title: Phase transformations, microstructure formation and in vitro osteoblast response in calcium silicate/brushite cement composites.
abstract: Self-setting simple calcium silicate/brushite (B) biocements with various Ca/P ratios were prepared by mutual mixing of both monocalcium silicate hydrate (CSH) or β-wollastonite (woll) powders with B and the addition of 2 wt% NaH2PO4 solution as a hardening liquid. The phase composition of the final composites and the texture of the surface calcium phosphate/silica layer were controlled by the starting Ca/P ratio in composites and the pH during setting. It was verified that the presence of continuous bone-like calcium phosphate coating on the surface of the samples was not essential for in vitro osteoblast proliferation. The nanocrystalline calcium deficient hydroxyapatite and amorphous silica were found as the main setting products in composite mixtures with a Ca/P ratio close to the region of the formation of deficient hydroxyapatite-like calcium phosphates. No CSH phase with a lower Ca/Si ratio was identified after transformation. The results confirmed a small effect of the monocalcium silicate addition on the compressive strength (CS) of cements up to 30 wt% (around 20-25 MPa) and a significant rise of the value in 50 woll/B cement (65 MPa). The final setting times of the cement composites varied between 5 and 43 min depending on the P/L ratio and the type of monocalcium silicate phase in the cement mixture. 10CSH/B and 50 woll/B cements with different textures but free of both the needle-like and perpendicularly-oriented hydroxyapatite particles on the surface of the samples had low cytotoxicity.
authors: Institute of Materials Research of SAS, Watsonova 47, Kosice 04001, Slovak Republic. Faculty of Metallurgy, Technical University of Kosice, Letna 9, 042 00 Kosice, Slovak Republic.
authors: T
authors: T
authors: Sopcak
authors: L
authors: L
authors: Medvecky
authors: M
authors: M
authors: Giretova
authors: A
authors: A
authors: Kovalcikova
authors: R
authors: R
authors: Stulajterova
authors: J
authors: J
authors: Durisin
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001843:Bone Cements / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D002130:Calcium Phosphates / Q000737:chemistry*; D049109:Cell Proliferation; D019245:Compressive Strength; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D051379:Mice; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects; D016062:Porosity; D011208:Powders; D017640:Silicates / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014961:X-Ray Diffraction
chemical_list: D001843:Bone Cements; D017610:Calcium Compounds; D002130:Calcium Phosphates; D011208:Powders; D017640:Silicates; C020243:calcium phosphate; C018392:tricalcium phosphate; C494366:calcium phosphate, dibasic, dihydrate; C031293:calcium silicate