Yazar "Gundogdu, Mustafa" seçeneğine göre listele

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    An evaluation of surface roughness after staining of different composite resins using atomic force microscopy and a profilometer
    (Wiley, 2020) Karataş, Özcan; Gul, Pinar; Gundogdu, Mustafa; Iskenderoglu, Demet T.
    Aim The aim of this study was to compare the surface roughness of different composite resins using atomic force microscope (AFM) and a profilometer after storage in different solutions. Materials and methods Eight different composite resins were used in this study. Twenty specimens of each composite resin material were prepared using a 2-mm thick and 8-mm diameter stainless steel mold. After the composites had been placed in the mold, they were polymerized with a LED curing unit. The surfaces of all specimens were polished using aluminum oxide discs, and the specimens were then divided into four groups. The specimens in the experimental groups were stored in cola, coffee, or red wine, while the control group was stored in distilled water. Specimen surface roughness was examined after 30 days using an AFM and a profilometer, and the data obtained were subjected to analysis. Results Evaluation of the surface roughness of composite resins using a profilometer revealed no statistically significant difference between the groups, but significant differences were found using the AFM. The mean surface roughness of nanohybrid composites was lower than that of microhybrid composites. Conclusions The surface roughness of the composite resins varies with storage in different solutions, depending on the organic matrix structure and inorganic fillers of the resin.
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    Öğe
    Effect of staining and bleaching on the microhardness, surface roughness and color of different composite resins
    (Wroclaw Medical Univ, 2021) Karataş, Özcan; Gul, Pinar; Akgul, Nilgun; Celik, Neslihan; Gundogdu, Mustafa; Duymus, Zeynep Yesil; Seven, Nilgun
    Background. There are studies that examined the effect of staining on the surface properties of composite resins, using different solutions and bleaching applications. However, the effect of both staining and bleaching on the same composite specimens is an issue that needs to be investigated. Objectives. The aim of this study was to investigate the surface microhardness, roughness and color changes (Delta E) of 2 different composite resins after staining and bleaching. Material and methods. A microhybrid and a nanohybrid composite were used in the study. One hundred and fifty specimens were prepared from each composite. The specimens were divided into 5 groups and stained for 30 days with tea, coffee, cola, red wine, or distilled water (control). Subsequently, each group was divided into 3 subgroups. Each subgroup received a 14-day application of Opalescence (TM) Boost, Opalescence PF or VivaStyle (R) Paint On Plus bleaching materials. The color as well as surface microhardness and roughness of all specimens were determined at baseline, after staining and after bleaching. Data was analyzed using the repeated-measures analysis of variance (ANOVA) and the Bonferroni method. Results. A statistically significant decrease was observed in the surface microhardness of the microhybrid composite specimens after bleaching (p < 0.05).The highest Delta E values were observed in the red wine groups for both composite resins. Conclusions. Staining and bleaching may affect surface properties and color, depending on the type, filler and matrix content of the composite resin.