Objective: The purpose of this study was to evaluate the effect of aging and fiber‐reinforcement on the color stability, translucency, and microhardness of single‐shade resin composites versus multi‐shade resin composite.Materials and Methods: Four resin composites (Filtek Z250, Omnichroma, Vittra APS Unique, Zenchroma) were tested. Three subgroups of specimens were prepared for each of the composites: control, polyethylene fiber‐reinforcement, and glass fiber‐reinforcement‐ groups (n = 10/per group). The samples were subjected to aging for 10,000 thermal cycles. Color differences (ΔE₀₀) were calculated after aging. Relative translucency parameter (RTP₀₀) and microhardness values were calculated before and after aging. A two‐way analysis of variance and the generalized linear model was used (p < 0.05).Results: The lowest and highest ΔE₀₀values were found for Filtek Z250 (0.6 ± 0.2) and Omnichroma resin composites (1.6 ± 0.4), respectively. The ΔE₀₀value of the polyethylene fiber‐reinforcement group (1.2 ± 0.6) was significantly higher than the ΔE₀₀value of the glass fiber‐reinforcement group (1.0 ± 0.4,p < 0.001). The RTP₀₀value of the glass fiber‐reinforcement group (1.92 ± 0.78) was significantly higher than the RTP₀₀value of the polyethylene fiber‐reinforcement group (1.72 ± 0.77,p < 0.001). The highest microhardness values were found in glass fiber‐reinforcement group (76.48 ± 17.07,p < 0.001).Conclusion: Single‐shade resin composites were more translucent, had higher color change, and lower hardness than multi‐shade resin composite. For relative translucency and microhardness, statistical significance was found in the material and fiber type interaction. The glass fiber‐reinforcement provided higher translucency, lower color change and higher microhardness values than polyethylene fiber‐reinforcement group after aging. Thermocycling had a significant impact on the color stability, translucency parameter, and microhardness of the tested resin composite materials.Clinical Significance: Single‐shade resin composite materials have greater color‐changing potential. The glass fiber‐reinforcement optimize resin material mechanical properties and color stability more than polyethylene fiber‐reinforcement.

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.

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 (ΔE₀₀) 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 ΔE₀₀ values than the other resin composites, and Charisma Smart had significantly lower ΔE₀₀ 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 ΔE₀₀ 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.

SUMMARY: The study aimed to evaluate the effect of thickness on the translucency parameter (TP) and whiteness index for dentistry (WI_D) of single-shade resin composites compared with a multi-shade resin composite after thermocycling. A total of 100 resin composite samples of five brands (Filtek Z250, Omnichroma, Vittra APS Unique, Zenchroma, and Charisma Diamond One) with thicknesses of 2 mm and 4 mm were prepared (n=10). CIE L*a*b* coordinates were obtained using a spectrophotometer. The resin composite samples were subjected to 10,000 thermocycles. Before and after thermocycling, TP values were calculated with the CIEDE2000 formula, and whiteness values were calculated using the WI_D. The influence of thickness, resin composite, and aging on these variables was analyzed using the generalized linear model (p<0.05). Omnichroma and Filtek Z250 exhibited, respectively, the highest and the lowest TP₀₀ values compared with the other resin materials (p0.05). Vittra APS Unique had a lower TP than Zenchroma and Diamond One (p<0.001). Before thermocycling, the highest WI_D showed the combination of Vittra APS Unique with thicknesses of 2 mm (48.33±1.18). After thermocycling, the highest WI_D was shown in the combination of Vittra APS Unique with thicknesses of 2 mm (45.33±0.55) and 4 mm (46.23±0.94) (p<0.001). After thermocycling, the lowest WI_D was for the combination of Filtek Z250 with thicknesses 2 mm (21.16±0.93) and 4 mm (20.70±0.91) (p<0.001). The TP and WI_D values of the resin composites varied across different composites and thicknesses. Single-shade resin composites of different thicknesses demonstrated higher translucency and whiteness values than multi-shade resin composite, both before and after thermocycling.

Background: Flipped classroom (FC) model has become increasingly popular in dental education (DE) with its strengths for students. However, major concerns are lack of interaction, unwillingness to complete the assignments, low engagement during the pre‐class activities because of an unwell‐designed instructional setting of FC.Objectives: The recent study aims to investigate the effects of video‐driven discussions integrated into the flipped classroom (VdDs‐FC) model on dental students' (DSs) learning achievement, practical performance, and higher‐order thinking skills in a restorative dentistry course.Methods: This study adopted a sequential explanatory design from mixed‐methods research. A total of 96 DSs participated in a dentistry faculty of Türkiye. They were randomly divided into two groups: VdDs‐FC group and the conventional flipped classroom (c‐FC) group.Results and conclusions: The results showed that the VdDs‐FC model had significant positive effects on the practical performance of DSs in practical subjects and their problem‐solving and critical thinking skills. However, there was no significant difference between the two groups in learning achievement and creativity. The use of FC in the c‐FC group did not lead to any difference in the students' achievements. Moreover, the qualitative results indicated that the VdDs‐FC model has the potential for enhancing peer learning, practical classroom activities, and higher‐order thinking skills.Implications: This study also includes several instructional implications and suggestions for educators, researchers, and practitioners on use of FC in dentistry.

The objective of the study was the impact of universal adhesives on color coordinates and color change of single-shade resin composites compared with a multi-shade composite after thermocycling. Five resin composites (Filtek Z250, Omnichroma, Vittra APS Unique, Zenchroma, and Charisma Diamond One) were used. The composites were randomly divided into three subgroups: two universal adhesive groups (Single Bond and Gluma Bond) and one control group (n=10). Color measurements were performed initially and after 10,000 thermocycling. Color change (ΔE₀₀) values were calculated using the CIEDE2000 formula. The two-way variance analysis was used (p<0.05). The lowest and highest ΔE₀₀ were exhibited in the Filtek Z250 and Charisma Diamond One (p<0.001, p<0.001, respectively). The highest ΔE₀₀ was exhibited in the Gluma Bond (p<0.001). An adhesive system may adversely affect the color change of resin composite materials. L and a values of resin composites decreased, and the b values increased after thermocycling.