Background. The aging process can induce a change in the surface microstructure of materials, the chemical compositions of matrices, and the filler particles of resin composites. This study is aimed at evaluating the effects of accelerated artificial aging (AAA) on the color change, translucency parameter (TP), and surface hardness of resin composites. Methods. Five resin composite materials (Tetric N-Ceram, Filtek Z250, Charisma Smart, Herculite Classic, and Escom100) were evaluated. A spectrophotometer was used for color measurements ( L ∗ , a ∗ , and b ∗ ). TP and color changes ( Δ E 00 ) were calculated using the CIEDE2000 formula. The resin materials were subjected to aging for 300 hours. The hardness and TP values were measured before and after AAA. One- and two-way ANOVA and the Tukey test were used. The significance level was accepted as p < 0.05 . Results. Escom100 had significantly higher Δ E 00 values than the other resin composites, and Charisma Smart had significantly lower Δ E 00 values than the other tested materials ( p < 0.05 ). Before and after AAA, Charisma Smart had the lowest TP values, and Filtek Z250 exhibited the highest hardness values ( p < 0.05 ). For TP and surface hardness, the effect size value of the composite material was found to be higher than that of AAA. Conclusions. After AAA, the investigated resin composites had Δ E 00 values that were above clinically acceptable thresholds. After aging, the tested materials generally exhibited decreases in L ∗ values and a ∗ values, while increases in b ∗ values were observed. The ΔTP values of the resin composites were similar. AAA significantly increased the surface hardness of the tested materials.

Polymerization plays an important role in the color and translucency of resin composite materials. The aim of this study was to evaluate the effect of light-curing distances of resin composites on color change (ΔE00) and translucency change (ΔTP) after accelerated aging (AA). Four resin composites (G-Aenial Anterior, Charisma Smart, GrandioSO, and Admira Fusion) were used. The resin composites were cured from 0 mm, 2 mm, and 4 mm distances. A spectrophotometer was used to determine the color measurements and calculate the color change and translucency using the CIEDE2000 formula. The resin composites were submitted to AA for 300 h. Two-way analysis of variance and multiple comparisons Tukey’s test were used (p < 0.05). ΔE00 at 0 mm and 2 mm distance was similar, but higher was found at 4 mm distance. The highest and lowest ΔE00 were observed in the G-Aenial Anterior and Charisma Smart respectively. But no differences were observed between Charisma Smart and Admira Fusion. Translucency changes at 2 mm and 4 mm distances were similar, but lower translucency changes were observed at a distance of 0 mm. The translucency change values of the materials were found to be similar after accelerated aging. Increasing the light-curing distance can lead to deterioration of color stability and a tendency to decrease translucency. Clinicians should position the light-curing device as close to the material as possible.

Objective: This study aimed to investigate the effects of polishing system on the color stability, surface roughness, and hardness of resin composites in the presence and absence of accelerated artificial aging (AAA). Methods: Six resin composites (Universal Restorative 200, G-Aenial Anterior, Ceram-X Duo, Admira, IPS Empress Direct, Clearfil Majesty Esthetic) were evaluated. Thirty disc-shaped samples were prepared for each composite group. Resin composite groups were divided into three subgroups: control (Mylar strip), disc (Optidisc), and rubber (Dimanto) (n=10). Color change (ΔE00) was calculated using the CIEDE 2000 formula. Before and after AAA, the surface roughness (Ra, μm) and hardness (VHN) values were measured. Data were analysed using ANOVA, the Bonferroni test, and Pearson correlation (p

AMAÇ: Bu in vitro çalışmanın amacı, iki farklı polisaj sistemi uygulanan üç farklı kompozit rezinin iki farklı renk sistemine göre termal döngü işlemine tabii tutularak translusensi değerlerini karşılaştırmaktır. GEREÇ ve YÖNTEMLER: 60 adet disk şeklindeki kompozit materyaller(Tetric N-Ceram, Escom100 , Filtek 3M-ESPE Bulk-fill) üç gruba ayrıldı(n=20) ve her gruptaki örnekler iki polisaj sistemine göre alt gruplara ayrıldı(n=10). Translüsensi değerleri termal döngü önce ve sonrasında(10.000 döngü), CIELAB(L*a*b) ve CIEDE 2000 renk sistemlerine göre ölçümler yapılarak tespit edildi. Elde edilen verileri karşılaştırmak için üç yönlü varyas analizi(ANOVA) ve Bonferroni testinden yararlanıldı. Renk sistemleri arasındaki ilişkinin incelenmesi için Pearson korelasyon analizi kullanıldı. Tüm analizlerde anlamlılık düzeyi p&lt;0,05 olarak belirlendi. BULGULAR: Kompozit rezin materyallere ait translüsensi değerleri karşılaştırıldığında gruplar arasında anlamlı farklılıklar elde edildi (p&lt;0.05). Bulgulara göre translüsensi değeri en fazla olan kompozit materyal Escom100 iken en az olan materyalin ise 3M-ESPE Bulk-Fill olduğu tespit edildi ve istatistiksel olarak anlamlı fark bulundu (p&lt;0.05). CIELAB(L*a*b) ve CIEDE 2000 renk sistemleri arasında istatistiksel olarak anlamlı bir farklılık bulundu ve pozitif bir korelasyonun olduğu tespit edildi (p&lt;0.05). Polisaj sistemlerinin renk sistemlerine göre termal döngü öncesinde kompozit rezinlere etkileri benzerdir. Termal döngü sonrasında polisaj tekniklerinin renk sistemlerine etkisi istatistiksel olarak anlamlı bulunmuştur (p&lt;0,05). SONUÇ: Kompozit materyaller translusensi değerleri arasında farklılıklar göstermektedir. CIELAB(L*a*b) ve CIEDE 2000 renk sistemlerinin translüsensi değişim ölçümlerinde istatistiksel olarak anlamlı bir uyum olduğu tespit edilmiştir. Dişe en yakın estetiği sağlamak amacıyla hem uygulanan polisaj sistemlerinin hem de kompozit rezinlerin translüsensi özelliğinin dikkate alınması gerekmektedir.

Background: Polymerization plays an important role in the optical and mechanical properties resin composite materials. Aim: The current study aimed to evaluate the effect of different polymerization times on the color change, translucency parameter (TP), and surface hardness of resin composites after thermocycling. Materials and Methods: Microhybrid resin composite (Filtek Z250; used in the control group) and bulk-fill resin composites (Filtek One Bulk-Fill Restorative, Tetric EvoCeram Bulk-Fill, and Tetric N-Ceram Bulk-Fill) were used. Each bulk-fill composite was placed as a single layer. Polymerization of the bulk-fill composites in the first group was completed in 20 s, and that in the second group was completed in 40 s (n = 10). Filtek Z250's polymerization was completed with 2 mm (20 s) + 2 mm (20 s). The color change (ΔE 00) and translucency parameter (TP 00) were calculated using the CIEDE2000 formula. Before and after thermocycling, the TP and surface hardness values were measured. The data were analyzed using one- and two-way analysis of variance, paired-samples t-test, and Tukey's test (P < 0.05). Results: After thermocycling, the ΔE 00 values of the resin composite samples were 1.66–2.56. Compared to the control group, the Filtek One Bulk-Fill 20 s group exhibited the lowest color change values. The Filtek Z250 group exhibited lower TP and significantly higher microhardness values than the other bulk-fill resin groups before and after thermocycling (P < 0.05). There were no observed differences in the Tetric N-Ceram and Tetric EvoCeram groups before and after thermocycling. Conclusion: Under the conditions of 10,000 thermal cycles, different curing times did not affect the color change and hardness values of the bulk-fill materials. However, differences were observed among the composite materials. After thermocycling, the surface hardness and TP values decreased in all the resin composites. Depending on the material content, effective results can be obtained from the 20 s polymerization of bulk-fill resin composites.