title: Degradation properties and ion release characteristics of Resilon and phosphate glass/polycaprolactone composites.
abstract: OBJECTIVE
  To (i) characterise the degradation pattern and ion release characteristics of bioactive glass/polycaprolactone (PCL) composites; (ii) compare the degradation behaviour of composites containing phosphate glass to that of Resilon; and (iii) determine the potential to control the degradation of the composites by modifying the iron content of phosphate glasses.
  
  
  METHODS
  The degradation behaviour of the phosphate glass/PCL samples (n = 3) and that of Resilon were determined in two aqueous solutions (buffered distilled water, Hanks Buffered Saline Solution) over a 7-day period using weight change measurement, ion chromatography, light microscopy (LM) and scanning electron microscopy (SEM).
  
  
  RESULTS
  An initial increase in weight of the samples was followed by loss. All phosphate glass/PCL composites released various amounts of iron, sodium, calcium and phosphate ions into solution. The Resilon samples released only sodium and calcium ions. The visual methods (LM, SEM) showed distinct precipitate (calcium phosphate) formation on the surface of the phosphate glass/PCL composites but only a faint surface residue on the surface of Resilon.
  
  
  CONCLUSIONS
  The degradation pattern of the composites containing phosphate glass was different from that of Resilon. The phosphate glass/PCL composites encouraged precipitate formation on the material surface, which may be advantageous in creating a marginal and apical seal.
authors.affiliation: Division of Restorative Dental Sciences, Unit of Endodontology, UCL Eastman Dental Institute, University College London, London, UK.
authors.forename: P
authors.initials: P
authors.lastname: Borbely
authors.forename: K
authors.initials: K
authors.lastname: Gulabivala
authors.forename: J C
authors.initials: JC
authors.lastname: Knowles
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002021:Buffers; D002118:Calcium / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D002852:Chromatography, Ion Exchange; D005898:Glass / Q000737:chemistry*; D006801:Humans; D007501:Iron / Q000737:chemistry; D007552:Isotonic Solutions / Q000737:chemistry; D008422:Materials Testing; D008853:Microscopy; D008855:Microscopy, Electron, Scanning; D010710:Phosphates / Q000737:chemistry; D011091:Polyesters / Q000737:chemistry*; D012387:Root Canal Filling Materials / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D002021:Buffers; D002130:Calcium Phosphates; C072670:Hanks Balanced Salt Solution; D007552:Isotonic Solutions; D010710:Phosphates; D011091:Polyesters; D012387:Root Canal Filling Materials; C486892:resilon sealer; D014867:Water; C016240:polycaprolactone; C020243:calcium phosphate; D012964:Sodium; D007501:Iron; D002118:Calcium