Physical characterization of 3 implant systems made of distinct materials with distinct surfaces

Dental implants undergo various surface treatments. Studies that have characterized their surface and subsurface by using the same methods are scarce.

The purpose of this study is to physically characterize the surface and subsurface of implant systems made of commercially pure (cp) titanium (Ti) grade (gr) 4 and Ti alloy gr 23 and to evaluate whether airborne-particle abrasion and acid etching is an appropriate surface treatment for Ti alloy gr 23.

Implant groups (n=3) were as follows: TG4AO, cp Ti gr 4, treated with anodic oxidation (3.5×8 mm) (NobelReplace Conical; Nobel Biocare); TG23AE, Ti gr 23 (TiAlV ELI) airborne-particle abraded-and-etched (3.9×8 mm) (V3; MIS); and TG4AE, cp Ti gr 4, airborne-particle abraded and etched (3.3×8 mm) (BL; Institut Straumann AG). Surface roughness, surface topography, and elemental and surface composition were investigated with optical profilometry, scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The presence and size of Ti hydride (TiH) needles were determined on metallographic sections. Depth profiling was obtained by time-of-flight secondary ion mass spectrometry (ToF-SIMS) to determine possible enrichment of an alloying element at the implant surface.

The mean arithmetic deviation roughness (S_a), of TG4AO was 0.80 μm. The S_a of TG4AO was 1.22 μm, and the S_a of TG4AO was 1.59 μm. The difference between the groups was significant (P<.001). TG23AE and TG4AE displayed a macrotexture and microtexture with pores; TG4AO showed a 3-to 12-μm canyon-like structure. The surface and subsurface compositions were as follows: for TG4AO, αTi and phosphorus-rich anatase; for TG23AE, α-Ti matrix with β-Ti grains; and for TG4AE, α-Ti and δ-TiH_2-x. TiH needles were found only on TG4AE; the Ti oxide layer of TG4AO was rough, 3-to 16-μm thick, and porous. The time-of-flight secondary ion mass spectrometry (ToF SIMS) concentration profile of TG23AE did not show enrichment of any alloying element.

The roughness, topography, and composition of the surfaces were different for all implants tested. Airborne-particle abrasion and subsequent etching was an appropriate treatment for Ti gr 23 alloy implants.