Photofunctionalization of Titanium: An Alternative Explanation of Its Chemical-Physical Mechanism.
OBJECTIVE
To demonstrate that titanium implant surfaces as little as 4 weeks from production are contaminated by atmospheric hydrocarbons. This phenomenon, also known as biological ageing can be reversed by UVC irradiation technically known as photofunctionalization. To propose a new model from our experimental evidence to explain how the changes in chemical structure of the surface will affect the adsorption of amino acids on the titanium surface enhancing osteointegration.


METHODS
In our study XPS and AES were used to analyze the effects of UVC irradiation (photofunctionalization) in reversing biological ageing of titanium. SEM was used to analyze any possible effects on the topography of the surface.


RESULTS
UVC irradiation was able to reverse biological ageing of titanium by greatly reducing the amount of carbon contamination present on the implant surface by up to 4 times, while the topography of the surface was not affected. UVC photon energy reduces surface H2O and increases TiOH with many -OH groups being produced. These groups explain the super-hydrophilic effect from photofunctionalization when these groups come into contact with water.


CONCLUSIONS
Photofunctionalization has proven to be a valid method to reduce the amount of hydrocarbon contamination on titanium dental implants and improve biological results. The chemisorption mechanisms of amino acids, in our study, are dictated by the chemical structure and electric state present on the surface, but only in the presence of an also favourable geometrical composition at the atomical level.
Prosthodontic Department, Poznan University of Medical Science, Poznan, Poland.
Marco
http://orcid.org/0000-0002-1842-0551
M
Roy
Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa Medical School, Pisa, Italy.
Alfonso
A
Pompella
A. Chelkowski Institute of Physics, University of Silesia, Katowice, Poland.|Silesian Center for Education and Interdisciplinary Research, Chorzów, Poland.
Jerzy
J
Kubacki
A. Chelkowski Institute of Physics, University of Silesia, Katowice, Poland.|Silesian Center for Education and Interdisciplinary Research, Chorzów, Poland.
Jacek
J
Szade
Private Practice, Pisa, Italy.
Robert A
RA
Roy
Prosthodontic Department, Poznan University of Medical Science, Poznan, Poland.
Wieslaw
W
Hedzelek
D000327:Adsorption; D015921:Dental Implants; D006838:Hydrocarbons / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008855:Microscopy, Electron, Scanning; D055668:Photochemical Processes; D056951:Photoelectron Spectroscopy; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry / Q000528:radiation effects*; D014466:Ultraviolet Rays
D015921:Dental Implants; D006838:Hydrocarbons; C009495:titanium dioxide; D014025:Titanium