Three-dimensional and chemical changes on the surface of a 3-year clinically retrieved oxidized titanium dental implant.

OBJECTIVE: To report the main topographical features in the micro- and nano-scales and to assess implant chemical changes of the surface of a 3-year clinically retrieved oxidized titanium dental implant, and compare them with a similar, unused implant. MATERIALS AND METHODS: The surface of the oxidized titanium dental implants was assessed by surface electron microscopy (SEM) analysis at increasing magnifications. X-ray photoelectron spectroscopy (XPS) measurement was performed to analyze the implants surface chemistry. XPS spectra were acquired before and after sputtering with an Ar(+) ion etching of 3keV. RESULTS: With a length of 10-40µm, and a width of 0.05-0.1µm, numerous cracks were ubiquitous along the implant surfaces. Chimney-like structures formed micropores between 1 and 5µm, with up to 40% of them partially or totally broken in the retrieved implant. In relation to chemical composition, Ti and O were predominant in both the unused and in the retrieved implant. N was present in high concentrations (11.49at%) at the retrieved implant surface, in contrast with those observed for the unused implant (1.14at%). Also, C was present in higher concentrations in the retrieved implant surface, while drastically decreased following the sputter-cleaning process. CONCLUSION: While cracks were ubiquitous present from the manufacturing, broken chimney-like structures forming micropores in the clinically retrieved implant may be attributable to excessive mechanical friction forces during the insertion of the implant. Chemical composition of the implant surface may be subjected to changes because of the in vivo environment, with increase of N and C, and decrease of Ca and P.