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Öğe Color stability of bulk-fill resin composites exposed to caffeinated beverage: An in vitro study(Mosher & Linder, Inc, 2022) Ozyurt, Esra; Kurt, AysegulPurpose: To evaluate the in vitro color stability and surface properties of bulk-fill resin composites after exposure to coffee and cola. Methods: Color stability was evaluated in a conventional resin composite (Filtek Z250) and three bulk-fill resin composites (Filtek One Bulk Fill, Tetric N-Ceram Bulk Fill, and Beautifil Bulk Fill as giomer). Color change (CIEDE 2000 AE00) was calculated after 12 days of immersion in distilled water (control), coffee, or cola (Diet Coke). Water sorption (%Wsp) and solubility (%Wsl) ratios were calculated for each material in each solution. One sample of each material from each condition was observed with scanning electron microscopy and atomic force microscopy. Generalized linear modeling and Bonferroni correction were used for AE00 value analysis. One-way ANOVA and Kruskal Wallis tests were performed to analyze %Wsp and %Wsl ratios. Results: Tetric N-Ceram Bulk Fill showed the highest AE00 value in distilled water. Beautifil Bulk Fill had the highest AE00 value in coffee and cola. Beautifil Bulk Fill had the highest %Wsl ratio. Filtek One Bulk Fill and Tetric N -Ceram Bulk Fill had the highest and lowest %Wsp ratios, respectively. Coffee and cola exposure had surface property-disrupting and discoloration effects on both conventional and bulk-fill resins.Öğe The Effect of Cleaning Solutions on a Denture Base Material: Elimination of Candida albicans and Alteration of Physical Properties(Wiley, 2018) Kurt, Aysegul; Erkose-Genc, Gonca; Uzun, Meltem; Sari, Tugrul; Isik-Ozkol, GulbaharPurposeTo evaluate the antimicrobial efficiency of three cleaning solutions and their effect on the physical properties of a denture base material. Materials and MethodsA heat-cured polymethyl-methacrylate (PMMA) denture base material (Meliodent) and three cleaning solutions (alkaline-peroxide, 30 minutes; 1% sodium-hypochlorite, 10 minutes; and 0.1% polymeric-guanidine solution, 5 minutes) were used. For antifungal activity test, 40 disc-shaped specimens were fabricated and allocated into a control group (distilled water) and 3 experimental groups (n = 10) according to the cleaning solutions. Antifungal activity against Candida albicans (ATCC 2091) was assessed with colony-forming units. An additional 40 rectangular plate specimens were fabricated for mechanical tests. Ten specimens were kept intact to be used as the control group for flexural strength test. The remaining 30 specimens were distributed into three groups according to the cleaning solutions. The surface roughness and Vickers hardness of the specimens were consecutively measured after 48 hours of water storage at 37 2 degrees C (t0), two disinfection cycles (t1), and 7 days of storage (t2) in one of the solutions. Finally, all 40 rectangular specimens were subjected to flexural strength test. Data were analyzed with Kruskal-Wallis test for antifungal activity, ANOVA for flexural strength test, and analysis of covariance for surface roughness and hardness tests. Significance was set at 0.05. ResultsThe antifungal activities of polymeric guanidine and sodium hypochlorite were comparable to each other and significantly higher than alkaline peroxide (p < 0.05). The changes in the surface roughness of the specimens were statistically comparable among the cleaning solutions and time periods (p > 0.05); however, the decrease in the Vickers hardness of the specimens stored in sodium hypochlorite was significantly higher from t0 to t1 and t0 to t2 (p < 0.05) than other groups, resulting in comparable hardness changes. The flexural strengths of all groups were comparable with the control after t2 (p > 0.05). ConclusionThe use of polymeric guanidine disinfectant solution could be an alternative method for cleaning PMMA denture base materials.Öğe Effect of different beverages on color stability and surface properties of composite resin materials(Wiley, 2021) Ozyurt, Esra; Kurt, AysegulThe aim of this in vitro study was to investigate the effect of frequently consumed beverages on the color stability and surface properties of direct and indirect dental composite materials. The two dental composite materials (direct and indirect) and four beverages (distilled water, tea, coffee, cola) were assessed. The specimens were prepared for evaluating monomer conversion, water sorption, and color stability (n = 10) and taking scanning electron and atomic force microscopy images (n = 3). The data were analyzed using independent t-test, Mann-Whitney U test, two-way analysis of variance, and Spearman's correlation (P < .05). Indirect dental composite materials had better monomer conversion, color stability, and surface roughness value when compared to direct dental composite materials (P < .001, P = .002, P = .002, respectively). The control group had lower Delta E-00 values when compared to the tea (P < .001) and coffee (P < .001) groups. There was a negative correlation between monomer conversion and surface roughness (r = -0.481, P = .032). Color stability and surface roughness value of direct dental composite materials differed from indirect dental composite materials after immersed in different beverages. The tested beverages significantly influenced color stability.Öğe Effect of different beverages on surface properties and cariogenic biofilm formation of composite resin materials(Wiley, 2021) Kurt, Aysegul; Ozyurt, Esra; Topcuoglu, NursenThe consumption of certain beverages may affect the physical and biological properties of resin composites (RCs) according to type. This in vitro study aimed to evaluate the surface properties and cariogenic biofilm formation in microhybrid and nanohybrid RCs after immersion in different beverages. The effects of four beverages (distilled water-control, tea, coffee, and cola) on two RCs (microhybrid and nanohybrid) were evaluated. Changes in the surface properties were evaluated for each group using surface roughness measurement (n = 10), scanning electron microscopy (SEM) (n = 4) observation, and energy-dispersive X-ray spectroscopy (EDX) (n = 5) analysis. In vitro Streptococcus mutans biofilm formation on the specimens of each group was determined using confocal laser scanning microscopy and SEM analysis (n = 14). The data were analyzed using two-way analysis of variance, with Bonferroni as a post-hoc test and Pearson's correlation (p < .05). Microhybrid RC presented more surface roughness (p = .014) and cariogenic biofilm formation (p = .040). The surface roughness (F = 0.733, p = .536) and cariogenic biofilm formation (F = 1.685, p = .181) values were not affected by the beverages. However, according to qualitative SEM and EDX measurements, these parameters varied depending on the beverage groups. No correlation was found between surface roughness and cariogenic biofilm formation (r = 0.135, p = .287). Microhybrid RCs had a rougher surface and a higher amount of cariogenic biofilm formation than nanohybrid RCs after being subjected to different beverages.Öğe Effect of different polishing techniques for composite resin materials on surface properties and bacterial biofilm formation(Elsevier Sci Ltd, 2019) Kurt, Aysegul; Cilingir, Aylin; Bilmenoglu, Caglar; Topcuoglu, Nursen; Kulekci, GuvenObjectives: Both direct and indirect techniques are used for composite resin material (CRM) restorations. Polishing processes are needed in both techniques after intraoral adjustment. However, it is unclear as to which polishing technique should be preferred with respect to decreasing biofilm. The purpose of this in vitro study was to evaluate the surface properties and Streptococcus mutans biofilm formation on direct and indirect CRMs after using different polishing techniques. Methods: Two CRMs (direct and indirect) and four polishing techniques (aluminium oxide discs, diamond polishing paste, aluminium oxide polishing paste, and silicon carbide brush) were evaluated. The specimens were prepared for taking scanning electron microscopy images (n = 2) and determining surface roughness, surface free energy, and bacterial biofilm formation (BBF) with colony-forming unit counting and confocal laser scanning microscopy assays (n = 7). The data were analysed using two-way analysis of variance with Bonferroni as a post hoc test and Pearson's correlation (p < .05). Results: The surface roughness values in the control group were higher than those in the diamond polishing paste group (p = 0.025), but the values in the aluminium oxide polishing paste and silicon carbide brush groups were comparable with those in the control group (p = 0.156 and p = 1.000, respectively). The highest surface free energy values were recorded in the silicon carbide brush group (p < 0.001), whereas there were no differences found among the other groups (p > 0.05). The highest BBF was seen in the silicon carbide brush (p < 0.001) and direct CRM (p < 0.001) groups. Conclusion: BBF on the surface of direct CRMs differed from that on indirect CRMs after polishing the surface. The tested polishing techniques significantly influenced surface properties and BBF. Clinical significance: In situations that require the intraoral adjustment of CRMs, polishing with a diamond polishing paste seems to be a good option to polish the surface of both direct and indirect CRMs because the diamond polishing paste results better in terms of decreasing biofilm formation and improving surface properties.Öğe The effects of water flow rate on shear bond strength of self etch resin cement to dentin surface after Er, Cr: YSGG laser etching(Taylor & Francis Ltd, 2017) Kurt, Aysegul; Yilanci, Hilal; Yondem, Isa; Usumez, AslihanThe aim of the present study was to evaluate the effect of water flow rate on the morphological features of dentin and shear bond strength (SBS) of self-etching resin cement after Er, Cr: YSGG laser etching. Dentin specimens obtained from extracted human third molars were randomly assigned to four groups (n = 23), including one that received no laser irradiation (control-group D) and three others with different laser parameters: 2.25 W, 50 Hz, 60% air with water flow rates of 19 mL/min-100% water (group A), 2.25 W, 50 Hz, 6.75 mL/min-50% water (group B), and 2.25 W, and 50 Hz, 2.75 mL/min-25% water (group C). The morphological features of each group were examined with scanning electron microscopy and atomic force microscopy. The SBS of resin cement disks (Panavia F2.0, Kuraray; Tokyo, Japan) (3 mm in diameter and 2 mm in height) to the dentin specimens was measured using a universal testing machine at a cross head speed of 0.5 mm/min. Bond strength values were analyzed with one-way ANOVA/Tukey tests. There were no significant differences between the SBS values of groups A and B (p > 0.05). However, the SBS values of these groups were significantly higher when compared to groups C and D (p < 0.001). Er, Cr: YSGG laser application with water flow rates of 6.75 or 19 mL/min resulted in better dentin surface alterations and increased the SBS of self-etching resin cement to dentin.Öğe Evaluation of residual monomer release and toxicity of self-adhesive resin cements(Japanese Soc Dental Materials Devices, 2018) Kurt, Aysegul; Altintas, Subutay Han; Kiziltas, Mustafa Volkan; Tekkeli, Serife Evrim; Guler, Eray Metin; Kocyigit, Abdurrahim; Usumez, AslihanThe aim of this study was to evaluate the amount of leached residual monomers from self-adhesive resin cements and evaluate their toxicity in-vitro. A total of 60 disk-shaped specimens (5 mm in diameter and 0.5 mm in thickness) were prepared from each cement (RelyX U200, SpeedCEM, G-Cem) (n=20). Specimens were immersed in artificial saliva and the amount of released monomers [urethane dimethacrylate (UDMA) and triethyleneglycol dimethacrylate (TEGDMA)] was identified. Then, the cytotoxicity and genotoxicity effect on cells were evaluated using the defined amounts of released monomers from cements. The highest monomer release was detected in G-Cem (p<0.05). The highest cytotoxicity value was identified from SpeedCEM (p<0.01) and the highest genotoxicity values were calculated from RelyX U200 (p<0.05). Released UDMA and TEGDMA from self-adhesive resin cements induced cytotoxicity and genotoxicity effect on cells.Öğe Evaluation of the Internal and Marginal Discrepancies of Co-Cr Metal Copings Prepared via CAD/CAM and Conventional Casting(Dennis Barber Ltd, 2019) Dayan, Suleyman Cagatay; Kiseri, Burim; Gencel, Burc; Kurt, AysegulThe aim of this study was to assess the internal and marginal discrepancies of chromium-cobalt (Co/Cr) copings fabricated using different techniques. A typodont molar tooth was prepared and replicated in die stone and scanned. Forty Co-Cr alloy copings were produced using four different production techniques: conventional casting (C-group), direct metal laser sintering (DMLS-group), micro-stereolithography/casting combination (mu SLA-group), and computer-aided milling (M-group) (n = 10). The internal and marginal discrepancies at various reference points were determined via digital microscopy. Analysis of variance (ANOVA) and Tukey's multiple comparisons tests were used for statistical analysis (p=0.05). The marginal and cervical discrepancies of the C-group were similar to those of the M-group (p>0.05) and better than those of the mu SLA-group (p<0.05). The marginal and internal discrepancies of all groups were within clinically acceptable limits, but further improvements in the mu SLA and DMLS techniques may be required prior to clinical implementation.Öğe Evaluation of the Polymerization Depth of Bulk Fill Resin Composites Polymerized by Different Procedures: An In-Vitro Study(Marmara Univ, Inst Health Sciences, 2019) Ozyurt, Esra; Kurt, Aysegul; Yildirim, HandanObjective: The aim of this study is to investigate the depth of cure (DOC) of the bulk fill composite samples prepared in different thicknesses with two different modes of light curing device with Vickers hardness tester. Methods: Five different bulk-fill composite materials were used in the present study. 20 sample of 2 mm and 20 sample of 4 mm thick samples were prepared, 10 samples from each group were polymerized for 20 seconds with the standard mode (Mode 1) of the light curing device and 10 samples polymerized with soft-start mode (Mode 2) for 25 seconds (n=10). Hardness measurements were made from the upper and lower surfaces of each sample and the hardness ratio was calculated. The statistical analysis was performed using three-way analysis of variance (ANOVA) and Tukey multiple comparisons (p = 0.05). Results: The hardness ratios of all composites were determined to be over 80%, which is clinically acceptable. There was a statistically significant difference between the DOC levels according to the composites (p<0.05). There was a statistically significant difference according to the thickness (p<0.05). There was no statistically significant difference according to polymerization procedures (p>0.05). Conclusions: The surface hardness ratios of all groups were determined to be over 80%, which is clinically acceptable. The polymerization with soft start technique may not different from the standard-mode for polymerization depth.Öğe The influence of different tooth proportions obtained using digital smile design on the perception of smile esthetics(Wiley, 2024) Dag, Onur Dogan; Dagli, Isil; Kurt, AysegulObjectiveThe aim of this study is to examine the effect of designs using different esthetic dental proportions made with a digital smile design program on the esthetic perception of individuals of different ages, genders and educational statuses.Materials and MethodsDifferent smile designs were made on facial photos taken of a female and male model using a smile design program. Four different dental proportions (golden proportion [GPR], golden percentage [GPE]), Preston proportion [P] and recurring esthetic dental proportion [RED]) and two different tooth shapes (oval and square) were used. Images with 16 different smile designs were presented to 4th and 5th-year students of a faculty of dentistry, dentists, specialist dentists and laypersons for scoring.ResultsThe gender of the participants did not affect the scores given (p > 0.05), and participants over the age of 30 and lay people had higher scores (p < 0.05). The GPR design was scored lower than RED when all designs were subdivided by tooth shape and gender (p < 0.001).ConclusionsThe esthetic perceptions of people of different ages and dentistry education levels may differ from each other. Using the GPR when designing a digital smile may not be suitable for both genders.Clinical SignificanceIf esthetic dental proportions are to be utilized when designing a smile, it may be more appropriate to use the P and RED proportions instead of the GPR. In addition, if the patients whose smiles will be designed are young and have received dental education, it should be considered that their esthetic expectations may be high. Trial registration ClinicalTrials.gov Identifier: NCT0567043.Öğe Osteoblast behaviour on zirconia fabricated by additive and subtractive technology(Elsevier Sci Ltd, 2023) Roser, Christoph J.; Erber, Ralf; Rammelsberg, Peter; Lux, Christopher J.; Kurt, Aysegul; Rues, Stefan; Schwindling, Franz SebastianZirconia is an attractive material for the manufacturing of oral implants and patient-individual barriers for guided bone regeneration. This study compared osteoblast behaviour on additive manufactured and milled 3-mol % yttria-stabilized tetragonal polycrystal zirconia (ZrO2).Two groups of samples (O5 x 2 mm) were manufactured by stereolithography (LithaCon 230, Lithoz, Vienna, Austria) and subsequently heat-treated and sintered. One group remained superficially unmodified (AM-ZrO2unmod.), while the other was polished according to DIN EN ISO 6872 standard using automated grinding (AMZrO2-pol.). For comparison, milled samples (e.max ZirCAD LT, Ivoclar Vivadent, Schaan, Liechtenstein) were sintered and polished similarly (Mil-ZrO2-pol.). Surface roughness was characterized using tactile profilometry. Adhesion, proliferation and coverage of human fetal osteoblasts (hFOB 1.19) as well as expression of osteogenic marker genes ALPL and RUNX2 were determined (and statistically compared using Kruskal-Wallis-analyses and Dunn's Post-hoc-tests).The surface roughness of AM-ZrO2-unmod. Was 45 times higher than that of the polished groups. No significant differences were detected between the three groups regarding cell adhesion and proliferation. With regard to cell coverage, AM-ZrO2-pol. Significantly outperformed the two other groups (p < 0.05). ALPL- and RUNX2mRNA expression was insignificantly superior for AM-ZrO2-unmod. Compared to the two other groups. Therefor no detrimental effect on osteoblast behaviour caused by the investigated, acrylic binder-based 3D printing workflow was observed.
