title: Effect of Sodium Hypochlorite on Push-out Bond Strength of Four Calcium Silicate-based Endodontic Materials when used for repairing Perforations on Human Dentin: An in vitro Evaluation.
abstract: OBJECTIVE
  This study aimed to evaluate the push-out bond strength of NeoMTA Plus (NMTA), EndoSequence root repair material fast set putty (ERRMF), biodentine (BD), and ProRoot white mineral trioxide aggregate (PMTA) when used as perforation repair materials after exposure to 2.5% sodium hypochlorite (NaOCl) during the early setting phase.
  
  
  METHODS
  Horizontal midroot sections were prepared from single-rooted human teeth. Sections (n = 144) were randomly divided into four groups: PMTA, BD, NMTA, and ERRMF. Materials were condensed and allowed to set for 10 minutes. The groups were further divided into two subgroups. The NaOCl group included specimens that were immersed in 2.5% NaOCl for 30 minutes, and the control group included specimens on which a wet cotton pellet was placed over the test material. After 48 hours, the highest force applied to the materials at the time of dislodgement was recorded. Slices were then examined under a digital microscope to evaluate the nature of the bond failure. The surfaces of two specimens from each subgroup were observed by scanning electron microscopy. Data were statistically analyzed with two-way and one-way analysis of variances, independent t-tests, and chi-square tests. The statistical significance was set at 0.05.
  
  
  RESULTS
  In NaOCl-treated groups, PMTA showed a significantly higher push-out bond strength than the other three materials (p = 0.00). In the control groups, the bond strength of BD was significantly higher than that of PMTA, ERRMF, and NMTA (p < 0.05). Compared with the control group, NaOCl treatment significantly increased the push-out bond strength of PMTA (p = 0.00) and ERRMF (p = 0.00) and significantly reduced the bond strength of BD (p = 0.00) and NMTA (p = 0.03). None of the specimens showed an adhesive type of failure. The majority of the samples exhibited a cohesive failure type. Morphological observations revealed that the surfaces exhibited cubic crystals. In ERRMF, the crystals were few in number. Sodium hypochlorite enhanced the crystallization of NMTA.
  
  
  CONCLUSIONS
  The push-out bond strengths of PMTA and ERRMF were significantly increased after exposure to 2.5% NaOCl in the early setting phase, and those of BD and NMTA were significantly decreased.
  
  
  CONCLUSIONS
  The results of the present study suggest that early exposure of NaOCl increase the push-out bond strength of PMTA and ERRMF. PMTA had the highest push-out values. Therefore, it would be a potentially useful perforation repair material for single visit endodontic treatment.
authors.affiliation: Department of Restorative Dental Science, College of Dentistry King Saud University, Riyadh, Kingdom of Saudi Arabia, e-mail: s_alsubait@yahoo.com.
authors.forename: Sara A
authors.initials: SA
authors.lastname: Alsubait
mesh_terms: D017607:Aluminum Compounds / Q000627:therapeutic use; D017610:Calcium Compounds / Q000627:therapeutic use*; D002130:Calcium Phosphates / Q000627:therapeutic use; D001840:Dental Bonding; D003799:Dental Stress Analysis; D003804:Dentin / Q000293:injuries* / Q000601:surgery; D004338:Drug Combinations; D006801:Humans; D066298:In Vitro Techniques; D010087:Oxides / Q000627:therapeutic use; D057872:Pulp Capping and Pulpectomy Agents / Q000627:therapeutic use*; D017640:Silicates / Q000627:therapeutic use*; D012973:Sodium Hypochlorite / Q000009:adverse effects*
chemical_list: D017607:Aluminum Compounds; D017610:Calcium Compounds; D002130:Calcium Phosphates; D004338:Drug Combinations; C550603:EndoSequence root repair material; D010087:Oxides; D057872:Pulp Capping and Pulpectomy Agents; D017640:Silicates; C086631:mineral trioxide aggregate; C506393:tricalcium silicate; D012973:Sodium Hypochlorite; C031293:calcium silicate
keywords: Biodentine; Bond strength; EndoSequence root repair material fast set putty; Mineral trioxide aggregate; NeoMTA Plus; Perforation repair; Scanning electron microscopy; Sodium hypochlorite Type of bond failure.