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Öğe Bonded Surface Area and Bond Strength: A Micro-Shear Test(Int Amer Assoc Dental Researchi A D R/A A D R, 2002) Şengün, A.; Özer, Faruk; Ceylan, N.[Abstract not Available]Öğe Cytotoxic Effects of Dental Desensitizers on Human Gingival Fibroblasts(Wiley-Liss, 2006) Şengün, A.; Büyükbaş, S.; Hakkı, S. S.The purpose of this study was to evaluate the effects of three different desensitizers on the cell viability and morphology of human gingival fibroblasts (HGF). Human gingival tissues were obtained from individuals who have clinically, healthy periodontium. HGF were grown at 37 degrees C in humidified atmosphere of 5% CO2 in Dulbecco's modified eagle's medium, supplemented with glutamine, penicillin, streptomycin, and 10% fetal bovine serum. The cells were treated with different concentrations (0.1, 0.3, and 0.5 mu L/mL) of desensitizers (Gluma Desensitizer, Seal&Protect, and MicroPrime). After 24- and 48-h exposure to the desensitizer solutions, the viable cells were examined using a hemocytometer. To monitor HGF viability, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay was used and cell morphology was also observed at 48 h. Following exposure to concentrations of 0.1 mu L/mL of test materials for 24 h, cell survival rates for Gluma Desensitizer (106%) and Micro Prime (62%) were not significantly different from the control, while it was significant for Seal&Protect (50%). Growing cells were significantly inhibited by all tested materials for 48 h (p < 0.05) in survival rates of 51, 47, and 31%, respectively. On the basis of the MTT assay, the cytotoxic effect of MicroPrime was more prominent, especially at high concentrations, than does Gluma Desensitizer and Seal&Protect. After exposure to Seal&Protect and MicroPrime, HGF became retracted, rounded in appearance and had loss of normal organization, leading to enlargement of intercellular space when compared with Gluma Desensitizer. As a conclusion, taking the limitations of an in vitro experiment into consideration, the cytotoxic effects were varied, depending on the chemical composition and exposure periods of the tested desensitizers.Öğe The Effect of Simulated Intrapulpal Pressure on Bond Strength to Enamel and Dentine(WILEY, 2003) Şengün, A.; Öztürk, B.; Özer, F.The purpose of this study was to evaluate the effect of simulated intrapulpal pressure on the shear bond strength (SBS) of a self-etching bonding system (Clearfil Liner Bond II) to both enamel and dentine surfaces. Forty-two caries-free human molar teeth were randomly assigned to two equal groups (n =21). One group of 21 teeth was connected to a special pulpal pressure machine, which is developed to simulate in vivo conditions. The buccal and lingual surfaces of the teeth were prepared with a diamond wheel to create flat dentine and enamel surfaces. A self-etching bonding system was then applied under pulpal pressure and 2.5 mm diameter composite cylinders were bonded to the prepared surfaces. The samples were then stored in distilled water at room temperature for 24 h under pulpal pressure before SBS was tested. The second restored group was used as a control and the teeth were not connected to the pulpal pressure apparatus during material application and test procedures. They were stored for 24 h in distilled water at room temperature before the SBS test. Fracture analysis of the enamel and dentinal surfaces was performed using a stereomicroscope. Shear bond strength values to dentine was significantly reduced with pulpal pressure (P < 0.001). However, in the enamel, SBS was increased (P < 0.001). In the control group, the SBS values to dentine and enamel did not show any significant difference (P > 0.05). Based on these results, it can be concluded that further analysis of enamel histology and bonding mechanisms are needed.Öğe Effects of Antibacterial Agents on Bond Strength of a Self-Etching Adhesive System to Caries-Affected Dentin on the Gingival Wall(Int Amer Assoc Dental Researchi A D R/A A D R , 2003) Şengün, A.; Koyutürk, A. E.; Şener, Y.; Özer, F.[Abstract not Available]Öğe Evaluation of Antibacterial Effectiveness of Desensitizers Against Oral Bacteria(Int Amer Assoc Dental Researchi a D R/a a D R, 2003) Duran, I.; Şengün, A.; Hadimli, Hasan Hüseyin; Ülker, M.; Özer, F.[Abstract not Available]Öğe Influence of Dentinal Regions on Bond Strengths of Different Adhesive Systems(Wiley, 2003) Özer, Füsun; Ünlü, Nimet; Şengün, A.This in vitro study assessed comparatively the shear bond strengths of three composite resins, 3M Valux Plus (3MVP), Herculite (H), Clearfil AP-X (CAP-X), a polyacid modified composite resin Dyract (D), and a resin modified glass-ionomer materials Vitremer (V), to cervical and buccal dentine regions of extracted human molar teeth. Four different bonding systems, 3M ScotchBond Multipurpose (SB), Clearfil Liner Bond 2 (LB2), Opti Bond (OB), and Prime & Bond 2.1 (PB 2.1) were used with the manufacturer's respective composite and compomer materials. One hundred freshly extracted mandibular molar teeth were selected for this study. Flat buccal dentine surfaces were created on 50 teeth and cylindrical rods of the five materials were bonded to the dentine surfaces. For assessment of cervical bond strengths, the materials were bonded to mesial and distal enamel bordered occlusal dentinal surfaces of the remaining 50 teeth. The five groups of restorative procedures were applied as follows; Group 1: SB + 3MVP, Group 2: LB2 + CAP-X, Group 3: OB + H, Group 4: PB2.1 + D, Group 5: Vitremer primer (VP) VP + V. Each restorative procedure thus had 20 specimens (10 buccal + 10 cervical). After 24 h of water storage (37 degreesC), the specimens were tested on a Universal Testing machine in shear with a cross head speed of 0.5 mm min(-1) . The bond strength values were calculated in MPa and the results were evaluated statistically using Kruskal-Wallis one-way/anova and Mann-Whitney U -tests. It was found that the bond strengths of SB + 3MVP, LB2 + CAP-X and VP + V to buccal dentine surfaces were significantly stronger (P < 0.05) than those to the occluso-cervical dentine floors. When the bond strengths to the occluso-cervical dentine and buccal dentine surface were compared, there was no significant difference between the materials (P > 0.05). Vitremer was found the least successful adhesive material in terms of shear bond strength on both buccal and occluso-cervical dentine surfaces.Öğe Influence of Surface Preparation in Resin/enamel Interface: a Sem Study.(Int Amer Assoc Dental Researchi a D R/a a D R, 2002) Şengün, A.; İpekdal, I.; Özer, F.; Yaşar, E.[Abstract not Available]Öğe Restoring Function and Esthetics in a Patient With Amelogenesis Imperfecta: a Case Report(QUINTESSENCE PUBLISHING CO INC, 2002) Şengün, A.; Özer, F.Amelogenesis Imperfecta is a hereditary disorder that affects enamel on primary and permanent teeth. It is a rare dental disease but represents a major restorative challenge for the dentist. A 14-year-old boy presented with sensitive, discolored, and mutilated teeth and a decreased vertical dimension of occlusion. The aim of treatment was to reduce dental sensitivity, to restore esthetics, and to correct the vertical dimension of occlusion. To modify the occlusion, and to protect the dentin from chemical and thermal attacks, nickel-chrome onlays were placed on the molars. To improve the esthetics of the incisors and premolars, resin composite restorations were applied. The patient was regularly recalled during the postoperative period. Radiographic and clinical examinations 10 months posttreatment revealed no evidence of disorders associated with the restored teeth or their supporting structures.Öğe Three Dimensional Microscopic Investigation of Resin/Cavity Wall Integrity.(Amer Assoc Dental Research, 2000) Özer, F.; Şengün, A.; Belli, Sema; Unlu, N.; Alkaya, F.[Abstract not Available]Öğe Vitamin D Receptor Gene Polymorphism is Associated With Dental Caries.(INT AMER ASSOC DENTAL RESEARCHI A D R/A A D R, 2003) Şengün, A.; Duran, I.; Erdal, M. E.; Özkaya, M.; Özturk, B.; Özer, Faruk[Abstract not Available]
