La Spettrometria ToF-SIMS nell'analisi chimica di impianti dentari.

Surface analysis of dental implants is an interesting field of investigation in order to explain part of the biologic interactions that happen in the early phases of osseointegration. Objectives. The aim of the present study was to compare the physicalchemical features of titanium dental implants, made with different surface treatments, by ToF-SIMS (time-of-flight secondary ion mass spectrometry). The ToF-SIMS is a analytic surface-sensitive technique that probes only the outermost atomic or molecular layers of theimplant surface, believed to be decisive to early biological events of peri-implant healing, such as the absorption of ions and serum proteins. The ToF-SIMS spectrometry allows not only to analyze primary and secondary components of a surface, but also to find organic and inorganic residual, considered contaminants. Methods. Four different typologies of implant surfaces (SLA, SLActive, TiOblast e Osseospeed) were analyzed. A customized tray was realized, to insert the implants in the vacuum chamber. Six areas of each implant were tested (three in coronal and three in apical portion) positive and negative ionic spectra were identified. Results. All surfaces showed the presence of unexpected ions such as iron, aluminium and silicon dioxide. SLA and SLActive surfaces, even though they have the same topographic feature, showed some chemical differences. In fact, the first was associated to a higher emission of vanadium, while the second demonstrated a relative higher emission of Titanium oxide, significant of increased hydrophilic properties. TiOblast surface, notwithstanding the similarity with Osseospeed, showed a higher emission of iron, aluminium, silicon dioxide, hydrocarbons and an unexpected presence of fluoride. Conclusion. The elements and chemical compounds found on the analyzed surfaces were not related with the chemical composition of the metal, rather, they are due to fabrication, lubrication and storage of the fixture. ToF-SIMS analysis seems to be a valid method to study the physical-chemical properties of implant surfaces.