Comparison of two dental implant surface modifications on implants with same macrodesign: an experimental study in the pelvic sheep model

Objectives The aim of this study was to compare two different surfaces of one uniform macro‐implant design in order to focus exclusively on the osseointegration properties after 2, 4 and 8 weeks and to discuss the animal model chosen. Material and methods In six mature sheep, n = 36 implants with a highly crystalline and phosphate‐enriched anodized titanium oxide surface (TiU) and n = 36 implants with a hydrophilic, sandblasted, large grit and acid‐etched surface (SLA) were placed in the pelvic bone. TiU implants were custom‐made to match the SLA implant design. The implant stability and bone‐to‐implant contact (BIC) were assessed by resonance frequency (ISQ), backscatter scanning electron microscopy (B‐SEM), light microscopy (LM), micro‐CT and intravital fluorochrome staining. Biomechanical removal torque testing was performed. Results Overall, no statistically significant differences in BIC total (trabecular + cortical) between TiU and SLA were found via LM and B‐SEM. BIC values (B‐SEM; LM) in both groups revealed a steady rise in trabecular bone attachment to the implant surface after 2, 4 and 8 weeks. In the 2‐ to 4‐week time interval in the TiU group (P = 0.005) as well as in the SLA group (P = 0.01), a statistically significant increase in BIC trabecular could be observed via LM. B‐SEM values confirmed the statistically significant increase for TiU (P = 0.001). In both groups, BIC trabecular values after 8 weeks were significantly higher (P ≤ 0.05) than after 2 weeks (B‐SEM; LM). Biomechanical data confirmed the histological data. Conclusion The two surfaces proved comparable osseointegration in this sheep model.