title: Apatite formation on bioactive calcium-silicate cements for dentistry affects surface topography and human marrow stromal cells proliferation.
abstract: The effect of ageing in phosphate-containing solution of bioactive calcium-silicate cements on the chemistry, morphology and topography of the surface, as well as on in vitro human marrow stromal cells viability and proliferation was investigated. A calcium-silicate cement (wTC) mainly based on dicalcium-silicate and tricalcium-silicate was prepared. Alpha-TCP was added to wTC to obtain wTC-TCP. Bismuth oxide was inserted in wTC to prepare a radiopaque cement (wTC-Bi). A commercial calcium-silicate cement (ProRoot MTA) was tested as control. Cement disks were aged in DPBS for 5 h ('fresh samples'), 14 and 28 days, and analyzed by ESEM/EDX, SEM/EDX, ATR-FTIR, micro-Raman techniques and scanning white-light interferometry. Proliferation, LDH release, ALP activity and collagen production of human marrow stromal cells (MSC) seeded for 1-28 days on the cements were evaluated. Fresh samples exposed a surface mainly composed of calcium-silicate hydrates CSH (from the hydration of belite and alite), calcium hydroxide, calcium carbonate, and ettringite. Apatite nano-spherulites rapidly precipitated on cement surfaces within 5 h. On wTC-TCP the Ca-P deposits appeared thicker than on the other cements. Aged cements showed an irregular porous calcium-phosphate (Ca-P) coating, formed by aggregated apatite spherulites with interspersed calcite crystals. All the experimental cements exerted no acute toxicity in the cell assay system and allowed cell growth. Using biochemical results, the scores were: fresh cements>aged cements for cell proliferation and ALP activity (except for wTC-Bi), whereas fresh cements<aged cements for collagen synthesis. Summarizing (1) non-aged cements showed higher cell proliferation than aged cements, probably favoured by the presence of Si-OH gel and the early formation of apatite nano-spherulites; (2) the alpha-TCP doped cement aged for 28 days displayed the highest bioactivity and cell proliferation; (3) the deleterious effect of bismuth on cell proliferation was reduced by the progressive increase of the biocoating thickness on aged cement. In conclusion, the experimental cements have adequate biological properties to be used as root-end/root repair filling materials or pulp capping materials. The alfa-TCP doped cement represents a new potential bioactive material for expanded applications in dentistry.
authors.affiliation: Laboratory of Biomaterials and Oral Pathology, Dept. of Odontostomatological Sciences, University of Bologna, Via S. Vitale 59, Bologna, Italy. mgiovanna.gandolfi@unibo.it
authors.forename: Maria Giovanna
authors.initials: MG
authors.lastname: Gandolfi
authors.forename: Gabriela
authors.initials: G
authors.lastname: Ciapetti
authors.forename: Paola
authors.initials: P
authors.lastname: Taddei
authors.forename: Francesca
authors.initials: F
authors.lastname: Perut
authors.forename: Anna
authors.initials: A
authors.lastname: Tinti
authors.forename: Marcio Vivan
authors.initials: MV
authors.lastname: Cardoso
authors.forename: Bart
authors.initials: B
authors.lastname: Van Meerbeek
authors.forename: Carlo
authors.initials: C
authors.lastname: Prati
mesh_terms: D001031:Apatites / Q000138:chemical synthesis / Q000494:pharmacology*; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology; D001729:Bismuth / Q000494:pharmacology; D001854:Bone Marrow Cells / Q000187:drug effects*; D017610:Calcium Compounds / Q000737:chemistry* / Q000494:pharmacology; D002130:Calcium Phosphates / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis; D003287:Contrast Media / Q000494:pharmacology; D004356:Drug Storage; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007368:Interferometry; D008422:Materials Testing; D054118:Nanospheres; D056951:Photoelectron Spectroscopy; D012823:Silicate Cement / Q000737:chemistry* / Q000494:pharmacology; D017640:Silicates / Q000737:chemistry* / Q000494:pharmacology; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D017154:Stromal Cells / Q000187:drug effects; D013499:Surface Properties / Q000187:drug effects
chemical_list: D001031:Apatites; D001672:Biocompatible Materials; D017610:Calcium Compounds; D002130:Calcium Phosphates; D003287:Contrast Media; D017640:Silicates; D012823:Silicate Cement; D003094:Collagen; C033301:bismuth oxide; C018392:tricalcium phosphate; C031293:calcium silicate; D001729:Bismuth