title: 3D micro-CT analysis of void formations and push-out bonding strength of resin cements used for fiber post cementation.
abstract: OBJECTIVE
  To investigate the void parameters within the resin cements used for fiber post cementation by micro-CT (µCT) and regional push-out bonding strength.
  
  
  METHODS
  Twenty-one, single and round shaped roots were enlarged with a low-speed drill following by endodontic treatment. The roots were divided into three groups (n=7) and fiber posts were cemented with Maxcem Elite, Multilink N and Superbond C&B resin cements. Specimens were scanned using µCT scanner at resolution of 13.7 µm. The number, area, and volume of voids between dentin and post were evaluated. A method of analysis based on the post segmentation was used, and coronal, middle and apical thirds considered separately. After the µCT analysis, roots were embedded in epoxy resin and sectioned into 2 mm thick slices (63 sections in total). Push-out testing was performed with universal testing device at 0.5 mm/min cross-head speed. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests (α=.05).
  
  
  RESULTS
  Overall, significant differences between the resin cements and the post level were observed in the void number, area, and volume (P<.05). Super-Bond C&B showed the most void formation (44.86 ± 22.71). Multilink N showed the least void surface (3.51 ± 2.24 mm(2)) and volume (0.01 ± 0.01 mm(3)). Regional push-out bond strength of the cements was not different (P>.05).
  
  
  CONCLUSIONS
  µCT proved to be a powerful non-destructive 3D analysis tool for visualizing the void parameters. Multilink N had the lowest void parameters. When efficiency of all cements was evaluated, direct relationship between the post region and push-out bonding strength was not observed.
authors.affiliation: Department of Prosthodontics, Inonu University Faculty of Dentistry, Malatya, Turkey.
authors.forename: İsmail Hakkı
authors.identifier: 0000-0002-4165-7688
authors.initials: İH
authors.lastname: Uzun
authors.affiliation: Department of Prosthodontics, Inonu University Faculty of Dentistry, Malatya, Turkey.
authors.forename: Meral Arslan
authors.identifier: 0000-0002-7361-7242
authors.initials: MA
authors.lastname: Malkoç
authors.affiliation: Department of Endodontics, 19 Mayıs University Faculty of Dentistry, Samsun, Turkey.
authors.forename: Ali
authors.identifier: 0000-0002-6834-4307
authors.initials: A
authors.lastname: Keleş
authors.affiliation: Prosthodontist, Eskişehir, Turkey.
authors.forename: Ayşe Tuba
authors.identifier: 0000-0003-4707-5432
authors.initials: AT
authors.lastname: Öğreten
keywords: Fiber post; Micro ct; Push-out bonding; Resin cement; Void formation