Failure in the adhesion of hydroxyapatite coatings to surgical screws: A Fourier Transform Infrared Spectroscopy (FTIR) qualitative study

Mariana Pereyra ^* Marco Navatta Eduardo Méndez

• Faculty of Sciences, University of the Republic, Montevideo, Uruguay

Failure in the adhesion between hydroxyapatite and the metallic substrate in commercial biomaterials is one of the significant drawbacks in implantology. The demand for , and confident analytical methods are in demand to characterize these coatings is met through a rigorous research process. We have chosen Ffourier-transform infrared spectroscopy (FTIR) is the chosen as the method to characterize hydroxyapatites after a carefulfollowing a meticulous data analysis from FTIR spectra. To fully characterize hydroxyapatite materials, we constructed a FTIR library was constructed from FTIR spectra of different types of hydroxyapatites, to consider considering several chemical environments. The analytical procedure consisted of involved the registry of the spectra, localization of the leading absorption bands from the minima of the second derivative spectra, and reconstitution of the original spectra by curve deconvolution. Such a library was employed to analyze commercial surgical screws that failed in their use in different implants. Our methodology identified the structural reasons for such failure, caused by the selective removal of non-apatitic environments during adsorption onto the metallic implant. This method identifies the adhesion degree of the apatite coating on the implant before implantation in a biological organism, thereby preventing additional patient interventions and the associated costs.