title: Vibrational spectroscopic study of tetracalcium phosphate in pure polycrystalline form and as a constituent of a self-setting bone cement.
abstract: Polycrystalline tetracalcium phosphate (TTCP), a material of considerable interest for human implantation due to its similarity to hydroxyapatite, was studied by means of Raman and FT-IR spectroscopy. The spectra were interpreted on the basis of group theoretical considerations. In addition, the setting reaction of a calcium phosphate cement (CPC) consisting of an equimolar mixture of TTCP and dicalcium phosphate (DCPA) was investigated by Raman spectroscopy. The band of the totally symmetric phosphate mode v1 of TTCP showed marked factor group splittings. The splitting components arose at coincident wave numbers in the IR and Raman spectra. This observation was in accordance with space group P2(1) (factor group C2(2), Z = 4). The characteristic splitting of v1 allowed the setting reaction of CPC to hydroxyapatite to be followed. According to the Raman spectroscopic results, considerable amounts of TTCP must be present at the sample surface after 24 h of setting in an aqueous environment.
authors.affiliation: Lehrstuhl und Abteilung für Experimentelle Zahnmedizin, Klinik und Poliklinik für Zahn-, Mund- und Kieferkrankheiten, Universität Würzburg, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Posset
authors.forename: E
authors.initials: E
authors.lastname: Löcklin
authors.forename: R
authors.initials: R
authors.lastname: Thull
authors.forename: W
authors.initials: W
authors.lastname: Kiefer
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D001843:Bone Cements / Q000138:chemical synthesis / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry* / Q000302:isolation & purification; D003460:Crystallization; D008422:Materials Testing; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: D001672:Biocompatible Materials; D001843:Bone Cements; D002130:Calcium Phosphates; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous