IADR Abstract Archives
Topography-dependent Antibacterial, Osteogenic and Anti-aging Properties of Pure Titanium
Objectives: The major dilemmas for current implant dentistry are the implant associated infection and insufficient osseointegration. Moreover, biological aging of titanium implant also brings great uncertainty to clinical results. The aim of this study was to fabricate a kind of titanium surface with antibacterial and enhanced osteogenic properties and uncover the mechanism behind titanium aging.
Methods: Titanium discs were sandblasted, etched with the mixture of 98% H2SO4, 36% HCl and H2O (volume ratio of 6:1:5) for 1min (MS0) and secondary etched with the mixture of 98% H2SO4 and 30% H2O2 (volume ratio of 1:1) for 30min (MS30) or 60min (MS60). Samples packed dry under ambient conditions for 30 days were named Aged-MS0, Aged-MS30 and Aged-MS60. Both physicochemical and biological properties were comparatively studied (n=5 for each test item) before and after aging treatment and statistically analyzed (ANOVA, p<0.05).
Results: MS30, MS60 showed nano-micro-hierarchical topography and were superhydrophilic while MS0 showed micro-submicro structures with contact angle over 5°. In vitro cell study showed MS30 had the highest alkaline phosphatase activity (p<0.05), produced the most osteocalcin (p<0.05) and deposited the most calcium (p<0.05), followed by MS0 and MS60. Less escherichia coli and staphylococcus aureus were retained on MS60 and MS30 than MS0 (p<0.05). Compared with the corresponding fresh samples, aged samples had identical surface topography and X-ray diffraction pattern. However, hydrocarbon contamination and the thickness of the amorphous TiO2 layer increased with the antibacterial and osteogenic abilities decreased. Moreover, compared with the surfaces with microscale structure, the nano-micro-hierarchical surfaces were more capable to retain hydrophilicity and bioactivity during aging.
Conclusions: The nano-micro-hierarchical titanium surface had greater antibacterial, osteogenic and anti-aging properties. Biological aging of titanium is attributed to two decisive factors during aging period: the progressively thickened amorphous TiO2 layer by autoxidation and the unavoidable accumulation of hydrocarbons on Ti implant surface.
Methods: Titanium discs were sandblasted, etched with the mixture of 98% H2SO4, 36% HCl and H2O (volume ratio of 6:1:5) for 1min (MS0) and secondary etched with the mixture of 98% H2SO4 and 30% H2O2 (volume ratio of 1:1) for 30min (MS30) or 60min (MS60). Samples packed dry under ambient conditions for 30 days were named Aged-MS0, Aged-MS30 and Aged-MS60. Both physicochemical and biological properties were comparatively studied (n=5 for each test item) before and after aging treatment and statistically analyzed (ANOVA, p<0.05).
Results: MS30, MS60 showed nano-micro-hierarchical topography and were superhydrophilic while MS0 showed micro-submicro structures with contact angle over 5°. In vitro cell study showed MS30 had the highest alkaline phosphatase activity (p<0.05), produced the most osteocalcin (p<0.05) and deposited the most calcium (p<0.05), followed by MS0 and MS60. Less escherichia coli and staphylococcus aureus were retained on MS60 and MS30 than MS0 (p<0.05). Compared with the corresponding fresh samples, aged samples had identical surface topography and X-ray diffraction pattern. However, hydrocarbon contamination and the thickness of the amorphous TiO2 layer increased with the antibacterial and osteogenic abilities decreased. Moreover, compared with the surfaces with microscale structure, the nano-micro-hierarchical surfaces were more capable to retain hydrophilicity and bioactivity during aging.
Conclusions: The nano-micro-hierarchical titanium surface had greater antibacterial, osteogenic and anti-aging properties. Biological aging of titanium is attributed to two decisive factors during aging period: the progressively thickened amorphous TiO2 layer by autoxidation and the unavoidable accumulation of hydrocarbons on Ti implant surface.
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