECTIVES

To determine the association between tobacco and peri-implant diseases in a sample of patients who had received implant-supported restorations in a university dental clinic. Furthermore, the study aimed to investigate patient- and implant-related variables associated with peri-implant diseases.

MATERIALS AND METHODS

The present retrospective study analyzed data from 117 patients treated with implant-supported restorations from 2001 to 2013. A total of 450 implants were evaluated. Patients were selected from an electronic database, and patient- and implant-related variables were evaluated. Detailed information regarding the smoking history (i.e., smoking status, lifetime cumulative dose, duration of exposure, intensity of the habit, and smoking cessation) was recorded. The primary study outcome was peri-implant status [i.e., health (H), peri-implant mucositis (PM) and peri-implantitis (PI)]. Univariate and multinomial regression models comparing PM and PI versus peri-implant health were conducted.

RESULTS

A total of 117 subjects [55 (47%) females and 62 (53%) males] with a mean age at examination of 64.2 years (SD 11.6) and rehabilitated with 450 implants were included. The average number of implants per patient was 4.6 (SD 3.3) with a mean time in function of 8.0 years (SD 1.9). Fifty-six patients (47.9%) were non-smokers, 42 (35.9%) were former-smokers, and 19 (16.2%) were current-smokers. Thirty-nine subjects (33.4%) were H, whereas 41 (35%) and 37 (31.6%) exhibited PM and PI, respectively. At implant level, the corresponding values were 142 (31.6%), 230 (51.1%) and 78 (17.3%). In the multinomial regression model, significant associations for peri-implant diseases were observed for the mean number of implants per patient (p = .016), function time (p = .048), implants placed simultaneously with guided bone regeneration (p = .016), implant surface (p = .020), keratinized mucosa at the buccal aspect (p = .032), and access to interproximal hygiene (p < .001). In addition, ever smokers >23 pack-years exhibited a significantly higher risk for peri-implantitis (p = .002). Finally, the multinomial regression analysis revealed that subjects who had stopped smoking more than 21 years before the last examination presented a significantly lower risk of peri-implant diseases than a smoking cessation of ≤21 years (p = .028).

CONCLUSIONS

Smoke intensity was associated with an increased risk of the development of peri-implantitis. Moreover, the risk of peri-implant diseases might be similar in those subjects who had stopped smoking for more than 21 years with respect to never-smokers.

Impact of local drug delivery and natural agents as new target strategies against periodontitis: new challenges for personalized therapeutic approach

Periodontitis is a persistent inflammation of the soft tissue around the teeth that affects 60% of the population in the globe. The self-maintenance of the inflammatory process can cause periodontal damage from the alveolar bone resorption to tooth loss in order to contrast the effects of periodontitis, the main therapy used is scaling and root planing (SRP). At the same time, studying the physiopathology of periodontitis has shown the possibility of using a local drug delivery system as an adjunctive therapy. Using local drug delivery devices in conjunction with SRP therapy for periodontitis is a potential tool since it increases drug efficacy and minimizes negative effects by managing drug release. This review emphasized how the use of local drug delivery agents and natural agents could be promising adjuvants for the treatment of periodontitis patients affected or not by cardiovascular disease, diabetes, and other system problems. Moreover, the review evidences the current issues and new ideas that can inspire potential later study for both basic research and clinical practice for a tailored approach.

Antioxidant, anti-inflammatory and antimicrobial activity of natural products in periodontal disease: a comprehensive review

Periodontal diseases (PD) are common chronic inflammatory oral pathologies that are strongly linked to others not found in the mouth cavity. The immune system mediates the host response, which includes the upregulation of proinflammatory cytokines, metalloproteinases, and reactive oxygen species (ROS); the latter may play an important role in the establishment and progression of inflammatory diseases, particularly periodontal disease, via the development of oxidative stress (OS). Natural antioxidants have powerful anti-inflammatory properties, and some can reduce serum levels of key PD indicators such tumor necrosis factor (TNF) and interleukin IL-1. This review compiles, through a thorough literature analysis, the antioxidant, anti-inflammatory, and antibacterial effects of a variety of natural products, as well as their therapeutic potential in the treatment of PD.

Maqui Berry and Ginseng Extracts Reduce Cigarette Smoke-Induced Cell Injury in a 3D Bone Co-Culture Model

Cigarette smoking-induced oxidative stress has harmful effects on bone metabolism. Maqui berry extract (MBE) and ginseng extract (GE) are two naturally occurring antioxidants that have been shown to reduce oxidative stress. By using an osteoblast and osteoclast three-dimensional co-culture system, we investigated the effects of MBE and GE on bone cells exposed to cigarette smoke extract (CSE). The cell viability and function of the co-culture system were measured on day 14. Markers of bone cell differentiation and oxidative stress were evaluated at gene and protein levels on day 7. The results showed that exposure to CSE induced osteoporotic-like alterations in the co-culture system, while 1.5 µg/mL MBE and 50 µg/mL GE improved CSE-impaired osteoblast function and decreased CSE-induced osteoclast function. The molecular mechanism of MBE and GE in preventing CSE-induced bone cell damage is linked with the inhibition of the NF-κB signaling pathway and the activation of the Nrf2 signaling pathway. Therefore, MBE and GE can reduce CSE-induced detrimental effects on bone cells and, thus, prevent smoking-induced alterations in bone cell homeostasis. These two antioxidants are thus suitable supplements to support bone regeneration in smokers.

Chloro-aluminum phthalocyanine-mediated photodynamic therapy in the treatment of stage-II chronic periodontitis among smokers

PURPOSE

To assess the clinical periodontal, bacterial, and immunological outcomes of chloro-aluminum phthalocyanine-mediated photodynamic therapy (PDT) as an adjunct to dental scaling (DS) versus DS alone among cigarette smokers (CS) and never-smokers (NS).

METHODS

A total of 26 patients (13 CS and 13 NS) with clinical and radiographic diagnosis of stage-II chronic periodontitis were recruited. Each patient from both groups were subjected with two parallel therapies (split-mouth): PDT + DS (test side) and DS alone (control side). Periodontal parameters were investigated by evaluating plaque scores (PS), bleeding on probing (BOP), probing depth (PD), clinical attachment loss (CAL), and alveolar bone loss (ABL). Subgingival plaque was collected to detect and quantify Porphyromonas gingivalis and Tannerella forsythia using real-time quantitative polymerase chain reaction (RT-qPCR) assay. Gingival crevicular fluid was sampled for the quantification of interleukin (IL)-1β and tumor necrosis factor-alpha (TNF-α) using enzyme linked immunosorbent assay. All assessments were performed at baseline, 3 months, and 6 months.

RESULTS

Bleeding on probing was significantly reduced at 6 months after PDT + DS in CS groups (p < .05). Mean PD and CAL significantly reduced after both PDT + DS and DS subgroups and among NS and CS groups (p < .05). At 6 months follow-up, the copy number of both P. gingivalis and T. forsythia remained significantly high in CS group (p < .01). Only PDT + DS subgroup in CS significantly reduced the counts of P. gingivalis and T. forsythia at 3 months and 6 months (p < .05). Only at 6 months did PDT + DS showed statistically significantly reduced IL-1β levels in the NS group (p < .01). TNF-α levels significantly reduced in CS group with PDT + DS and DS alone at both 3 months and 6 months follow-up (p < .01).

CONCLUSION

Chloro-aluminum phthalocyanine-mediated PDT helped to improve the non-surgical periodontal therapy outcomes among stage-II chronic periodontitis patients among smokers and never-smokers.

Oxidative stress and inflammation regulation of sirtuins: New insights into common oral diseases

Sirtuins are a family of nicotinamide adenine dinucleotide (NAD)⁺-dependent histone deacetylases, comprising seven members SIRT1-SIRT7. Sirtuins have been extensively studied in regulating ageing and age-related diseases. Sirtuins are also pivotal modulators in oxidative stress and inflammation, as they can regulate the expression and activation of downstream transcriptional factors (such as Forkhead box protein O3 (FOXO3a), nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-kappa B (NF-κB)) as well as antioxidant enzymes, through epigenetic modification and post-translational modification. Most importantly, studies have shown that aberrant sirtuins are involved in the pathogenesis of infectious and inflammatory oral diseases, and oral cancer. In this review, we provide a comprehensive overview of the regulatory patterns of sirtuins at multiple levels, and the essential roles of sirtuins in regulating inflammation, oxidative stress, and bone metabolism. We summarize the involvement of sirtuins in several oral diseases such as periodontitis, apical periodontitis, pulpitis, oral candidiasis, oral herpesvirus infections, dental fluorosis, and oral cancer. At last, we discuss the potential utilization of sirtuins as therapeutic targets in oral diseases.

Lipopolysaccharide-Preconditioned Dental Follicle Stem Cells Derived Small Extracellular Vesicles Treating Periodontitis via Reactive Oxygen Species/Mitogen-Activated Protein Kinase Signaling-Mediated Antioxidant Effect

Purpose

Lipopolysaccharide (LPS) pretreatment can enhance the therapeutic effect of dental follicle stem cells-derived small extracellular vesicles (DFC-sEV) for periodontitis, and this study aimed to investigate the underlying mechanisms and clinical application Of LPS-preconditioned DFC-sEV in periodontitis.

Methods

The protein spectrum of DFC-sEV before and after LPS pretreatment was determined by liquid chromatography-tandem mass spectrometry and bioinformatic analysis. Their effects on inflammatory periodontal ligament stem cells (PDLSCs) and macrophages were investigated for cell proliferation, migration, type 2 macrophage (M2) polarization, and intracellular reactive oxygen species (ROS) levels separately. In addition, the regulation of ROS/Jun amino-terminal kinases (JNK) and ROS/extracellular signal-related kinases (ERK) signaling by LPS-preconditioned DFC-sEV was also studied to reveal the antioxidant mechanism. In vivo, two kinds of DFC-sEV loaded with 0.2% hyaluronic acid (HA) gel were applied for canine periodontitis to evaluate the therapeutic potential.

Results

The proteomic analysis showed that thirty-eight proteins were differentially expressed in LPS-preconditioned DFC-sEV, and interestingly, the highly expressed proteins were mainly involved in antioxidant and enzyme-regulating activities. In addition to promoting PDLSCs and macrophage proliferation, LPS-preconditioned DFC-sEV inhibited intracellular ROS as an antioxidant. It reduced the RANKL/OPG ratio of PDLSCs by inhibiting ROS/JNK signaling under inflammatory conditions and promoted macrophages to polarize toward the M2 phenotype via ROS/ERK signaling. Furthermore, LPS-preconditioned DFC-sEV loaded with the HA injectable system could sustainably release sEV and enhance the therapeutic efficacy for periodontitis in canines.

Conclusion

LPS-preconditioned DFC-sEV could be effectively used as an auxiliary method for periodontitis treatment via antioxidant effects in a subgingival environment, and loading it with HA is feasible and effective for clinical applications.

Ethanol- and Cigarette Smoke-Related Alternations in Oral Redox Homeostasis

Alcohol abuse as well as smoking cigarettes has been proven to negatively affect the oral environment. The aim of this work was to provide a systematic review of the literature on the influence of ethanol and cigarette smoking on oral redox homeostasis. A search was performed for scientific articles indexed in the PubMed, Medline and Web of Science databases. We identified 32,300 articles, of which 54 were used for the final review, including the results from 2000 to 2021. Among the publications used to write this article, n = 14 were related to the influence of alcohol consumption (clinical studies n = 6, experimental studies n = 8) and n = 40 were related to the influence of smoking (clinical studies n = 33, experimental studies n = 7) on oral redox homeostasis. The reviewed literature indicates that alcohol abusers and smokers are more likely to suffer from salivary gland dysfunction, as well as develop precancerous lesions due to DNA damage. Compared to alcohol abstainers and non-smokers, alcohol drinkers and smokers are also characterized by a deterioration in periodontal health measured by various indicators of periodontal status. In summary, alcohol abuse and smoking are associated with disrupted oral redox homeostasis, which may lead not only to tooth loss, but also contribute to various adverse effects related to mental health, digestive processes and chronic inflammation throughout the human body.

Antioxidant Activity of Resveratrol Diastereomeric Forms Assayed in Fluorescent-Engineered Human Keratinocytes

Resveratrol is a powerful antioxidant molecule. In the human diet, its most important source is in Vitis vinifera grape peel and leaves. Resveratrol exists in two isoforms, cis- and trans. The diastereomeric forms of many drugs have been reported as affecting their activity. The aim of this study was to set up a cellular model to investigate how far resveratrol could counteract cytotoxicity in an oxidant agent. For this purpose, a keratinocyte cell line, which was genetically engineered with jelly fish green fluorescent protein, was treated with the free radical promoter Cumene hydroperoxide. The antioxidant activity of the trans-resveratrol and its diastereomeric mixture was evaluated indirectly in these treated fluorescent-engineered keratinocytes by analyzing the cell number and cell proliferation index. Our results demonstrate that cells, which were pre-incubated with resveratrol, reverted the oxidative damage progression induced by this free radical agent. In conclusion, fluorescent-engineered human keratinocytes represent a rapid and low-cost cellular model to determine cell numbers by studying emitted fluorescence. Comparative studies carried out with fluorescent keratinocytes indicate that trans-resveratrol is more efficient than diastereomeric mixtures in protecting cells from the oxidative stress.

The Effects of Nutraceuticals and Bioactive Natural Compounds on Chronic Periodontitis: A Clinical Review

The paper aims to review the current clinical evidence of various herbal agents as an adjunct treatment in the management of chronic periodontitis patients. Gingivitis and periodontitis are two common infectious inflammatory diseases of the supporting tissues of the teeth and have a multifactorial etiology. An important concern about chronic periodontitis is its association with certain systemic disease. New treatment strategies for controlling the adverse effects of chronic periodontitis have been extensively assessed and practiced in sub-clinical and clinical studies. It has been shown that the phytochemical agents have various therapeutic properties such as anti-inflammatory and antibacterial effects which can be beneficial for the treatment of periodontitis. The findings of this review support the adjunctive use of herbal agents in the management of chronic periodontitis. Heterogeneity and limited data may reduce the impact of these conclusions. Future long-term randomized controlled trials evaluating the clinical efficacy of adjunctive herbal therapy to scaling and root planing are needed.

The Advent of COVID-19; Periodontal Research Has Identified Therapeutic Targets for Severe Respiratory Disease; an Example of Parallel Biomedical Research Agendas

The pathophysiology of SARS-CoV-2 infection is characterized by rapid virus replication and aggressive inflammatory responses that can lead to acute respiratory distress syndrome (ARDS) only a few days after the onset of symptoms. It is suspected that a dysfunctional immune response is the main cause of SARS-CoV-2 infection-induced lung destruction and mortality due to massive infiltration of hyperfunctional neutrophils in these organs. Similarly, neutrophils are recruited constantly to the oral cavity to combat microorganisms in the dental biofilm and hyperfunctional neutrophil phenotypes cause destruction of periodontal tissues when periodontitis develops. Both disease models arise because of elevated host defenses against invading organisms, while concurrently causing host damage/disease when the immune cells become hyperfunctional. This represents a clear nexus between periodontal and medical research. As researchers begin to understand the link between oral and systemic diseases and their potential synergistic impact on general health, we argue that translational research from studies in periodontology must be recognized as an important source of information that might lead to different therapeutic options which can be effective for the management of both oral and non-oral diseases. In this article we connect concepts from periodontal research on oral inflammation while exploring host modulation therapy used for periodontitis as a potential strategy for the prevention of ARDS a deadly outcome of COVID-19. We suggest that host modulation therapy, although developed initially for management of periodontitis, and which inhibits proteases, cytokines, and the oxidative stress that underlie ARDS, will provide an effective and safe treatment for COVID-19.

Longitudinal evaluation of clinical, spectral and tissue degradation biomarkers in progression of periodontitis among cigarette and electronic cigarette smokers

OBJECTIVES

To longitudinally evaluate the periodontal parameters and MMP-8 and CTX (C-terminal crosslinked telopeptide of type I collagen) levels from diseased and healthy sites from cigarette and electronic cigarette (e-cig) smokers and characterize the gingival crevicular fluid (GCF) samples using Raman spectroscopy In addition, to longitudinally determine if MMP-8 and CTX are predictive factors for attachment loss in periodontitis sites.

METHODS

Sixty periodontally healthy and 60 periodontitis/diseased sites from 30 e-cig and 30 cigarette smokers were monitored at baseline, 3 months, and 6-months. GCF was sampled to study the MMP-8 and CTX concentrations using enzyme-linked immunosorbent assay. Infra-red absorption spectra of GCF were acquired at all time points and processed to identify key functional groups.

RESULTS

A significantly increased attachment loss was observed at 6 months for both smokers when compared with baseline (p < 0.01). This difference was significantly high for cigarette smokers compared with e-cig users (p < 0.01). MMP-8, CTX, smoking pack-years were significantly correlated with probing depth and clinical attachment loss among both e-cig and cigarette smokers. For MMP-8 and CTX, the periodontitis sites showed a statistically significant difference between e-cig and cigarette smokers at both 3- and 6 months follow-up. From baseline to 6 months follow-up, periodontitis sites from both groups showed higher spectral band intensities with deconvulations and Raman shifts for Amide I and Amide II peaks.

CONCLUSION

Cigarette smokers showed higher periodontal worsening than e-cig smokers. Smoking, MMP-8, CTX are prognostic factors for clinical attachment loss in cigarette and e-cig smokers.

CLINICAL SIGNIFICANCE

Data for Raman scattering and spectral information identifying collagen degradation among e-cig and cigarette smokers have been analyzed. This type of analysis proves a robust diagnostic and prognostic tool for periodontal diseases. Smoking, MMP-8, and CTX are prognostic factors for clinical attachment loss in cigarette and e-cig smokers.

The Effect of Melatonin on Periodontitis

BACKGROUND

Periodontitis is a chronic disease with a complex etiology that includes bacterial colonization, excessive inflammation, and oxidative stress. The hormone melatonin has antioxidant properties and might contribute to alleviating chronic conditions by reducing oxidative stress. The aim of this study was to analyze the effect of exogenous melatonin on periodontitis in an animal model of the disease as well as in patients with periodontitis.

METHODS

In rats with ligature-induced periodontitis, melatonin was administered in drinking water for two weeks. In the human study, patients with treatment-resistant periodontitis were asked to rinse their mouths with a solution containing melatonin or placebo every evening for two weeks. Periodontal status as well as salivary markers of oxidative stress were assessed at the end of the study.

RESULTS

Neither radiography nor μCT revealed any significant effects of melatonin on alveolar bone loss. Gum recession was the only improved macroscopic measure in rats (p < 0.05). Analysis of salivary markers of oxidative stress revealed no effects of treatment in rats or humans despite clearly elevated melatonin concentrations in melatonin treated groups.

CONCLUSION

Our results do not support the use of melatonin for the treatment of periodontitis. However, the negative outcome is limited by the short duration of the study and the chosen route of application as well as the dose of melatonin.

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.

Resveratrol and insulin association reduced alveolar bone loss and produced an antioxidant effect in diabetic rats

BACKGROUND

The present investigation studied the effects of systemic administration of resveratrol (RSV) on the development of experimental periodontitis (EP) and on the release of markers of inflammation, bone metabolism, and oxidative stress in diabetic rats.

METHODS

Seventy-five male rats were divided into five groups: DM+PLAC: Diabetes Mellitus + placebo solution; DM+INS: DM + insulin therapy; DM+RSV: DM + RSV; DM+RSV+INS: DM + RSV and insulin; NDM: non-diabetic. Streptozotocin was used to induce DM and EP was induced by the placement of a ligature at the fist mandibular and the second maxillary molars. Euthanasia occurred 30 days after the initiation of the study and mandible specimens were subjected for morphometric analysis of bone level. Gingival tissues from mandibular molars were collected for quantification of inflammatory and oxidative stress markers by multiplex assay system and ELISA assay, respectively. Maxillary gingival tissues were processed for real-time polymerase chain reaction (real-time PCR) assessment of markers of bone metabolism and oxidative stress.

RESULTS

Morphometric analysis revealed greater bone loss in DM+PLAC and DM+INS in comparison to the other treatments (P < 0.05). RSV used in conjunction with INS reduced the levels of interleukin (IL)-1β, IL-6, IL-17, interferon-gamma (IFN-γ) and superoxide dismutase 1 (SOD) (P < 0.05). RSV alone reduced nicotinamide adenine dinucleotide phosphatase oxidase (NADPH oxidase) levels, in comparison to DM+INS and DM+RSV+INS (P < 0.05). All treatments upregulated mRNA levels for osteoprotegerin (OPG) in comparison to PLAC (P < 0.05). Sirtuin 1 (SIRT) mRNA levels were lower in PLAC when compared to DM+RSV, DM+RSV+INS and NDM (P < 0.05).

CONCLUSION

RSV reduced the progression of EP and the levels of NADPH oxidase. Co-treatment with RSV and insulin reduced the levels of pro-inflammatory factors (either proteins or mRNA) and increased the levels of SOD. The data also demonstrated that treatment with RSV and INS alone or in combination had beneficial effects on bone loss.

Clinical peri-implant health and biological bone marker levels in tobacco users treated with photodynamic therapy

BACKGROUND

What impact does tobacco smoking have on photodynamic therapy (PDT) outcome is still unknown. The aim of the present clinical trial was to evaluate the clinical, radiographic, and biological bone markers after provision of PDT in cigarette, e-cigarette, and never-smokers with peri-implantitis (PI) at 6 months post treatment.

MATERIALS AND METHODS

Twenty-five healthy patients with PI were divided into three groups: Group I: cigarette smokers; Group II: e-cigarettes users; Group III: never-smokers. Full-mouth mechanical debridement with adjunctive methylene blue-mediated PDT was performed. Clinical recordings included peri-implant plaque index (Pi), bleeding on probing (BOP) and probing depth (PD). Peri-implant sulcular fluid was collected for the assessment of biological bone biomarkers including receptor activator of nuclear factor-ligand (RANK-L) and osteoprotegrin (OPG). All assessments were performed at baseline, 3 months and 6 months. P-value of <0.05 was considered significant.

RESULTS

BOP in Group II and III significantly reduced at 3 months (p < 0.05). Group I showed significant reduction only at 6 months (p < 0.05). Mean PD showed no statistically significant difference between the groups at any time-point. Inter-group comparison showed Group III demonstrating statistically significantly reduced mean RANK-L levels at both 3 and 6 months (p < 0.05). A slight increase in the OPG levels were observed at 3 months and followed by a slight decrease at 6 months for all the study groups when compared with baseline values, however, these values did not show statistical significance (p > 0.05).

CONCLUSION

Adjunctive PDT helped in reducing the clinical peri-implant inflammation. However, no significant change was observed for biological bone biomarkers among tobacco smokers.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

This comprehensive review of the 2019 restorative dental literature is offered to inform busy dentists regarding remarkable publications and noteworthy progress made in the profession. Developed by the Scientific Investigation Committee of the American Academy of Restorative Dentistry, each author brings discipline-specific expertise to 1 of 8 sections of the report: (1) prosthodontics; (2) periodontics, alveolar bone, and peri-implant tissues; (3) implant dentistry; (4) dental materials and therapeutics; (5) occlusion and temporomandibular disorders; (6) sleep-related breathing disorders; (7) oral medicine and oral and maxillofacial surgery; and (8) dental caries and cariology. The report targets important information likely to influence day-to-day dental treatment decisions. Each review is not intended to stand alone but to update interested readers so that they may visit source material when greater detail is desired. As the profession moves toward evidence-based clinical decision-making, an incredible volume of potentially valuable dental literature continues to increase. It is the intention of this review and its authors to provide assistance in negotiating the extensive dental literature published in 2019. It is our hope that readers find this work useful in the clinical management of dental patients.

Calcitriol suppresses lipopolysaccharide-induced alveolar bone damage in rats by regulating T helper cell subset polarization

BACKGROUND

Although the immunomodulatory properties of calcitriol in bone metabolism have been documented for decades, its therapeutic role in the management of periodontitis remains largely unexplored. In this study, we hypothesized that calcitriol suppresses lipopolysaccharide (LPS)-induced alveolar bone loss by regulating T helper (Th) cell subset polarization.

METHODS

To test this hypothesis, we determined the effect of calcitriol intervention on the development of LPS-induced periodontitis in rats in terms of bone loss (micro-CT analysis), local inflammatory infiltration levels, the number of osteoclasts (hematoxylin and eosin staining) and the level of osteoclastogenesis (tartrate-resistant acid phosphatase method). Furthermore, immunohistochemistry was used to assess the expression levels of the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) as well as the cytokine levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), IL-17, and IL-10 throughout the LPS-injected region. Finally, the polarization potential of Th cells in peripheral blood was analyzed using flow cytometry.

RESULTS

Calcitriol intervention decreased alveolar bone loss in response to LPS injection and inflammatory cell infiltration. Analysis of osteoclast number and RANKL and OPG expression showed that bone resorption activity was largely suppressed in response to calcitriol administration, along with decreased IL-17 levels but increased IL-4 and IL-10 levels in periodontal tissues (the LPS-injected region). Similarly, the percentages of Th2 and Treg cells in peripheral blood increased, but the percentages of Th1 and Th17 cells decreased in rats receiving calcitriol.

CONCLUSION

Our findings suggest that calcitriol can be used to inhibit bone loss in experimental periodontitis, likely via the regulation of local and systemic Th cell polarization.

Oxidative stress, nutritional antioxidants and beyond

Free radical-induced oxidative stress contributes to the development of metabolic syndromes (Mets), including overweight, hyperglycemia, insulin resistance and pro-inflammatory state. Most free radicals are generated from the mitochondrial electron transport chain; under physiological conditions, their levels are maintained by efficient antioxidant systems. A variety of transcription factors have been identified and characterized that control gene expression in response to oxidative stress status. Natural antioxidant compounds have been largely studied for their strong antioxidant capacities. This review discusses the recent progress in oxidative stress and mitochondrial dysfunction in Mets and highlights the anti-Mets, anti-oxidative, and anti-inflammatory effect of polyphenols as potential nutritional therapy.

Can Resveratrol Treatment Control the Progression of Induced Periodontal Disease? A Systematic Review and Meta-Analysis of Preclinical Studies

Resveratrol is an anti-inflammatory compound found in several foods. Periodontal disease (PD) is associated to other systemic diseases, and inflammation may be responsible for the association. Consequently, controlling inflammation not only may benefit oral health but also may assist with the management of other chronic inflammatory conditions. We aimed to investigate the effects of resveratrol administration on PD control in preclinical studies. A systematic search was performed for scientific articles using both electronic databases and a manual search using combinations of the following keywords: "resveratrol" OR "3,5,4'-trihydroxystilbene" AND "periodontal disease" OR "periodontitis" OR "gingivitis". Only in vivo original studies investigating resveratrol treatment on experimental animal models of PD were selected. A quality assessment of the studies was performed using the Animal Research Reporting In Vivo Experiment (ARRIVE) guidelines, and the risk of bias was assessed using the Syrcle tool. The search returned 570 articles, and 11 matched the inclusion criteria. A meta-analysis showed that resveratrol treatment attenuated alveolar bone loss (τ2 = 0.0041; 95% CI: -0.14; -0.04). The ARRIVE criteria reported a good quality of studies in general (mean score 28.5 ± 2.5). However, five Syrcle domains indicated a high risk of bias or did not present information clearly. We concluded that, in preclinical studies, resveratrol treatment prevented PD progression.