title: Fluoride-containing nanoporous calcium-silicate MTA cements for endodontics and oral surgery: early fluorapatite formation in a phosphate-containing solution.
abstract: OBJECTIVE
  To test the chemical-physical properties and apatite-forming ability of experimental fluoride-doped calcium silicate cements designed to create novel bioactive materials for use in endodontics and oral surgery.
  
  
  METHODS
  A thermally treated calcium silicate cement (wTC) containing CaCl(2) 5%wt was modified by adding NaF 1%wt (FTC) or 10%wt (F10TC). Cements were analysed by environmental scanning electron microscopy with energy-dispersive X-ray analysis, IR and micro-Raman spectroscopy in wet conditions immediately after preparation or after ageing in a phosphate-containing solution (Dulbecco's phosphate-buffered saline). Calcium and fluoride release and pH of the storage solution were measured. The results obtained were analysed statistically (Tukey's HSD test and two-way anova).
  
  
  RESULTS
  The formation of calcium phosphate precipitates (spherulites) was observed on the surface of 24 h-aged cements and the formation of a thick bone-like B-type carbonated apatite layer (biocoating) on 28 day-aged cements. The rate of apatite formation was FTC>F10TC>wTC. Fluorapatite was detected on FTC and F10TC after 1 day of ageing, with a higher fluoride content on F10TC. All the cements released calcium ions. At 5 and 24 h, the wTC had the significantly highest calcium release (P<0.001) that decreased significantly over the storage time. At 3-28 days, FTC and F10TC had significantly higher calcium release than wTC (P<0.05). The F10TC had the significantly highest fluoride release at all times (P<0.01) that decreased significantly over storage time. No significant differences were observed between FTC and wTC. All the cements had a strong alkalinizing activity (OH(-) release) that remained after 28 days of storage.
  
  
  CONCLUSIONS
  The addition of sodium fluoride accelerated apatite formation on calcium silicate cements. Fluoride-doped calcium silicate cements had higher bioactivity and earlier formation of fluorapatite. Sodium fluoride may be introduced in the formulation of mineral trioxide aggregate cements to enhance their biological behaviour. F-doped calcium silicate cements are promising bone cements for clinical endodontic use.
authors: Laboratory of Biomaterials and Oral Pathology, Department of Odontostomatological Science, University of Bologna, Bologna, Italy. mgiovanna.gandolfi@unibo.it
authors: M G
authors: MG
authors: Gandolfi
authors: P
authors: P
authors: Taddei
authors: F
authors: F
authors: Siboni
authors: E
authors: E
authors: Modena
authors: M P
authors: MP
authors: Ginebra
authors: C
authors: C
authors: Prati
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D001031:Apatites / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D001843:Bone Cements / Q000737:chemistry*; D002021:Buffers; D002118:Calcium / Q000737:chemistry; D017610:Calcium Compounds / Q000737:chemistry*; D002124:Calcium Fluoride / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D055598:Chemical Phenomena; D011232:Chemical Precipitation; D004338:Drug Combinations; D005459:Fluorides / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D015591:Microspectrophotometry; D049329:Nanostructures / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012823:Silicate Cement / Q000737:chemistry; D017640:Silicates / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry; D012969:Sodium Fluoride / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013997:Time Factors
chemical_list: D017607:Aluminum Compounds; D001031:Apatites; D001672:Biocompatible Materials; D001843:Bone Cements; D002021:Buffers; D017610:Calcium Compounds; D002130:Calcium Phosphates; D004338:Drug Combinations; D010087:Oxides; D010710:Phosphates; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D012823:Silicate Cement; D012965:Sodium Chloride; C030782:carboapatite; D012969:Sodium Fluoride; C025105:fluorapatite; D002124:Calcium Fluoride; D005459:Fluorides; C031293:calcium silicate; D002118:Calcium