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Featured researches published by Nejat Nizam.


Photomedicine and Laser Surgery | 2012

Low-Level Laser Irradiation Affects the Release of Basic Fibroblast Growth Factor (bFGF), Insulin-Like Growth Factor-I (IGF-I), and Receptor of IGF-I (IGFBP3) from Osteoblasts

Işıl Saygun; Nejat Nizam; Ali Ugur Ural; Muhittin Serdar; Ferit Avcu; Tolga Fikret Tözüm

OBJECTIVE It was the aim of the present study to evaluate whether the laser irradiation of osteoblasts could enhance the release of growth factors including basic fibroblast growth factor (bFGF), insulin-like growth factor-I (IGF-I), and receptor of IGF-I (IGFBP3). BACKGROUND DATA Low-level laser therapy (LLLT) has been shown to have biostimulatory effects on various cell types by enhancing production of some cytokines and growth factors. MATERIALS AND METHODS Human mesenchymal stem cells (MSCs) were seeded in osteogenic medium and differentiated into osteoblasts. Three groups were formed: in the first group (single dose group), osteoblasts were irradiated with laser (685 nm, 25 mW, 14.3 mW/cm(2), 140 sec, 2 J/cm(2)) for one time; and in the second group, energy at the same dose was applied for 2 consecutive days (double dose group). The third group was not irradiated with laser and served as the control group. Proliferation, viability, bFGF, IGF-I, and IGFBP3 levels were compared between groups. RESULTS Both of the irradiated groups revealed higher proliferation, viability, bFGF, IGF-I, and IGFBP3 expressions than did the nonirradiated control group. There was increase in bFGF and IGF-I expressions and decrease in IGFBP3 in the double dose group compared to single dose group. CONCLUSIONS The results of the present study indicate that LLLT increases the proliferation of osteoblast cells and stimulates the release of bFGF, IGF-I, and IGFBP3 from these cells. The biostimulatory effect of LLLT may be related to the enhanced production of the growth factors.


Inflammation | 2014

Serum and Salivary Matrix Metalloproteinases, Neutrophil Elastase, Myeloperoxidase in Patients with Chronic or Aggressive Periodontitis

Nejat Nizam; Pınar Gümüş; Jari Pitkänen; Taina Tervahartiala; Timo Sorsa; Nurcan Buduneli

Salivary, serum matrix metalloproteinase-8 (MMP-8), tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), neutrophil elastase (NE), and myeloperoxidase (MPO) levels were investigated in generalized chronic periodontitis (GCP), generalized aggressive periodontitis (GAgP), and healthy groups. Whole-mouth clinical periodontal measurements were recorded. Salivary, serum concentrations of MMP-8, MPO, TIMP-1, and NE were determined by immunofluorometric assay or ELISA in 18 patients with GCP, 23 patients with GAgP, 18 individuals with healthy periodontium. Patients in the GAgP group were younger than the other groups (p < 0.05). The study groups were similar in gender, smoking status. Plaque index was higher in GCP than GAgP group (p < 0.05). Biochemical data were similar in periodontitis groups. Salivary, serum MPO, and salivary NE concentrations were higher; TIMP-1 concentrations were lower in the periodontitis groups than the controls (p < 0.05). The present data support a close relationship between salivary, serum protease content and clinical periodontal parameters in patients with generalized periodontitis.


Journal of Periodontology | 2014

Saliva and Serum Levels of Pentraxin-3 and Interleukin-1β in Generalized Aggressive or Chronic Periodontitis

Pınar Gümüş; Nejat Nizam; Ayse Nalbantsoy; Özgün Özçaka; Nurcan Buduneli

BACKGROUND Pentraxin-3 (PTX3) is a multifactorial protein involved in immunity and inflammation, which is rapidly produced and released by several cell types in response to inflammatory signals. The aim of the present study is to evaluate saliva, serum levels of PTX3, interleukin (IL)-1β in patients with generalized chronic periodontitis (CP) or aggressive periodontitis (AgP), and periodontally healthy individuals. METHODS A total of 94 participants (25 patients with AgP, 25 patients with CP, and 44 periodontally healthy individuals matched with AgP and CP groups) were recruited. Saliva and serum samples were collected. Clinical periodontal measurements were recorded. PTX3, IL-1β levels in serum, and saliva samples were determined by enzyme-linked immunosorbent assay. Data were tested statistically using Kruskal-Wallis, Mann-Whitney U, and Spearman ρ rank test. RESULTS Serum and saliva data were similar in CP and AgP groups. Saliva levels of IL-1β were significantly higher in the AgP and CP groups than controls (P <0.05). Salivary PTX3 levels were similar in the CP and control groups. Significantly higher salivary concentrations of PTX3 were detected in the AgP group than the control group (P <0.05). Saliva PTX3 levels correlated with plaque index and bleeding on probing in the CP group (P <0.05). Serum and saliva PTX3 levels correlated with those of IL-1β in the AgP group (P <0.05). CONCLUSIONS It may be suggested that PTX3 is related with periodontal tissue inflammation. Its salivary concentrations may have a diagnostic potential. Additional intervention and follow-up studies coupling PTX3 concentrations with microbiologic analysis would better clarify its role in periodontal diseases.


Journal of Periodontology | 2009

Therapeutic efficacy of vasoactive intestinal peptide in escherichia coli lipopolysaccharide-induced experimental periodontitis in rats.

Ali Gürkan; Gülnur Emingil; Nejat Nizam; Basak Doganavsargil; Murat Sezak; Necil Kutukculer; Gül Atilla

BACKGROUND The aim of the present study was to evaluate the therapeutic efficacy of vasoactive intestinal peptide (VIP), an immunoregulatory molecule, in experimental periodontitis. METHODS Sixty-three male Sprague-Dawley rats were divided into five groups: control; lipopolysaccharide (LPS); LPS + 0.1 nmol VIP; LPS + 1 nmol VIP; and LPS + 10 nmol VIP. Saline was injected into the gingiva of control rats on days 1, 3, and 5, whereas the other groups received injections of Escherichia coli LPS. VIP groups received intraperitoneal injections of relevant dosages on days 2, 4, 6, 8, and 10. The control and LPS groups were given saline instead of VIP in the same manner. On day 11, serum samples were obtained, and rats were sacrificed. Alveolar bone loss; serum levels of tumor necrosis factor-alpha, interleukin (IL)-1beta, -10, and -18, soluble receptor activator of nuclear factor-kappa B ligand (sRANKL), and osteoprotegerin (OPG); and the immune expression of RANKL and OPG were evaluated. RESULTS The application of VIP caused a dose-dependent decline in alveolar bone loss compared to the LPS group, but the differences were not significant (P >0.05). A reduction in the histologic findings of inflammation was observed in all VIP groups. The 1- and 10-nmol VIP groups showed significantly lower serum sRANKL and OPG levels compared to the LPS group (P <0.05). The number of positively stained vessels for endothelial OPG was greater in the 1-nmol VIP group than in the LPS group (P <0.05). CONCLUSION When periodontitis was induced by E. coli LPS, VIP downregulated the inflammatory response and inhibited alveolar bone loss, possibly by differentially regulating the tissue levels of RANKL and OPG.


Journal of Periodontology | 2014

Altered antigenic profiling and infectivity of Porphyromonas gingivalis in smokers and non-smokers with periodontitis.

Iris Zeller; Justin A Hutcherson; Richard J. Lamont; Donald R. Demuth; Pınar Gümüş; Nejat Nizam; Nurcan Buduneli; David A. Scott

BACKGROUND Cigarette smokers are more susceptible to periodontal diseases and are more likely to be infected with Porphyromonas gingivalis than non-smokers. Furthermore, smoking is known to alter the expression of P. gingivalis surface components and compromise immunoglobulin (Ig)G generation. The aim of this study is to evaluate whether the overall IgG response to P. gingivalis is suppressed in smokers in vivo and whether previously established in vitro tobacco-induced phenotypic P. gingivalis changes would be reflected in vivo. METHODS The authors examined the humoral response to several P. gingivalis strains as well as specific tobacco-regulated outer membrane proteins (FimA and RagB) by enzyme-linked immunosorbent assay in biochemically validated (salivary cotinine) smokers and non-smokers with chronic periodontitis (CP: n = 13) or aggressive periodontitis (AgP: n = 20). The local and systemic presence of P. gingivalis DNA was also monitored by polymerase chain reaction. RESULTS Smoking was associated with decreased total IgG responses against clinical (10512, 5607, and 10208C; all P <0.05) but not laboratory (ATCC 33277, W83) P. gingivalis strains. Smoking did not influence IgG produced against specific cell-surface proteins, although a non-significant pattern toward increased total FimA-specific IgG in patients with CP, but not AgP, was observed. Seropositive smokers were more likely to be infected orally and systemically with P. gingivalis (P <0.001), as determined by 16S RNA analysis. CONCLUSION Smoking alters the humoral response against P. gingivalis and may increase P. gingivalis infectivity, strengthening the evidence that mechanisms of periodontal disease progression in smokers may differ from those of non-smokers with the same disease classification.


Journal of Periodontology | 2014

The Effect of α-Tocopherol and Selenium on Human Gingival Fibroblasts and Periodontal Ligament Fibroblasts In Vitro

Nejat Nizam; Feridun Discioglu; Işıl Saygun; Vehbi Bal; Ferit Avcu; Cansel Kose Ozkan; Muhittin Serdar

BACKGROUND The aim of the present study is to evaluate the effect of α-tocopherol and selenium on gingival fibroblasts (GFs) and periodontal ligament fibroblasts (PDLFs) in terms of proliferation, basic fibroblast growth factor (bFGF) release, collagen type I synthesis, and wound healing. METHODS Primary cultures of human GFs and PDLFs were isolated. Four test groups and a control group free of medication was formed. In group E, 60 μM α-tocopherol was used, and in groups ES1, ES2, and ES3, the combination of 60 μM α-tocopherol with 5 × 10(-9) M, 10 × 10(-9) M, and 50 × 10(-9) M selenium was used, respectively. Viability, proliferation, bFGF, and collagen type I synthesis from both cell types were evaluated at 24, 48, and 72 hours, and healing was compared on a new wound-healing model at 12, 24, 36, 48, and 72 hours. RESULTS α-Tocopherol alone significantly increased the healing rate of PDLFs at 12 hours and increased bFGF and collagen type I release from GFs and PDLFs at 24, 48, and 72 hours. The α-tocopherol/selenium combination significantly enhanced the proliferation rate of both cells at 48 hours, decreased the proliferation of PDLFs at 72 hours, and increased the healing rate of GFs at 12 hours and PDLFs at 12 and 48 hours. bFGF and collagen type I synthesis was also increased in both cell types at 24, 48, and 72 hours by α-tocopherol/selenium combination. CONCLUSION α-Tocopherol and α-tocopherol/selenium combination is able to accelerate the proliferation rate and wound-healing process and increase the synthesis of bFGF and collagen type I from both GFs and PDLFs.


Infection and Immunity | 2016

Subgingival Plaque in Periodontal Health Antagonizes at Toll-Like Receptor 4 and Inhibits E-Selectin Expression on Endothelial Cells

Thao T. To; Pınar Gümüş; Nejat Nizam; Nurcan Buduneli; Richard P. Darveau

ABSTRACT The ability of the subgingival microbial community to induce an inappropriate inflammatory response ultimately results in the destruction of bone and gingival tissue. In this study, subgingival plaque samples from both healthy and diseased sites in the same individual were obtained from adults with chronic periodontitis and screened for their ability to either activate Toll-like receptor 2 (TLR2) or TLR4 and to antagonize TLR4-specific activation by agonist, Fusobacterium nucleatum LPS. Subgingival plaque from diseased sites strongly activated TLR4, whereas matched plaque samples obtained from healthy sites were significantly more variable, with some samples displaying strong TLR4 antagonism, while others were strong TLR4 agonists when combined with F. nucleatum LPS. Similar results were observed when TLR4 dependent E-selectin expression by endothelial cells was determined. These results are the first to demonstrate TLR4 antagonism from human plaque samples and demonstrate that healthy but not diseased sites display a wide variation in TLR4 agonist and antagonist behavior. The results have identified a novel characteristic of clinically healthy sites and warrant further study on the contribution of TLR4 antagonism in the progression of a healthy periodontal site to a diseased one.


Journal of Esthetic and Restorative Dentistry | 2015

Micro- and macrosurgical techniques in the coverage of gingival recession using connective tissue graft: 2 years follow-up.

Nejat Nizam; Orhun Bengisu; Şule Sönmez

OBJECTIVE The aim was to evaluate the clinical results of micro- and macrosurgical approaches in the coverage of gingival recession using connective tissue graft. MATERIAL AND METHODS Twenty-one teeth in microsurgical group (test group) and 21 in macrosurgical group (control group) were treated using coronally positioned flap and subgingival connective tissue graft. Recession depth (RD), recession width (RW), root surface area (RSA), keratinized tissue width (KTW), probing depth, clinical attachment level, pain level during healing, and aesthetic results were evaluated for 24 months. RESULTS RD, RW, and RSA were significantly lower at 1, 3, 6, and 24th months compared with baseline in both groups. RD was also significantly lower in the 1st month compared with 24th month in control group. RD and RSA at 24th month were significantly lower in microsurgical group. KTW significantly and similarly increased by 6th month in both groups. The pain levels in the donor and the recipient area decreased earlier in the microsurgical group, and aesthetic scores improved similarly in both groups. CONCLUSION A microsurgical approach to root coverage with gingival recession is likely to preserve the clinical outcomes longer than macrosurgical approach, at least for 24 months. Healing appears to be faster using microsurgery, but aesthetic outcomes are similar. CLINICAL SIGNIFICANCE This study evaluated the clinical results of microsurgical versus macrosurgical approaches to root coverage in cases of gingival recession. Based on the results of the study, pain levels in the donor and the recipient areas decreased earlier in the microsurgical group, and microsurgical approach resulted in significantly greater amount of root coverage at 24 months.


Journal of Dental Research | 2016

Differentiation of Chronic and Aggressive Periodontitis by FTIR Spectroscopy.

N. Simsek Ozek; I. Zeller; Diane E. Renaud; Pınar Gümüş; Nejat Nizam; Feride Severcan; Nurcan Buduneli; David A. Scott

Without longitudinal clinical data, it is difficult to differentiate some cases of chronic periodontitis (CP) and aggressive periodontitis (AgP). Furthermore, both forms of disease are exacerbated by tobacco use. Therefore, this cross-sectional study was planned, primarily, to determine the ability of Fourier-transform infrared (FTIR) spectroscopy to distinguish CP and AgP patients by analysis of human saliva samples and, secondarily, to assess the potential confounding influence of smoking on discriminating disease-specific spectral signatures. FTIR spectra were collected from patients with a clinical diagnosis of CP (n = 18; 7 smokers) or AgP (n = 23; 9 smokers). Self-reported smoking status, which may be unreliable, was confirmed by salivary cotinine analysis. Spectral band area analysis and hierarchical cluster analyses were performed to clarify if the 2 periodontitis groups as well as smoker and nonsmoker patients could be differentiated from each other. Significant variations in lipid, amino acid, lactic acid, and nucleic acid content were found between nonsmoker CP and AgP groups. Although significantly lower lipid, phospholipid, protein, amino acid, lactic acid, and nucleic acid content was noted in the smoker AgP group compared with the nonsmoker AgP group, in the CP group, phospholipid, protein, amino acid, and lactic acid content was significantly lower for smokers compared with the nonsmokers. Based on these variations, nonsmoker CP and AgP patients were discriminated from each other with high sensitivity and specificity. Successful differentiation was also obtained for the smoker CP and AgP groups. Thiocyanate levels successfully differentiated smokers from nonsmokers, irrespective of periodontal status, with 100% accuracy. Differentiation of AgP and CP forms, concomitant with determination of smoking status, may allow the dental health professional to tailor treatment accordingly.


Gaziantep Medical Journal | 2014

Double papilla flap and connective tissue graft in the coverage of gingival recessions using microsurgery: case series -

Nejat Nizam; Aliye Akcalı

The aim of the present case series is to share the clinical results of double papilla flap and connective tissue graft in the coverage of gingival recession using microsurgery which is routinely used in our clinic. A total of 8 patients, mean age 29.75 ± 7.4 (6 female, 2 male) with 8 defects were included. Connective tissue graft was harvested from palate and sutured to the recipient area and then was completely covered with a double papilla flap. Plaque index (PI), gingival index (GI), probing pocket depth and clinical attachment levels were evaluated before the treatment (baseline) and at 6th month, recession depth was measured at baseline, 1st, 3rd and 6th month, and keratinized tissue width was assessed at baseline, 3rd and 6th month. Recession depth at baseline and 6th months were 4.38 ± 0.83 mm and 0.25 ± 0.46 mm, respectively with root coverage percentage of 94.72% ± 9.79. During the evaluation period partial coverage was observed in 2 patients and full coverage was detected in 6 patients. Clinical attachment levels at baseline and 6th month were 5.56 ± 0.67 mm, and 1.56 ± 0.56 mm respectively, and keratinized tissue width was 0.25 ± 0.46 mm and 3.00 ± 0.89 mm at the same evaluation period. According to the results of the present case series, it can be concluded that double papilla flap and connective tissue graft using microsurgery is effective in the treatment of gingival recessions and the newly formed attachment level maintained stability in short term.

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David A. Scott

University of Louisville

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Feride Severcan

Middle East Technical University

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