title: Retention of posts luted with phosphate monomer-based composite cement in canals obturated using a eugenol sealer.
abstract: OBJECTIVE
  To examine the effect post-obturation sequencing had on retention of endodontic posts luted with a phosphate monomer-based resin cement into canals previously obturated using a eugenol-based sealer.
  
  
  METHODS
  64 single-rooted teeth were decoronated, and root canals were filed, cleaned, and shaped with a size 5 Gates Glidden drill and 0.12 taper rotary instrumentation. Teeth were then divided into 4 groups of 16 specimens each. Group 1 was not obturated, and served as a control. The other three groups were obturated with gutta percha and a eugenol-based sealer. Post space preparation and post cementation were completed at three different post-obturation intervals - immediate (Group 2), 1 week (Group 3), and 4 weeks (Group 4). Ten-mm deep post spaces were prepared with a size 6 Gates Glidden drill, and size 5 Paraposts were cemented with Panavia 21 OP. Following 48-hour of storage, specimens were mounted in PVC pipe with acrylic, and the posts were removed in tensile mode using a universal testing machine at 1 mm min(-1), with data recorded in kilograms.
  
  
  RESULTS
  Group 1 (controls) mean = 61.80, SD = 16.21; Group 2 (immediate) mean = 38.70, SD = 12.97; Group 3 (1 week) mean = 43.15, SD = 14.66; Group 4 (4 weeks) mean = 18.82, SD = 8.00. Using ANOVA and Bonferroni tests, Group 1 demonstrated significantly greater mean retention strength values than Groups 2 and 3 (P < 0.05), which in turn had significantly greater mean retention strength values than Group 4 (P < 0.05).
authors.affiliation: Department of Restorative Dentistry, University of the Pacific School of Dentistry, San Francisco, California 94115, USA. mhagge@sf.uop.edu
authors.forename: Mark S
authors.initials: MS
authors.lastname: Hagge
authors.forename: Ralan D M
authors.initials: RD
authors.lastname: Wong
authors.forename: James S
authors.initials: JS
authors.lastname: Lindemuth
mesh_terms: D000704:Analysis of Variance; D017268:Dental Prosthesis Retention; D003799:Dental Stress Analysis; D006801:Humans; D008422:Materials Testing; D011176:Post and Core Technique; D011897:Random Allocation; D012387:Root Canal Filling Materials; D018709:Statistics, Nonparametric; D013718:Tensile Strength; D013997:Time Factors; D015035:Zinc Oxide-Eugenol Cement
chemical_list: D012387:Root Canal Filling Materials; D015035:Zinc Oxide-Eugenol Cement; C076543:Kerr Pulp Canal Sealer