title: Micro-Computed Tomography of Tooth Volume Changes Following Post Removal.
abstract: OBJECTIVE
  To measure tooth volume change before and after post removal using micro-CT and to compare the difference among various combinations of prefabricated post and cement systems.
  
  
  METHODS
  Forty-eight extracted maxillary anterior teeth and mandibular canines were sectioned 13 mm from the apex. Root canals were properly instrumented. Preparations were filled with gutta percha using lateral condensation. Post space was prepared with a touch and heat device, leaving 5 mm of gutta percha from the apex. Specimens were scanned with micro-CT to establish objective baseline volume and divided into two groups of post systems: stainless steel (SS) ParaPost and glass-fiber reinforced composite (FRC) post. Half the posts for each group were cemented with Ketac Cem radiopaque glass-ionomer cement, and the other half with SpeedCEM dual-curing resin cement. The posts and residual cement were removed by the same operator, using the ultrasonic vibration technique under an endodontic operating microscope. The remaining tooth root structure was scanned again using micro-CT with volume reported (mm3). The statistical difference between the combination of posts and cements was measured using the Kruskal-Wallis ANOVA test (α = 0.001). The independent variables were evaluated separately using post hoc Tukey examination to determine which groups resulted in a statistically significant difference.
  
  
  RESULTS
  There was a statistical difference of tooth root volume change among the groups. Post hoc exam revealed a statistically significant difference in tooth root volume change between group 1 (SS + GI) and the other groups (α = 0.0002).
  
  
  CONCLUSIONS
  Compared to other post and cement combinations, serrated parallel-sided SS posts cemented with GI cement had the most tooth root structure loss upon post removal using the ultrasonic vibration technique.
authors: Department of Restorative Dentistry, University of Illinois at Chicago College of Dentistry, Chicago, IL.
authors: Jiyeon J
authors: JJ
authors: Kim
authors: Department of Endodontics, University of Illinois at Chicago College of Dentistry, Chicago, IL.
authors: Satish
authors: S
authors: Alapati
authors: Department of Restorative Dentistry, University of Illinois at Chicago College of Dentistry, Chicago, IL.
authors: Kent L
authors: KL
authors: Knoernschild
authors: Division of Orthodontics, The Ohio State University College of Dentistry, Columbus, OH.
authors: Yong-Hoon
authors: YH
authors: Jeong
authors: Division of Orthodontics, The Ohio State University College of Dentistry, Columbus, OH.
authors: Do Gyoon
authors: DG
authors: Kim
authors: Division of Restorative Sciences and Prosthodontics, The Ohio State University College of Dentistry, Columbus, OH.
authors: Damian J
authors: DJ
authors: Lee
mesh_terms: D003738:Dental Cements; D003804:Dentin; D005899:Glass Ionomer Cements; D006801:Humans; D009929:Organ Size; D011176:Post and Core Technique; D014092:Tooth Root / Q000033:anatomy & histology*; D055114:X-Ray Microtomography
chemical_list: D003738:Dental Cements; D005899:Glass Ionomer Cements
keywords: Tomography; canal; endodontic; post removal; post space