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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 Effects of contemporary orthodontic composites on tooth color following short-term fixed orthodontic treatment: a controlled clinical study(Tubitak Scientific & Technological 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 staining solutions on the discoloration of orthodontic adhesives: An in-vitro study(Mosby-Elsevier, 2010) Corekci, Bayram; Irgin, Celal; Malkoc, Siddik; Ozturk, BoraIntroduction: Our aim was to evaluate the effects of staining solutions on the discoloration of orthodontic adhesives. Methods: Six orthodontic adhesives were investigated (Transbond XT [3M Unitek, Monrovia, Calif, USA], Heliosit Orthodontic [Ivoclar Vivadent, Liectenstein], Light Bond [Reliance Orthodontic Products, Itasca, IL, USA], Bisco Ortho [Bisco, Schamburg, IL, USA], Quick Cure [Reliance Orthodontic Products, Itasca, IL, USA], and Filtek Supreme XT [3M ESPE, St Paul, Minn, USA]), and 5 beverages (tea, cola, coffee, red wine, and yogurt). Sixty specimens were prepared. Five specimens from each group were stored in each of the 5 staining solutions. The 5 remaining specimens from each group served as the controls and were stored in distilled water. The specimens were immersed in staining solutions and water at 37 degrees C +/- 1 degrees C for 5 days. The test period was 25 days. Before and after the test period, color measurements were carried out with a spectrophotometer, and color changes (Delta E*) were calculated. Statistical differences were evaluated by using analysis of variance (ANOVA) and the Tukey HSD tests. Results: Adhesive materials, staining agents, and their interactions were found to play statistically significant roles (P <0.001) in color changes. Among the adhesive materials, the Light Bond water control group consistently showed the lowest Delta E* value for all materials, and the Filtek Supreme XT group showed the highest Delta E* value for all materials. After the in-vitro experimental process for staining solutions and water, unsatisfactory color stability was observed for the conventional adhesive systems except for Light Bond, Transbond XT, and Bisco Ortho water control group (Delta E* >3.7), respectively. Conclusions: In esthetically critical areas, discoloration of adhesive materials for fixed orthodontics can cause patient dissatisfaction. Orthodontic composites will discolor from staining beverages during their lifespan. (Am J Orthod Dentofacial Orthop 2010;138:741-6)Öğe Effects of Time Delay on Degree of Conversion of Contemporary Orthodontic Band Adhesives(Aves Press Ltd, 2013) Corekci, Bayram; Toy, Ebubekir; Malkoc, Siddik; Ozturk, Bora; Gunduz, S. BenizObjective: For prolonged use in the oral cavity, orthodontic band adhesives should have certain physical properties to ensure the best clinical performance. The degree of conversion (DC) of orthodontic band adhesives has been found to affect their mechanical properties. The aim of this study was to investigate the effects of time delay on the DC of orthodontic band adhesives. Materials and Methods: Fourier-transform infrared spectroscopy was used to evaluate the DC of 3 adhesives (Bisco Ortho Band Paste LC, Multi Cure Glass Ionomer Band Cement, Transbond Plus Light Cure Band Adhesive) immediately after they had been polymerized and stored in artificial saliva at 37 +/- 1 degrees C for 30 days. Thirty disc-shaped specimens (10 for each adhesive) were fabricated in Teflon molds (6.0 x 1.0 mm). The samples for each adhesive were divided further into 2 groups (n=5). Results: The DC was significantly influenced by the band adhesive type (p < 0.05), and there were significant differences among band adhesive types for the DC after 30 days. Conclusion: The value of the DC could change with time delay.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)
