Aim: To investigate the surface roughness, surface hardness, and solubility of bulk-fill composites after exposure to food-simulating liquids (FSLs). Materials and Methods: A total of 200 disc-shaped samples (8 mm diameter × 4 mm depth) were prepared using four bulk-fill composites (SonicFillTM, Tetric® EvoCeram Bulk Fill, Beautifil-Bulk Restorative, FiltekTM Bulk Fill Posterior Restorative) and a microhybrid composite (FiltekTM Z250) ( n = 40). Following the measurement of initial weights of the samples ( m1), the surface roughness measurements were gauged using a contact-profilometer. The samples were stored in four different FSLs for 7 days, and then the second surface roughness values were recorded. The samples were stored in a desiccator to reach the constant mass and the values were recorded as m2, then the solubility levels were calculated. The Vickers microhardness values of the samples were determined. A total of 20 specimens were evaluated in terms of surface morphology with a scanning electron microscope (SEM). Data were statistically analyzed with the two-way ANOVA and Bonferroni tests ( P < .05). Results: Beautifil-Bulk Restorative was affected at most in terms of surface roughness after storage in FSLs and citric acid caused the highest values in this group ( P < .005). Beautifil-Bulk Restorative and Filtek Z250 showed the highest surface hardness values, while the Tetric EvoCeram group had the lowest. The highest solubility values were found in Beautifil-Bulk Restorative, and citric acid and ethanol yielded the highest solubility values for all of the composites. Conclusion: Beautifil-Bulk Restorative is the most affected group in all parameters evaluated and also affected overly by citric acid among the FSLs in consequence of its prereacted glass ionomer fillers.

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Introduction:The novel coronavirus disease, COVID-19, which evolved in Wuhan city of China, has become an important public health emergency that paralyzed life and negatively affected the entire world. Objectives: The aim of the study was to evaluate a possible effect of coronavirus pandemic on healthcare from the perspective of academicians. Material and methods: A questionnaire consisting of education and functioning of medical-related faculties in the process of COVID-19 was completed by academicians in medical sciences. Data obtained from surveys were presented in pie/column charts and percentages. Results: A total of 103 academicians contributed to the survey. Most of the participants were concerned about themselves and their families. Due to the COVID-19 pandemic, academicians indicated a permanent change in healthcare system. In addition, they expressed worries about theoretical part of distance education and the effects of distance education on clinical practices. Conclusions: According to obtained results, academicians in medical sciences reported significant changes occurring not only in providing healthcare services but also in educational aspect, which is a subject of concern. In this period, in which restrictive and compelling effects are felt in the medical sector as in many other industries, there are still uncertainties regarding the future, and it can be seen that the "normal life" will never be the same as before.

BackgroundThe aim of this study was to compare the effects of food simulating liquids (FSLs) on the surface roughness, surface hardness and solubility of bulk fill composites. MethodsTwo-hundred samples were prepared from four high viscosity bulk fill composites (SonicFillTM, Tetric® EvoCeram Bulk Fill, Beautifil-Bulk Restorative, FiltekTM Bulk Fill Posterior Restorative) and a microhybrid composite (FiltekTM Z250). After the initial weights of the samples were recorded (m1), surface roughness measurements were evaluated with a profilometer. The samples were stored in 4 different FSLs for 7 days, then the second surface roughness values were recorded. Then the samples were stored in a desiccator to reach the constant mass and the values were recorded as m2. The solubility levels were calculated according to the ISO 4049: 2009 specification. The surface hardness values of the samples were determined by using the Vickers microhardness measuring device. Twenty specimens from each group were evaluated in terms of surface morphology with scanning electron microscope (SEM).ResultsBeautifil Bulk Restorative was the most affected group in terms of surface roughness after storage in FSLs and citric acid caused the highest values in this group (p<0,005). Beautifil Bulk Restorative and Filtek Z250 groups showed the highest surface hardness values, while the Tetric EvoCeram group had the lowest. The highest solubility values were detected in Beautifil Bulk Restorative group, and citric acid and ethanol caused the highest solubility values on all the tested composites. ConclusionsBeautifil Bulk Restorative group showed significant differences from the other groups in all tested parameters.

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 (Ra 0 ) measurements were performed with a contact profilometer, the samples were subjected to a pH-cycling model for 10 days and Ra 1 values were recorded. Then, the samples were subjected to toothbrushing simulation for 4 min and final values (Ra 2 ) 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.

Background: The aim of this study was to compare the effects of food simulating liquids (FSLs) on the surface roughness, surface hardness and solubility of bulk fill composites. Methods: Two-hundred samples were prepared from four high viscosity bulk fill composites (SonicFill TM , Tetric® EvoCeram Bulk Fill, Beautifil-Bulk Restorative, Filtek TM Bulk Fill Posterior Restorative) and a microhybrid composite (Filtek TM Z250). After the initial weights of the samples were recorded (m 1 ), surface roughness measurements were evaluated with a profilometer. The samples were stored in 4 different FSLs for 7 days, then the second surface roughness values were recorded. Then the samples were stored in a desiccator to reach the constant mass and the values were recorded as m 2 . The solubility levels were calculated according to the ISO 4049: 2009 specification. The surface hardness values of the samples were determined by using the Vickers microhardness measuring device. Twenty specimens from each group were evaluated in terms of surface morphology with scanning electron microscope (SEM). Results: Beautifil Bulk Restorative was the most affected group in terms of surface roughness after storage in FSLs and citric acid caused the highest values in this group (p<0,005). Beautifil Bulk Restorative and Filtek Z250 groups showed the highest surface hardness values, while the Tetric EvoCeram group had the lowest. The highest solubility values were detected in Beautifil Bulk Restorative group, and citric acid and ethanol caused the highest solubility values on all the tested composites. Conclusions: Beautifil Bulk Restorative group showed the highest surface roughness and solubility values among the tested groups, while the same group showed the highest surface hardness. Key Words: Bulk fill composites, food simulating liquids, solubility, surface hardness, surface roughness.