title: Push-out bond strength of MTA with antiwashout gel or resins.
abstract: OBJECTIVE
  Assessment of the push-out bond strength of four MTA-based formulations for use as root-end filling materials.
  
  
  METHODS
  MTA Plus mixed with (i) water ('MTA-W'); (ii) a proprietary water-based antiwashout gel ('MTA-AW'); (iii) Superbond C&B chemically curing resin ('MTA-Chem'); and (iv) Heliobond light-curing resin ('MTA-Light') was tested. Root slices 3 mm thick human had a 1.5 mm diameter hole drilled centrally and were treated with 17% EDTA for 60s. Forty specimens divided into groups 1-4 were prepared and filled with MTA-W, MTA-AW, MTA-Chem and MTA-Light, respectively. Groups 3 and 4 were etched with 37% phosphoric acid for 60s, and bonding agent was applied to the dentine surface. Specimens were stored for 28 days in Hanks' Balanced Salt Solution at 37 °C. Push-out strength was tested with a punch and die (punch diameter 1.3 mm, die diameter 2.0 mm, punch speed 1 mm min(-1)). Stereomicroscopy was used to classify failure mode (adhesive, cohesive or mixed type).
  
  
  RESULTS
  The resulting push-out strengths were 5.1 MPa (MTA-W), 4.3 MPa (MTA-AW), 4.7 MPa (MTA-Chem) and 11.0 MPa (MTA-Light). MTA-W had higher push-out strength than MTA-AW (P = 0.022). The same was noted for MTA-Light relative to the other materials (P < 0.05). All materials exhibited adequate push-out strengths compared with MTA-W. Failure was predominantly mixed, except for MTA-Chem (predominantly adhesive).
  
  
  CONCLUSIONS
  All materials exhibited adequate push-out strength. Previous studies have shown the new formulations have additional advantages including increased washout resistance and faster setting time, making them promising for future dental applications.
authors.affiliation: Department of Metallurgy and Materials Engineering, Faculty of Engineering, University of Malta, Msida, Malta.
authors.forename: L M
authors.initials: LM
authors.lastname: Formosa
authors.forename: B
authors.initials: B
authors.lastname: Mallia
authors.forename: J
authors.initials: J
authors.lastname: Camilleri
mesh_terms: D017607:Aluminum Compounds / Q000008:administration & dosage*; D017610:Calcium Compounds / Q000008:administration & dosage*; D001840:Dental Bonding / Q000379:methods*; D004338:Drug Combinations; D005782:Gels; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D010087:Oxides / Q000008:administration & dosage*; D012117:Resins, Synthetic / Q000008:administration & dosage*; D017640:Silicates / Q000008:administration & dosage*
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D004338:Drug Combinations; D005782:Gels; D010087:Oxides; D012117:Resins, Synthetic; D017640:Silicates; C086631:mineral trioxide aggregate
keywords: antiwashout; bond strength; composite resins; mineral trioxide aggregate; push out; root-end filling materials