Influence of Interfacial Bonding on the Mechanical and Impact Properties Ring-Opening Metathesis Polymer (ROMP) Silica Composites

Influence of the Physical Inclusion of ZrO2/TiO2 Nanoparticles on Physical, Mechanical, and Morphological Characteristics of PMMA-Based Interim Restorative Material

Polymethyl methacrylate (PMMA) is often used in restorative dentistry for its easy fabrication, aesthetics, and low cost for interim restorations. However, poor mechanical properties to withstand complex masticatory forces are a concern for clinicians. Therefore, this study aimed to modify a commercially available PMMA-based temporary restorative material by adding TiO2 and ZrO2 nanoparticles in different percentages as fillers and to investigate its physio-mechanical properties. Different percentages (0, 0.5, 1.5, and 3.0 wt%) of TiO2 and ZrO2 nanoparticles were mixed with the pristine PMMA resin (powder to liquid ratio: 1 : 1) and homogenized using high-speed mixer. The composites obtained were analyzed for their flexural strength (F.S.), elastic modulus (E.M.), Vickers hardness (H.V.), surface roughness Ra, morphology and water contact angle (WCA). The mean average was determined with standard deviation (SD) to analyze the results, and a basic comparison test was conducted. The results inferred that adding a small amount (0.5 wt%) of TiO2 and ZrO2 nanoparticles (NPs) could significantly enhance the physio-mechanical and morphological characteristics of PMMA interim restorations. EM and surface hardness increased with increasing filler content, with 3.0 wt.% ZrO2 exhibiting the highest EM (3851.28 MPa), followed by 3.0 wt.% TiO2 (3632.34 MPa). The WCA was significantly reduced from 91.32 ± 4.21° (control) to 66.30 ± 4.23° for 3.0 wt.% ZrO2 and 69.88 ± 3.55° for 3.0 wt.% TiO2. Therefore, TiO2 and ZrO2 NPs could potentially be used as fillers to improve the performance of PMMA and similar interim restorations.

Surface Morphology and Mechanical Properties of Polyether Ether Ketone (PEEK) Nanocomposites Reinforced by Nano-Sized Silica (SiO2) for Prosthodontics and Restorative Dentistry

In the field of orthopedics and traumatology, polyether ether ketone (PEEK) serves a significant role as a suitable alternative to traditional metal-based implants like titanium. PEEK is being used more commonly to replace traditional dental products. For bonding with various adhesive agents and preserved teeth, the surface alteration of PEEK was investigated. The aim of this research was to understand how different types and contents of nano-sized silica (SiO2) fillers influenced the surface and mechanical properties of PEEK nanocomposites used in prosthodontics. In this work, PEEK based nanocomposites containing hydrophilic or hydrophobic nano-silica were prepared by a compression molding technique. The influence of nano-SiO2 type and content (10, 20 and 30% wt) on surface properties of the resultant nanocomposites was investigated by the use of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), surface roughness analysis, and contact angle measurement. The crystalline structures of PEEK/SiO2 nanocomposites were examined by X-ray diffraction (XRD) spectroscopy. Mechanical properties were measured by microhardness, elastic compression modulus, and flexural strength. All nanocomposites showed increased surface roughness compared to pure PEEK. SEM images revealed that nanocomposites filled with low content hydrophobic nano-SiO2 showed uniform dispersion within the PEEK matrix. The introduction of 10 wt% of hydrophobic nano-SiO2 to the PEEK matrix improved elastic modulus, flexural strength, and microhardness, according to the findings. The addition of nano-SiO2 fillers in a higher weight percentage, over 10%, significantly damages the mechanical characteristics of the resultant nanocomposite. On the basis of the obtained results, PEEK/SiO2 nanocomposites loaded with low content hydrophobic nano-SiO2 are recommended as promising candidates for orthopedic and prosthodontics materials.