title: Push-out strength of modified Portland cements and resins.
abstract: OBJECTIVE
  Modified calcium-silicate cements derived from white Portland cement (PC) were formulated to test their push-out strength from radicular dentin after immersion for 1 month.
  
  
  METHODS
  Slabs obtained from 42 single-rooted extracted teeth were prepared with 0.6 mm diameter holes, then enlarged with rotary instruments. After immersion in EDTA and NaOC1, the holes were filled with modified PCs or ProRoot MTA, Vitrebond and Clearfil SE. Different concentrations of phyllosilicate (montmorillonite-MMT) were added to experimental cements. ProRoot MTA was also included as reference material. Vitrebond and Clearfil SE were included as controls. Each group was tested after 1 month of immersion in water or PBS. A thin-slice push-out test on a universal testing machine served to test the push-out strength of materials. Results were statistically analyzed using the least squares means (LSM) method.
  
  
  RESULTS
  The modified PCs had push-out strengths of 3-9.5 MPa after 1 month of immersion in water, while ProRoot MTA had 4.8 MPa. The push-out strength of PC fell after incubation in PBS for 1 month, while the push-out strength of ProRoot MTA increased. There were no significant changes in Clearfil SE Bond or Vitrebond after water or PBS storage.
authors.affiliation: Department of Oral Sciences, Alma Mater Studiorum, University of Bologna, Via San Vitale 59, 40125 Bologna, Italy. francesco.iacono@hotmail.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Iacono
authors.forename: Maria Giovanna
authors.initials: MG
authors.lastname: Gandolfi
authors.forename: Bradford
authors.initials: B
authors.lastname: Huffman
authors.forename: Jeremy
authors.initials: J
authors.lastname: Sword
authors.forename: Kelli
authors.initials: K
authors.lastname: Agee
authors.forename: Francesco
authors.initials: F
authors.lastname: Siboni
authors.forename: Franklin
authors.initials: F
authors.lastname: Tay
authors.forename: Carlo
authors.initials: C
authors.lastname: Prati
authors.forename: David
authors.initials: D
authors.lastname: Pashley
mesh_terms: D017607:Aluminum Compounds; D000704:Analysis of Variance; D001546:Bentonite; D017610:Calcium Compounds; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D003799:Dental Stress Analysis; D004338:Drug Combinations; D006801:Humans; D016018:Least-Squares Analysis; D008422:Materials Testing; D010087:Oxides; D019279:Resin Cements; D012387:Root Canal Filling Materials / Q000737:chemistry; D017640:Silicates
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D003738:Dental Cements; D004338:Drug Combinations; D010087:Oxides; D019279:Resin Cements; D012387:Root Canal Filling Materials; D017640:Silicates; C472247:accelerated Portland cement; C086631:mineral trioxide aggregate; D001546:Bentonite