This is an editorial article. It has no abstract.

Polymethyl methacrylate (PMMA) remains the material of choice for denture base fabrication; however, its relatively low flexural and impact strength predisposes dentures to fracture during function and accidental loading. Various reinforcement strategies, particularly metal oxide nanoparticles and glass fibres, have been investigated in vitro, although comparative evidence remains limited and methodologically heterogeneous. This systematic review critically compared the effects of zirconium oxide (ZrO₂) and titanium oxide (TiO₂) nanoparticles versus glass fiber reinforcement on the flexural and impact strength of PMMA denture base resins. The review was conducted in accordance with PRISMA 2020 guidelines and a systematic search of PubMed, Scopus, EBSCOhost, and Google Scholar identified eligible in vitro studies published between 2014 and 2024. Five studies met the inclusion criteria. Glass fiber reinforcement consistently demonstrated the greatest improvement in flexural and impact strength, with progressive enhancements reported up to approximately 7 wt%fiber content. Among nanoparticle reinforcements, ZrO₂ showed superior mechanical performance compared with TiO₂, with optimal reinforcement observed at concentrations around 3 wt%, while higher concentrations were associated with reduced strength due to particle agglomeration and poor dispersion. Considerable heterogeneity was observed across studies in terms of PMMA type, reinforcement concentration, specimen preparation and mechanical testing protocols, precluding meta-analysis. Overall, the available in vitro evidence indicates that glass fiber reinforcement provides the most reliable mechanical enhancement of PMMA denture base resins, whereas nanoparticle-based reinforcement offers benefits only within narrow concentration ranges, underscoring the need for standardized methodologies and clinically relevant testing in future research.

This is an editorial article. It has no abstract.

This research presents an eco-friendly approach for extracting chitosan from shrimp shell waste through ultrasound-assisted extraction (UAE) to prepare biocompatible aerogel scaffolds for biomedical applications. The study investigates the influence of various ultrasonic treatment times (10, 20, 30, 40 min) on the yield and structural and physicochemical properties of the extracted chitosan via characterization using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Among the tested conditions, the 30 min UAE-treated chitosan aerogels showed optimal porosity and structural integrity. Biocompatibility of the aerogels was evaluated, and the results confirmed their non-cytotoxic nature. The bioactivity of the chitosan aerogels was evaluated in terms of their in vitro wound closure ability and antibacterial properties. The aerogels demonstrated a wound closure rate of around 51% after 72 h, significantly higher than the untreated control (37%). In addition, they exhibited clear antibacterial activity against Escherichia coli and Staphylococcus aureus. This sustainable extraction and fabrication method not only adds value to marine waste but also produces functional biomaterials with potential applications in wound healing, tissue engineering, and regenerative medicine, supporting global efforts toward sustainability and circular bioeconomy.

This is an editorial article. It has no abstract.