Engie Mohamed Safwat

Although aluminum (Al) alloys are rarely used in orthopedics, their low density and low cost warrant research into their suitability for biocompatible applications. This study compared a typical 354 aluminum alloy with a modified version (M354) containing 0.35 wt% Zr and 0.14 wt% Ni. Both alloys were inspected using optical micrographs. Field Emission Microscopy with Energy-Dispersive X-ray (FE-SEM/EDX) and Atomic Force Microscopy (AFM) were used to analyze the surfaces of both alloys after incubation in simulated body fluid. Furthermore, the alloys were subjected to corrosion tests and in-vitro MTT cytotoxicity and alkaline phosphatase (ALP) assays. Optical micrographs revealed a more refined grain structure for M354 due to precipitation of Al _x (Zr, Ti)Si and Al ₃ Ni containing particles on the grain boundaries. FE-SEM /EDX analysis showed increased calcium content on M354 compared to the 354 alloy following incubation. AFM revealed a higher initial surface roughness for M354, which decreased after incubation, while the roughness of the 354 alloy increased, indicating M354’s strong bioactivity. M354 alloy exhibits a more positive potential than the non-modified 354 version, M354 likewise showed higher cell proliferation. Both alloys exhibited higher ALP activity than the control, indicating that the alloying elements had no adverse effects on cell biocompatibility.

Background: The objective of the study was to prepare and assess novel remineralizing oral films loaded with fluorapatite powder and composed of a combination of hydroxyethyl cellulose (HC) and cellulose nanofibers (CF). Methods: Three concentrations of the prepared nano-fluorapatite were tried and tested after loading in the cellulose blends and films were prepared using solvent cast technique. Along with SEM, measurements of thickness of film, bending tolerance, time of disintegration, surface pH and release of ions were made. The produced film’s ability to remineralize demineralized teeth in vitro was investigated. Results: The findings showed that the films’ thicknesses were uniform, their folding endurance exceeded 300, and their disintegration times exceeded 24 h. High amounts of fluoride and calcium ions were released, and nearly neutral pH values were observed. The distribution of fluorapatite powder particles was uniform, as demonstrated by SEM. The Vickers microhardness (VHN) of enamel and morphological analysis results showed that in comparison with the demineralized specimens, there was a substantial microhardness value increase following 15 and 30 days remineralization. Conclusions: Newly developed prepared films are a successful method for remineralizing early-stage demineralized tooth lesions.

Natural-based materials represent green choices for biomedical applications. In this study, resin pulp capping restoration enclosing strengthening silica and bioactive portlandite nanofillers were prepared from industrial wastes. Silica nanoparticles were isolated from rice husk by heat treatment, followed by dissolution/precipitation treatment. Portlandite nanoparticles were prepared by calcination of carbonated lime waste followed by ultrasonic treatment. Both were characterized using x-ray diffraction, energy dispersive x-ray, and transmission electron microscopy. For preparing pulp capping restoration, silica (after silanization) and/or portlandite nanoparticles were mixed with 40/60 weight ratio of bisphenol A-glycidyl methacrylate and triethylene glycol dimethacrylate. Groups A, B, and C enclosing 50 wt.% silica, 25 wt.% silica + 25 wt.% portlandite, and 50 wt.% portlandite, respectively, were prepared. All groups underwent microhardness, compressive strength, calcium release, pH, and apatite forming ability inspection in comparison to mineral trioxide aggregate (MTA) positive control. In comparison to MTA, all experimental groups showed significantly higher compressive strength, group B showed comparable microhardness, and group C showed significantly higher calcium release. Groups B and C showed prominent hydroxyapatite formation. Thus, the preparation of economic, silica-fortified, bioactive pulp capping material from under-utilized agricultural residues (rice husk) and zero-value industrial waste (carbonated lime from sugar industry) could be achieved.

In this research, Mg–3Zn–xSi (x = 0, 0.1, 0.3, and 0.6 wt%) biodegradable alloys were produced by simple stir casting method, their microstructure and phase changes were evaluated using X-ray diffraction (XRD), optical microscope (OM) and scanning electron microscope coupled with energy dispersive x-ray analysis (SEM–EDS). Potentiodynamic polarization was conducted to measure the alloys’ corrosion behavior in simulated body fluid (SBF). Tensile strength test and in-vitro biocompatibility evaluation regarding MTT cytotoxicity, ALP osseointegration assay and MG-63 cell growth pattern were conducted. Electrochemical investigations showed that Mg–3Zn alloys enclosing Si attained degradation rates suitable for structural support until bone healing, while the Mg–3Zn alloy without Si had a corrosion rate of 0.128 mm/year which is much lower than the required value. None of the inspected alloys exhibited a significant cytotoxic effect, meanwhile, Mg–Zn base alloy and the alloy with 0.3 wt% Si demonstrated the highest ALP level. The optimum cell growth pattern was demonstrated for Mg–Zn base alloy and the alloy with 0.1 wt% Si. Evidence of calcium phosphate precipitation was observed in the four investigated Mg–3Zn alloys. Therefore, based on the fore mentioned results, Mg–3Zn–xSi alloys were suggested as viable biodegradable materials due to their compatible degradation rates, proved cytocompatibility, high cell viability and excellent osseointegration potential.

Introduction: Dental erosion has a great effect on oral health, when diagnosed it is irreversible, this sets the importance of different preventive measures being investigated against dental erosion. Aim: This in vitro study aims to evaluate the effectiveness of silver diamine fluoride and Potassium iodide (SDF-KI) in comparison to casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF) varnish, sodium fluoride (NaF) varnish, silver diamine fluoride (SDF) alone and deionized water as a control group in the prevention of dental erosion in primary teeth and assessing its staining effect. Materials and methods: Forty deciduous teeth enamel specimens were randomly allocated into the five study groups. Tested materials were applied. An erosive challenge was done by immersing the specimens in a citric acid-containing soft drink with pH 2.85, for 5 min, 4 times/day, for 5 days. Changes in surface microhardness, mineral loss, and color change were evaluated besides recording of the surface topography and surface roughness for selected specimens. Results: The highest decrease in surface microhardness was recorded in the control group (−85.21 ± 10.60%), with a statistically significant difference (p = 0.002). SDF-KI group (−61.49 ± 21.08%) showed no statistically significant difference when compared to CPP-ACPF, NaF, and SDF groups. For calcium and phosphorous loss, control group was statistically significantly higher compared to the treatment groups (p = 0.003) and (p < 0.001) respectively, while there was no statistically significant difference between the tested treatment groups. The highest mean value for color change was recorded in SDF group (26.26 ± 10.31), followed by SDF-KI group (21.22 ± 12.87) with no statistically significant difference between groups. Conclusions: SDF-KI is as effective as CPP-ACPF, NaF varnishes and SDF in the prevention of dental erosion in primary teeth, there was no statistically significant difference regarding its staining potential.

Background: Enormous improvements in dental materials’ manufacturing for the aim of producing durable dental materials without compromising the aesthetic properties were developed. One of the approaches that fulfill this aim is the use of reinforcing glass fibers as fillers into dental materials, typically resin polymers, in order to obtain glass fiber-reinforced composites. Glass fiber-reinforced composite offered many advantages to the dental materials though some limitations were recorded in many literature. Methods: In this review, a study of the glass fibers’ types, factors affecting the properties and the properties of glass fibers reinforced materials was carried out; in addition, research papers that experimentally studied their applications in dentistry were presented. Conclusion: The success of glass fibers reinforced composites in dentistry depends on glass fibers’ composition, orientation, distribution, amount, length and adhesion; these factors once employed according to the required clinical situation would provide the essential reinforcement to the dental restorations and appliances.

INPLASY202120038 Efficacy of hemostatic agents in endodontic surgery: A protocol of systematic review and network meta-analysis Keywords: Bleeding; Endodontic surgery; Evidence-based dentistry; Hemostasis; Hemostatic agent; Systematic review; Network meta-analysis. Download PDF – 202120038