title: Calcium silicate and calcium hydroxide materials for pulp capping: biointeractivity, porosity, solubility and bioactivity of current formulations.
abstract: OBJECTIVE
  The chemical-physical properties of novel and long-standing calcium silicate cements versus conventional pulp capping calcium hydroxide biomaterials were compared.
  
  
  METHODS
  Calcium hydroxide-based (Calxyl, Dycal, Life, Lime-Lite) and calcium silicate-based (ProRoot MTA, MTA Angelus, MTA Plus, Biodentine, Tech Biosealer capping, TheraCal) biomaterials were examined. Calcium and hydroxyl ion release, water sorption, interconnected open pores, apparent porosity, solubility and apatite-forming ability in simulated body fluid were evaluated.
  
  
  RESULTS
  All calcium silicate materials released more calcium. Tech Biosealer capping, MTA Plus gel and Biodentine showed the highest values of calcium release, while Lime-Lite the lowest. All the materials showed alkalizing activity except for Life and Lime-Lite. Calcium silicate materials showed high porosity values: Tech Biosealer capping, MTA Plus gel and MTA Angelus showed the highest values of porosity, water sorption and solubility, while TheraCal the lowest. The solubility of water-containing materials was higher and correlated with the liquid-to-powder ratio. Calcium phosphate (CaP) deposits were noted on materials surfaces after short aging times. Scant deposits were detected on Lime-Lite. A CaP coating composed of spherulites was detected on all calcium silicate materials and Dycal after 28 days. The thickness, continuity and Ca/P ratio differed markedly among the materials. MTA Plus showed the thickest coating, ProRoot MTA showed large spherulitic deposits, while TheraCal presented very small dense spherulites.
  
  
  CONCLUSIONS
  calcium silicate-based cements are biointeractive (ion-releasing) bioactive (apatite-forming) functional biomaterials. The high rate of calcium release and the fast formation of apatite may well explain the role of calcium silicate biomaterials as scaffold to induce new dentin bridge formation and clinical healing.
authors.affiliation: 1 Unit of Odontostomatological Sciences, Laboratory of Biomaterials and Oral Pathology, Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna - Italy.
authors.forename: Maria Giovanna
authors.initials: MG
authors.lastname: Gandolfi
authors.forename: Francesco
authors.initials: F
authors.lastname: Siboni
authors.forename: Tatiana
authors.initials: T
authors.lastname: Botero
authors.forename: Maurizio
authors.initials: M
authors.lastname: Bossù
authors.forename: Francesco
authors.initials: F
authors.lastname: Riccitiello
authors.forename: Carlo
authors.initials: C
authors.lastname: Prati
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D002126:Calcium Hydroxide / Q000737:chemistry*; D003738:Dental Cements / Q000737:chemistry*; D016062:Porosity; D057872:Pulp Capping and Pulpectomy Agents / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D012995:Solubility
chemical_list: D001672:Biocompatible Materials; D017610:Calcium Compounds; D003738:Dental Cements; D057872:Pulp Capping and Pulpectomy Agents; D017640:Silicates; D002126:Calcium Hydroxide; C031293:calcium silicate