Chemical interaction between titanium implant surface and amino acids.

The purpose of this study was to investigate the chemical interaction between titanium implant surface and amino acids. Pure titanium disks were pretreated with 10 N HCl and ultrapure water at room temperature for 30 minutes each. Disks were then modified with one of the three amino acids--L-aspartic acid, L-serine, or L-threonine--at 37 degrees C for 12 hours. Modification with oxalic acid was used as a control. By means of X-ray photoelectron spectroscopy (XPS), amino acid powders and the modified surfaces without or with ultrasonic water rinsing were chemically analyzed. It was revealed that the N 1s peak which originated from amino acids was not or hardly detected in the wide scan spectra of amino acid-modified surfaces. Moreover, the COO- peak which originated from oxalic acid could hardly be detected in the narrow scan spectrum of the C is region of oxalic acid-modified surface with ultrasonic water rinsing. Based on the results of this study, it was concluded that amino acids could not chemically bond to the titanium surface.