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Objective: The aim of the investigation was to evaluate the effect of food simulating fluids and thermocycling on surface roughness and wear resistance of CAD/CAM (Lava TM Ultimate, 3M ESPE), (SR Nexco® Paste, Ivoclar Vivadent) and (Filtek TM Z350 XT, 3M ESPE) resin composites.Methods: A total of 360 disks were fabricated and divided into three groups. Each group was divided into 12 subgroups (n=10); 6 subgroups for measuring surface roughness and the other 6 subgroups for measuring wear resistance. Four subgroups are immersed for 1 month in different food simulating fluids (distilled water, ethanol, heptane and citric acid). The fifth subgroup was thermocycled for 5000 cycle, while the control subgroups were examined after 24 hours postpolymerization. Surface roughness was assessed using environmental scanning electron microscope. Wear resistance testing was carried out by custom made toothbrush machine. The results were tabulated and statistically analyzed. Results:The results revealed that the food simulating fluids and thermocycling had a deteriorating effect on the three tested materials. Lava TM Ultimate showed the least significant deterioration when compared to SR Nexco® Paste and Filtek TM Z350 XT. Conclusion:Lava TM Ultimate had better resistance to both food simulating fluids and thermocycling, which may be due to its higher nanofillers percentage and its highly cross linked matrix.

Background: Hollywood smile refers to a complete prosthetic reconstruction of both jaws or at least all visible teeth using crowns, veneers and, quite often, implants. Such a name has been selected since Hollywood actors and celebrities widely use it. Fixed exposure to the celebrity's personal life has a significant impact on people's choice of dental treatments, exclusively dental esthetics, for example, the Hollywood smile. This study aims to measure public awareness and Knowledge about the Hollywood smile and to assess the satisfaction of those who have it. Methods: In this cross-sectional study, 384 pre-designed, pre-tested and self-administered Arabic questionnaires were distributed to the participants through social media platforms. The inclusion criteria were both genders, Saudi citizens aged 18 – 60 years old, mentally sound, who use social media and have a Hollywood smile or are thinking and planning to receive a Hollywood smile. The collected data were analyzed using Statistical Package for the Social Sciences (SPSS) software. Results: The total mean score for knowledge was 13.22±4.26/ (moderate level) for twenty-one Hollywood smile knowledge questions. The participants' knowledge significantly differed concerning gender, occupation and level of education. 0nly 4.43% of participants had a Hollywood smile, with 76.47% of satisfaction. There was no significant difference in Knowledge between satisfied and non-satisfied about the Hollywood smile (p>0.05). Conclusion: The overall knowledge of Hollywood smile was moderate and needed improvement. The study found only 4.43% of participants to be having Hollywood smiles. Further studies are needed to assess the satisfaction further.

Objective: To evaluate the influence of the application of various adhesives on the strength of the bonding established amongst resin-modified glass-ionomer cement (RMGIC) and resin composite restoration (RBC).Materials and method: Twenty discs were made-up with (RMGIC) and divided into four groups (n = 5) based on the adhesive resin system applied. Cylinders of resin composite were bonded to the RMGI discs utilizing different adhesive resin systems in the first three groups. While the fourth group was used as a control receiving no adhesive resin treatment. Microshear bond strength was measured and the data was registered with computer software in MPa. Results:The results revealed that applying different adhesive resin systems statistically significantly increased the bond strength between the tested materials. Conclusion:Microshear bond strength of (RMGIC) to resin composite improved considerably using different adhesive resin systems. The outcomes vary depending upon the type of adhesive resin system utilized.