title: Synthesis of bioactive and machinable miserite glass-ceramics for dental implant applications.
abstract: OBJECTIVE
  To synthesize and characterize machinable, bioactive glass-ceramics (GCs) suitable for dental implant applications.
  
  
  METHODS
  A glass in the SiO2-Al2O3-CaO-CaF2-K2O-B2O3-La2O3 system was synthesized by wet chemical methods, followed by calcination, melting and quenching. Crystallization kinetics were determined by differential thermal analysis (DTA). GC discs were produced by cold pressing of the glass powder and sintered using schedules determined by DTA. The crystalline phases and microstructure of GC samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Dynamic Young's modulus (E), true hardness (Ho), fracture toughness (KIC) and brittleness index (BI) were evaluated. Bioactivity was studied by examining the formation of hydroxyapatite (HA) on the GC surfaces after soaking in simulated body fluid (SBF). Attachment and proliferation of MC3T3-E1 osteoblastic cells were assessed in vitro.
  
  
  RESULTS
  Miserite [KCa5(Si2O7)(Si6O15)(OH)F] was the main crystalline phase of the GC with additional secondary phases. Microstructural studies revealed interlocking lath-like crystalline morphology. E, Ho, and KIC values for the GCs were 96±3 GPa, 5.27±0.26 GPa and 4.77±0.27 MPa m(0.5), respectively. The BI was found to be 1.11±0.05 μm(-0.5), indicating outstanding machinability. An HA surface layer was formed on the GC surfaces when soaked in SBF, indicating potential bioactivity. MC3T3-E1 cells exhibited attachment, spreading and proliferation on GC surfaces, demonstrating excellent biocompatibility.
  
  
  CONCLUSIONS
  We present a novel approach for the synthesis of miserite GC with the physical and biological properties required for non-metallic dental implant applications.
authors.affiliation: Department of Medical Biophysics, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada.
authors.forename: Selma A
authors.initials: SA
authors.lastname: Saadaldin
authors.forename: S Jeffrey
authors.initials: SJ
authors.lastname: Dixon
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Costa
authors.forename: Amin S
authors.initials: AS
authors.lastname: Rizkalla
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D002448:Cell Adhesion; D049109:Cell Proliferation; D002516:Ceramics / Q000138:chemical synthesis* / Q000737:chemistry; D055598:Chemical Phenomena; D017076:Computer-Aided Design; D003460:Crystallization; D015921:Dental Implants; D003764:Dental Materials / Q000138:chemical synthesis* / Q000737:chemistry; D004055:Differential Thermal Analysis; D017886:Durapatite / Q000737:chemistry; D055119:Elastic Modulus; D005898:Glass / Q000737:chemistry; D006244:Hardness; D006358:Hot Temperature; D051379:Mice; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000502:physiology; D044367:Phase Transition; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; D015921:Dental Implants; D003764:Dental Materials; C588156:KCa5(Si2O7)(Si6O15)(OH)F; C023506:Glass ceramics; D017886:Durapatite; C020243:calcium phosphate; D014025:Titanium