Micro/Nanostructured Bioactive Titanium Implant Surface with Sol-Gel Silicate Glass Nanoparticles.

PURPOSE: To develop a surface coating of sol-gel 70S30C bioactive glass (BAG) nanoparticles on titanium disks and dental implants and characterize the BAG coating from the standpoint of average surface roughness, adhesion strength, and coating stability upon implant insertion under clinical settings. MATERIALS AND METHODS: BAG was prepared using a modified sol-gel technique, then milled into nanoparticles. The resultant powder was characterized in terms of phase structure, composition, and particle size. Titanium disks and dental implants were coated with BAG nanoparticles via electrophoretic deposition. Surface characterization of coated implants was conducted. Uncoated and BAGcoated implants were examined for average surface roughness using a confocal laser scanning microscope. Pull-off tests were conducted to measure the adhesion strength of the BAG coating to the underlying disks. To measure the amount of coating loss and evaluate the effect of insertion on coating thickness, coated implants were inserted under clinical settings into artificial and natural bones. RESULTS: BAG nanoparticles had an amorphous structure with particle sizes < 20 nm in diameter. Electrophoresis resulted in a continuous coating that covered the whole implant surface. Microscopic analysis confirmed the porous nanostructure of the BAG coating, which formed a homogenous surface with microcracks. The BAG coating had a uniform thickness of 35.38 ± 4.67 µm. The average surface roughness was significantly lower for BAG-coated implants, with less surface irregularities (3.34 ± 0.45 µm for uncoated implants, 1.45 ± 0.23 µm for BAG-coated implants). An adhesion strength of 18.51 ± 3.37 MPa was recorded for the BAG coating. After insertion into artificial bone, 66.23 ± 10.23% of the coating weight remained on the implant surface. A reduction in the thickness of the BAG coating only occurred in sites of high friction with bone after implant insertion into bovine bone. CONCLUSIONS: Coating titanium implants with 70S30C BAG nanoparticles is attainable through electrophoretic deposition and results in a homogenous coating layer with a moderately rough surface, considerable adhesion strength, and high coating stability during implant insertion. Int J Oral Maxillofac Implants 2023;38:591-606. doi: 10.11607/jomi.10272.

Biomimetic Coating of Titanium Surface Using Bioactive Glass Nanoparticles.

PURPOSE: The aim of this study was to coat titanium substrate with bioactive glass nanoparticles and characterize the deposited surface coat. MATERIALS AND METHODS: Amorphous bioglass nanoparticles < 20 nm in diameter were prepared using a modified sol-gel technique followed by a ball-milling process. The prepared nanoparticles were used to coat airborne particle-abraded titanium disks. The in vitro bioactivity of the bioglass nanopowder was confirmed using simulated body fluid. Coated surfaces were characterized in terms of microstructure, composition, thickness, phase structure, surface roughness, wettability, and tissue behavior in a rabbit model. RESULTS: Bioglass nanoparticles showed apatite formation under a scanning electron microscope (SEM) after 5 days, confirming that bioactivity was enhanced with increasing degradation rate for up to 2 weeks. An optimized deposition technique and heat-treatment process produced a homogenous coating with a uniform thickness of 32 to 39 µm. Chemical analysis confirmed the presence of silicon and calcium on the coated disks. Amorphous coated surfaces exhibited porous nano/microroughness with microcracks and super-hydrophilicity. The interface of the coated disks with subcutaneous tissue revealed good tissue adhesion, high cellular activity, and rich vascularization, with multinucleated cells in the microenvironment surrounding the coat, as confirmed using histomorphometric analysis. CONCLUSION: The results of this study show that it is feasible to coat titanium surfaces with bioactive glass nanoparticles with super-hydrophilicity and high biologic activity. These particles may promote the regenerative environment around dental implants.