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Öğe Biological and physical properties of calcium hydroxide-based pulp-capping materials and their modifications(Nihon Univ, School Dentistry, 2024) Akin, Dilek; Ozkaya, Cigdem Atalayin; Armagan, Guliz; Birim, Dervis; Ates, Mustafa; Tezel, HuseyinPurpose: To evaluate the biological and physical properties of calcium hydroxide -containing pulp -capping materials and their modifications with different solutions and antioxidant Resveratrol (RES) addition. Methods: Calcium hydroxide+distilled-water:C, calcium hydroxide+saline:S, calcium hydroxide+synthetic tissue fluid:STF, Dycal:D, calcium hydroxide+distilled-water+RES:C+RES, calcium hydroxide+saline+RES:S+RES, calcium hydroxide+synthetic tissue fluid+RES:STF+RES, Dycal+RES:D+RES were tested. Cytotoxicity was determined by WST-1. Antibacterial -activity was evaluated by agar -diffusion. The water -absorption and solubility were examined for ISO -6876 and ISO -3107. The color -change was evaluated by spectrophotometer. Radiopacity was evaluated for ISO -6876 and ISO -9917. The normal distribution and homogeneity were determined and comparisons were made with appropriate analysis and post hoc tests (P < 0.05). Results: The highest cell -viability was determined in the C+RES and the lowest was in D and D+RES after 24 h (P < 0.0001). RES-addition increased cell -viability and the highest rate was detected in C+RES, S+RES and STF+RES after 48 h (P < 0.0001). A limited inhibition -zone against Streptococcus mutans was detected in D and D+RES. RES-addition did not change the water -absorption in S and STF or the solubility in S group. Conclusion: RES-addition may be used to increase the biocompatibility of calcium hydroxide without any adverse effect on physical properties. Saline may be the first choice as a mixing solution.Öğe Does post-bleaching fluoridation affect the further demineralization of bleached enamel? An in vitro study(Biomed Central Ltd, 2014) Kemaloglu, Hande; Tezel, Huseyin; Ergucu, ZeynepBackground: Topical fluoride agents have been shown to be the most effective method in treating demineralized enamel after in-office bleaching treatments. Thus, this study aimed to examine the effects of two different post-bleaching fluoridation agents: 1.5% titanium tetrafluoride (TiF4) (9200 ppm) and 2.1% sodium fluoride (NaF) (9500 ppm), on the calcium loss of enamel after an acidic challenge. Methods: Ten maxillary premolars were sectioned into four pieces and then divided into the following four groups: Group 1: Control, kept in artificial saliva, no treatment; Group 2: 38% hydrogen peroxide (HP); Group 3: 38% HP followed by 1.5% TiF4; Group 4: 38% HP followed by 2.1% NaF solution. The specimens were subjected to demineralization for 16 days, refreshing the solution every 4 days; that is, on the 4th, 8th, 12th, and 16th days. Calcium ion (Ca2+) concentration was determined by an atomic absorption spectrophotometer. Data were analyzed using Friedman and Wilcoxon tests (p = 0.05). Results: The loss of Ca2+ in each of the test groups was compared with that of the control group, depicting that there was a statistically significant difference among the groups after 4, 8, 12, and 16 days and in total (p < 0.05). The calcium released from the fluoride-applied groups was lower when compared with the 38% HP and control group. At the end of the 16th day, the total amount of calcium released from the TiF4-treated samples (9.12 mg/mL) was less than from the NaF-treated samples (13.67 mg/mL) (p < 0.05). Conclusions: Regarding the results of our in vitro study, the risk of further demineralization was significantly reduced with the use of TiF4 and NaF after bleaching with 38% HP. TiF(4)was found to be more effective in preventing Ca2+ release owing to acid attack when compared with NaF. In the case of an intra-oral acidic exposure, the use of topical 1.5% TiF4 and 2.1% NaF agents might be beneficial after bleaching with 38% HP.Öğe Effect of bleaching agents on calcium loss from the enamel surface(Quintessence Publishing Co Inc, 2007) Tezel, Huseyin; Ertas, Ozlem Sogut; Ozata, Ferit; Dalgar, Hande; Korkut, Ziya OnurObjectives: To compare the Ca2+ loss of enamel treated with 38% hydrogen peroxide (HP), 35% HP with light, and 10% carbamide peroxide (CP). Method and Materials: Ten extracted premolars were sectioned buccolingually and longitudinally so that 4 specimens were obtained from each tooth. The specimens were randomly assigned to 1 of 4 groups to receive the following bleaching agents: 38% HP, 35% HP with light, 10% CP, and no agent (control). The specimens were treated with an artificial caries solution (pH 4) for 16 days; the solution was replaced on days 4, 8, 12, and 16. Calcium concentration was determined by an atomic absorption spectrophotometer. Repeated measures ANOVA was performed on concentrations on days 4, 8, 12, and 16. Results: At the end of day 16, calcium ions released per square millimeter were calculated cumulatively as follows: 38% HP group: 27.52 +/- 5.22 mu g/mL; 35% HIP with light group: 25.15 +/- 4.99 mu g/mL; 10% CP group: 19.53 +/- 4.03 mu g/mL; control group: 18.35 +/- 4.00 mu g/mL. The differences between the control group and the 35% HP with light group and between the control group and 38% HIP group were statistically significant. Although demineralization differences were observed between the control group and the 10% CP group, this difference was not significant. Conclusions: It can be concluded that 35% HP with light and 38% HP may cause significantly more loss of Ca2+ from the enamel surfaces than 10% CP. Also, 10% CP does not vary significantly from the control.Öğe The effects of extended polymerization time for different resin composites on reactive oxygen species production and cell viability(Nihon Univ, School Dentistry, 2021) Ozkaya, Cigdem Atalayin; Tezel, Huseyin; Armagan, Guliz; Tuzcu, Fulya; Sahbaz, Ufuk; Dagci, TanerPurpose: The present study was conducted to determine oxidative stress and cell viability after contact with resin composites polymerized for different times. Methods: Disk-shaped specimens of Admira Fusion. Ceram X One Universal. Solare x and Filtek Z550 (n = 12) were prepared, and two subgroups with polymerization times of 20 and 40 s were employed. The specimens were incubated with mouse fibroblast cells for 48 and 72 h, and changes in reactive oxygen species (ROS) production and cellular viability were determined by an assay with a cell-permeable fluorescent dye, 2',7'-dichlorodihydrofluorescein diacetate (H2DCF-DA), and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, respectively. Results: At 72 h, ROS production in the presence of Admira Fusion polymerized for 40 s was reduced relative to that in the presence of Admira Fusion polymerized for 20 s (P < 0.05). Cell viability was maximal in the Admira Fusion and Solare x groups and there was no difference relative to the control group at 48 h. Cell viability was higher in the Admira Fusion and Solare x groups polymerized for 40 s than for the same materials polymerized for 20 sat 72 h (P < 0.05). Conclusion: Extension of the polymerizaton lime has a material-specific effect and may be used as a strategy to increase the biocompability of resin composites.Öğe The improvement of biocompatibility of adhesives: The effects of resveratrol on biocompatibility and dentin micro-tensile bond strengths of self-etch adhesives(Springer Heidelberg, 2019) Atalayin, Cigdem; Tezel, Huseyin; Ergucu, Zeynep; Unlu, Nimet; Armagan, Guliz; Dagci, Taner; Kose, TimurObjectiveThe aim of this in vitro study is to evaluate the effects of resveratrol (RES) addition on the cytotoxicity and microtensile bond strength (mu TBS) of different adhesives.Materials and methodsFive self-etching adhesives (G-aenial Bond-GC, Optibond All in One-Kerr, Gluma Self Etch-Kulzer, Clearfil S-3 Bond-Kuraray, and Nova Compo-B Plus-Imicryl) were tested. They were applied to L-929 cell culture by the extract method. In the test groups, 0.5 mu M RES (Sigma-Aldrich) was added into the medium. Cell viability was assessed by MTT assay after 24h. Human extracted third molars were used for mu TBS test (n=7). The adhesives with or without 0.5 mu M RES addition were applied on dentin surfaces. A composite build-up was constructed. Then, the specimens were sectioned into multiple beams with the non-trimming version of the microtensile test and subjected to microtensile forces. Statistical analysis was performed using ANOVA and post hoc Tukey test (p?0.05).ResultsThe extracts of all adhesives decreased the cell viability. However, RES addition increased the cell viability in all groups (p?0.05). RES addition did not cause any decrease in mu TBS values of the adhesives compared to baseline. Optibond All in One showed the highest mu TBS after RES addition. It was followed by Clerafil S-3 Bond and Nova Compo-B Plus. No difference was determined between the Optibond All in One and Clearfil S-3 Bond. There was difference between Optibond All in One and Nova Compo-B Plus (p?0.05).ConclusionRES addition may improve the biocompatibility without causing negative influence on mu TBS of the adhesives.Clinical relevanceRES addition has clinical applicable potential to overcome the adverse biocompatibility of adhesives.Öğe In vivo performance of different scaffolds for dental pulp stem cells induced for odontogenic differentiation(Sociedade Brasileira De Pesquisa Odontologica, 2016) Atalayin, Cigdem; Tezel, Huseyin; Dagci, Taner; Karabay Yavasoglu, Nefise Ulku; Oktem, Gulperi; Kose, TimurThis study was designed to determine the in vivo performance of three different materials as scaffolds for dental pulp stem cells (DPSC) undergoing induced odontogenic differentiation. An odontogenic medium modified by the addition of recombinant human bone morphogenetic protein 2 was used in the experimental groups to induce differentiation. Mesenchymal stem cell medium was used in the control groups. DPSC were transplanted onto the backs of mice via three scaffolds: copolymer of L-lactide and DL-lactide (PLDL), copolymer of DL-lactide (PDL) and hydroxyapatite tricalcium phosphate (HA/TCP). The expression levels of dentin sialo-phosphoprotein (DSPP), dentin matrix protein-1 (DMP1), enamelysin/matrix metalloproteinase 20 (MMP20) and phosphate-regulating gene with homologies to endopeptidases on X chromosome (PHEX) were analysed using RT-PCR. The expressions in the experimental groups were compared to those in the control groups. The transcript expressions at 6 and 12 weeks were significantly different for all scaffolds (p < 0.05), except for the expression of DSPP in the PLDL group with regard to the time variable. Although there was a decrease in the expression of enamelysin/MMP20 in PLDL and HA/TCP at 12 weeks, all other expressions increased and reached their highest level at 12 weeks. The highest DSPP expression was in the PDL group (p < 0.05). The highest expression of DMP1 was detected in the HA/TCP group (p < 0.05). The highest expression of PHEX was in the PLDL group (p < 0.05). Consequently, PLDL and PDL seemed to be promising scaffold candidates for odontogenic regeneration at least as HA-TCP, when they were applied with the DPSC induced for odontogenic differentiation.Öğe Medium modification with bone morphogenetic protein 2 addition for odontogenic differentiation(Sociedade Brasileira De Pesquisa Odontologica, 2016) Atalayin, Cigdem; Tezel, Huseyin; Dagci, Taner; Yavasoglu, Nefise Ulku Karabay; Oktem, GulperiThe aim of this study was to evaluate whether medium modification improves the odontogenic differentiation of human dental pulp stem cells (DPSC) in vitro and in vivo. DPSC isolated from human impacted third molar teeth were analysed for clusters of differentiation with flow cytometry. Odontogenic differentiation was stimulated by medium modification with the addition of bone morphogenetic protein 2 (BMP2). The expression of dentin sialophosphoprotein, dentin matrix protein 1, enamelysin/matrix metalloproteinase 20 and the phosphate-regulating gene with homologies to endopeptidases on the X chromosome of the cells were analysed with RT-PCR at 7, 14 and 21 days. Then, DPSC were transplanted on the back of immunocompromised mice via a hydroxyapatite tricalcium phosphate scaffold, and the structure of the formed tissue was investigated. The cells were identified as mesenchymal stem cells with a 98.3% CD73 and CD90 double-positive cell rate. The increase in mineralization capacity and expression of human enamel-dentin specific transcripts proportional to the culture period were determined after differentiation. Six weeks after transplantation, an osteo-dentin matrix was formed in the group in which odontogenic differentiation was stimulated, and the odontogenic characteristics of the matrix were confirmed by histological examination and RT-PCR analysis. Odontogenic differentiation of the isolated and characterized human DPSC was improved with medium modification by the addition of BMP2 in vitro and in vivo. The defined medium and applied technique have a potential use for forming reparative dentin in the future, but the effects of the method should be investigated in long-term studies.Öğe Procrastination and predictor variables among a group of dental students in Turkey(Routledge Journals, Taylor & Francis Ltd, 2018) Atalayin, Cigdem; Balkis, Murat; Tezel, Huseyin; Kayrak, GulThe aim of this study was to assess the prevalence of procrastination among a group of Turkish dental students and to determine the predictors and consequences of procrastination. A total number of 273 females and 179 males (aged between 18 and 28) were included in the study. Tuckman procrastination scale, Academic Life Satisfaction Scale, Concern over Mistake Scale, Poor Time Management Scale, Self-Doubt Scale, Irrational Beliefs about Studying Scale, Positive and Negative Affect Schedule and Life Satisfaction Scale were used to gather data. Results indicated that 50% of participants were more likely to procrastinate their academic assignments or tasks. Procrastination score did not differ according to gender. The findings suggested that procrastinating students had a higher level of poor time management, self-doubt and irrational beliefs about studying, and poor academic performance and well-being than their non-procrastinating counterparts. Preventive strategies are necessary to overcome procrastination which affects the academic achievement, satisfaction, and well-being of dental students.Öğe The protective effect of resveratrol against dentin bonding agents-induced cytotoxicity(Japanese Soc Dental Materials Devices, 2015) Atalayin, Cigdem; Armagan, Guliz; Konyalioglu, Sibel; Kemaloglu, Hande; Tezel, Huseyin; Ergucu, Zeynep; Keser, Aysegul; Dagci, Taner; Onal, BanuThis study was designed to evaluate the cytotoxicity of four dentin bonding agents and the effects of an antioxidant addition. Group A: G-aerial Bond, Group B: Optibond All in One, Group C: Gluma Self Etch and Group D: Clearfil S-3 Bond were added to the medium using extract method. The cells were cultured with or without resveratrol (RES) addition. MTT, reactive oxygen species (ROS), DCF, Comet and 8-OHdG measurements were performed. The agents had a dose-dependent (1:1>1:10>1:20) cytotoxic effect. Considering 1:10 concentration; Group D at 1 h (p<0.01) and Group B and D at 24 h had the weakest cytotoxic effect (p<0.05). After RES addition, the highest cell viability was determined in Groups B+RES and D+RES at 1 h and in Groups A+RES and B+RES at 24 h (p<0.01). The dentin bonding agents induced ROS production and DNA damage regarding to their composition. However, RES addition decreased the indicated parameters.
