Comparative Analysis of Osseointegration Using Titanium Implants Coated with Graphene and Niobium: An Animal Model...

Surface modification may influence tissue-implant interactions. This exploratory study compared the biomechanical, coating-integrity, and histological responses associated with uncoated titanium and carbon- or niobium-containing surface-processing conditions in a rabbit model.

Twelve adult male New Zealand White rabbits were initially enrolled and allocated to 30- and 60-day healing periods. Two animals were lost before endpoint and were not replaced; ten rabbits completed the study and were analyzed, with five animals at each period. Each rabbit received four implant-site conditions: uncoated titanium, carbon-based diamond-like carbon (Graphene-DLC), niobium deposited by chemical vapor deposition (Nb-CVD), and niobium deposited by sol-gel processing (Nb-Gel). Implant stability was assessed using reverse-torque testing after formalin fixation. Histological evaluation included hematoxylin and eosin and Picrosirius Red staining.

At 60 days, the uncoated titanium and Graphene-DLC conditions showed the highest reported mean reverse-torque values, whereas some niobium-containing conditions showed lower reported coating-integrity scores. Ordinal histological outcomes were interpreted descriptively because the sample was small, implant sites were clustered within rabbits, and implant condition was fixed to anatomical site.

Under this protocol, the observed differences describe combined implant-site conditions and do not provide unbiased causal evidence of coating-specific effects. The findings are exploratory and support further studies using randomized or counterbalanced allocation, clustered analysis, and independent biomechanical and histological specimens.