title: Accuracy of cast posts fabricated by the direct and the indirect techniques.
abstract: BACKGROUND
  Patterns for custom cast posts and cores can be fabricated either by the direct or the indirect technique. Which technique is more accurate is unknown.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to investigate the effect of pattern fabrication technique on the accuracy of post fit.
  
  
  METHODS
  Ten intact extracted premolar teeth with a single canal and similar dimensions received root canal treatment. The teeth were sectioned 2 mm above the cementoenamel junction. A total of 20 cast post and core patterns, 2 for each tooth, were fabricated, 10 with the direct technique and 10 with the indirect technique. Patterns were cast to produce 20 cast post and cores. Each tooth was scanned using a microcomputed tomography (μCT) system with a resolution of 14.5 μm, once with the post of the direct technique and once with the post of the indirect technique. Ct analyzer software was used to calculate the overall space between the post and canal walls and the space areas in 3 different standardized sections. The Student paired t test was used to determine any significant difference in the scores of the groups.
  
  
  RESULTS
  The overall space between the canal walls and posts made with the direct technique ranged between 7.86 and 17.39 mm(3), with a mean value of 12.25 mm(3), whereas with the indirect technique, the space ranged between 6.68 and 18.02 mm(3), with a mean of 11.92 mm(3). No significant differences were found between the results of either technique (P>.05).
  
  
  CONCLUSIONS
  Within the limitations of this study, neither the indirect nor direct pattern fabrication technique influenced the accuracy of post fitting.
authors.affiliation: Assistant Professor, Prosthodontic Department, College of Dentistry, Riyadh Colleges of Dentistry and Pharmacy, Riyadh, Saudi Arabia. Electronic address: mohammadrayyan1979@gmail.com.
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Rayyan
authors.affiliation: General Dentist, Security Forces Polyclinic, Ministry of Interior, Riyadh, Saudi Arabia.
authors.forename: Roa'a A
authors.initials: RA
authors.lastname: Aldossari
authors.affiliation: General Dentist, Graduate of Riyadh Colleges of Dentistry and Pharmacy, Riyadh, Saudi Arabia.
authors.forename: Sarah F
authors.initials: SF
authors.lastname: Alsadun
authors.affiliation: Private practice, Al Khobar, Saudi Arabia.
authors.forename: Fatimah R
authors.initials: FR
authors.lastname: Hijazy
mesh_terms: D001641:Bicuspid / Q000000981:diagnostic imaging / Q000601:surgery; D003735:Dental Casting Technique / Q000592:standards; D017267:Dental Prosthesis Design; D006801:Humans; D011176:Post and Core Technique / Q000592:standards; D055114:X-Ray Microtomography