Evaluation of a setting reaction pathway in the novel composite TiHA–CSD bone cement by FT-Raman and FT-IR spectroscopy

The aim of this study was to determine a setting reaction pathway in a novel, surgically handy implant material, based on calcium sulfate hemihydrate (CSH) and titanium doped hydroxyapatite (TiHA). The previous studies confirmed superior biological properties of TiHA in comparison to the undoped hydroxyapatite (HA) what makes it highly attractive for future medical applications. In this study the three types of titanium modified HA powders: untreated, calcined at 800 °C, sintered at 1250 °C and CSH were used to produce bone cements. The Fourier Transform-InfraRed (FT-IR) spectroscopy and Raman spectroscopy were applied to evaluate processes taking place during the setting of the studied materials. Our results undoubtedly confirmed that the reaction pathways and the phase compositions differed significantly for set cements and were dependent on the initial heat treatment of TiHA powder. Final materials were multiphase composites consisting of calcium sulfate dihydrate, bassanite, tricalcium phosphate, hydroxyapatite and calcium titanate (perovskite). The FT-IR and Scanning Electron Microscopy (SEM) measurements performed after the incubation of the cement samples in the simulated body fluid (SBF), indicate on high bioactive potential of the obtained bone cements.

► FT-Raman and FT-IR are feasible techniques for analyzing the pathway of cement setting process.
► The close relationship between heat treatment of TiHA, composition and microstructure of final materials was stated.
► Calcium sulfate was the main setting phase in cements composed with untreated or calcined at 800 °C TiHA.
► α-TCP was the main setting phase in the case of cement consisted of TiHA sintered at 1250 °C.
► The ATR–FTIR and SEM indicated on high bioactive potential of the obtained bone cements.