Relative contributions of implant hydrophilicity and nanotopography to implant anchorage in bone at Early Time Points.

OBJECTIVE: To compare the contributions of implant hydrophilicity and nanotopography on anchorage in bone. The effect of elevated calcium surface chemistry on bone anchorage was also investigated. MATERIALS AND METHODS: A full factorial study design was implemented to evaluate the effects of ultraviolet (UV) light and/or sodium lactate (SL) and discrete crystalline deposition of nanocrystals (DCD) treatments on the osseointegration of dual acid-etched (AE) titanium alloy (Ti6Al4V) and grit blasted and AE (BAE) commercially pure titanium (CpTi) implants. Sodium hydroxide (NaOH)-treated CpTi implants were immersed in simulated body fluid (SBF) to increase calcium surface chemistry. Implants were placed in the femora of Wistar rats and tested using pull-out testing (BAE implants: 5, 9, 14 days) or tensile testing (AE implants: 9 days, NaOH implants: 28 days). RESULTS: Ti6Al4V-AE implants with DCD- and UV-treated surfaces significantly increased bone anchorage compared with untreated Ti6Al4V-AE alloy implants. Pull-out testing of BAE-CpTi implants with the DCD treatment showed increased disruption force values compared with surfaces without the DCD treatment at 5, 9 and 14 days by 4.1N, 13.9N and 15.5N, respectively, and UV-treated implants showed an increase at 14 days by 8.4N. No difference was found between NaOH + SBF and NaOH + H2 O groups. CONCLUSIONS: Bone anchorage of implants was found to be improved by UV-treating implants or nanotopographically complex surfaces. However, implant nanotopography was found to have a greater contribution to the overall bone anchorage and is more consistent compared with the time-dependent nature of the UV treatment.