Mustafa S. Tukmachi

Background/Objectives: The use of zirconia implants is gaining traction as a potential alternative to titanium. Although having excellent properties, the zirconia surface has limited osteogenic potential. The purpose of this study was to produce, for the first time, mechanically stable, thick micron-scale hydroxyapatite coatings on zirconia implant material using radiofrequency (RF) magnetron sputtering. Methods: Zirconia samples were coated with HA using an RF magnetron sputtering device at a temperature of 125 °C for 20 h with 155 W of power. The procedure included rotating the substrate at a speed of 10 rpm while an argon gas flow was maintained continuously. Field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) analysis, atomic force microscopy, and Vickers hardness measurements were used to evaluate the coat’s characteristics. Results: A smooth hydroxyapatite coating layer that was consistent and free of cracks was observed in all FESEM pictures. The EDX study revealed that the substrate surface contains HA particles, and the ratio of calcium (Ca) to phosphorus (P) was 16.58 to 11.31, which is very close to the ratio in original HA. FESEM cross-section pictures showed good adhesion between the coating and substrate without any gaps, and the coating thickness was 5 µm on average. A statistically significant difference was found in the roughness analysis between the samples of uncoated Zr and HA-coated Zr (p-value < 0.05). Conclusions: Zirconia implant material can be coated with a uniform layer of HA, displaying good adhesion and a thickness of a few micrometers when using magnetron sputtering for an extended period of time.

Background and Aim : Silver nanoparticles represent a widely utilized nanotechnology product, prized for their versatile properties including electrical and thermal conductivity, and antimicrobial efficacy. This study aimed to assess the impact of incorporating silver nanoparticles‐delaminated clay nanohybrid (AgNPs‐DC) into acrylic resin on its antibacterial and antifungal characteristics, flexural strength, alongside evaluating the toxicity, and biocompatibility of the resultant composite. Materials and Methods: Two concentrations of silver nanoparticles were initially integrated into the clay. Subsequently, cold‐cure poly‐methyl methacrylate (PMMA) was modified with varying percentages (0.2, 0.5, 1, and 1.5 wt%) of AgNPs‐DC. Various analytical techniques including X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), energy‐dispersive X‐ray (EDX) analysis, flexural strength, and elemental mapping were utilized to verify synthesis and determine physiochemical properties. Cytotoxicity assessments were conducted using mouse fibroblast cell line (L929), while antibacterial activity against standard strains of Escherichia coli ( ATCC 25922 ), Enterococcus faecalis ( ATCC 29212 ), and Candida albicans ( ATCC 10239 ) were evaluated using the colony count method. Results: EDX analysis confirmed the presence of clay and silver nanoparticles in the final acrylic resin. Samples with higher concentrations of silver nanoparticles (10%), AgNPs‐DC (1.0% and 1.5%), and synthesized acrylic powder (80 µg/mL) exhibited increased cytotoxicity, with diminished cell viability after 5 days of incubation. Moreover, an escalation in AgNPs‐DC concentration correlated with a significant reduction in colony counts of E. faecalis , E. coli , and C. albicans in groups with 5wt% of silver nanoparticles ( p = 0.018, p < 0.001, and p = 0.004, respectively). Encapsulation of AgNPs‐DC within the polymer mitigated its toxicity, while higher concentrations of silver nanoparticles (10%) demonstrated enhanced antimicrobial properties. The mean flexural strength in groups with concentrations of 0.2 and 0.5 wt% of AgNPs‐DC was significantly higher than in groups with concentrations of 1 and 1.5 wt% of AgNPs‐DC. ( p < 0.05). Conclusion: In conclusion, this study underscores the potential of PMMA modification with AgNPs‐DC nanoparticles to confer satisfactory antibacterial and antifungal characteristics. Nonetheless, the cytotoxicity of the synthesized polymer increased with nanoparticle concentration and duration. Notably, ball milling proved effective in reducing nanoparticle aggregation.

Polyetheretherketone (PEEK) has favorable biomechanical properties to be used as an implant material. Unfortunately, it is hydrophobic and does not promote cellular adhesion, which could result in poor integration with bone tissue. Bio-functionalization of PEEK surface with osteogenic peptides derived from bone extracellular matrix proteins is an excit-ing approach to encourage bone formation around the implant. In the current study, bone-forming peptide-2 was immo-bilized on PEEK surface using two different methods, using dopamine and a diglycidyl ether as conjugate compounds, respectively. Peptide quantification test revealed that the two strategies resulted in the most amount of peptides were attached with 0.5 mM concentration and no further peptides were grafted with a higher peptide concentration. Both methods showed good peptide stability after agitation in aqueous solution. Peptide grafting was confirmed with ATR-FTIR. Surface characterizations with AFM and wettability tests resulted in a significant increase in surface roughness and surface area ratio for the peptide-grafted PEEK compared to unmodified PEEK, which led to a signifi-cant enhancement in the wettability of the modified PEEK surface

Background: Polyetheretherketone (PEEK) is a promising implant material due to its superior biomechanical strength. However, due to its hydrophobic nature and lack of cellular adhesion properties, it has poor integration with bone tissue. Methods: A fractional CO2 laser was used with various parameters for surface texturing of PEEK substrate to enhance its surface properties. An optical microscope and field-emission scanning electron microscope (FESEM) were used to examine the surface morphology of untextured and laser-textured samples. Energy dispersive X-ray spectroscopy (EDX) was performed to determine the effect of the laser on the microstructure of PEEK. Surface microroughness, atomic force microscopy (AFM), and wettability were investigated. Results: There were significant increases in microroughness, nanoroughness, surface area ratio, and wettability after laser texturing with no change in the elemental composition. The best results were obtained by using 400 µs laser pulse duration with a dot separation distance of 0.2 mm and a 60° staggered dots pattern. Conclusions: Laser surface texturing of PEEK implant material by fractional CO2 laser is an easy and fast method of introducing patterned topographical features with no need for additional devices. With further investigations, this method of PEEK modification might have the potential to be used in the implant field.