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  • [ X ]
    Öğe
    Gıdaları taklit edensolüsyonların bulk-fillkompozitlerin renklenmesine etkisi
    (2020) Cabadağ, Özge Gizem; Gönülo, Nihan; Almasifar, Lena; Misilli, Tuğba
    Amaç: Bu çalışmanın amacı gıdaları taklit eden solüsyonlarda bekletilen yüksek viskoziteli bulk-fill kompozitlerin ve bir adet geleneksel kompozit rezinin renkledirici bir solüsyona maruz bırakılması sonrası renk değişimini değerlendirmektir. Gereç ve Yöntem: 4 farklı yüksek viskoziteli bulk-fill kompozit (Tetric EvoCeram Bulk Fill, SonicFill, Filtek Bulk Fill Posterior, Beautifil Bulk Restorative) ve bir adet geleneksel mikrohibrit tipte kompozit rezin (Filtek Z250) kullanılarak, 8 mm çapında ve 4 mm kalınlığında disk şeklinde toplam 180 adet örnek hazırlandı. Hazırlanan örnekler gıdaları taklit eden solüsyonlarda (etanol, heptan, sitrik asit, yapay tükürük) bekletilmek üzere rastgele 4 alt gruba ayrıldı (n=9) ve bu solüsyonlarda 7 gün süreyle 37±1ºC’de etüvde bekletildi. Ardından örneklerin tümü çözünebilir kahve solüsyonunda 6 gün süreyle tutuldu. Tüm örneklerden, gıdaları taklit eden solüsyonlarda bekletilmesi sonrası ve kahve solüsyonunda bekletilmesi sonrası Vita Easy-Shade (VITA Zahnfabrik) dijital spektrofotometre cihazı yardımıyla renk değerleri elde edildi. Renk değişim değerleri (?E00), CIEDE2000 renk sistemine göre kaydedilerek, istatistiksel analizi için çift yönlü varyans analizi, ikili karşılaştırmalar için Bonferroni testi kullanıldı (?=.05). Bulgular: Test edilen kompozit grupları arasında en yüksek ?E00 değerleri Beautifil Bulk Restorative grubunda tespit edilirken (p?0.001), en fazla renk değişimi kahve solüsyonu öncesi sitrik asite maruz bırakıldığında gözlenmiştir (p=0.027). Sonuç: Gıdaları taklit eden solüsyonların ve materyallerin farklı yapısal özellikleri kompozit rezinlerin renk stabilitesinde etkilidir.
  • [ X ]
    Öğe
    Shear Bond Strength of Aged Composite Restorations Repaired with a Universal Injectable Composite
    (Pera Yayincilik Hizmetleri, 2019) Gonulol, Nihan; Almasifar, Lena; Cabadag, Ozge Gizem; Misilli, Tugba; Kalyoncuoglu, Elif
    Objective: The purpose of this study was to analyze the shear bond strength of a universal injectable composite used in the repair of aged composites. Methods: A total of 100 disk-shaped specimens (8 mmx2 mm) were produced using five different composites (n=20) (Gradia Direct Posterior, Tetric N Ceram BulkFill, Filtek Z250, SonicFill and Filtek BulkFill Posterior). Specimens were polymerized using an LED light curing unit for 20 s and stored at 37 degrees C in distilled water for 3 weeks. Specimens were subdivided into two groups per composite for repair using either the same composite used for the specimen or G-aenial Universal Flo. Following acid-etching and silane application, a universal adhesive (G-Premio BOND) was applied and light-cured. The repair materials were placed on the bonded surfaces of the specimens and polymerized in silicone molds (2 mmx2 mm). After thermocycling to simulate aging, shear bond strength (SBS) was tested using a universal testing machine at a crosshead speed of 1 mm/min. Failure modes were examined using a stereomicroscope at x40 magnification. Results: No statistically significant differences were found among the tested composites repaired with their own substrates. However, the SBS SonicFill and Filtek Bulk Fill Posterior groups had significantly lower bond strengths when repaired with G-aenial Universal Flo in comparison to repairs made with their own substrates (p<0.05). Conclusion: When repaired with their own substrates, reliable bond strengths were obtained for all the composites tested.
  • [ X ]
    Öğe
    The effect of curing lights and modes on dentin bond strength of bulk-fill composites applied in different thickness
    (Taylor & Francis Ltd, 2019) Misilli, Tugba; Gonulol, Nihan; Cabadag, Ozge Gizem; Almasifar, Lena; Misilli, Umut
    To investigate shear bond strength (SBS) to dentin of a conventional and three bulk-fill composites applied in different increment thickness and cured by mono- and multi-wave LED LCUs. Two hundred and fifty-two extracted sound human molars were prepared for SBS test. The teeth were divided into four groups according to the resin composites used. Conventional composite: Tetric N-Ceram (control); high-viscosity bulk-fills: Tetric N-Ceram Bulk Fill, X-tra Fil, and SonicFill. Each group was subdivided (n = 7) according to increment thickness (2, 4, and 6 mm) and cured by standard mode of a mono-wave LED or two different modes (standard and xtra power) of a multi-wave LED. The failure mode was stereomicroscopically determined at 40x magnification. Data were analyzed using Three-way ANOVA and further comparisons were assessed by Bonferroni's multiple comparison test. There were no significant differences within X-tra fil and Tetric N-Ceram Bulk Fill groups for any of the variables (p > 0.05). A significant decrease in SBS values with increase of layer thickness was observed for SonicFill and control groups. Also, curing mode had a significant effect on both composites at 6 mm thickness and standard mode of multi-wave LED caused the highest SBS value (p < 0.05). Adhesive failure was the most common fracture pattern especially at 6 mm thickness applications. Based on the results of this study, the bulk-fill composites can be safely applied in one-step with 4 mm increments, although the examined composites performed better at 2 mm thickness. The performance of the composites at 6 mm increment may show differences related to the curing lights and modes.
  • Küçük Resim
    Öğe
    The Effect of Ph-cycling and Toothbrushing Simulations on Surface Roughness of Bulk-Fill Composites
    (Marmara University, 2021) Misilli, Tuğba; Gönülol, Nihan; Cabadağ, Özge Gizem; Almasifar, Lena; Dinç, Derya
    Objective: This study aimed to compare surface roughness values (Ra) of different posterior composites after pH-cycling and toothbrushing simulation. Methods: Fifty disc-shaped specimens (8x2 mm) were prepared by using three bulk-fill composites [Filtek Bulk Fill Posterior (FBF), SonicFill 2 (SF), X-tra fil (XF)], a flowable [G-aenial Universal Flo (GF)], and a microhybrid composite [Filtek Z250 (Z250)]. After initial roughness (Ra0 ) measurements were performed with a contact profilometer, the samples were subjected to a pH-cycling model for 10 days and Ra1 values were recorded. Then, the samples were subjected to toothbrushing simulation for 4 min and final values (Ra2 ) were recorded. From each group, a representative sample was analyzed with an optical profilometer. The values were analyzed by two-way ANOVA with repeated measures on one factor (period) followed by Tukey’s test (p<0.05). Results: Significant differences were found among materials regardless of experimental periods. The lowest Ra values were determined in GF and Z250 groups. The highest value was obtained in SF, but this value was not statistically significant different from that obtained in XF group. Brushing procedure after chemical degradation led to an increase in surface roughness of all materials except FBF, which was not statistically significant. Conclusion: While Ra values showed differences depending on the materials, pH-cycling and toothbrushing simulation did not have a significant effect on these values.