title: The roles of different scale ranges of surface implant topography on the stability of the bone/implant interface.
abstract: We sought to deconvolute the effects of sub-micron topography and microtopography on the phenomena of bone bonding and interfacial stability of endosseous implants. To address this experimentally, we implanted custom-made titanium alloy implants of varying surface topographical complexity in rat femora, for 6, 9 or 12 days. The five surfaces were polished, machined, dual acid etched, and two forms of grit blasted and acid etched; each surface type was further modified with the deposition of nanocrystals of calcium phosphate to make a total of 10 materials groups (n = 10 for each time point; total 300 implants). At sacrifice, we subjected the bone-implant interface to a mechanical disruption test. We found that even the smoothest surfaces, when modified with sub-micron scale crystals, could be bone-bonding. However, as locomotor loading through bone to the implant increased with time of healing, such interfaces failed while others, with sub-micron features superimposed on surfaces of increasing microtopographical complexity remained intact under loading. We demonstrate here that higher order, micron or coarse-micron, topography is a requirement for longer-term interfacial stability. We show that each of these topographical scale-ranges represents a scale-range seen in natural bone tissue. Thus, what emerges from an analysis of our findings is a new means by which biologically-relevant criteria can be employed to assess the importance of implant surface topography at different scale-ranges.
authors: Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario, Canada. davies@ecf.utoronto.ca
authors: John E
authors: JE
authors: Davies
authors: Elnaz
authors: E
authors: Ajami
authors: Rahim
authors: R
authors: Moineddin
authors: Vanessa C
authors: VC
authors: Mendes
mesh_terms: D000497:Alloys; D000818:Animals; D005269:Femur; D008297:Male; D016348:Osseointegration; D019736:Prostheses and Implants; D051381:Rats; D017208:Rats, Wistar; D013314:Stress, Mechanical; D014025:Titanium
chemical_list: D000497:Alloys; D014025:Titanium