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Öğe Comparison of in vitro cytotoxicity and genotoxicity of MMA-based polymeric materials and various metallic materials [MMA tabanli{dotless} polimerik materyallerin in vitro sitotoksisite ve genotoksisitesinin çeşitli metalik materyallerle karşi{dotless}laşti{dotless}ri{dotless}lmasi{dotless}](2010) Gülçe Iz S.; Deliloglu Gürhan S.I.; Şen B.H.; Endogan T.; Hasirci N.Aim: To determine the in vitro cytotoxicity and genotoxicity of some polymeric and metallic implant materials used as base materials in dentistry, based on ISO (International Organization for Standardization) and OECD (Organization for Economic Co-Operation and Development) test protocols. Materials and methods: Three different acrylate-based polymeric materials were tested for their in vitro cytotoxicity and genotoxicity (polymethylmethacrylate microspheres [PMMA], a solid cement prepared by mixing PMMA with its monomer methylmethacrylate [PMMA+MMA], a solid cement prepared by mixing PMMA, MMA, and hydroxyapatite [PMMA+MMA+HA], as wells as 4 different metallic materials (titanium [Ti grade 4], nickel alloy 625 [Ni-625], stainless steel alloy 304L [SS-304L], and stainless steel alloy 321 [SS-321]). Cytotoxic effects of the materials were determined using L929 mouse fibroblasts by MTT assay. Cell attachment properties related to the biocompatibility of the materials were analyzed using a scanning electron microscope (SEM). Genotoxicity of the materials was determined with human peripheral lymphocytes via micronucleus assay. Results: The highest compatibility was exhibited by Ti grade 4, followed by Ni-625, SS-304L and, SS-321. Among the polymeric materials, PMMA+MMA+HA had the highest biocompatibility, followed by PMMA+MMA and PMMA. Conclusion: The biocompatibility of the metallic materials was higher than that of the polymeric materials. Ti, the most inert metal, exhibited the highest biocompatibility. The addition of HA reduced the cytotoxic and mutagenic effects of MMA monomer and leachable ingredients. © TÜBİTAK.Öğe Dens invaginatus in a primary molar: Report of case(2002) Eden E.K.; Koca H.; Şen B.H.A case of dens invaginatus in a mandibular second primary molar of an elevenyear-old boy is presented. The tooth was extracted and examined by scanning electron microscopy. SEM findings demonstrated the presence of defective enamel and cementum in the pulp chamber. Dentinal tissues were also irregular and had fewer and thinner tubules. This case of dens invaginatus in primary molar is an unusual case of the malformation being the only one in the literature.Öğe Diagnostic accuracy of proximal enamel subsurface demineralization and its relationship with calcium loss and lesion depth(2012) Önem E.; Baksi B.G.; Şen B.H.; Sögüt Ö.; Mert A.Objective: The aim of this study was to determine the relationship between the amount of calcium loss, lesion depth, and the accuracy of storage phosphor plate (SPP) and film radiographs for the detection of artificial proximal demineralization. Methods: Standard enamel windows of extracted premolars were exposed to a demineralizing solution for 60 h, 80h, 100 h and 120 h. Solutions were analysed for calcium concentration by atomic absorption spectrometer and the lesion depths were calculated by a specific formula. All teeth were radiographed with SPPs and F-speed films before and after acid application. Images were evaluated by five observers. Stereomicroscopic and scanning electron microscopic (SEM) observations were carried out to visualize enamel surfaces after acid exposure. Receiver operating characteristic analysis was used for diagnostic accuracy (A z). A zs were compared with factorial analysis of variance and t-tests. The relationship between A zs and lesion depths was determined with Pearson's correlation test. Results: Strong positive correlation was found between A zs of both radiographic methods and lesion depths. No difference was found between the A zs of two radiographic systems for any of the demineralization durations (p > 0.05). Pair-wise comparisons revealed no significant difference in Azs of SPPs (p > 0.05), while significant differences were obtained for the A zs of films for different demineralization periods (p < 0.05). Stereomicroscopic and SEM observations confirmed demineralizations from superficial to deeper layers of enamel. Conclusion: Subsurface enamel demineralization was not accurately detectable with either storage phosphor plates or F-speed films. The amount of calcium loss and the depth of demineralization have a strong relationship with diagnostic accuracy with a significant effect particularly on F-speed films. © 2012 The British Institute of Radiology.Öğe Effect of exposure parameters on the radiopacity of root canal sealers(2013) Önem E.; Baksi B.G.; Şen B.H.Background: The aim of this study was to test the effect of different kilovoltage, milliampere, and exposure time settings on the radiopacity of two endodontic sealers using an image plate system. Materials and methods: MM-Seal (MicroMega, Besancon, France) and Diaket (3M Espe, Seefeld, Germany) were packed into a polytetrafluoroethylene ring mold with an internal diameter of 10. mm and a depth of 1. mm. Five discs of each material were imaged alongside an aluminum step-wedge. Sets of radiographs were obtained using storage phosphor plates (SPPs). The SPPs were exposed at 60, 65, or 70. kVp, 7 or 8. mA for 0.12 or 0.16. s. Radiographic densities of the sealers and each step of the step-wedge were analyzed with Image Tool 3.0 SDK software (University of Texas Health Sciences Center, TX, USA). Three readings were made for each image. The mean was calculated to give the radiographic density expressed as mean gray values. Three-way ANOVA was used to test the differences in radiopacity of sealers with respect to kilovoltage, milliampere, exposure time, and the interaction of the three factors. Results: No significant difference in sealers' radiopacity was found with change in three exposure parameters (p>. 0.05). However, standard deviations of the measurements for lower exposures were greater; MM-Seal was significantly more radiopaque than Diaket (p<. 0.0001) at any parameter. Conclusions: Differences in kilovoltage, milliampere, and exposure time do not affect the radiopacity measurements of sealers on SPP images. However, choosing the proper exposure parameters may optimize the gray value range of the sealers allowing for better discrimination of the sealer and surrounding structures thereby providing better clinical guidance. © 2012 Japanese Stomatological Society.Öğe Evaluation of the smear layer removal and erosive capacity of EDTA, boric acid, citric acid and desy clean solutions: An in vitro study(BioMed Central Ltd., 2015) Turk T.; Kaval M.E.; Şen B.H.Background: The purpose of this study was to investigate the smear layer removal and erosive capacity of various irrigation solutions with sequential use of NaOCl on instrumented root canal walls. Methods: The root canals of single-rooted teeth were instrumented with ProTaper rotary instrument. Then, the teeth were randomly divided into five experimental groups. The root canals were irrigated with one of the following solutions (5 mL/1min): 5% EDTA, 5% boric acid (BA), a mixture of BA and CA, 2.5% citric acid (CA) and 5% Desy Clean. After irrigating with 2.5% NaOCl and distilled water, the roots were split into two halves and each half was prepared for SEM examination. Representative photographs were taken from each third at x500 and x1000 magnifications. Double blind scoring was performed by two calibrated observers for smear layer and erosion. The scores were statistically analyzed using Kruskal-Wallis, Dunn's post hoc and Spearman's correlation tests (p = 0.05). Results: There were statistically significant differences among the solutions by means of smear layer and erosion (p < 0.05). While 2.5% CA solution was the most effective solution in removal of smear layer, it was also the most erosive solution (p < 0.05). 5% Desy Clean removed smear layer effectively and caused less erosion. There was a negative, but statistically significant correlation between presence of smear layer and erosion (r = -0.684; p < 0.0001). Conclusion: Desy Clean can be a promising agent as an irrigation solution with optimal smear layer removal capacity and less erosive effects. © 2015 Turk et al.Öğe Idiopathic root resorption of the entire permanent dentition: Systematic review and report of a case(2008) Sogur E.; Sogur H.D.; Baksi B.G.; Şen B.H.A rare case of idiopathic root resorption affecting the entire dentition was described. Root resorptions of all of the maxillary and mandibular teeth were coincidentally diagnosed on patient's radiographic examination. The patient's medical and dental findings were non-contributory, other than the increased mobility of upper incisors. No significant familial findings could be identified. Detailed radiographic examination revealed resorption affecting the apical part of the roots, resulting in vertical shortening of the teeth. The character of the resorption was as if a tapering occurred throughout the lateral root surfaces. Involved teeth were endodontically treated and the patient was subsequently followed-up for 18 months. Following endodontic therapy, all periapical lesions demonstrated clinical and radiographic evidence of healing. Endodontic therapy resulted in a high degree of success to stop resorption process and maintain the dentition. © 2008 The Authors.Öğe Nanoleakage inhibition within hybrid layer using new protective chemicals and their effect on adhesion(2011) Dündar M.; Özcan M.; Çömlekoglu M.E.; Şen B.H.Hybrid-layer degradation occurs because of acidic properties of currently used adhesive systems. Titanium tetrafluoride couples with tooth surface, and titanium compounds are not substituted. Caffeic acid phenethyl esther inhibits endogenous matrix metalloproteinases that cause hybrid-layer degradation. It was hypothesized that titanium tetrafluoride and caffeic acid phenethyl esther application on exposed dentine surfaces before adhesive applications would inhibit nanoleakage and hybrid-layer degradation without compromising the bond strength of the adhesives. In ultracut thin sections, human dentine-chemical agent-adhesive composite interfaces were observed under transmission electron microscope with complementary scanning electron microscopy. Microtensile bond strength tests were also accomplished. Titanium tetrafluoride and titanium tetrafluoride + caffeic acid phenethyl esther applications decreased bond strength values. Caffeic acid phenethyl esther showed decreased silver nitrate penetration for cements based on Bisphenol glycydilmethacrylate and methyl methacrylate, whereas cement based on 4-methacryloyloxyethyl trimellitate anhydride methyl methacrylate showed almost no infiltration. Caffeic acid phenethyl esther application before cementation could inhibit nanoleakage and biodegradation of the hybrid layer. © 2011 International & American Associations for Dental Research.Öğe Pixel intensity and fractal dimension of periapical lesions visually indiscernible in radiographs(2013) Sogur E.; Baksi B.G.; Gröndahl H.-G.; Şen B.H.Introduction: The purpose of the study was to analyze pixel intensity (PI) and fractal dimension (FD) values in radiographs of chemically created but visually undetectable periapical lesions. Methods: Artificial lesions were created by applying 70% perchloric acid to the sockets of left and right first premolars in 12 cadaver mandibles. For preparation of relatively small lesions, the acid was applied for 30 and 60 minutes. Before and after each acid application, radiographs were taken (60 kVp, 7 mA, and 1.5 mm Al equivalent filtration for 0.12 second) with storage phosphor plates. An optical bench was used to standardize projection geometry. Image plates were scanned immediately after exposure, and the acquired images were saved uncompressed in TIF format. Six observers evaluated the images by using a 5-grade scale, and the images scored as "definitely absent" by all observers were used for the calculations of PI and FD. Box-counting FDs and differences in mean PI were computed for regions of interest at the apical areas of each premolar. Repeated-measures analysis of variance, Tukey test, and Pearson correlation coefficient test were used for statistical analysis. Results: A significant difference was found in FD values after both acid application periods (P <.05), whereas a difference in PI was detected only in images obtained after 60-minute acid application (P <.05). There was a negative correlation between FD and PI values (-0.754, P <.05). Conclusions: Calculation of FD can be a tool for the early detection of periapical lesions given the presence of baseline radiographs. © 2013 American Association of Endodontists.Öğe Preliminary evaluation of titanium tetrafluoride as an alternative ceramic etchant to hydrofluoric acid(2009) Erhan Çömlekoğlu M.; Dündar M.; Ali Güngör M.; Şen B.H.; Artunç C.Purpose: The etching of dental ceramics with a glassy matrix by means of hydrofluoric acid (HF) is highly effective and after the application of a silane coupling agent, a strong link between the adhesive and the ceramic is achieved. The purpose of this study was to investigate whether aqueous titanium tetrafluoride (TiF4) solution could be used as an alternative ceramic etchant or not. Materials and Methods: Seventy lithia-based all-ceramic specimens (IPS Empress 2, Ivoclar Vivadent) (diameter: 4 mm, height: 4 mm) were prepared and ultrasonically cleaned for 15 min in ethanol and deionized water, then divided into 1 control and 4 experimental groups (n = 14/group). The control group was acid etched with 4.9% HF for 20 s as described by the manufacturer. The experimental groups were treated with 2.5% TiF4 solution for 60 s, 2.5% TiF4 solution for 120 s and 5% TiF4 solution for 60 s, as well as 5% TiF4 solution for 120 s. Seven of the ceramic specimens in each group were luted to the other seven by a dual-curing cement (Variolink II, Ivoclar Vivadent,) with silane application (Monobond-S). After storage of luted specimens in deionized water at 37°C for 24 h, the specimens were embedded in plastic holders with cyanoacrylate, and the shear-bond strength (SBS) tests were performed with a Shimadzu universal testing machine at a crosshead speed of 0.5 mm/min. A one-way ANOVA and Bonferroni correction, followed by the Tukey test, were applied for statistical analysis. Scanning electron microscopic examination was performed to evaluate the pattern of debonding. Results: Significantly higher SBS values (p ? 0.05) were obtained for the control group (28.71 ± 9.74). The SBS for 2.5%-60 s (25.25 ± 5.13) and 2.5%-120 s TiF4 (22.65 ± 5.68) were significantly higher than 5%-60 s (16.77 ± 3.92) and 5%-120 s TiF4 (18.54 ± 3.52) groups (p ? 0.05). Differences between 60- and 120-s groups irrespective of TiF4 concentrations were insignificant (p > 0.05). Conclusion: Aqueous TiF4 solution exhibited similar shear bond strength values in comparison to commonly used HF and can be considered as an alternative ceramic etchant within the limitations of this preliminary report. © 2009 by Quintessence Publishing Co Inc.Öğe Prevalence of candida albicans in oral cavities and root canals of children(2002) Akdeniz B.G.; Koparal E.; Şen B.H.; Ateş M.; Denizci A.A.The aim of this study was to examine the prevalence of C. albicans in the oral cavities and root canals of children. Twenty healthy and caries-free children and 13 children with caries, were screened. Imprint samples and sterile paper points were used to obtain the samples from oral cavities and root canals respectively. The production of germ tubes and the development of chlamydospores identified yeast cultures. Sixty-nine percent of children with caries and 5% of caries-free children were found to be Candida carriers. The difference in candidal prevalence between two groups was significant (p<0.05). Sixty-one point five percent of children were positive for Candida in the root canal. Since, increase in the C. albicans in the oral cavity provides a potential source of the fungus particularly when resistance falls below a certain threshold, attention to strategies for the reduction of this pervasive and persistent pathogen becomes important. Therefore, reduction of caries and/or introduction of antifungal agents during root canal treatment of children may be offered.Öğe Prevalence of odontogenic sinus tracts in patients referred for endodontic therapy(2013) Sogur E.; Şen B.H.; Baksi B.G.; Mert A.Objectives: The primary aim of this study was to assess the prevalence, location and distribution of odontogenic sinus tracts in a population of Turkish adult patients referred for endodontic therapy. The second aim was to investigate the influence of the factors such as sex, age, systemic disease, existence and diameter of periapical radioluceny on the prevalence of the clinically detected sinus tracts among Turkish population. Materials and Methods: A total of 499 patients' records according to the demographic data and the presence of periapical radiolucency and of sinus tract were included to the present study. The location of the sinus tracts was recorded as well. Data were analyzed using Pearson chi-square and Fisher's Exact Tests (p=0.05). Results: The number of the teeth who had sinus tracts was 37 (7.4%). Sixteen of 37 teeth with sinus tracts were associated with posterior teeth (43%). No significant differences were found in the prevalence of sinus tracts between two genders (p>0.05). 40-50year age group showed the highest prevalence of sinus tracts. Conclusions: Approximately one in thirteen teeth referred for root canal treatment had a sinus tract. Fourtythree percent of sinus tracts were associated with posterior teeth with high prevalence of openings in buccal aspects of the gingiva. Therefore, practitioners should be careful while examining posterior teeth referred for endodontic treatment.Öğe Prostatic calculi: Silent stones [Litiasis prosttica: clculos silentes](2010) Köseoglu H.; Aslan G.; Şen B.H.; Tuna B.; Yörükoglu K.Introduction: Introduction and Objectives Prostate stones are frequently encountered duriñóng transurethral resection of the prostate in urology practice. We aimed to demonstrate the physical and chemical properties of prostate stones. We also aimed to determine possible relationship between inflammation of prostate gland and prostate stones. Methods: The consecutive patients (excluding subjects with PSA<4 ng/ml and urolithiasis), who underwent TURP operation and who were observed to have prostatic calculi duriñóng TURP, were included in the study. The prostatic stones obtained from each patient duriñóng TURP were analysed for chemical composition and observed under electron microscopy (SEM) for structure and surface morphology. The pathological specimens were assessed by the uropathologist for the final diagnosis and existence and degree of inflammation. Results: Five patients were included in the study. From each patient at least three (range 38) samples of stones (diameter varying from 1 mm up to 5 mm) were obtained. The stones were made of mixed composition of calcium phosphate and calcium carbonate. The stones were found to have lobular surface made up of small spheres under SEM. Histopathological examination of the TURP specimens revealed being prostatic hyperplasia accompanied with inflammation of mild to severe degree. Conclusions: Prostatic stones are concentrically precipitated calcium stones within the prostatic ductuli with granular grape like morphology. Histopathological inflammation seems to be associated with these prostatic calculi. © 2010 AEU. Published by Elsevier España, S.L. All rights reserved.Öğe Random/aligned electrospun PCL/PCL-collagen nanofibrous membranes: Comparison of neural differentiation of rat AdMSCs and BMSCs(Institute of Physics Publishing, 2012) Çapkin M.; Çakmak S.; Kurt F.Ö.; Gumusderelioglu M.; Şen B.H.; Türk B.T.; Deliloglu-Gürhan S.I.In this study, the aligned (A) and randomly oriented (R) polycaprolactone (PCL-A and PCL-R) and PCL/collagen (PCL/Col-A and PCL/Col-R) nanofibers were electrospun onto smooth PCL membranes (PCLMs) prepared by solvent casting. In order to investigate the effects of chemical composition and nanotopography of fibrous surfaces on proliferation and on neural differentiation of mesenchymal stem cells (MSCs), adipose and bone marrow-derived rat MSCs (AdMSCs and BMSCs) were cultivated in suitable media i.e. inducing medium containing basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF), and cell maintenance medium (CMM). BMSCs adhered and proliferated on all nanofibrous membranes more efficiently than AdMSCs. PCL/Col-A was found as the most convenient surface supporting proliferation in both cell types. Immunofluorescence staining indicated that BMSCs and AdMSCs are prone for differentiation to oligodendrocytes more than they differentiate to other neuronal cell types. PCL-A nanofibrous membranes supported differentiation of MSCs to O4+ (an oligodendrocytes surface antigen) cells in both culture media. The intensity of immunoreactivity of O4+ cells differentiated from BMSCs on PCL-A was highest when compared with the other groups (p < 0.001). Some BIII-T signed neural cells were investigated on PCL-A nanofibrous membranes, but the intensity of immunoreactivity was lower than that of O4+ cells. In conclusion, this study can be evaluated to establish the cell therapy strategies in neurodegenerative disorders, which are relevant to oligodendrocyte abstinence using BMSCs or AdMSCs on aligned nanofibrous membranes. © 2012 IOP Publishing Ltd.Öğe Treatment of extraoral sinus tracts from traumatized teeth with apical periodontitis(1995) Çalişkan M.K.; Şen B.H.; Ozinel M.A.Abstract When a draining lesion is encountered on the skin of the face, an endodontic origin should always be considered in differential diagnosis. Non-surgical endodontic therapy, sometimes complimented by surgery, or extraction are the choices for the treatment of these cases. Three cases of extraoral sinus tract on the chin caused by necrotic pulp of traumatized lowrer anterior teeth are presented. A paste consisting of calcium hydroxide and barium sulfate powder mixed with glycerin was used. Usage of calcium hydroxide paste was advocated for rapid and successful treatment of extraoral lesions communicating with necrotic teeth. Copyright © 1995, Wiley Blackwell. All rights reserved
