Hydrophilic surface of Ti6Al4V-ELI alloy improves the early bone apposition of sheep tibia.

Objective: The aim of this preclinical study was to compare histologically and histomorphometrically both sandblasted/acid-etched implant surfaces with or without maintained in an isotonic solution of 0.9% sodium chloride in early stages of osseointegration.

Material And Methods: Both implant surfaces were composed of a titanium/aluminum/vanadium alloy (Ti6Al4V-ELI), but they had different surface chemistries: sandblasted/acid-etched titanium surface (FN) or sandblasted/acid-etched surface maintained in an isotonic solution of 0.9% sodium chloride (FA). The surface morphology, topography and chemistry were evaluated by scanning electron microscopy (SEM), confocal microscopy (CM) and X-ray photoelectron spectroscopy (XPS), respectively. Dynamic contact angle (DCA) was employed for wettability evaluation. One implant from each group was placed in the left tibia of twenty healthy, skeletally mature Santa Ines sheep (n = 5). Bone area (BA) and bone-to-implant contact (BIC) were performed on thin sections (30 μm) at 7, 14, 21 and 28 days after implant installation.

Results: Despite the roughness and morphology similarities between the groups, at the XPS evaluation, the FA group presented 2.3 times less carbon on the surface (FN: 27.3% and FA: 11.6%), sharply enhanced hydrophilicity and significantly enhanced BA and BIC at 14, 21 and 28 days of healing (P < 0.05) compared with the FN.

Conclusion: The data suggest that the hydrophilic FA accelerates the BA apposition and BIC interface around the implants during early stages of bone formation, providing highest degree of osseointegration.