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    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)
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    Cytotoxicity Testing of Temporary Luting Cements with Two- and Three-Dimensional Cultures of Bovine Dental Pulp-Derived Cells
    (HINDAWI PUBLISHING CORPORATION, 2013) Ulker, Hayriye Esra; Ulker, Mustafa; Gumus, Hasan Onder; Yalcin, Muhammet; Sengun, Abdulkadir
    This study evaluated the cytotoxicity of eugenol-containing and eugenol-free temporary luting cements. For cytotoxicity testing, bovine pulp-derived cells transfected with Simian virus 40 Large T antigen were exposed to extracts of eugenol-containing (Rely X Temp E) and eugenol-free (Provicol, PreVISION CEM, and Rely X Temp NE) temporary luting cements for 24 h. The cytotoxicity of the same materials was also evaluated in a dentin barrier test device using three-dimensional cell cultures of bovine pulp-derived cells. The results of the cytotoxicity studies with two-dimensional cultures of bovine dental pulp-derived cells revealed that cell survival with the extracts of Rely X Temp E, Provicol, PreVISION CEM, and Rely X Temp NE was 89.1%, 84.9%, 92.3%, and 66.8%, respectively. Rely X Temp NE and Provicol showed cytotoxic effects on bovine dental pulp-derived cells (P < 0.05). The results of the dentin barrier test revealed that cell survival with the above-mentioned temporary cement was 101.5%, 91.9%, 93.5%, and 90.6%, respectively. None of the temporary luting cements significantly reduced cell survival compared with the negative control in the dentin barrier test (P > 0.05). Biologically active materials released from temporary luting cements may not influence the dentine-pulp complex if the residual dentine layer is at least 0.5 mm thick.
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    Effect of alternative modes of application on microleakage of one-step self-etch adhesives
    (ELSEVIER TAIWAN, 2013) Ulker, Mustafa; Ulker, Hayriye Esra; Karabekiroglu, Said; Botsali, Murat Selim; Cetin, Ali Riza
    Background/purpose: Contemporary one-step self-etch adhesives are certainly the most user-friendly adhesives; however, typically could not compete with the more traditional multi-step adhesives. This in vitro study evaluated the efficacy of two modes of application (double application or placement of a hydrophobic resin coating) for the reduction of microleakage, using three different one-step self-etch adhesives (AdheSE One VivaPen, lvoclar Vivadent, Schaan, Liechtenstein; Xeno V, Dentsply De Trey, Konstanz, Germany; OptiBond All-In-One, Kerr Italia S.r.l, Scafati, Italy). Materials and methods: We prepared Class V cavities with the occlusal margin in enamel and gingival margin in dentin on both buccal and lingual surfaces of 108 human molar teeth. Cavities were divided into nine groups according to the combination of adhesives and application modes used (n = 24). For applying adhesives, we followed three types of procedures: (1) according to the manufacturers' directions; (2) using a double-application method; and (3) with the additional placement of a hydrophobic resin layer after following the manufacturers' directions. We restored the cavities with a composite resin. After thermocycling (500 cycles at 5 degrees C/55 degrees C) and immersion in 0.5% basic fuchsin, we sectioned the teeth and evaluated them for microleakage using a stereo microscope (20x). Enamel and dentin margins were scored separately, and we analyzed the data using Kruskal-Wallis, Bonferroni-corrected Mann-Whitney U, and Wilcoxon signed-rank tests. Results: Application of a hydrophobic resin over the cured Xeno V adhesive decreased the amount of microleakage at the enamel margins, compared with the application according to the manufacturer's instructions (P = 0.005). Both application modes decreased the amount of microleakage at the dentin margins with AdheSE One VivaPen adhesive, compared with application according to the manufacturer's instructions (P < 0.001). With the OptiBond All-In-One adhesive, no significant difference between application modes was observed. Conclusion: Alternative modes of application did not adversely affect the sealing ability of one-step self-etch adhesives. Depending on the type of adhesive, alternative modes of application may contribute to low microleakage values. Copyright (C) 2012, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC. All rights reserved.
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    Evaluation of HEMA released from four different adhesive systems by HPLC
    (SAGE PUBLICATIONS LTD, 2015) Altunsoy, Mustafa; Botsali, Murat Selim; Ulker, Hayriye Esra
    Purpose: This study evaluated the elution of 2-hydroxyethyl methacrylate (HEMA) from 4 different adhesives, using high-performance liquid chromatography (HPLC). Materials and methods: The adhesives were applied on a bovine dentin surface and polymerized using an LED curing unit (n=5). After polymerization, specimens were stored in 75% ethanol solution (6 mL). Residual HEMA that was eluted from adhesives (after 10 minutes, 1 hour, 24 hours, 7 days and 30 days) was analyzed using HPLC. Statistical analyses were performed using 1-way ANOVA, Tukey HSD test and paired 2-sample t-test. Results: There were statistically significant differences among adhesive systems for the cumulative released HEMA and among the time periods (p<0.05). Clearfil SE Bond showed the highest amount of HEMA released, while Easy Bond showed the lowest. Among the time periods, the highest eluted HEMA value was detected in 10 minutes for all adhesives, and elution continued for up to 30 days. Conclusions: The HEMA eluted from adhesives was in different amounts, and the elution continued for a long time. The amount of eluted HEMA from adhesives used in this study was not viewed as critical for toxic reactions in biological tissues.
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    Intrapulpal Thermal Changes during Setting Reaction of Glass Carbomer (R) Using Thermocure Lamp
    (HINDAWI PUBLISHING CORP, 2016) Kahvecioglu, Firdevs; Tosun, Gul; Ulker, Hayriye Esra
    Objectives. Tomeasure the temperature increase induced during thermocure lamp setting reaction of glass carbomer and to compare it with those induced by visible light curing of a resin-modified glass ionomer and a polyacid-modified composite resin in primary and permanent teeth. Materials and Methods. Nonretentive class I cavities were prepared in extracted primary and permanent molars. Glass carbomer (GC) was placed in the cavity and set at 60 degrees C for 60 sn using a special thermocure lamp. Resin-modified glass ionomer (RMGIC) and polyacid-modified composite resin (PMCR) were placed in the cavities and polymerized with an LED curing unit. Temperature increases during setting reactions were measured with a J-type thermocouple wire connected to a data logger. Data were examined using two-way analysis of variance and Tukey's honestly significant difference tests. Results. The use of GC resulted in temperature changes of 5.17 +/- 0.92 degrees C and 5.32 +/- 0.90 degrees C in primary and permanent teeth, respectively (p > 0.05). Temperature increases were greatest in the GC group, differing significantly fromthose in the PMCR group (p < 0.05). Conclusion. Temperature increases during polymerization and setting reactions of the materials were below the critical value in all groups. No difference was observed between primary and permanent teeth, regardless of the material used.
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    Residual monomer release from orthodontic adhesives cured with different light sources
    (TAYLOR & FRANCIS LTD, 2016) Botsali, Murat Selim; Sozer, Ozlem Akinci; Altunsoy, Mustafa; Demir, Abdullah; Ulker, Hayriye Esra
    Introduction: The aim of this study was to evaluate the residual monomer release from orthodontic adhesives cured with light-emitting diode (LED) and halogen light sources.Methods: Seven hundred and twenty stainless steel brackets were divided into 3 groups according to the adhesive system used (Transbond XT light-cure adhesive [TXT], Transbond LR capsule [LR], and Light Bond light-cure adhesive paste [LB]), and each group was divided into 2 subgroups according to light-curing procedure (LED or halogen). Brackets were bonded with adhesives onto tooth buccal surfaces and polymerized. Each specimen contained 24 brackets that simulated the oral environment (n=5). The specimens were immersed in a 75% ethanol/water solution at 37 degrees C for 10min, 1h, 1 d, 7 d, 14 d, and 30 d, respectively. Eluted monomers (Bis-GMA, UDMA, and TEGDMA) were detected using HPLC.Results: There was residual monomer release at all time periods, and the highest amount of release was observed cumulatively on the 30th day. The cumulative Bis-GMA released from adhesives was not different (p>0.05). The cumulative TEGDMA released from adhesives was statistically different (p<0.05). There was no statistical difference between QTH and LED light-curing units for each adhesive (p>0.05).Conclusions: The release of residual monomers stays at a high level for a long time after polymerization. The total leaching of residual monomers from the Light Bond light-cure sealant resin plus Light Bond light-cure adhesive paste was higher than that of other materials for both curing units. Different curing units (LED or QTH) did not affect the monomer release from the orthodontic adhesives.