A new implant with solid core and porous surface: the biocompatability with bone.

Bone implants require materials that promote osteogenesis while maintaining mechanical compatibility. Traditional titanium implants have been widely used, but their surface properties and mechanical behavior may limit integration with surrounding bone. Research has shown that surface roughness and hydrophilicity influence cell adhesion and proliferation, but the long-term effects of these properties remain unclear. While sand-blasted and acid-etched titanium surfaces have demonstrated improved osteogenic potential, their performance in vivo is still under investigation. The mechanical mismatch between titanium and bone can lead to stress shielding, potentially affecting implant longevity. Recent studies have explored porous structures to enhance osseointegration, but the interplay between porosity and cell behavior is not fully understood. The need for a titanium implant with a transitional porous-solid structure that mimics bone properties has led to new fabrication techniques. This gap motivated the development of a novel titanium implant with a solid core and porous surface to better align with bone mechanics and promote osteogenic activity.

This study aimed to evaluate the biocompatibility and osteogenic potential of a newly developed titanium implant with a transitional porous-solid structure. The primary goal was to assess how this material's surface properties and mechanical characteristics influence bone cell behavior in vitro and in vivo. The researchers sought to determine whether the implant's hydrophilicity and roughness could support cell adhesion and proliferation. They also aimed to compare its performance with conventional titanium surfaces, such as sand-blasted and acid-etched titanium. The study's motivation stemmed from the need to improve osseointegration rates and reduce implant failure. By analyzing both mechanical and biological responses, the researchers hoped to identify a titanium implant that better mimics natural bone properties. This approach could lead to implants with enhanced long-term stability and reduced complications. The findings could inform future design strategies for orthopedic and dental implants.

The study evaluated a newly developed titanium implant with a transitional porous-solid structure. Material properties were analyzed using surface roughness and hydrophilicity measurements. Biomechanical testing included compressive strength assessments to compare the implant's modulus with that of bone. In vitro experiments involved culturing MC3T3-E1 cells on the implant surface and assessing adhesion and proliferation rates. ALP activity was measured to evaluate osteogenic differentiation potential. In vivo testing was conducted in a rabbit bone defect model to assess osseointegration. Bone-to-implant contact (BIC) and bone volume ratios were quantified using histomorphometric and micro CT analyses. The study compared the new implant with sand-blasted and acid-etched titanium surfaces, as well as machined titanium. These methods allowed the researchers to evaluate both mechanical and biological performance comprehensively.

The FFcTi implant demonstrated surface roughness comparable to sand-blasted and acid-etched titanium but was more hydrophilic than both. Its compressive modulus was 15.8 ± 6.3 GPa, closely matching that of bone. In vitro, MC3T3-E1 cells showed high initial adhesion on FFcTi surfaces, but proliferation rates were lower than on machined titanium during the first six days. By day 11, proliferation levels were similar across all surfaces. ALP activity was higher on FFcTi than on machined titanium but lower than on sand-blasted and acid-etched titanium. In vivo, FFcTi showed significantly higher BIC and bone volume ratios within 50 μm compared to machined titanium. Micro CT confirmed these findings, showing similar trends in bone volume ratios within 100 and 500 μm. These results suggest that FFcTi supports early osteogenic activity and osseointegration better than conventional titanium surfaces.

The FFcTi implant with a transitional porous-solid structure exhibited favorable mechanical and biological properties. Its hydrophilic surface and roughness supported initial cell adhesion, while its modulus matched that of bone, reducing stress shielding risks. In vitro, the implant showed moderate proliferation and higher ALP activity compared to machined titanium but lower than sand-blasted and acid-etched surfaces. In vivo, FFcTi demonstrated superior osseointegration in a rabbit model, with higher BIC and bone volume ratios within 50 μm. These findings suggest that FFcTi could offer improved integration with bone compared to conventional titanium implants. The study supports the potential of FFcTi for use in orthopedic and dental implants. Further research is needed to evaluate long-term performance and clinical outcomes. The authors propose that FFcTi represents a promising advancement in implant design for bone applications.