Browsing by Author "Alp,G."

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Citation Count: 3
Effect of surface finishing methods and aging on surface roughness and optical properties of zirconia-reinforced lithium silicate glass-ceramic;
(Cumhuriyet University Faculty of Dentistry, 2019) Alp,G.; Subaşi,G.M.
Objectives: The effects of three different surface finishing methods and aging on the surface roughness and optical properties of zirconia-reinforced lithium silicate (ZLS) glass-ceramic were investigated. Materials and Methods: Rectangular specimens (0.6 mm thickness) were sliced from ZLS blocks (N=36). Three different types of surface finishing [glazing combined with crystallization (ZLS-CF) or after crystallization (ZLS-G) and polishing (ZLS-P)] (n=12) and 5000 thermocycles were applied. Three sets of measurements were performed before and after aging to determine the color coordinates and surface roughness (Ra) by using a colorimeter and profilometer, respectively. The mean surface roughness (Ra) values were calculated. Color differences and translucency parameter (TP) values were calculated using the color difference ΔEab and TP formulas. One-way ANOVA was used to analyze the color difference, translucency, and surface roughness values (α=.05). Results: Significant differences in the ΔE values were not observed (p=.736) for specimens with different types of surface finishing. A significant difference was observed between the translucency values for different surface finishing groups before aging (p < .001). A significant difference in the surface roughness data between samples with different kinds of surface finishing was observed both before and after aging (p < .001). The ZLS-P group exhibited lowest surface roughness values before and after aging (p < .001). A positive significant correlation between the ΔE and translucency change values was observed in both the ZLS-G (p=.005) and ZLS-P (p < .001) groups. Conclusions: The surface finishing type did not affect the color change of ZLS glass-ceramic. The translucency values for different surface finished ZLS glass-ceramic specimens changed before aging. After aging, the surface finishing did not affect the translucency of ZLS glass-ceramic. All tested groups exhibited surface roughness values higher than the plaque accumulation threshold (Ra=0.2 mm). © 2019 Cumhuriyet University Faculty of Dentistry.; Amaç: Bu çalişmanin amaci üç farkli yüzey bitirme yönteminin ve yaşlandirmanin, zirkonya ile güçlendirilmiş lityum silikat (ZLS) cam-seramiğin yüzey pürüzlülüğü ve optik özellikleri üzerindeki etkilerini araştirmaktir. Gereç ve Yöntemler: Dikdörtgen şeklindeki örnekler (0,6 mm kalinlikta) ZLS bloklardan (N=36) kesildi. üç farkli tipte yüzey bitirme işlemi [kristalizasyon ile birlikte glazür (ZLS-CF), kristalizasyon sonrasi glazür (ZLS-G) ve polisaj (ZLS-P)] (n=12) ve 5000 termal siklus uygulandi. Yaşlandirma öncesi ve sonrasinda üçer defa renk koordinatlari ve yüzey pürüzlülüğü (Ra) ölçümleri kolorimetre ve profilometre cihazlari kullanilarak yapildi. Ortalama yüzey pürüzlülüğü (Ra) değerleri hesaplandi. Renk farkliliklari ve translusensi parametresi (TP) değerleri, ΔEab renk farkliliği ve TP formülleri kullanilarak hesaplandi. Renk farki, translusensi ve yüzey pürüzlülük değerlerini analiz etmek için tek-yönlü ANOVA kullanildi (α=,05). Bulgular: Farkli yüzey bitirme tiplerine sahip örneklerde ΔE değerlerinde anlamli farkliliklar gözlenmedi (p=,736). Yaşlandirma öncesinde farkli tipteki yüzey bitirme gruplarinda translusensi değerleri arasinda anlamli fark gözlendi (p <, 001). Yaşlandirma öncesi ve sonrasinda farkli tipteki yüzey bitirme gruplarinda yüzey pürüzlülüğü verilerinde anlamli fark gözlendi (p <, 001). ZLS-P grubu yaşlandirma öncesi ve sonrasi en düşük yüzey pürüzlülüğü değerlerini gösterdi (p <, 001). Hem ZLS-G (p=,005) hem de ZLS-P (p <, 001) gruplarinda ΔE ve translusensi değişim değerleri arasinda pozitif yönde anlamli bir korelasyon bulundu. Sonuçlar: Yüzey bitirme tipi ZLS cam-seramiğin renk değişimini etkilemedi. Farkli yüzey bitirme işlemi uygulanan ZLS cam-seramik örneklerinde translusensi değerleri yaşlandirmadan önce değişirken, yaşlandirmadan sonra yüzey bitirme tipi ZLS cam-seramiğin translusensisini etkilemedi. Test edilen tüm gruplar, plak akümülasyon eşik değerinden daha yüksek yüzey pürüzlülüğü değerleri sergiledi (Ra=0,2 mm). © 2019 Cumhuriyet University Faculty of Dentistry.
Citation Count: 3
Effects of different glaze treatments on the optical properties and roughness of lithium disilicate ceramics;
(Cumhuriyet University Faculty of Dentistry, 2019) Subaşi,G.M.; Alp,G.
Objectives: To investigate effects of different glaze procedures on the colour, translucency, and roughness of lithium disilicate (LDS) ceramics after short-term ageing. Materials and Methods: Eighteen LDS specimens (thickness: 0.6 mm) were divided into three groups (paste (EP), spray (ES), and powder-liquid glaze (EL)) based on the type of glaze treatment (n=6). After glaze firings, specimens were thermally aged (5000 cycles). Before and after thermocycling, the colour, translucency, and roughness values of the specimens were measured. Before and after thermocycling, the translucency and roughness data were analysed using a one-way analysis of variance (ANOVA) and compared using a Wilcoxon signed-rank test. Changes in colour, translucency, and roughness data were analysed using one-way ANOVA, and the correlations between them were analysed using Spearman's correlation analysis (p=.05). Results: The EL group showed the highest and clinically unacceptable colour change value (p≥.005). Before and after ageing, the EL group exhibited higher translucency than the other groups (p <.001), and the EL and EP groups exhibited higher roughness values than the ES group (p≥.001). Wilcoxon signed-rank test results showed that although a significant difference between the initial and final translucency values was observed in the EL group (p=.028), no significant differences between the initial and final roughness values were observed in each group. Only in the EL group, a significant correlation was found between the colour and translucency change values (r=.943, p=.005). Conclusions: After short-term ageing, based on the evaluation of the LDS ceramics' colour and translucency changes, ES and EP treatments are preferable for glazing. When dentists select a material (EP, EL, ES) for glazing LDS ceramics, they should consider the effects of this material on the optical properties and surface roughness of LDS ceramics. © 2019 Cumhuriyet University Faculty of Dentistry.; Amaç: Farkli glaze işlemlerinin lityum disilikat seramiklerin (LDS) renk, translüsensi ve pürüzlülük üzerindeki etkisinin kisa dönem yaşlandirma sonunda incelenmesidir. Gereç ve Yöntemler: On sekiz LDS örnek (kalinlik: 0,6 mm) yapilan glaze işlemine göre üç gruba (pasta (EP), sprey (ES), toz-likit glaze (EL)) ayrildi (n=6). Glaze firinlamalari sonrasi tüm örnekler termal olarak yaşlandirildi (5000 devir). Yaşlandirma öncesi ve sonrasi örneklerin renk, translüsensi ve pürüzlülük değerleri ölçüldü. Yaşlandirma öncesi ve sonrasi translüsensi ve pürüzlülük verileri tek yönlü varyans analizi (ANOVA) ile analiz edildi ve Wilcoxon işaretli siralar testi ile karşilaştirildi. Renk, translüsensi ve pürüzlülük değişim verileri tek yönlü ANOVA ile analiz edildi ve aralarindaki kolerasyonlar Spearman kolerasyon analizi ile analiz edildi (p=,05). Bulgular: EL grubu en yüksek ve klinik olarak kabul edilemez renk değişim değeri göstermiştir (p≤,005). Yaşlandirma öncesi ve sonrasi, EL grubu diğer gruplardan daha yüksek translüsensi değeri göstermiştir (p <, 001) ve EL ve EP gruplari, ES grubundan daha yüksek pürüzlülük değerleri göstermiştir (p≤,001). Wilcoxon işaretli siralar test sonuçlari göstermiştir ki, EL grubunun başlangiç ve sonuç translüsensi değerleri arasinda anlamli fark (p=,028) gözlenir iken, her bir grubun başlangiç ve sonuç pürüzlülük değerleri arasinda anlamli bir farklilik bulunamamiştir. Sadece EL grubunda renk ve translüsensi değişim değerleri arasinda anlamli bir kolerasyon bulunmuştur (r=0,943, p=,005). Sonuçlar: Kisa dönem yaşlandirma sonrasinda, LDS seramiğin renk ve translüsensi değişimleri değerlendirildiğinde, ES ve EP işlemleri glaze için tercih edilebilir. Diş hekimleri LDS seramiklerin glaze işlemi için materyal (EP, EL, ES) seçeceklerinde, bu materyalin LDS seramiklerin optik özellik ve yüzey pürüzlülüğü üzerindeki etkisini göz önünde bulundurmalidirlar. © 2019 Cumhuriyet University Faculty of Dentistry.
Citation Count: 72
Evaluation of flexural strength and surface properties of prepolymerized CAD/CAM PMMA-based polymers used for digital 3D complete dentures;
(Quintessenz Verlags GmbH, 2018) Arslan,M.; Murat,S.; Alp,G.; Zaimoglu,A.
Ziel: Ziel dieser In-vitro-Studie war es, die Biegefestigkeit, die Rauheit (Ra) und die Hydrophobizität von PMMA-basierten CAD/CAM-Kunststoffen zu untersuchen. Zudem sollten die Eigenschaften verschiedener CAD/CAM-PMMA- Kunststoffe und konventionell heißpolymerisiertem PMMA nach Temperaturwechselbelastung verglichen werden. Material und Methode: Jeweils 20 quaderförmige Probekörper (64 × 10 × 3,3 mm) wurden aus drei verschiedenen PMMA-basierten CAD/CAM-Kunststoffrohlingen (M-PM-Disc [M], AvaDent Puck [A] und Pink CAD/CAM-Disc [P]) und einem konventionell heißpolymerisierten PMMA (Promolux [C]) gemäß ISO-Norm 20795-1:2013 hergestellt. Die Proben wurden zwei Untergruppen (n = 10), einer Gruppe mit Temperaturwechselbelastung (Thermocycling) sowie einer Kontrollgruppe, zugeteilt, wobei die Proben der Belastungsgruppe 5.000 Temperaturzyklen (5 bis 55 °C bei 30 s Haltezeit) unterworfen wurden. Für die Messung der Rauheit (Ra) kam ein Profilometer zum Einsatz. Die Hydrophobizität wurde über den Kontaktwinkel mittels liegender Tropfen (Sessile-Drop-Technik) bestimmt. Zusätzlich wurde in einer Universalprüfmaschine bei einer Traversengeschwindigkeit von 1,0 mm/min die Biegefestigkeit der Proben getestet. Die Untersuchung der Oberflächenstruktur der Materialien erfolgte mithilfe eines Rasterelektronenmikroskops. Die Daten wurden mittels zweifaktorieller Varianzanalyse und Tukey-Post-hoc- Test ausgewertet (α < 0,05). Ergebnisse: PMMA-basierte CAD/CAM-Kunststoffe zeigten in jeder Gruppe eine signifikant höhere Biegefestigkeit als konventionell heißpolymerisiertes PMMA (p < 0,001). Der CAD/CAM-PMMA-Kunststoff P wies vor und nach der Temperaturwechselbelastung die höchste, konventionelles PMMA die geringste Biegefestigkeit auf (p < 0,001). Bei den Ra-Werten der getesteten Prothesenkunststoffe fanden sich in der Kontrollgruppe keine signifikanten Unterschiede (p > 0,05). In der thermozyklisch belasteten Gruppe wurde der niedrigste Ra-Wert für den CAD/ CAM-PMMA-Kunststoff M beobachtet (p < 0,001), während die CAD/CAM-PMMA-Kunststoffe A und P sowie das konventionelle PMMA vergleichbare Ra-Werte zeigten (p > 0,05). In der Kontrollgruppe hatte konventionelles PMMA einen signifikant kleineren Kontaktwinkel, war also hydrophiler als die CAD/CAM-Kunststoffe (p < 0,01). In der Temperaturwechselbelastungsgruppe wiesen der CAD/CAM-Kunststoff A und konventionelles PMMA einen signifikant größeren Kontaktwinkel auf, waren also hydrophober als die CAD/CAM-Kunststoffe M und P (p < 0,001). Weitere signifikante Unterschiede zwischen einzelnen Materialien fanden sich hier nicht (p > 0,05). Schlussfolgerung: Die Biegefestigkeit und die Hydrophobizität PMMA-basierter CAD/CAM-Kunststoffe waren höher als die von konventionell heißpolymerisiertem PMMA, während die Ra-Werte von CAD/CAM-PMMA-Kunststoffen und konventionell polymerisiertem PMMA vergleichbar waren. Eine Temperaturwechselbelastung wirkte sich signifikant auf die Biegefestigkeit und die Hydrophobizität, nicht jedoch auf die Rauheit der Prothesenmaterialien aus. © Quintessenz.; Purpose: The objectives of this in vitro study were to evaluate the flexural strength (FS), surface roughness (Ra), and hydrophobicity of polymethylmethacrylate (PMMA)-based computer-aided design/computer-aided manufacturing (CAD/CAM) polymers and to compare the properties of different CAD/CAM PMMA-based polymers with conventional heat-polymerized PMMA following thermal cycling. Materials and methods: Twenty rectangular-shaped specimens (64 × 10 × 3.3 mm) were fabricated from three CAD/ CAM PMMA-based polymers (M-PM Disc [M], AvaDent Puck Disc [A], and Pink CAD/CAM Disc Polident [P], and one conventional heat-polymerized PMMA (Promolux [C]), according to ISO 20795-1:2013 standards. The specimens were divided into two subgroups (n = 10), a control and a thermocycled group. The specimens in the thermocycled group were subjected to 5000 thermal cycling procedures (5 to 55°C; 30 s dwell times). The Ra value was measured using a profilometer. Contact angle (CA) was assessed using the sessile drop method to evaluate surface hydrophobicity. In addition, the FS of the specimens was tested in a universal testing machine at a crosshead speed of 1.0 mm/min. Surface texture of the materials was assessed using scanning M. Arslana, S. Muratb, G. Alpc, A. Zaimoglud Evaluation of flexural strength and surface properties of prepolymerized CAD/CAM PMMA-based polymers used for digital 3D complete dentures Mustafa Arslan electron microscope (SEM). The data were analyzed using two-way analysis of variance (ANOVA), followed by Tukey's HSD post-hoc test (α < 0.05). Results: CAD/CAM PMMA-based polymers showed significantly higher FS than conventional heat-polymerized PMMA for each group (P < 0.001). CAD/CAM PMMAbased polymer [P] showed the highest FS, whereas conventional PMMA [C] showed the lowest FS before and after thermal cycling (P < 0.001). There were no significant differences among the Ra values of the tested denture base polymers in the control group (P > 0.05). In the thermocycled group, the lowest Ra value was observed for CAD/ CAM PMMA-based polymer [M] (P < 0.001), whereas CAD/CAM PMMA-based polymers [A] and [P], and conventional PMMA [C] had similar Ra values (P > 0.05). Conventional PMMA [C] had a significantly lower CA and consequently lower hydrophobicity compared to the CAD/ CAM polymers in the control group (P < 0.001). In the thermocycled group, CAD/CAM PMMA-based polymer [A] and conventional PMMA [C] had significantly higher CA, and consequently higher hydrophobicity when compared to CAD/CAM polymers [M] and [P] (P < 0.001). However, no significant differences were found among the other materials (P > 0.05). Conclusions: The FS and hydrophobicity of the CAD/ CAM PMMA-based polymers were higher than the conventional heat-polymerized PMMA, whereas the CAD/ CAM PMMA-based polymers had similar Ra values to the conventional PMMA. Thermocycling had a significant effect on FS and hydrophobicity except for the Ra of denture base materials. © Quintessenz.