Cimetidine Reduces Alveolar Bone Loss in Induced Periodontitis in Rat Molars

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of Locally Administered Tiludronic Acid on Experimental Periodontitis in Rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Expression of Protease Activated Receptor-1 in Chronic Periodontitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of Er,Cr:YSGG laser application in the treatment of experimental periodontitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Periodontal pathogens directly promote autoimmune experimental arthritis by inducing a TLR2- and IL-1-Driven Th17 response

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Porphyromonas endodontalis in chronic periodontitis: a clinical and microbiological cross-sectional study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Haplotypes of susceptibility to chronic periodontitis do not influence MMP-8 levels or the outcome of non-surgical periodontal therapy

Introduction: Chronic periodontitis (CP) is a multifactorial condition, presenting immunoinflammatory reaction, in which a myriad of molecules including cytokines and matrix metalloproteinases (MMPs) interplays, making the system extremely intricate. There is scarce information regarding interconnections of biological influence among IL-4, IL-8 and MMP-8, mainly considering genetic polymorphisms, and also, whether this can influence the outcome of periodontal therapy. Previously, we reported that variants in the interleukin 4 (IL4) and interleukin 8 (IL8) genes were associated with CP in Brazilians. The aim of this study was to investigate, in individuals with different genetic backgrounds with regard to the IL4 or IL8 haplotypes, differences in the immunological levels of MMP-8 in gingival crevicular fluid (GCF) before and after non-surgical periodontal treatment. A total of 141 patients participated of this study, classified as susceptible or not to CP, according to the presence of haplotypes formed by polymorphysms in the IL4 or IL8 genes. All individuals received non-surgical periodontal therapy and follow–up continued for 45 days. The GCF samples were collected at baseline and on the 45th day. The MMP-8 levels were determined by ELISA. Results: No association was found between genetic backgrounds and MMP-8 levels in GCF or the outcome of non-surgical periodontal therapy. Conclusions: In this longitudinal clinical study, the presence of IL4 or IL8 haplotypes previously associated with CP did not influence the outcome of non-surgical periodontal therapy and the MMP-8 levels in the GCF. Additional studies are necessary to determine the mechanisms by which the IL4 or IL8 haplotypes affect individual susceptibility to CP.

The H2S-releasing naproxen derivative, ATB-346, inhibits alveolar bone loss and inflammation in rats with ligature-induced periodontitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos de drogas antiplaquetárias na doença periodontal

The association between platelets, angiogenesis and progression or repair of periodontal disease has been little explored and, consequently, the results are inconclusive. The pathogenic bacteria present in the periodontal pocket release endotoxins that affect the endothelial integrity and are able to induce the production of chemical mediators derived from plasma proteins and blood clotting while altering platelet function. There is great interest in the modulation of platelet activity in vascular disorders, especially cardiovascular diseases. For this reason, antiplatelet drugs, that are commonly used in the prevention of thromboembolic diseases, such as myocardial infarction, ischemic stroke and peripheral arterial disease, have been used. Aspirin is the only non-steroidal antiinflammatory agent with antiplatelet activity. In the periodontium, instead of only reduces levels of inflammatory cytokines, also significantly affects bleeding on probing, suggesting a dose-dependent modulation of periodontitis. In contrast, clopidogrel and ticlopidine are thienopyridine drugs with no known antiinflammatory action, suggesting that this benefit is related to an antiinflammatory effect indirectly correlated to their antiplatelet activity already established. In the literature there is limited information about the effect of these drugs on periodontium and periodontal disease development. Antiplatelet drugs hypothetically can change both the pathogenesis of periodontitis and subsequent periodontal tissue repair by blocking the secretion of chemical mediators which in general are important in modulating inflammation and tissue repair.

The effect of conventional mechanical periodontal treatment on red complex microorganisms and clinical parameters in Down syndrome periodontitis patients: a pilot study

Periodontal disease (PD) is induced by a complex microbiota, such as Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola (together called the red complex), which triggers intense inflammatory reaction. Down syndrome (DS) individuals demonstrate a high prevalence of PD compared with those who are otherwise chromosomally normal (euploids). This pilot study aimed to evaluate the effect of non-surgical periodontal treatment in DS chronic periodontitis patients on clinical and microbiological parameters. Patients with chronic periodontitis, 23 DS and 12 euploids (control group), were submitted to non-surgical mechanical periodontal treatment, followed by maintenance for 45 days. Clinical parameters after periodontal treatment were similar in diseased and healthy sites, independent of the genetic background. Diseased sites of DS and control patients harbored similar levels of P. gingivalis and T. forsythia at baseline, but significantly higher levels of T. denticola were found in DS patients. Increased levels of P. gingivalis at healthy sites were found in DS individuals. Non-surgical periodontal therapy decreased the levels of red complex microorganisms and improved the tested clinical parameters of diseased sites in both groups. However, the levels of red complex bacteria were higher in diseased sites of DS patients after the periodontal treatment. We conclude in this pilot study that, although the mechanical periodontal treatment seemed to be effective in DS subjects over a short-term period, the red complex bacteria levels did not decrease significantly in diseased sites, as occurred in controls. Therefore, for DS patients, it seems that the conventional non-surgical periodontal therapy should be improved by utilizing adjuvants to reduce the presence of periodontopathogens.

Microorganisms in the female genital tract during pregnancy: tolerance versus pathogenesis

Microorganisms in the pregnant female genital tract are not always associated with pathology. The factors that influence the maternal response to microorganisms remain ill defined. We review the state of knowledge of microbe-host interactions in gestational tissues and highlight mechanisms that promote tolerance or pathogenesis. Tolerance to microorganisms is promoted during pregnancy by several mechanisms including upregulation of anti-inflammatory mediators, induction of endotoxin tolerance, and possibly by regulation of autophagy. Conversely, an altered vaginal microbiota or a pre-existing viral presence may result in induction of excessive inflammation and preterm labor. Although infections play a prevalent role in preterm birth, microbes are present in gestational tissues of women with healthy outcomes and may provide beneficial functions. The complex interactions between different microbial species and the maternal immune system during gestation remain incompletely elucidated.

Effects of electroacupuncture on experimental periodontitis in rats

Background: Acupuncture has shown the capability of modulating the immuno-inflammatory response of the host. This study aims to evaluate the effects of electroacupuncture (EA) on ligature-induced periodontitis in rats. Methods: Thirty-two animals were divided into four groups: 1) control; 2) experimental periodontitis (EP); 3) sham-treated (EP/EA-sham); and 4) treated with EA (EP/EA). For the EP groups, a ligature was placed around the right mandibular first molars at day 1. Sessions of EA or EA-sham were assigned every other day. For EA treatment, large intestine meridian points LI4 and LI11 and stomach meridian points ST36 and ST44 were used. EA-sham was performed in off-meridian points. Animals were euthanized at day 11. Histomorphometric and microtomographic analyses were performed. Immunolabeling patterns for the receptor activator of nuclear factor kappa B ligand (RANKL), osteoprotegerin (OPG), and tartrate-resistant acid phosphatase (TRAP) were assessed. Expressions of interleukin (IL)-1 beta, matrix metalloproteinase (MMP)-8, IL-6, and cyclooxygenase (COX)-2 messenger RNAs (mRNAs) were evaluated by quantitative reverse transcription-polymerase chain reaction. Data were analyzed statistically (P < 0.05, analysis of variance). Results: Histomorphometric and microtomographic analyses demonstrated that group EP/EA presented reduced alveolar bone loss when compared to group EP (P < 0.05). Reduced RANKL immunolabeling and fewer TRAP-positive multinucleated cells were observed in the EA-treated group in relation to group EP. No differences were observed in OPG expression among groups. EA treatment decreased the genic expression of IL-1 beta and MMP-8 (P < 0.05), increased the mRNA expression of IL-6 (P < 0.05), and did not modify the genic expression of COX-2 in animals with EP (P > 0.05). Conclusion: It can be concluded that EA reduced periodontal tissue breakdown and the expression of some proinflammatory mediators and a proresorptive factor in EP in rats.

Effectiveness of the diode laser in the treatment of ligature-induced periodontitis in rats: a histopathological, histometric, and immunohistochemical study

The aim of this study was to evaluate the effects of the use of a high-power gallium-aluminum-arsenide diode laser (GaAlAs; 808 nm, 1 W, 20 s, 20 Hz, 10 J) alone or as adjunctive therapy to scaling and root planing in the treatment of induced periodontitis in rats. Periodontitis was induced by placing a ligature around the mandibular first molar of 60 rats. After 7 days, the ligature was removed and the animals were divided into four groups as follows: C (control), no periodontal treatment; SRP, scaling and root planing (SRP); DL, diode laser (DL) irradiation treatment; and SRP/DL, both SRP and DL irradiation treatment. Five animals from each group were euthanized at 7, 15, and 30 days posttreatment. The effectiveness of the treatments was evaluated in the furcation area using histopathological analysis, histometric analysis of alveolar bone loss (ABL), and immunohistochemical detection of tartrate-resistant acid phosphatase (TRAP), runt-related transcription factor 2 (RUNX2), and osteocalcin (OCN). DL, alone or in combination with adjunctive therapy to SRP in the treatment of experimental periodontitis, resulted in a decreased local inflammatory response. At 7-days posttreatment, the DL and SRP/DL groups had fewer TRAP-positive cells and more RUNX2-positive cells. There was greater OCN immunolabeling in the DL group than in the C and SRP groups at 15 days. There was less ABL in the DL and SRP/DL groups at 15 and 30 days. In conclusion, DL was effective in the treatment of ligature-induced periodontitis in rats, both when used alone and when used as adjunctive therapy to SRP.

Evaluation of the progression and treatment of experimental periodontitis in rats subjected to chemotherapy with 5-fluorouracil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Clinical Influence of Different Intracanal Medications on Th1-type and Th2-type Cytokine Responses in Apical Periodontitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)