Morphologic evaluation and expression of matrix metalloproteinases-2 and 9 and nitric oxide during experimental periodontal disease in rat

The immunopathologic and inflammatory mechanisms involved in periodontal disease (PD) include the participation of host resident, inflammatory cells and chemical mediators. Metalloproteinases (MMPs) and nitric oxide (NO) play essential role in extracellular matrix turnover of periodontal tissue destruction. In this study, by means of RT-PCR through semi-quantitative densitometric scanning methods, the expression of MMPs -2 and -9 and inducible NO synthase (iNOS) was temporally and spatially investigated during the destructive mechanisms of experimentally induced PD in rats. Samples from different periods were microscopically analyzed and compared with the contralateral side (control). Our results showed significant expression of MMP-9 and iNOS in tissues affected by PD, as compared with controls, three days after PD induction, simultaneously with the beginning of alveolar bone loss. At 7 days post induction, only the MMP-9 mRNA presented a significantly higher expression, as compared with the respective controls. Thus, in the rat ligature-induced PD, MMP-9 and iNOS might importantly participate in the early stages of the disease, including inflammatory cell migration, tissue destruction and alveolar bone resorption. Also, we may suggest that the exuberant presence of PMNs may be related to the important expression of iNOS and MMP-9 found at 3 days post induction.

Evidence of the presence of T helper type 17 cells in chronic lesions of human periodontal disease

Periodontal disease is a chronic inflammation of the attachment structures of the teeth, triggered by potentially hazardous microorganisms and the consequent immune-inflammatory responses. In humans, the T helper type 17 (Th17) lineage, characterized by interleukin-17 (IL-17) production, develops under transforming growth factor-beta (TGF-beta), IL-1 beta, and IL-6 signaling, while its pool is maintained by IL-23. Although this subset of cells has been implicated in various autoimmune, inflammatory, and bone-destructive conditions, the exact role of T lymphocytes in chronic periodontitis is still controversial. Therefore, in this study we investigated the presence of Th17 cells in human periodontal disease. Gingival and alveolar bone samples from healthy patients and patients with chronic periodontitis were collected and used for the subsequent assays. The messenger RNA expression for the cytokines IL-17, TGF-beta, IL-1 beta, IL-6, and IL-23 in gingiva or IL-17 and receptor activator for nuclear factor-kappa B ligand in alveolar bone was evaluated by real-time polymerase chain reaction. The production of IL-17, TGF-beta, IL-1 beta, IL-6, and IL-23 proteins was evaluated by immunohistochemistry and the presence of Th17 cells in the inflamed gingiva was confirmed by immunofluorescence confocal microscopy for CD4 and IL-17 colocalization. Our data demonstrated elevated levels of IL-17, TGF-beta, IL-1 beta, IL-6, and IL-23 messenger RNA and protein in diseased tissues as well as the presence of Th17 cells in gingiva from patients with periodontitis. Moreover, IL-17 and the bone resorption factor RANKL were abundantly expressed in the alveolar bone of diseased patients, in contrast to low detection in controls. These results provided strong evidence for the presence of Th17 cells in the sites of chronic inflammation in human periodontal disease.

Short-Term effect of COX-2 selective inhibitor as an adjunct for the treatment of periodontal disease: a clinical double-blind study in humans

Adjunctive therapeutic strategies that modulate the inflammatory mediators can play a significant role in periodontal therapy. In this double-blind, placebo-controlled study, 60 subjects diagnosed as periodontitis patients were evaluated for 28 days after periodontal treatment combined with selective cyclooxygenase-2 (COX-2) inhibitor. The experimental group received scaling and root planning (SRP) combined with the Loxoprofen antiinflammatory drug (SRP+Loxoprofen). The control group received SRP combined with placebo (SRP+placebo). Plaque index (PI), probing pocket depth (PD) and bleeding on probing (BOP) were monitored with an electronic probe at baseline and after 14 and 28 days. Both groups displayed clinical improvement in PD, PI and BOP. They also showed statistically similar values (p>0.05) of PD reduction on day 14 (0.4 mm) and on day 28 (0.6 mm). At the baseline, few deeper sites (>7 mm) from SRP+Loxoprofen group were responsible and most PD reduction was observed after 14 days (p<0.05). The percentage of remaining deep pockets (>7 mm) after 14 days in the SRP+Loxoprofen group was significantly lower (p<0.05) than in the SRP+placebo group. Loxoprofen presents potential effect as an adjunct of periodontal disease treatment, but long-term clinical trials are necessary to confirm its efficacy.

Precursor system of liquid crystalline phase containing propolis microparticles for the treatment of periodontal disease: Development and characterization

Precursor systems of liquid crystalline phase were prepared using the surfactant PPG-5-Ceteth-20, isopropyl myristate, and water; gelatin microparticles containing propolis were then added into these systems. Homogeneity of dispersion, the in-system microparticle morphology, and sedimentation behavior of each formulation were evaluated. The rheological and mechanical properties (hardness, compressibility, and adhesiveness), the work of syringing, and the propolis release profile were also evaluated. All the formulations exhibited pseudoplastic flow and thixotropy, and they displayed storage modulus, loss modulus, dynamic viscosity, and loss tangent that depended on temperature, frequency, and composition. Mechanical properties varied significantly among the formulations being affected by changes in the composition and temperature. Raising the concentration of surfactant and adding propolis microparticles significantly decreased the work of syringing. The drug release was non-Fickian (anomalous) and there was no significant difference between the tested systems in the times required for 10%, 30%, and 50% release of the initial drug loading.

Circulating matrix metalloproteinase-8 (MMP-8) and MMP-9 are increased in chronic periodontal disease and decrease after non-surgical periodontal therapy

Background: Periodontal disease shares risk factors with cardiovascular diseases and other systemic inflammatory diseases. The present study was designed to assess the circulating matrix metalloproteinases (MMPs) from chronic periodontal disease patients and, subsequently, after periodontal therapy. Methods: We compared the plasma concentrations of MMP-2. MMP-3, MMP-8, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1) and TIMP-2, and total gelatinolytic activity in patients with periodontal disease (n =28) with those of control subjects (n = 22) before and 3 months after non-surgical periodontal therapy. Results: Higher plasma MMP-3, MMP-8, and MMP-9 concentrations were found in periodontal disease patients compared with healthy controls (all P<0.05), whereas MMP-2, TIMP-1, and TIMP-2 levels were not different. Treatment decreased plasma MMP-8 and MMP-9 concentrations by 35% and 39%, respectively (both P<0.02), while no changes were found in controls. MMP-2, MMP-3, TIMP-1, and TIMP-2 remained unaltered in both groups. Plasma gelatinolytic activity was higher in periodontal disease patients compared with controls (P<0.001) and decreased after periodontal therapy (P<0.05). Conclusions: This study showed increased circulating MMP-8 and MMP-9 levels and proteolytic activity in periodontal disease patients that decrease after periodontal therapy. The effects of periodontal therapy suggest that it may attenuate inflammatory chronic diseases. (C) 2009 Published by Elsevier B.V.

Nonsurgical Periodontal Therapy Combined with Laser and Photodynamic Therapies for Periodontal Disease in Immunosuppressed Rats

Background. Periodontal disease is often associated with systemic diseases and is characterized by destruction of the tissues supporting the teeth. Patients using immunosuppressive drugs such as tacrolimus are among those who suffer from tissue destruction. Objective. We sought to evaluate the effects of laser and photodynamic therapies (PDT; nonsurgical) as an adjunct to scaling and rootplaning (SRP) in the treatment of corona-induced periodontitis in rats immunosuppressed with tacrolimus (Prograf). Materials and Methods. The animals were divided into 5 groups. Each groups had 6 rats. Group I, the control group, received only saline solution throughout the study period of 42 days and did not receive periodontal treatment; group II received saline solution and SRP; group III received tacrolimus (1 mg/kg per day) and was treated with SRP; group IV animals were treated identically to group III and then administered laser treatment; and in group V, the animals were treated identically to group III and then administered PDT. Results. Statistical analysis indicated decreased bone loss with the progression of time (P = .035). There was no difference between the bone loss associated with the types of treatment administered to groups I, II, and III (P > .9) or groups IV and V (P > .6). The analysis also indicated that immunosuppression was not a bone loss-determining factor. Conclusion. Laser and PDT therapies were effective as an adjunctive treatment to SRP in reducing bone loss caused by experimental periodontitis induced in animals being treated systemically with tacrolimus.

Periodontal disease in gestational and type 1 diabetes mellitus pregnant women

Objective: The present study evaluated the relationship between periodontal disease and its clinical variables in Brazilian non-diabetic pregnant women (C), gestational diabetes mellitus (GDM), or type 1 diabetes mellitus (T1DM). Subjects and methods: A periodontal exam was performed in one hundred and sixty-one pregnant women (GDM:80; T1DM:31; C:50) by a single-blinded calibrated examiner who recorded plaque index (PI), gingival index (GI), bleeding index (BI), gingival margin location (GM), probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), and tooth mobility index (MI). The medical variables were age, pregestational body mass index (pre-BMI), fasting plasma glucose (FPG), and glycated hemoglobin (HbA(1c)). Results: The GI, GM, PD, CAL, BOP, and MI were significantly higher (P < 0.01) among GDM and T1DM than for C. The PI was higher in GDM and similar between C and T1DM. The Adjusted Final Model for medical variables to evaluate the effects of groups on periodontal parameters confirmed these results. Conclusions: The presence of periodontal disease was significantly higher in Brazilian diabetic pregnancies (GDM and T1DM) when compared to non-diabetic pregnant women (C). The degree of periodontal disease was similar between the GDM and T1DM groups. Age, pregestational BMI, and HbA(1c) were factors related to CAL development in these two types of diabetes mellitus.

Periodontal disease in adults with untreated congenital growth hormone deficiency: a case-control study

P>Aim The aim of this study was to investigate the possible associations between isolated growth hormone deficiency (IGHD) and periodontal attachment loss (PAL) in adults affected by congenital IGHD. Materials and methods Forty-five previously identified IGHD subjects were eligible for this study. The final study sample comprised 32 cases (gender:20M/12F; age:44.8 +/- 17.5) matched for age, gender, diabetes, smoking status and income to 32 controls (non-IGHD subjects). Participants were submitted to a full-mouth clinical examination of six sites per tooth and were interviewed using a structured, written questionnaire. Periodontitis was defined as proximal PAL >= 5 mm affecting >= 30% of teeth. Results No significant differences were observed in the percentage of sites with visible plaque between IGHD and non-IGHD subjects (59.4% versus 46.9%, p=0.32). IGHD subjects had significant less supragingival calculus (31.3% versus 59.4%, p=0.02) and more bleeding on probing (71.9% versus 18.8%, p < 0.01) than controls. PAL >= 5 mm was significantly more prevalent (100% versus 71.9%, p < 0.01) and affected more teeth (30.5% versus 6.7%, p < 0.01) in cases than in controls. After adjusting for supragingival calculus, IGHD cases had a higher likelihood of having periodontitis than controls (OR=17.4-17.8, 95% CI=2.3-134.9, p=0.004-0.005). Conclusion Congenital IGHD subjects have a greater chance of having PAL.

The broad effects of the functional IL-10 promoter-592 polymorphism: modulation of IL-10, TIMP-3, and OPG expression and their association with periodontal disease outcome

Periodontal diseases are infectious diseases, in which periodontopathogens trigger chronic inflammatory and immune responses that lead to tissue destruction. It occurs through the generation of metalloproteinases and the activation of bone resorption mechanisms. Anti-inflammatory cytokines such as IL-10 seem to attenuate periodontal tissue destruction through the induction of tissue inhibitors of metalloproteinases (TIMPs) and the inhibitor of osteoclastogenesis osteoprotegerin (OPG). A high individual variation in levels of IL-10 mRNA is verified in periodontitis patients, which is possibly determined by genetic polymorphisms. In this study, the IL-10 promoter -592C/A single nucleotide polymorphism ( SNP), which is associated with a decrease in IL-10 production, was analyzed by RFLP in 116 chronic periodontitis (CP) patients and 173 control (C) subjects, and the IL-10, TIMPs, and OPG mRNA expression levels in diseased gingival tissues were determined by real-time-PCR. The IL-10-592 SNP CA (P=0.0012/OR=2.4/CI:1.4-4.1), AA (P=0.0458/OR=2.3/CI:1.1-4.9), and CA+AA (P=0.0006/OR=2.4/CI: 1.4-3.4) genotypes and the allele A (P=0.0036/OR=1.7/CI:1.2-2.4) were found to be significantly more prevalent in the CP group when compared with control subjects. Both CA and AA genotypes were associated with lower levels of IL-10, TIMP-3, and OPG mRNA expression in diseased periodontal tissues and were also associated with disease severity as mean pocket depth. Taken together, the results presented here demonstrate that IL10-592 SNP is functional in CP, being associated with lower levels of IL-10 mRNA expression, which is supposed to consequently decrease the expression of the downstream genes TIMP-3 and OPG, and influence periodontal disease outcome. J. Leukoc. Biol. 84: 1565-1573; 2008.

Are Teeth Close to the Cleft More Susceptible to Periodontal Disease?

Objective: To evaluate whether teeth close to the cleft area present higher prevalence and severity of periodontal disease than teeth in other regions. Design: Cross-sectional. Setting: Hospital for Rehabilitation of Craniofacial Anomalies, University of Sao Paulo. Patients: There were 400 Individuals with complete unilateral or bilateral cleft lip and palate, aged 15 to 49 years, without any previous periodontal treatment. Main Outcome Measures: All clinical parameters were evaluated in six sites for each tooth. The arithmetic means were calculated for each sextant. Results: Of the sextants, 86.75% presented means of probing depth smaller than or equal to 3 mm. No sextant exhibited means of probing depth greater than or equal to 6 mm. There was a statistically significant difference (p < .001) in probing depth according to age, types of cleft, and sextant; 95.87% of sextants presented mean attachment levels smaller than or equal to 3 mm, The sextant with cleft did not present higher means of probing depth, clinical attachment level, plaque index, and gingival index. There was gingival bleeding in 99.08% of the sample and plaque In 97.40%. The type of cleft was not an Important factor Influencing the prevalence of periodontal disease. Age seems to be an Important factor influencing the prevalence and severity of periodontal disease for all aspects Investigated. Conclusions: Periodontal disease In individuals with clefts occurred in a similar manner as observed in other populations. The presence of the cleft does not seem to Increase the prevalence of the disease.

A modified orthodontic protocol for advanced periodontal disease in Class II division 1 malocclusion

An interdisciplinary approach is often the best option for achieving a predictable outcome for an adult patient with complex clinical problems. This case report demonstrates the combined periodontal/orthodontic treatment for a 49-year-old woman presenting with a Class II Division 1 malocclusion with moderate maxillary anterior crowding, a 9-mm overjet, and moderate to severe bone loss as the main characteristics of the periodontal disease. The orthodontic treatment included 2 maxillary first premolar extractions through forced extrusion. Active orthodontic treatment was completed in 30 months. The treatment outcomes, including the periodontal condition, were stable 17 months after active orthodontic treatment. The advantages of this interdisciplinary approach are discussed. Periodontally compromised orthodontic patients can be satisfactorily treated, achieving most of the conventional orthodontic goals, if a combined orthodontic/periodontic approach is used. (Am J Orthod Dentofacial Orthop 2011; 139:S133-44)

Stromal-derived factor-1 alpha (CXCL12) levels increase in periodontal disease

Background: The CXC chemokine receptor 4 (CXCR4) and its ligand, stromal cell-derived factor-1 (SDF-1 alpha or CXC chemokine ligand 12) are involved in the trafficking of leukocytes into and out of extravascular tissues. The purpose of this study was to determine whether SDF-1 alpha secreted by host cells plays a role in recruiting inflammatory cells into the periodontia during local inflammation. Methods: SDF-1 alpha levels were determined by enzyme-linked immunosorbent assay in gingival crevicular fluid (GCF) of 24 individuals with periodontitis versus healthy individuals in tissue biopsies and in a preclinical rat model of Porphyromonas gingivalis lipopolysaccharide-induced experimental bone loss. Neutrophil chemotaxis assays were also used to evaluate whether SDF-1 alpha plays a role in the recruitment of host cells at periodontal lesions. Results: Subjects with periodontal disease had higher levels of SDF-1 alpha in their GCF compared to healthy subjects. Subjects with periodontal disease who underwent mechanical therapy demonstrated decreased levels of SDF-1 alpha. Immunohistologic staining showed that SDF-1 alpha and CXCR4 levels were elevated in samples obtained from periodontally compromised individuals. Similar results were observed in the rodent model. Neutrophil migration was enhanced in the presence of SDF-1 alpha, mimicking immune cell migration in periodontal lesions. Conclusions: SDF-1 alpha may be involved in the immune defense pathway activated during periodontal disease. Upon the development of diseased tissues, SDF-1 alpha levels increase and may recruit host defensive cells into sites of inflammation. These studies suggest that SDF-1 alpha may be a useful biomarker for the identification of periodontal disease progression.

Short-term induction of thrombocytopenia delays periodontal healing in rats with periodontal disease: participation of endostatin and vascular endothelial growth factor

Background and Objective: Platelets contain factors, including VEGF and endostatin, that can modulate the healing process. We evaluated the effects of severe thrombocytopenia on periodontal healing in rats and determined the contribution of VEGF and endostatin to the healing process. Material and Methods: Rats were distributed into three test groups and two control groups. Cotton ligatures were placed at the gingival margin level of the lower first molar in the test groups. Sham-operated rats and rats in one of the periodontitis groups were killed 15 days later. Rats in the remaining two periodontitis groups had the ligatures removed in order to study the spontaneous recovery from the periodontal disease 15 days later, and these rats were treated with rabbit antiplatelet serum, in order to induce thrombocytopenia, or normal rabbit serum. An additional group without ligatures received antiplatet serum in the same period. Results: After ligature removal, rats treated with normal rabbit serum showed reduced myeloperoxidase activity, decreased alveolar bone loss and increased numbers of blood vessels. Thrombocytopenia caused a delay in alveolar bone regeneration, a decrease in the number of vessels and a modest decrease in myeloperoxidase activity. In the rats with periodontitis, serum endostatin concentrations were slightly decreased and serum VEGF remained unchanged compared with sham-operated animals. After ligature removal, a significant VEGF increase and endostatin decrease were observed in the rats treated with normal rabbit serum. Thrombocytopenia led to a dramatic fall in both VEGF and endostatin concentrations. Conclusion: Thrombocytopenia leads to a delay of periodontal healing in the situation of experimental periodontitis, which might be mediated in part by a decrease in the serum concentration of VEGF and endostatin derived from the platelets. However, other factors derived from the platelets may also have contributed to a delay of periodontal healing in the rats with thrombocytopenia.

Myeloperoxidase as Inflammatory Marker of Periodontal Disease: Experimental Study in Rats

Rationale: Previous studies have used myeloperoxidase (MPO) as an inflammatory marker to estimate the accumulation of neutrophils in inflamed regions. Objective: The aim of this experimental study was to quantify the levels of MPO related to experimental periodontal disease in rats. Methods: Periodontal disease was induced in a group of rats using placement of a ligature around molar teeth. A group of rats without ligature placement served as a control. Measurements were made on the 3rd, 7th, 15th and 30th day from baseline. Gingival tissues were taken for quantification of MPO levels by ELISA. Results: The rats with induced periodontal disease showed statistically higher MPO levels (p 0.05) when compared to control rats. A significant increase in the levels of MPO released on days 7 and 30 was observed, with higher levels in the group with induced periodontitis. Conclusion: The levels of MPO were found to be higher in rats with induced periodontal disease, confirming the hypothesis that MPO may serve as an inflammatory marker for periodontitis.

Risk indicators for aggressive periodontitis in an untreated isolated young population from Brazil

This study aimed to assess the prevalence of aggressive periodontitis (AgP), and to investigate the association between demographic, socioeconomic and behavioral risk indicators with AgP in an untreated and isolated young population in Southeastern Brazil. For this cross-sectional survey, 134 subjects aged 12-29 years were selected by a census. Of those eligible, 101 subjects received a full-mouth clinical examination, and were interviewed using a structured written questionnaire. Cases were defined as individuals with 4 or more teeth with attachment loss > 4 mm or > 5 mm in the age groups 12-19 and 20-29, respectively. Overall, 9.9% of the subjects presented AgP (10.3% of the 12-19-year-olds and 9.7% of the 20-29-year-olds). The only risk indicator significantly associated with AgP in this isolated population was a high proportion of sites (> 30%) presenting supragingival calculus [OR = 23.2]. Having experienced an urgency dental treatment was a protective factor for AgP [OR = 0.1]. The authors concluded that this isolated and untreated population from Brazil presented a high prevalence of AgP. Local plaque-retaining factors played a major role in the prevalence of AgP in this isolated population, and should be included in further studies evaluating this destructive periodontal disease form.