Influence of obesity on experimental periodontitis in rats: histopathological, histometric and immunohistochemical study

Adjuvant effects of Saccharomyces cerevisiae in the treatment of experimental periodontitis in rats undergoing chemotherapy

Surgical procedures, radiotherapy, and chemotherapy, individually or in association, are current oncological treatments. Among the most used chemotherapy drugs, 5-fluorouracil (5FU) is an antimetabolite with a broad spectrum of action. This study evaluated the effects of probiotics (PRO) as an adjuvant to the treatment of experimental periodontitis (EP) in rats immunosuppressed with 5FU.108 rats were randomly allocated to six different groups: EP; SS - systemic treatment with saline solution (SS); 5FU - systemic treatment with 5FU; 5FU+PRO - systemic treatment with 5FU, followed by the local administration of Saccharomyces cerevisiae ; 5FU+SRP - systemic treatment with 5-FU, followed by scaling and root planing (SRP); and 5FU+SRP+PRO - systemic treatment with 5FU followed by local treatments with SRP and PRO. Immunosuppression was obtained at two points: at the time of ligature installation and after 48 h. Six animals from each group were euthanized at seven, 15, and 30 d and hemimandibles were collected and processed for histopathological, histometric, and immunohistochemical analysis. Data were subjected to statistical analysis (α=5%). At 7 d, the 5FU+PRO group showed less bone resorption and better structured connective tissue compared with the EP, SS, 5FU+SRP, and 5FU+SRP+PRO groups. At 15 d, the 5FU+SRP group showed a greater intensity of the inflammatory response (p<0.05). At 30 d, the 5FU+SRP+PRO group showed better structured bone tissue and a higher percentage of bone tissue (PBT) than the EP, SS, 5FU, and 5FU+PRO groups (p<0.05). The use of Saccharomyces cerevisiae as monotherapy or as an adjuvant to periodontal therapy may have a positive effect on bone repair in immunosuppressed conditions.

Association between lipid metabolism and periodontitis in obese patients: a cross-sectional study

BACKGROUND

To investigate the association between clinical periodontal parameters of periodontitis, serum lipid metabolism markers and adipokines' levels in patients with obesity and periodontitis.

METHODS

A total of 112 patients admitted to Hospital of Xi'an Jiaotong University were included in this study. They were divided into normal body weight group (18.5 < body mass index, BMI < 25, n = 36), overweight group (25 ≤ BMI < 30, n = 38), and obesity group (BMI ≥ 30, n = 38) accordingly. The diagnosis of periodontitis was based on the newest international classification of periodontitis. Full-mouth clinical periodontal measurements included: plaque index, periodontal pocket depth, clinical attachment level, and bleeding on probing. Gingival crevicular fluid samples were analyzed for: Interleukin-1β, tumor necrosis factor-α, Interleukin-6 and C-reactive protein. Serum triglycerides, total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol and glycosylated hemoglobin levels were measured. Visfatin, leptin, resistin, and adiponectin levels in serum were also measured.

RESULTS

The ratio of participants without periodontitis was significantly highest in normal weight group, and the proportion of severe periodontitis (stage III and IV) was highest in obesity group. The periodontal pocket depth, clinical attachment level, and the inflammatory cytokines in gingival crevicular fluid in obesity group and overweight group were higher than those in normal body weight group. The BMI and waist-to-hip ratio (WHR) were significantly positive correlated with periodontal pocket depth and clinical attachment level. Using a Multivariate logistic regression model, periodontitis correlates to BMI, WHR, serum levels of triglyceride, total cholesterol, low density lipoprotein, and adipokines such as visfatin, leptin, and resistin.

CONCLUSIONS

Obesity is positively correlated with the aggravation of periodontitis. Obesity may aggravate the damage to periodontal tissue by regulating the secretion level of adipokines.

Omega-3 Effects on Ligature-Induced Periodontitis in Rats with Fructose-Induced Metabolic Syndrome

Both periodontal disease (PD) and metabolic syndrome (MS) represent disorders of concern worldwide. Current evidence indicates that PD and MS might negatively influence each other, increasing the risk for cardiovascular diseases (CVD), via mutual inflammatory pathways. A failure of the inflammation resolution mechanisms is crucial for these comorbidities. Fish oil-derived omega-3 has been linked with resolution-driven responses in different pathological conditions during the last years. This study evaluated the impacts of omega-3 supplementation in a rat model combining ligature-induced PD and 10% fructose intake-elicited MS. Our main findings show that 10% fructose ingestion led to an elevation of Lee index and white adipose tissue (WAT) weight, along with hepatic alterations, accompanied by an increase of leptin, and a decrement of adiponectin serum amounts, regardless of PD induction. Noteworthy, the co-induction of PD and MS resulted in higher levels of glycemia and triglycerides, being this latter effect lessened by omega-3 supplementation. In this case, the beneficial effects of omega-3 might be associated with its ability to recover the decline of serum adiponectin levels in rats with PD plus MS. As expected, PD induction led to alveolar bone loss, independent of MS induction. However, the supplementation with omega-3 restored alveolar bone in PD control animals, but not in the rats with PD combined with MS. Our study extends the knowledge about PD and MS as comorbidities, showing novel effects of omega-3 supplementation in this context.

Colitis induced by dextran sulphate sodium causes histopathological and immunological changes in the periodontal tissues of Wistar rats

OBJECTIVE

This study investigated the impact of colitis induced by dextran sulphate sodium (DSS)-induced colitis (DIC) on histopathological and immunological outcomes in the periodontal tissues of Wistar rats.

BACKGROUND

Inflammatory bowel diseases (IBD) and periodontitis have been reported to present a bidirectional relationship. However, the inflammatory pathway that connects both diseases needs further investigation.

MATERIAL AND METHODS

Twenty-five male Wistar rats were allocated in four groups: unilateral ligature-induced periodontitis for 14 days: LIP (n = 7); dextran sulphate sodium-induced colitis only: DIC (n = 6); DIC + LIP (n = 6) and controls (n = 6). Digital images were obtained from the histological sections. In order to assess the attachment loss (AL), the linear distance between the cementoenamel junction (CEJ) and the alveolar bone crest was measured on the mesial root using histological photomicrography's ImageJ software. Immunological analyses of gingival tissues and plasma were performed by Bio-Plex Th1/Th2 Assay.

RESULTS

The DIC group showed inflammatory cells extending to the periodontal connective tissues, which contained significantly elevated expressions of IL-1α, IL-1β, IL-2, IL-6, IL-12, IL-13, GM-CSF, IFN-γ and TNF-α compared to controls. There was no significant difference in bone loss between controls and DIC. There were no significant histopathological differences between DIC + LIP and LIP. However, DIC + LIP presented a significantly lower IL-2 and IL-5 than the LIP group. There was no bone loss difference between LIP+DIC and LIP groups. DIC + LIP group presented significantly higher levels of GM-CSF in plasma.

CONCLUSION

DSS-induced colitis was associated with an overexpression of Th1/Th2- related cytokines in the gingival tissue.

Is Obesity a Risk Factor for Periodontal Disease in Adults? A Systematic Review

There is inconclusive evidence about the link between the severity and prevalence of periodontitis in obese adults. Therefore, this systematic review aims to explore the possibility of significant evidence on the association between obesity and periodontitis and to determine the necessity to consider obesity as a risk factor for periodontitis. We followed the PRISMA protocol, and studies that met the eligibility criteria were included in this review. The risk of bias in individual studies was also evaluated. This review included 15 observational studies (9 cross-sectional studies, 2 case-control, and 4 cohort studies). The total study subjects from these studies were 6603 (males = 3432; females = 3171). Most studies showed a significant association between obesity and periodontitis. Among these studies, a few showed obese females to be at a higher risk, and one study found no association between obesity and periodontal disease at all. Based on the evidence obtained from this review, the body mass index (BMI) should be routinely assessed in patients to assess the risk for periodontal disease and to offer personalized management of periodontitis. Based on the findings of this review, we recommend the need to initiate awareness among clinicians and implement dental hygiene care prevention measures for obese patients.

The Link between Stroke Risk and Orodental Status-A Comprehensive Review

One of the primary causes of disability and mortality in the adult population worldwide is stroke. A person's general health is significantly impacted by their oral and dental health. People who have poor oral health are more susceptible to conditions such as stroke. Stroke risk has long been linked to oral and dental conditions. The risk of stroke and its cost impact on the healthcare systems appear to be significantly reduced as a result of the decline in the incidence and prevalence of oral and dental illnesses. Hypothetically, better management of oral hygiene and dental health lead to reduced stroke risk. To the authors' best knowledge, for the first time, the potential link between dental health and stroke were cross-examined. The most typical stroke symptoms, oral and dental illnesses linked to stroke, and the role of oral healthcare professionals in stroke prevention are revealed. The potential mediating processes and subsequent long-term cognitive and functional neurological outcomes are based on the available literature. It must be noted that periodontal diseases and tooth loss are two common oral health measures. Lack of knowledge on the effects of poor oral health on systemic health together with limited access to primary medical or dental care are considered to be partially responsible for the elevated risk of stroke. Concrete evidence confirming the associations between oral inflammatory conditions and stroke in large cohort prospective studies, stratifying association between oral disease severity and stroke risk and disease effects on stroke survival will be desirable. In terms of clinical pathology, a predictive model of stroke as a function of oral health status, and biomarkers of systemic inflammation could be useful for both cardiologists and dentists.

Obesity, Bone Loss, and Periodontitis: The Interlink

Obesity and periodontitis are both common health concerns that have given rise to considerable economic and societal burden worldwide. There are established negative relationships between bone metabolism and obesity, obesity and diabetes mellitus (DM), and DM and periodontitis, to name a few, with osteoporosis being considered a long-term complication of obesity. In the oral cavity, bone metabolic disorders primarily display as increased risks for periodontitis and alveolar bone loss. Obesity-driven alveolar bone loss and mandibular osteoporosis have been observed in animal models without inoculation of periodontopathogens. Clinical reports have also indicated a possible association between obesity and periodontitis. This review systematically summarizes the clinical periodontium changes, including alveolar bone loss in obese individuals. Relevant laboratory-based reports focusing on biological interlinks in obesity-associated bone remodeling via processes like hyperinflammation, immune dysregulation, and microbial dysbiosis, were reviewed. We also discuss the potential mechanism underlying obesity-enhanced alveolar bone loss from both the systemic and periodontal perspectives, focusing on delineating the practical considerations for managing periodontal disease in obese patients.

The effects of Lactobacillus reuteri on the inflammation and periodontal tissue repair in rats: a pilot study

Objective

The aim of this study was to evaluate the effects of probiotic (PRO) Lactobacillus reuteri (DSM17938) as an adjuvant to the treatment of experimental periodontitis (EP).

Material and methods

Fifty-four male adult Wistar rats were included. EP was induced and maintained for 7 days. Subsequently, the ligature was removed and the animals were allocated into three different experimental groups (n = 18/group): EP – no local treatment, the animals received four systemic saline solution (SS) administrations; SRP+SS, the animals underwent SRP treatment, followed by SS administration; and SRP+PRO, the animals received SRP treatment, followed by the systemic administration of PROs (Lactobacillus reuteri ; 0.16 ml/day). Six animals from each group were euthanised at 7, 15 and 30 days. Histological and histometric analyses of alveolar bone loss (BL) and immunohistochemical analyses for TRAP, RANKL, OPG, OCN, and PCNA were performed. Shapiro–Wilk, ANOVA, post-hoc Tukey, Kruskal–Wallis, Student–Newman Keuls were performed.

Results

The SRP+PRO group presented a reduction in inflammation. At 15 days, a lower BL was observed in the SRP+SS and SRP+PRO groups. Greater immunolabeling was noticed for PCNA at 15 days in the SRP+PRO group than in the SRP+SS group. The SRP+PRO group demonstrated a higher OCN immunolabeling pattern than the EP group at 15 and 30 days.

Conclusion

The use of Lactobacillus reuteri as an adjuvant to SRP for the treatment of EP showed promising results in the control of local inflammatory responses, and enhanced the periodontal tissue repair process according to the employed concentration.

Obesity influences the proteome of periodontal ligament tissues following periodontitis induction in rats

BACKGROUND AND OBJECTIVES

Many studies have been conducted to better understand the molecular mechanism involved with periodontitis progression. There has been growing interest in the potential impact of obesity on periodontitis onset and progression, but the mechanisms involved remain to be elucidated. The present study was designed to determine the impact of obesity on experimentally induced periodontitis in rats and identify novel pathways involved.

METHODS

Sixteen Holtzman rats were distributed into two groups (n = 8): ligature-induced periodontitis (P) and obesity plus ligature-induced periodontitis (OP). Obesity was induced by a high-fat diet for 70 days, whereas periodontitis was induced for 20 days, with a cotton thread placed around the upper first molars bilaterally. Alveolar bone loss was measured by microtomographic analysis and histologically by histometry on the hemimaxillae. The protein composition of the periodontal ligament was evaluated by proteomic analysis.

RESULTS

Data analysis (body weight, adipose tissue weight, and blood test) confirmed obesity induction, whereas bone loss was confirmed by micro-CT and histologic analyses. Proteome analysis from the periodontal ligament tissues (PDL) identified 819 proteins, 53 exclusive to the P group, 28 exclusive to the OP group, and 738 commonly expressed. Validation was performed by immunohistochemistry for selected proteins (spondin1, vinculin, and TRAP).

CONCLUSION

Histologically, it was found that obesity did not significantly affect bone loss resulting from periodontitis. However, the present study's findings indicated that obesity affects the proteome of PDL submitted to experimental periodontitis, allowing for identifying potential targets for personalized approaches.

Do cytokines associate periodontitis with metabolic disorders? An overview of current documents

Periodontitis is an oral chronic inflammatory condition affecting the adult population worldwide. Many microorganisms act as an initiator for induction of inflammatory immune responses, which participate in the destruction of connective tissue surrounding the teeth and thereby result in tooth loss. Cytokines may have indispensable roles in its pathogenesis through enhancing inflammatory and immune responses. Cytokines can affect functions of some cells of different tissues, such as the cells of the pancreas, liver, and adipose tissues. There is evidence that periodontitis is associated with metabolic disorders, like liver cirrhosis, obesity, and diabetes mellitus. Hence, this review was focused on determining how cytokines can participate in the correlation of periodontitis with metabolic disorders.

The Association between Nutritional Alterations and Oral Lesions in a Pediatric Population: An Epidemiological Study

The oral conditions of an individual are the result of different factors, including the subject's genotype, oral hygiene habits, the type of diet, and lifestyle, such as smoking. Nutrition in the first years of life can affect dental health for a long time. To prevent mouth diseases, it is also important to eliminate unfavorable eating behaviour and to amplify protective ones. Eating habits, especially in pediatric age, are an easily modifiable and controllable factor, and diet, in addition to influencing the health of the oral cavity, plays a fundamental role in systemic health. Indeed, a sugar-rich diet can lead to conditions, such as diabetes, being overweight, and obesity. The present research was an epidemiological study, with the aim of highlighting some of the associations between nutrition and oral health. In particular, we studied those lesions of hard and soft tissues that are diagnosed most frequently by dentists: caries, enamel hypoplasia, periodontal disease, and aphotoxic lesions and their associations with nutritional deficiencies and excesses including proteins, vitamin A, vitamin D, B vitamins, and iron and calcium minerals. To perform this study, we recruited 70 patients from the pediatric and orthodontic clinics, aged between 3 and 15 years (y), with mean age of 10.4 y.o. The study was conducted by providing a questionnaire to pediatric patients' (supported from their parents or guardians) on individual eating habits, followed by an accurate oral cavity specialistic examination. The nutritional data were processed by using Grana Padano Observatory (OGP) software, freely provided online by the OPG. The statistical tests performed were the chi-square (χ²) for independence, and Cramér's V test was used to evaluate the associations between eating habits and oral pathologies. The results showed that certain nutritional vitamin deficiencies and nutritional excesses were associated with definite oral pathologies.

Influence of the treatment with the antineoplastic agents 5-fluorouracil and cisplatin on the severity of experimental periodontitis in rats

PURPOSE

The determination on how antineoplastic agents interfere on the progression of periodontitis is critical for improvement and even development of novel therapeutic approaches for periodontal management. This study evaluated the influence of chemotherapy with 5-fluorouracil (5-FU) or cisplatin (CIS) on healthy periodontal tissues and on the progression of experimental periodontitis (EP).

METHODS

One hundred forty-four male rats were divided into six groups (n = 24). Each group was treated with physiological saline solution (PSS) 0.9%, 5-FU, or CIS. Experimental periodontitis (EP) was induced by ligature placement. Animals were euthanized at 7, 15, and 30 days after treatment. Data were statistically analyzed (p ≤ 0.05).

RESULTS

The groups with EP and treated with 5-FU or CIS showed lower percentage of bone volume in the furcation region and higher percentage of alveolar bone loss, higher number of TRAP-positive cells, and lower number of PCNA-positive cells when compared group with EP and treated with PSS (p ≤ 0.05). Groups with EP and treated with 5-FU or CIS showed high immunolabelling pattern of RANKL, TNF-α, and IL-1β, moderate of BAX, and low of HIF-1α. Histological analysis showed severe tissue breakdown in the groups with EP and treated with 5-FU or CIS.

CONCLUSIONS

Chemotherapy with antineoplastic agents 5-FU and CIS increased the intensity and duration of the inflammation and compromised tissue repair by reduction in cellular and vascular turnover. The more severe periodontal breakdown was caused by 5-FU.

Association between clinical measures of gingival inflammation and obesity in adults: systematic review and meta-analyses

OBJECTIVE

This study aimed to systematically review the literature about the association between clinical measures of gingival inflammation and obesity in adults.

MATERIAL AND METHODS

Searches for studies were performed in five databases (Medline-PubMed, Scopus, Web of Science, Cochrane Library, and Embase) to compile studies of any design that evaluated the association between clinical measures of gingival inflammation and obesity in adults. Selection of studies, data extraction and risk of bias analysis were performed independently by two reviewers, and a third researcher was involved to resolve disagreements. Meta-analyses were performed for measures of gingival inflammation as compared to body mass index (BMI). Independent analyses were performed for studies involving periodontitis, gingivitis, and population-based/studies that did not provide a periodontal diagnosis. Standard mean deviation (SMD) and its 95% confidence interval (95%CI) were estimated.

RESULTS

Ninety studies were included (cross-sectional/clinical trials [n=82], case-control [n=3], cohorts [n=5]). Most of the studies demonstrated no significant difference in the measures of gingival inflammation regardless of the comparison performed. However, meta-analysis showed that among individuals with periodontitis, significantly higher levels of gingival inflammation are observed in those with obesity (n of individuals=240) when compared to those who were not obese (n of individuals=574) (SMD:0.26; 95%CI:0.07-0.44). When considering population-based/those studies that did not provide periodontal diagnosis, significantly higher measures of gingival inflammation were observed in the groups with higher BMI.

CONCLUSIONS

Within the limitations of the present study, it was concluded that higher measures of gingival inflammation may be expected for those with higher BMI.

CLINICAL RELEVANCE

Clinicians must be aware that higher measures of gingival inflammation may be expected for individuals with higher BMI. However, there is a necessity for further longitudinal studies regarding the association between obesity and gingival inflammation.

Food restriction reduces hepatic alterations associated with experimental periodontitis

BACKGROUND

Periodontitis is a chronic inflammatory and multifactorial disease that affects the periodontal structures and can cause alterations in the hepatic tissue. The aim of the present study was to evaluate whether a diet with food restriction can decrease oral and liver alterations associated with ligature-induced periodontitis.

METHODS

Twenty-four female Wistar rats were used in this study, randomized into three groups (n = 8 for each group): control (regular food); periodontitis (regular food + periodontitis induced with ligatures); and food restriction (diet with food restriction and periodontitis induction). The following periodontium parameters were analyzed tooth mobility (TM), probing pocket depth (PPD), gingival bleeding index (GBI), and alveolar bone height (ABH). In the liver, the levels of oxidative stress markers-malondialdehyde (MDA), glutathione (GSH), total cholesterol, and levels of myeloperoxidase (MPO) activity were measured. Liver samples were analyzed for histopathological score. In the blood tissue, the levels of enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose, total cholesterol, and the high-density lipoprotein (HDL) were also evaluated.

RESULTS

The animals that received a diet with food restriction + periodontitis showed a decrease in hepatic histopathological score (P < 0.05) when compared with the periodontitis group, the same for glucose, total cholesterol, ALT, AST, and ABH data. The group with food restriction + periodontitis showed a decrease in the histopathological liver score (P < 0.05) compared with the group with periodontitis.

CONCLUSION

This study revealed that food restriction reduced oral damages, as well as hepatic, blood and alveolar bone alterations associated with ligature-induced periodontitis in rats.

Comparative effects of different phenothiazine photosensitizers on experimental periodontitis treatment

AIM

The aim of the present study was to compare the effects of the phenothiazine photosensitizers methylene blue (MB), toluidine blue-O (TBO) and butyl toluidine blue (BuTB) in antimicrobial photodynamic therapy (aPDT), as adjuvant therapy to scaling and root planing (SRP) in the treatment of experimental periodontitis (EP) in rats.

MATERIAL AND METHODS

120 Wistar rats underwent ligation around the lower left molar. After seven days, the ligature was removed. The animals were separated into the following groups (n = 15): EP, no treatment; SRP, SRP and irrigation with saline solution; MB, SRP and deposition of MB; TBO, SRP and deposition of TBO; BuTB, SRP and deposition of BuTB; MB-aPDT, SRP and aPDT with MB; TBO-aPDT, SRP and aPDT with TBO and; BuTB-aPDT, SRP and aPDT with BuTB. The aPDT session was performed after SRP, with deposition of the photosensitizer and irradiation with a diode laser (DL; InGaAlP, 660 nm, 40 mW, 60 s, 2.4 J). Histological and histometric analysis was performed.

RESULTS

BuTB-aPDT group had a lesser extent of the inflammatory process compared to the EP, SRP, MB and TBO at all experimental periods (p < 0.05). At 15 days, the aPDT treated groups had a greater bone tissue structure than groups EP and SRP (p < 0.05) The BuTB showed lower Alveolar Bone Loss (ABL) compared to the TBO-aPDT group at 30 days (p < 0.05).

CONCLUSION

aPDT using the photosensitizer BuTB proved to be the adjuvant therapy that most favored the reduction of inflammatory infiltrate in the furcation area and ABL.

Lactobacillus reuteri associated with scaling and root planing in the treatment of periodontitis in rats submitted to chemotherapy

OBJECTIVE

The aim of this study was to evaluate the effects of Lactobacillus reuteri applied locally or systemically with scaling and root planing (SRP) to the treatment of experimental periodontitis (EP) in rats treated with 5-fluorouracil.

METHODS

A cotton ligature was installed on the molars of rats. The animals (n = 54) underwent chemotherapy and were divided into groups: SRP (n = 18), scaling and root planing only; LP (n = 18), SRP and 4 sessions of local probiotic (PRO); SP, SRP and 4 sessions of systemic PRO. The molar furcation area was submitted to histopathological, histometric of alveolar bone loss (ABL) and immunolabeling analysis after euthanasia at 7, 15 and 30 days. The data were submitted to statistical analysis (α = 5%).

RESULTS

At 15 days ABL was higher in LP compared to SP. At 30 days, ABL was higher in LP compared to SRP and SP. Higher immunolabeling of TGF-β1 was observed in LP and SP at 7 days compared to SRP (p < 0.05). Lower immunolabeling of OCN and higher immunolabeling of RANKL were observed at all periods in SRP compared to SP (p < 0.05). At 30 days, SRP showed lower immunolabeling of OPG compared to SP and LP (p < 0.05). In SP, lower immunolabeling was observed at 15 days compared at 30 days (p < 0.05).

CONCLUSION

The ABL was similar among the groups treated with SRP associated or not to probiotic therapeutic, although the systemic use of Lactobacillus reuteri considerably reduced inflammation and favored periodontal tissues repair.

Evaluation of recurrence of periodontal disease after treatment in obese and normal weight patients: Two-year follow-up

BACKGROUND

Obesity may represent a chronic low-grade inflammation, but there is a lack of long-term longitudinal studies. The aim of this longitudinal study was to evaluate the recurrence of periodontal disease in obese and normal weight patients submitted to scaling and root planing.

METHODS

The study included 22 patients who had received periodontal treatment 2 years previously, 13 obese and nine non-obese. The patients were evaluated for anthropometric measurements of body mass index, waist circumference, waist-to-hip ratio, and fat percentage through bioimpedance. The following periodontal parameters were recorded: visible plaque index (VPI), gingival bleeding index (GBI), probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP). The immunological evaluation analyzed the proinflammatory cytokines interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) in the gingival crevicular fluid (GCF).

RESULTS

Obese and normal weight patients did not differ in relation to the periodontal parameters of VPI, GBI, PD, CAL, or BOP 2 years after completion of the periodontal therapy. Sites with periodontitis in obese individuals showed higher levels of IL-6 and TNF-α in the gingival fluid (P <0.05).

CONCLUSION

Obese and normal weight individuals had similar periodontal behaviors, with low recurrence of the periodontal disease; however, obesity was related to increased inflammatory activity in gingival fluid, which may become a risk indicator for future greater recurrence of the disease in the presence of inadequate plaque control.

Antineoplastic agents exacerbate periodontal inflammation and aggravate experimental periodontitis

AIM

This study evaluated the effects of 5-fluorouracil (5-FU) and cisplatin (CIS) in healthy periodontal tissues and in the early stages of experimental periodontitis (EP) in rats.

METHODS

One hundred and eighty male rats were divided into three groups, which were submitted to the following systemic treatments: physiological saline solution (PSS); CIS and 5FU. Each group was subdivided into two subgroups: without (NEP) and with (EP) induction of EP. Animals were euthanized at 3, 5 and 7 days post-treatment. Histological, histometric (percentage of bone in the furcation [PBF]) and immunohistochemical (for tumour necrosis factor-α, interleukin-1β and receptor activator of nuclear factor-κB ligand) analyses were performed. Data were statistically analysed.

RESULTS

CIS-NEP and 5FU-NEP showed more inflammation than PSS-NEP at 3, 5 and 7 days. CIS-EP and 5FU-EP showed more inflammation and lower PBF than PSS-EP at all periods of evaluation. 5FU-EP showed lower PBF than CIS-EP at 5 and 7 days.

CONCLUSION

5-FU and CIS exacerbated periodontal inflammation and aggravated the progression of EP in its early stages.

TET1 Knockdown Inhibits Porphyromonas gingivalis LPS/IFN-γ-Induced M1 Macrophage Polarization through the NF-κB Pathway in THP-1 Cells

Tet-eleven translocation 1 (TET1) is a dioxygenase that plays an important role in decreasing the abundance of DNA methylation and changing the expression levels of specific genes related to inflammation. Porphyromonas gingivalis (Pg.) lipopolysaccharide (LPS) can induce periodontal diseases that present with severe bone loss and collagen fiber destruction accompanied by a high number of M1 macrophages. M1-polarized macrophages are pivotal immune cells that promote the progression of the periodontal inflammatory response, but the function of TET1 during M1 macrophage activation is still unknown. Our results showed that the mRNA and protein expression levels of TET1 decreased in THP-1 cells during M1 macrophage differentiation. TET1 knockdown resulted in a significant decrease in the production of proinflammatory markers such as IL-6, TNF-α, CCL2, and HLA-DR in Pg. LPS/IFN-γ- and Escherichia coli (E. coli) LPS/IFN-γ-induced M1 macrophages. Mechanistically, TET1 knockdown downregulated the activity of the NF-κB signaling pathway. After treatment with the NF-κB inhibitor BAY 11-7082, M1 marker expression showed no significant difference between the TET1 knockdown group and the control group. Taken together, these results suggest that TET1 depletion inhibited Pg. LPS/IFN-γ-induced M1 macrophage polarization through the NF-κB pathway in THP-1 cells.

Influence of adjuvant therapy with green tea extract in the treatment of experimental periodontitis

AIM

This study evaluated the effects of topical green tea extract solution (GTE) as adjuvant therapy to mechanical debridement for the treatment of experimental periodontitis (EP).

MATERIAL AND METHODS

We used 120 male rats (Rattus norvegicus albinus - Wistar), divided into the following four groups: NEP (sham) (n = 30): no experimental periodontitis (NEP), only simulation of EP by installation and removal of a ligature; EP (n = 30): EP induction by ligature; SRP (n = 30): EP, scaling and root planing (SRP), and irrigation with physiological saline solution; SRP/GT (n = 30): EP, SRP, and irrigation with GTE. Histologic analysis and immunohistochemistry were performed for detection of interleukin (IL)1ß, tumor necrosis factor-alpha (TNF-α), IL-10, and anti-tartrate resistant acid phosphatase (TRAP) in the furcation area. The percentage of bone in the furcation (PBF) was considered the primary variable and evaluated at 14, 22, and 37 days. The data from the histological analysis and the IL- 1B, TNF- A, and IL-10 were submitted to a Kruskal-Wallis variance test and Dunn's posttest (p ≤ 0.05). The histometric data and TRAP were submitted to analysis of variance (ANOVA) and Tukey's posttest (p ≤ 0.05).

RESULTS

The SRP/GT group showed lower inflammatory process, lower immunolabeling pattern of IL-1ß and TNF-α, and greater immunolabeling pattern of IL-10 compared with the EP and SRP groups at 22 days. Fewer TRAP-positive multinucleated osteoclasts were observed in all periods in the SRP/GT group (5.22 ± 0.65; 7.33 ± 0.80; 8.55 ± 1.15) compared with the SRP group (30.67 ± 8.55; 13.22 ± 0.77; 13.87 ± 0.77). Higher PBF was observed in all periods in the SRP/GT group (74.65 ± 7.14; 76.61 ± 5.36; 79.24 ± 3.75) compared with the SRP group (61.60 ± 9.48; 54.84 ± 9.06; 53.25 ± 9.66).

CONCLUSION

GTE adjuvant to SRP reduced inflammation, osteoclastic activity, and alveolar bone loss in EP.

Characterization of a diet-induced obesity rat model for periodontal research

OBJECTIVES

Obesity is associated with periodontitis, but the mechanisms underlying this association have yet to be unraveled. The present investigation was to evaluate a common rat model, in which obesity is induced by high-fat, high-sucrose diet (HFSD), for its applicability in periodontal research.

MATERIALS AND METHODS

Ten male Wistar rats were fed a 3-month HFSD along with a matching control group. Afterwards, the body weight, adipocyte morphology, leptin and adiponectin levels in adipose tissue, gingiva, and serum as well as the serum levels of triglyceride, cholesterol, and glucose were analyzed. For statistical analyses, parametric and non-parametric tests were applied (p < 0.05).

RESULTS

Body weight was significantly higher in the HFSD group after dieting as compared to control. HFSD caused a significant increase in serum triglyceride, low-density lipoprotein cholesterol, and leptin levels and a significant decrease in high-density lipoprotein cholesterol. Furthermore, adipose tissue from HFSD rats exhibited significantly larger adipocytes, displayed a significant upregulation of leptin and, surprisingly, elevated adiponectin levels, which is in contrast to chronic obesity in humans. Although leptin and adiponectin were also observed in gingival biopsies, no obvious differences between the groups were found.

CONCLUSIONS

Although this rat diet-induced obesity model is characterized by changes typical of obesity, it also has limitations, which have to be considered when data, especially with regard to adipokines, are extrapolated to humans.

CLINICAL RELEVANCE

The rodent diet-induced obesity model may be useful for unraveling pathomechanisms underlying the association between obesity and periodontal destruction but conclusions have to be drawn with caution.