Comparative study of osteoconduction on micromachined and alkali-treated titanium alloy surfaces in vitro and in vivo.

This study sought to evaluate osteoconduction of Ti-6Al-4V surfaces under various conditions, including micro-patterned, alkali-treated, micro-patterned plus alkali-treated, and surfaces without any treatment as the control. The through-mask electrochemical micromachining (EMM) was used to fabricate micro-hole arrays on the titanium alloy surface. In vitro calcium phosphate formation on titanium surfaces was in static and dynamic simulated body fluid (SBF). In vivo comparison was conducted in the medullary cavity of dog femur using the implant cages which could provide the same physiological environment for specimens with different surface conditions. In vitro experiments indicate good conduction of calcium phosphate on the alkali-treated surfaces, and also better calcium phosphate deposition on the micro-hole surface than on the flat surfaces in dynamic SBF. In vivo experiments confirm the beneficial effect of alkaline treatment on osteoconduction. The results of in vivo experiments also indicate a synergistic effect of the alkaline treatment and the topographic pattern on osteoconduction.