Muhammad Khawaja Hammad Uddin

Introduction: To improve the clinical outcomes and long-term durability of polymethyl methacrylate (PMMA) denture-based resins, they have undergone several developments and changes in their chemical composition to enhance their mechanical properties, including reinforcing them with natural fibers. Aim: This systematic review aimed to explore the influence of plant fiber reinforcement on the mechanical characteristics of PMMA denture resins. Material and methods: For this purpose, the formulated focus question was ‘Does incorporating plant fibers in PMMA denture resins improve their mechanical strength?’ Using the PRISMA protocol, three electronic databases (Google Scholar, PubMed, and ScienceDirect) were searched using the specific search words: (plant fibers, natural fibers, and PMMA) denture base resins between 2014 and 2024. After evaluating the papers against the inclusion criteria, only those that met all requirements were included in the study. Additionally, all articles were screened for quality assessment, with particular attention to potential bias arising from experimental design and methodological reporting. Results: This review included eight experimental laboratory-based studies that met the inclusion criteria. All studies had low risk of bias, except one, which had moderate risk of bias. The evaluation of reinforced resins’ flexural strength was a noticeable trend observed in studies, with the maximum weight percentage utilized in the studies being 10 wt%. While flexural strength was primarily assessed by the majority of studies, other mechanical properties – including hardness, impact strength, tensile strength, and compressive strength – were also evaluated. Conclusions: The analysis revealed that the flexural strength and surface hardness of PMMA denture resins were significantly enhanced through the addition of plant fiber reinforcement. However, limited and inconclusive data are present for other mechanical properties (impact, compressive, and tensile strength). Extended experimental studies related to aging and various storage protocols, as well as clinical trials, are essential to determine its clinical relevance and longevity

Objective: To investigate the relationship between concentration of Glycyrrhiza glabra (GG) and Piper nigrum (PN) on the inhibition zone of S. mutan, Lactobacili and E.coli and their effect on the physicomechanical properties of conventional Glass Ionomer Cement (GIC). Study Design and Setting: This experimental study tested the antibacterial activity and microhardness of modified-GIC at Baqai Medical University and NED University Karachi, Pakistan. Methodology: The herbs were added to GIC in 4-16% concentration separately and in combination. Sample characterization was done by Fourier Transform Infrared Spectroscopy (FTIR) in 4000-700 cm-1 range. The antibacterial efficacy was tested in-vitro using disc diffusion method on brain heart infusion (BHI) agar plates. Microhardness was tested by Vickers microhardness tester. The pH was measured using digital pH meter and the data was analyzed using Anova test on SPSS software to compare the inhibition zones and a Post-hoc Tukey’s test was conducted. Results: An increase was observed in the inhibitory zone of group 2 (GIC + GG), group 3 (GIC + PN) and group 4 (GIC+GG+PN) as compared to that of conventional GIC (control group) and the increase was more pronounced for GG as compared to PN. The modified groups showed increase in pH at all intervals. Microhardness of modified groups was equal to control group indicating that the addition of herbs into conventional GIC did not impact its physicomechanical properties. Conclusions: The tests revealed improved antibacterial activity of herb-modified GIC without significant changes in the physicomechanical properties

Marine-derived biowaste increment is enormous, yet could be converted into valuable biomaterial, e.g., hydroxyapatite-based bioceramic. Bioceramic material possesses superiority in terms of thermal, chemical, and mechanical properties. Bioceramic material also has a high level of biocompatibility when projected into biological tissues. Tuning the porosity of bioceramic material could also provide benefits for bioseparation application, i.e., ultrafiltration ceramic membrane filtration for food and dairy separation processes. This work presents the investigation of hydroxyapatite conversion from crab-shells marine-based biowaste, by comparing three different methods, i.e., microwave, coprecipitation, and sol–gel. The dried crab-shells were milled and calcinated as calcium precursor, then synthesized into hydroxyapatite with the addition of phosphates precursors via microwave, coprecipitation, or sol–gel. The compound and elemental analysis, degree of crystallinity, and particle shape were compared. The chemical compounds and elements from three different methods were similar, yet the degree of crystallinity was different. Higher Ca/P ratio offer benefit in producing a bioceramic ultrafiltration membrane, due to low sintering temperature. The hydroxyapatite from coprecipitation and sol–gel methods showed a significant degree of crystallinity compared with that of the microwave route. However, due to the presence of Fe and Sr impurities, the secondary phase of Ca₉FeH(PO₄)₇ was found in the sol–gel method. The secondary phase compound has high absorbance capacity, an advantage for bioceramic ultrafiltration membranes. Furthermore, the sol–gel method could produce a snake-like shape, compared to the oval shape of the coprecipitation route, another benefit to fabricate porous bioceramic for a membrane filter.