Wood Polymer Composites (WPCs) have attracted attention in recent years because of growing ecological, social, and economic awareness. This study focuses on polymer composites filled with olive pit particles. In the present study, the test specimens were prepared with different ratios of mixtures that contain polypropylene (PP), olive pit particles in four different concentrations (5.0, 10.0, 15.0, and 20.0 wt%), and maleic anhydride as modifier. The mechanical, thermal, and viscoelastic properties of the WPC were obtained using Dynamic Mechanic Analyzer test equipment and a thermogravimetric differential thermal analyzer. Fourier transform infrared spectroscopy was carried out in order to determine the chemical bonds of these materials. The specimens were also characterized by scanning electron microscopy. The results of the study demonstrated that olive pit particles could be used as reinforcement for PP because of their good thermal and mechanical effects.

Aim: To evaluate color stability (ΔE00), translucency (TP), and surface roughness (Ra) of zirconia-reinforced lithium silicate (ZLS) with lithium disilicate (LS) against different mouth rinses after thermocycling. Methods: A total of 270 specimens were prepared: LS (IPS Emax CAD (group EC)), ZLS-1 (Vita Suprinity (group VS)), and ZLS-2 (Celtra Duo (group CD)). For each specimen, ΔE00, TP, and Ra measurements were recorded with a clinical spectrophotometer (CM-3600A) and a 3D non-contact profilometer (AEP Nanomap-1000WLI), respectively, between baseline and after 10000 cycles of thermal cycling. Each group was divided into six subgroups (n=15) according to the immersion solution: five mouthwashes (Meridol, Klorhex, Listerine Cool Mint, Listerine Healthy White Natural Lemon&Salt, and Curasept ADS 212), and distilled water for 72 hours. Statistical analysis was performed by using a three-way robust ANOVA with Tukey HSD test (α=0.05). Results: Listerine Lemon&Salt and Cool Mint caused the highest ΔE00 and Ra values, while TP values of tested mouthwashes were similar (p=0.051). Group EC had the highest ΔE00 and Ra values with the lowest TP values against mouthwashes (p<0.05). Conclusion: Prolonged use of mouthwashes may cause color change and increased surface roughness in LS more than ZLS. Patients should be advised to use alcohol-containing mouthwashes with caution in daily use.