title: Push-Out Bond Strength and Surface Microhardness of Calcium Silicate-Based Biomaterials: An in vitro Study.
abstract: OBJECTIVE
  This was an in vitro evaluation of push-out bond strength and surface microhardness of calcium silicate-based biomaterials in coronal and apical root dentin.
  
  
  METHODS
  Ninety sections (2 mm thick) of coronal and apical root dentin were obtained from roots of 60 extracted teeth; the canals were enlarged to a standardized cavity diameter of 1.3 mm. Sections were randomly divided into 6 groups (n = 15 per group), and cavities were filled with Biodentine™, BioAggregate, or ProRoot mineral trioxide aggregate (MTA), according to the manufacturers' instructions. Push-out bond strength values were measured using a universal testing machine under a compressive load at a speed of 1 mm/min. Samples were analyzed under a light microscope to determine the nature of bond failure. Ten samples (2 mm thick) were prepared for all the materials, and Vickers microhardness was determined using a digital hardness tester. Data were analyzed using one-way analysis of variance and Tukey-Kramer multiple comparison tests at a significance level of p < 0.05.
  
  
  RESULTS
  Biodentine (42.02; 39.35 MPa) and ProRoot MTA (21.86; 34.13 MPa) showed significantly higher bond strengths than BioAggregate (6.63; 10.09 MPa) in coronal and apical root dentin, respectively (p < 0.05). Biodentine also differed significantly from ProRoot MTA in coronal dentin. Bond failure was predominantly adhesive in Biodentine and ProRoot MTA, while BioAggregate showed predominantly mixed failure. ProRoot MTA (158.52 HV) showed significantly higher microhardness and BioAggregate (68.79 HV) showed the lowest hardness.
  
  
  CONCLUSIONS
  Biodentine and ProRoot MTA showed higher bond strength and microhardness compared to BioAggregate.
authors.affiliation: Division of Endodontics, Restorative Dental Sciences Department, College of Dentistry, University of Dammam, Dammam, Saudi Arabia.
authors.forename: Abdul
authors.initials: A
authors.lastname: Majeed
authors.forename: Emad
authors.initials: E
authors.lastname: AlShwaimi
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry*; D002126:Calcium Hydroxide / Q000737:chemistry; D003799:Dental Stress Analysis / Q000379:methods*; D004338:Drug Combinations; D006244:Hardness; D006801:Humans; D006882:Hydroxyapatites / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D012387:Root Canal Filling Materials / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D017607:Aluminum Compounds; C557009:BioAggregate; D001672:Biocompatible Materials; D017610:Calcium Compounds; D004338:Drug Combinations; D006882:Hydroxyapatites; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; C506393:tricalcium silicate; D002126:Calcium Hydroxide; C031293:calcium silicate