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Öğe Cytotoxicity evaluation of dentin bonding agents by dentin barrier test on 3-dimensional pulp cells(MOSBY-ELSEVIER, 2011) Sengun, Abdulkadir; Yalcin, Muhammet; Ulker, Hayriye Esra; Ozturk, Bora; Hakki, Sema S.Objective. The aim of this study was to evaluate the effects of 4 dentin-bonding agents on the cell viability of bovine derived cells. Study design. Cytotoxicity of dentin-bonding agents (G-Bond [GB], Adper Prompt Self-Etch [APSE], Clearfil DC Bond System [CDCB], and Quadrant University-1-Bond [UB]) was analyzed with a dentin barrier test device using 3-dimensional (3D) pulp cell cultures. A commercially available cell culture perfusion chamber was separated into 2 compartments using a 500 mu m dentin disk. The 3D cultures were placed on a dentin disk and held in place with a special biocompatible stainless steel holder. Test materials were introduced into the upper compartment in direct contact with the cavity side of the dentin disks according to the manufacturer's instructions. Subsequently, the pulpal part of the perfusion chamber containing the cell cultures was perfused with a medium (2 mL/h). After an exposure period of 24 hours, cell survival was determined by using the MTT assay. Statistical analyses were performed using the Mann-Whitney U test. Results. In the dentin barrier test, cell survival rates of UB and CDCB were similar to the control group (P > .05). However, all other tested materials were cytotoxic for the 3D pulp-derived cell cultures (P > .05). Conclusions. Dentin-bonding agents include biologically active ingredients and may modify pulp cell metabolism when the materials are used in deep cavities in spite of a dentin barrier. If these adhesive agents are used in deep cavities, a biocompatible cavity liner should be used. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 112: e83-e88)Öğe Effect of accelerated aging on the bonding performance of fluoridated adhesive resins(JAPANESE SOC DENTAL MATERIALS DEVICES, 2014) Cobanoglu, Nevin; Ozturk, Bora; Sengun, Abdulkadir; Cetin, Ali Riza; Ozer, FusunThe purpose of this study was to investigate the dentin bond durability of a one-step, fluoride-containing, glass ionomer-based adhesive system, Reactmer Bond (RB), and that of a two-step, fluoride-containing, self-etch adhesive system, Clearfil Protect Bond (CPB). Enamel was removed from the occlusal surfaces of teeth, and flat dentin surfaces were entirely covered with a composite resin following the application of an adhesive material (n=10). After specimens were sectioned into rectangular sticks of 0.87 +/- 0.03 mm(2), the sticks were randomly assigned into two accelerated aging time period groups: 1 week or 1 year. Microtensile bond strengths were determined. Bond strength of RB increased significantly after 1 year (1 week=27.80 +/- 10.57 MPa versus 1 year=36.93 +/- 14.38 MPa) (p<0.05). In contrast, there was no significant difference in bond strength between the two time periods for CPB (1 week=51.74 +/- 17.8 MPa versus 1 year=56.03 +/- 18.85 MPa) (p>0.05). Both fluoride-containing adhesives seemed to demonstrate reliable bonding performance after 1 year of accelerated aging in water.Öğe Effect of caries removal techniques on bond strength to caries affected dentin on gingival wall: AFM observation of dentinal surface(TAYLOR & FRANCIS LTD, 2016) Cebe, Mehmet Ata; Ozturk, Bora; Karaarslan, Emine SirinObjective: The purpose of this study was to evaluate the effect of different caries removal techniques on the bond strength of two adhesive systems. Materials and Methods: Seventy human molar teeth that had proximal carious lesions were randomly divided into four groups according to the technique used to remove the caries: a conventional steel bur, an Er:YAG laser, a chemomechanical Carisolv((R)) gel, and air polishing. The groups were then divided into two subgroups according to the adhesives used: Clearfil S-3 (Kuraray Co., Ltd, Tokyo, Japan) and Adper SE Plus (3M ESPE, St Paul, MN, USA). The enamel and superficial dentin of the crown was flattened and caries were removed using different methods. Teeth were restored with composite and three 1mm(2) stick-shaped microtensile specimens were prepared from each tooth. For each removal technique, the surface roughness of one dentin sample was analyzed using atomic force microscopy (AFM). The microtensile bond strength data were then analyzed using a two-way ANOVA, Kruskal-Wallis and Mann-Whitney U tests, and multiple comparison tests (p=0.05). Results: The two-way ANOVA showed that the effects of the cavity preparation techniques and adhesive systems and their interaction were statistically significant (p<0.05). The TBS values were highest when bonding with Adper SE Plus to cavities prepared with the steel bur (37.20 +/- 11.65MPa) and lowest when bonding with Clearfil S-3 Bond to cavities prepared with the Er:YAG laser (16.74 +/- 6.95MPa). Conclusion: The caries removal techniques affected the bond strength values of the self-etch adhesive systems.Öğe The effect of different surface treatments on roughnessand bond strength in low fusing ceramics(SPRINGER LONDON LTD, 2011) Kara, Haluk Baris; Ozturk, A. Nilgun; Aykent, Filiz; Koc, Ozlem; Ozturk, BoraThe aim of this study was to evaluate the influence of different surface treatments (air abrasion, acid etching, and laser irradiation) on the surface roughness and bond strength of a low fusing ceramic. Thirty-six discs of low fusing ceramic (Finesse, Ceramco) were prepared (10 mm in diameter and 2 mm in thickness) according to the manufacturer's instructions. Specimens were divided into three groups (n = 12), and the following treatments were performed: Air abrasion with alumina particles (50 mu m), acid etching with 5% HF and Nd:YAG laser irradiation (distance: 1 mm, 100 mJ, 20 Hz, 2 W, and 141.54 J/cm(2)). Following determination of surface roughness (R-a) by profilometry, specimens were examined with scanning electron microscopy (SEM). The luting cement (Clearfil Esthetic Cement) was bonded to the ceramic specimens using Teflon tubes. After 24 h of water storage, shear bond strength test was performed using a universal testing machine at a crosshead speed of 1 mm/min. The data were analyzed with two-way analysis of variance (ANOVA) and Tukey HSD tests (alpha = .05). Two-way ANOVA indicated that surface roughness was significantly affected by surface treatments (p < .001). Tukey honestly significant difference (HSD) indicated that the air abrasion group had a significantly higher mean value (p < .05) than the other groups. Shear bond strength was significantly affected by surface treatments (p < .001). Tukey HSD indicated that the air abrasion group had a significantly higher mean value (p < .05) than the other groups. No significant difference was found between the acid-etching and laser-irradiation groups (p > .05). The SEM image of the laser irradiation surface appeared to be relatively smooth as compared to the images of other the groups. Air abrasion of low-fusing porcelain surfaces was effective in improving the bond strength as compared to the acid-etching and laser-irradiation methods.Öğe Effects of contemporary orthodontic composites on tooth color following short-term fixed orthodontic treatment: a controlled clinical study(TUBITAK SCIENTIFIC & TECHNICAL RESEARCH COUNCIL TURKEY, 2015) Corekci, Bayram; Toy, Ebubekir; Ozturk, Firat; Malkoc, Siddik; Ozturk, BoraBackground/aim: To determine the color alterations of natural teeth associated with different orthodontic composites used in comprehensive short-term treatment. Materials and methods: Twenty-two patients were treated with fixed appliances and 22 untreated subjects were also evaluated. Lower incisors were bonded with different orthodontic composites: 42 with Grengloo, 41 with Light Bond, 31 with Kurasper F, and 32 with Transbond XT. The color parameters of the Commission Internationale de l'Eclairage (CIE) were measured for each tooth with a spectrophotometer. Color assessment in relation to time, adhesive material, and their interaction was made with 2-way mixed analysis of variance (ANOVA) and 1-way ANOVA for the color differences (Delta E*). Further analyses were done using Tukey's honestly significant difference tests and paired-samples t-tests. Results: The color of teeth was affected by treatment. The mean L* and a* values increased, whereas the mean b* values decreased. Total color differences of teeth demonstrated visible color changes clinically after treatment, ranging from 1.12 to 3.34 Delta E units. However, there were no significant differences for color of enamel. Conclusion: Teeth may be discolored with fixed appliances during treatment. Moreover, contemporary orthodontic composites have similar effects of enamel discoloration.Öğe Effects of laser and acid etching and air abrasion on mineral content of dentin(SPRINGER LONDON LTD, 2011) Malkoc, Meral Arslan; Tasdemir, Serife Tuba; Ozturk, A. Nilgun; Ozturk, Bora; Berk, GizemThe aim of this study was to evaluate the mineral content of dentin prepared using an Er,Cr:YSGG laser at four different power settings, acid etching, and air abrasion. The study teeth comprised 35 molars which were randomly divided into seven equal groups. The occlusal third of the crowns were cut with a slow-speed diamond saw. The groups were as follows: group A, control group; group B, dentin etched with 35% buffered phosphoric acid for 30 s; group C, dentin abraded at 60 psi with 50-A mu m aluminium oxide for 1 s; groups D-G, dentin irradiated with the Er,Cr:YSGG laser at 1.50 W (group D), 2.25 W (group E), 3.00 W (group F), and 3.50 W (group G). The levels of Mg, P, Ca, K and Na in each dentin slab were measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Data were analysed by one way analysis of variance and Tukey HSD tests. There were no significant differences between the groups in the levels of Ca, P and Na, and the Ca/P ratio (p > 0.05); however, there were significant differences in the levels of K (p < 0.001) and Mg (p=0.13). In addition, the levels of Mg in the air abrasion group were higher than in the other groups (p < 0.01). Etching with the Er,Cr:YSGG laser system, air abrasion and acid etching did not affect the levels of Ca, P and Na, or the Ca/P ratio, in the dentin surface.Öğe Elution of monomer from different bulk fill dental composite resins(ELSEVIER SCI LTD, 2015) Cebe, Mehmet Ata; Cebe, Fatma; Cengiz, Mehmet Fatih; Cetin, Ali Riza; Arpag, Osman Fatih; Ozturk, BoraObjective. The purpose of this study was to evaluate the elution of Bis-GMA, TEGDMA, HEMA, and Bis-EMA monomers from six bulk fill composite resins over four different time periods, using HPLC. Methods. Six different composite resin materials were used in the present study: Tetric Evo Ceram Bulk Fill (Ivoclar Vivadent, Amherst, NY), X-tra Fill (VOCO, Cuxhaven, Germany), Sonic Fill (Kerr, Orange, CA, USA), Filtek Bulk Fill (3M ESPE Dental Product, St. Paul, MN), SDR (Dentsply, Konstanz, Germany), EQUIA (GC America INC, Alsip, IL). The samples (4 mm thickness, 5 mm diameter) were prepared and polymerized for 20s with a light emitted diode unit. After fabrication, each sample was immediately immersed in 75 wt% ethanol/water solution used as extraction fluid and stored in the amber colored bottles at room temperature. Ethanol/water samples were taken (0.5 mL) at predefined time intervals:10 m (T1), 1 h (T2), 24h (T3) and 30 days (T4). These samples were analyzed by HPLC. The obtained data were analyzed with one-way ANOVA and Tukey HSD at significance level of p < 0.05. Results. Amount of eluted Bis-EMA and Bis-GMA from Tetric Evo Ceram Bulk Fill and amount of eluted TEGDMA and HEMA from X-tra Fill higher than others composites (p < 0.05). Significance. Residual monomers were eluted from bulk fill composite resins in all time periods and the amount of eluted monomers was increased with time. (C) 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.Öğe Polymerization capacity of orthodontic composites analyzed by Fourier transform infrared spectroscopy(MOSBY-ELSEVIER, 2011) Corekci, Bayram; Malkoc, Siddik; Ozturk, Bora; Gunduz, Beniz; Toy, EbubekirIntroduction: The aim of this in-vitro study was to analyze the polymerization capacity of 5 orthodontic composites by determining the degree of monomer conversion (DC). Methods: Fourier transform infrared spectroscopy was used to evaluate the DC of the orthodontic composites immediately after polymerization and after storage in artificial saliva at 37 degrees C +/- 1 degrees C for 30 days. The resin-based adhesive composites investigated were Bisco Ortho (Bisco, Schaumburg, III), Heliosit Orthodontics (Ivoclar, Schaan, Liechtenstein), Kurasper F (Kuraray, Okayama, Japan), Light Bond (Reliance Orthodontic Products, Itasca, III), and Transbond XT (3M Unitek, Monrovia, Calif), cured with Elipar FreeLight 2 (3M ESPE, St Paul, Minn) for the testing of the DC values. Fifty cylindrical specimens were manufactured in molds. The data were analyzed by 2-factor analysis of variance (ANOVA) and Tukey HSD test. Results: According to 2-way ANOVA, the DC was significantly influenced by composite type (P < 0.05); after 30 days, there were no differences among the composite types for the DC. The interaction of orthodontic composites and time played a statistically significant role in the DC (P < 0.05), but there was no statistically significant influence of time for the DC (P > 0.05). Conclusions: The DC was found to change according to composite materials used, and Bisco Ortho showed the most DC performance. The DC of orthodontic composites is a complex process that is affected not only by inorganic filler content of the composite but also the monomer type and many other factors. Sufficient DC values of 5 commercially available orthodontic composites can be achieved with a new-generation light-emitting diode curing light. (Am J Orthod Dentofacial Orthop 2011;139:e299-e304)Öğe Push-out bonding strengths of four different dowel systems luted with two different adhesive systems(TAYLOR & FRANCIS LTD, 2014) Orucoglu, Hasan; Yavuz, Tevfik; Demir, Necla; Ozturk, Nilgun; Ozturk, BoraThis in vitro study investigates the bonding capacity of resin cements to dowels, using the push-out bonding strength of four different dowel systems, namely, stainless steel dowels (SSD), resin-supported polyethylene fiber dowels (RSPFD), zirconia dowels (ZD), and superpost glass fiber dowels (GFD), luted in root canals, using two different resin cements, namely, Multilink Automix Cement and Clearfil Esthetic Cement. Ninety-six maxillary central incisor teeth were sectioned below the cementoenamel junction, and the roots were treated endodontically. Then the roots were placed into four groups, based on the dowel systems used. The roots were further placed into two subgroups, based on the cement type used as subgroup A and subgroup B. Push-out bonding tests were performed on the bonded specimens, which were cut into 1mm thick sections. A two-way ANOVA test and Tukey's HSD tests were performed. The push-out bonding strength values for SSD, ZD, and RSPFD were not significantly different (p>0.05). The means for GFD were significantly higher than the means for ZD (p<0.05) when Multilink Automix Cement was used. However, when Clearfil Esthetic Cement was used, the means for RSPFD were significantly higher (p<0.001) than the means for the other systems. When Clearfil Esthetic Cement was used, the RSPF dowel system provided significantly higher bonding strength values than the other systems.
