The surface analysis of implant materials. 1. The surface composition of a titanium dental implant material

The surfaces of titanium (Ti) plates, as models for Ti implants, have been characterized by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (TOF SIMS). Plates were prepared with rough and smooth surface topographies--the rough being similar to that of an implant. The XPS data has been used to construct a model of the plates' surface chemical structure, from the gas-solid interface through to pure Ti metal. At the surface of as-received plates, which underwent the same preparative procedure as an implant, considerable surface contamination was detected. In particular, high levels of carbon (C) contaminants were detected; the nature of this C was elucidated by fitting the C 1s core line and from the secondary ion mass spectra. The oxygen (O) 1s core line could not be fitted using a minimum of 2 gaussian peaks, demonstrating the multiplicity of O environments. The detection of other elements in the XPS analysis further demonstrated that, in nominally pure Ti plates, the surface chemical composition deviates considerably from that of the bulk. The data obtained from the plates were confirmed by examination of a Ti abutment. The handling of Ti plates with stainless steel tweezers was investigated. No obvious change in surface chemistry was detected. All the above results bring into serious questions the validity of rigorous protocols demanded, in some techniques, in the handling and use of Ti implants.