Effect of Different Surface Finishing Processes on the Optical Properties of Zirconium Oxide Ceramics

Abstract

Abstract Objective: Zirconium oxide ceramics are widely used in dentistry due to their excellent mechanical and aesthetic properties. This study investigated the optical properties of zirconium oxide specimens applied with different surface finishing processes Materials and Methods: The study was conducted under in vitro conditions. Thirty zirconium oxide discs (diameter = 15 mm, thickness = 1.2 ± 0.2 mm) were produced and randomly divided into three groups: glazing (Control, Group C), grinding and polishing with EveDiacera (Group L), and grinding and polishing with a polishing paste (Group P). L, a*, and b* values were measured with a spectrophotometer, and color difference (ΔE00), translucency parameter (TP), whiteness index (WI), and modified metameric index (M-MI) were calculated. Data were analysed using ANOVA, Tukey HSD, paired t-tests, and Mann-Whitney U tests (p<0.05). Results: The mean ΔE00 values were 2.04 for Group C, 2.15 for Group P, and 1.81 for Group L. No significant differences were observed in ΔE00 among the groups (p>0.05). Post-treatment TP values significantly decreased in Groups P and L (p<0.001), and a significant difference was found between Group C and Group L (p=0.0017). WI values did not differ significantly between groups (p>0.05), although Group L showed a significant reduction after treatment (p=0.036). No significant differences in M-MI were observed under 4200K (p=0.112) or 5000K (p=0.325) illumination. Conclusion: Different surface finishing processes affect the translucency and whiteness of zirconia, while metamerism remained unaffected under various lighting conditions.

Keywords

• Dental zirconia
• metamerism
• optical properties
• translucency
• whiteness index

Farklı Yüzey Bitirme İşlemlerinin Zirkonyum Oksit Seramiklerin Optik Özellikleri Üzerindeki Etkisi

Abstract

Amaç: Zirkonyum oksit seramikler, mükemmel mekanik ve estetik özellikleri nedeniyle diş hekimliğinde yaygın olarak kullanılmaktadır. Bu çalışmada, farklı yüzey bitirme işlemleri uygulanmış zirkonyum oksit örneklerinin optik özellikleri incelenmiştir. Materyal ve Metot: Çalışma in vitro koşullarda gerçekleştirilmiştir. Otuz adet zirkonyum oksit disk (çap = 15 mm, kalınlık = 1,2 ± 0,2 mm) üretilmiş ve rastgele üç gruba ayrılmıştır: glaze uygulanmış grup (Kontrol, Grup C), EveDiacera ile taşlama ve polisaj yapılan grup (Grup L) ve taşlama ve polisaj pastası yapılan grup (Grup P). L, a ve b değerleri spektrofotometre ile ölçülmüş; renk farkı (ΔE00), yarı saydamlık parametresi (TP), beyazlık indeksi (WI) ve modifiye metamerik indeks (M-MI) hesaplanmıştır. Veriler ANOVA, Tukey HSD, eşleştirilmiş t-testi ve Mann-Whitney U testleri ile analiz edilmiştir (p<0,05) Bulgular: Ortalama ΔE00 değerleri Grup C için 2,04, Grup P için 2,15 ve Grup L için 1,81 olarak bulunmuştur. Gruplar arasında ΔE00 açısından anlamlı bir fark gözlenmemiştir (p>0,05). İşlem sonrası TP değerleri Grup P ve Grup L’de anlamlı şekilde azalmış (p<0,001) ve Grup C ile Grup L arasında anlamlı bir fark bulunmuştur (p=0,0017). WI değerleri gruplar arasında anlamlı farklılık göstermemiştir (p>0,05), ancak Grup L’de işlem sonrası anlamlı bir azalma görülmüştür (p=0,036). M-MI değerlerinde ise 4200K (p=0,112) veya 5000K (p=0,325) aydınlatma altında anlamlı bir fark gözlenmemiştir. Sonuç: Farklı yüzey bitirme işlemleri, zirkonyanın yarı saydamlığını ve beyazlığını etkilerken, çeşitli aydınlatma koşullarında metamerizm etkilenmemiştir.

Keywords

• Beyazlık indeksi
• dental zirkonya
• metamerizm
• optik özellikler
• yarı saydamlık

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